Image guided radiotherapy Research Papers (original) (raw)

2025, Physics and Imaging in Radiation Oncology

Background and purpose: The clinical feasibility of synthetic computed tomography (sCT) images derived from magnetic resonance imaging (MRI) images for external beam radiation therapy (EBRT) planning have been studied and adopted into clinical use recently. This paper evaluates the dosimetric and positioning performance of a sCT approach for different pelvic cancers. Materials and methods: Seventy-five patients receiving EBRT at Turku University Hospital (Turku, Finland) were enrolled in the study. The sCT images were generated as part of a clinical MRI-simulation procedure. Dose calculation accuracy was assessed by comparing the sCT-based calculation with a CT-based calculation. In addition, we evaluated the patient position verification accuracy for both digitally reconstructed radiograph (DRR) and cone beam computed tomography (CBCT) -based image guidance using a subset of the cohort. Furthermore, the relevance of using continuous Hounsfield unit values was assessed. Results: The mean (standard deviation) relative dose difference in the planning target volume mean dose computed over various cancer groups was less than 0.2 (0.4)% between sCT and CT. Among all groups, the average minimum gamma-index pass-rates were better than 95% with a 2%/2mm gamma-criteria. The difference between sCT-and CT-DRR-based patient positioning was less than 0.3 (1.4) mm in all directions. The registrations of sCT to CBCT produced similar results as compared with CT to CBCT registrations. Conclusions: The use of sCT for clinical EBRT dose calculation and patient positioning in the investigated types of pelvic cancers was dosimetrically and geometrically accurate for clinical use.

2025, Medical Physics

The aim of this study is to calculate setup margin based on six-dimensional (6D) corrected residual positional errors from kV cone beam computed tomography (CBCT) and from intrafraction projection kV imaging in coplanar and in noncoplanar couch positions in stereotactic radiotherapy. Methods: Six dimensional positional corrections were carried out before patient treatments, using a robotic couch and CBCT matching. A CBCT and stereoscopic ExacTrac image were acquired posttable position correction. Further, a series of intrafraction ExacTrac images were obtained for the variable couch position. Translational and rotational errors were identified as lateral (X), longitudinal (Y), vertical (Z); roll (Ɵ°), pitch (Φ°) and yaw (Ψ°). A total of 699 intrafraction image sets (361 coplanar and 338 noncoplanar) for 51 SRS/SRT patients were analysed. Rotational errors were corrected in terms of translational coordinates. Residual set-up margins were calculated from CBCT shifts. ExacTrac shifts give residual + intrafraction setup margins as a function of coplanar and noncoplanar couch positions. Results: The average residual positional error obtained from CBCT in X, Y, Z, Ɵ, Φ, Ψ were 0.

2025, Physica Medica

Introduction: Verifying the patient position is always an essential part of the treatment process, especially in hypofractionated treatments such as accelerated partial breast irradiation (APBI). The purpose of the study was to compare five image guidance techniques with respect to imaging dose and image quality. Methods and materials: We chose five types of imaging methods applicable for APBI and measured their dose exposure on four different accelerators (Synergy, TrueBeam, Artiste and CyberKnife). Absorbed dose was measured with ionization chamber in thorax phantom. Besides dose exposure image quality was also compared. Results: The lowest dose exposure was measured with kV-kV planar imaging followed by kV-CBCT, MV-MV pair and MV-CBCT in ascending order. Average phantom dose with kV-kV image pair on CyberKnife was 0.01 cGy as the lowest and with MV-CBCT on Artiste was 7.11 cGy as the highest. Average dose exposures of MV-MV images with TrueBeam, Synergy and Artiste were 1.18 cGy, 2.13 cGy and 1.61 cGy, respectively, with similar image quality. For the same machines the doses of kV-CT imaging were comparable: 0.65 cGy, 0.65 cGy and 0.52 cGy, with some differences in image quality. MV-CBCT technique resulted in the highest dose and poorest image quality. Conclusions: In APBI the position of the patient and tumour bed can be verified with many tools. When fiducials are available, often 2D imaging is enough to achieve appropriate positioning and the kV-kV method is recommended. Imaging with 2.5MV can also be a good solution instead of 6MV. Without fiducials 3D images should be acquired and the recommended method is the kV-CBCT.

2025, International Journal of Radiation Oncology*Biology*Physics

Purpose/Objective: We report the initial results of a prospective study in which patients undergoing radical prostatectomy at the Shands Teaching Hospital or Gainesville VA Hospital who were staged pT3N0 were offered adjuvant irradiation. In this report biochemical relapse-free survival is analyzed for all patients with 2 or more years of follow-up. Materials & Methods: During the period 1988-1995, 77 patients received adjuvant irradiation after radical prostatectemy. Of these, 75 were staged pT3N0. Two patients who underwent orchiectomy prior to irradiation treatment, and two patients staged pT2N0 were eliminated from this analysis. Median follow-up was 46 months, while the minimum was 24 months. PSA values were available for greater than 24 months of follow-up for 66 patients. External beam treatment was delivered to the surgical bed with no attempt to include regional lymph nodes. Patients routinely received 60 Gy delivered in a four-field arrangement. Based upon the surgeon's preference, some patients (26 out of 77) received adjuvant androgen suppression therapy during the interval between surgery and irradiation. The average length of the interval was 115 days. Comparison of the group receiving hormone treatment with the group treated with radiation alone demonstrated no significant differences in pre-operative serum PSA values, or the per cent of patients with positive margins or positive seminal vesicles. Results: Overall survival for the entire group was 93% and the crude distant metastasis rate was 9.2%. Biochemical relapsefree survival (BRFS) after 5 years was 69% for the entire group. Five-year BRFS was 82% for patients receiving androgen suppression and 64% for patients receiving radiation alone. BRFS was significantly improved for patients presenting with preoperative PSA less than or equal to 10 ng/ml (p=0.01); or post-operative PSA less than 1.0 ng/ml (p=O.05); but unaffected by positive seminal vesicles, 5-yr BRFS 62% (p=0.26), positive margins, 5-yr BRFS 73% (p=0.95), or extra-capsular extension, 5-yr BRFS 67% (p=0.67). Post-operative PSA was also a significant predictor after multivariate analysis (p=0.012). Post-operative and pre-operative PSA values were highly correlated. When patients were stratified by their pre-operative PSA values, a possible impact of androgen suppression was apparent. For patients with low pre-operative PSA values (<10 ng/ml), the 5-year BRFS was unaffected, 100% with hormone treatment and 93% without hormones. For patients presenting with intermediate PSA values (>10 ng/ml and <20 ng/ml), however, the 5-year BRFS was improved for patients with androgen suppression, 72% vs. 53%, respectively. Finally, when the presenting PSA value was greater than 20 ng/ml androgen suppression resulted in an eady improvement in BRFS, which disappeared in the fifth year of follow-up. Conclusion: Following irradiation in the adjuvant setting, patients with post-prostatectomy PSA values > 1 .O ng/ml, or preoperative PSA values greater than 15 ng/ml are at high risk for biochemical failure. High-risk patients may be more frequently controlled, however, when androgen suppressive therapy is employed during the interval between surgery and irradiation.

2025, Medical Dosimetry

Fluorine-18-fluorodeoxyglucose-positron emission tomography ( 18 F-FDG-PET)-guided focal dose escalation in oropharyngeal cancer may potentially improve local control. We evaluated the feasibility of this approach using volumetric-modulated arc therapy (RapidArc) and compared these plans with fixed-field intensitymodulated radiotherapy (IMRT) focal dose escalation plans. Materials and methods: An initial study of 20 patients compared RapidArc with fixed-field IMRT using standard dose prescriptions. From this cohort, 10 were included in a dose escalation planning study. Dose escalation was applied to 18 F-FDG-PET-positive regions in the primary tumor at dose levels of 5% (DL1), 10% (DL2), and 15% (DL3) above standard radical dose (65 Gy in 30 fractions). Fixed-field IMRT and double-arc RapidArc plans were generated for each dataset. Dose-volume histograms were used for plan evaluation and comparison. The Paddick conformity index (CI Paddick ) and monitor units (MU) for each plan were recorded and compared. Both IMRT and RapidArc produced clinically acceptable plans and achieved planning objectives for target volumes. Dose conformity was significantly better in the RapidArc plans, with lower CI Paddick scores in both primary (PTV1) and elective (PTV2) planning target volumes (largest difference in PTV1 at DL3; 0.81 Ϯ 0.03 [RapidArc] vs. 0.77 Ϯ 0.07 [IMRT], p ϭ 0.04). Maximum dose constraints for spinal cord and brainstem were not exceeded in both RapidArc and IMRT plans, but mean doses were higher with RapidArc (by 2.7 Ϯ 1 Gy for spinal cord and 1.9 Ϯ 1 Gy for brainstem). Contralateral parotid mean dose was lower with RapidArc, which was statistically significant at DL1 (29.0 vs. 29.9 Gy, p ϭ 0.01) and DL2 (29.3 vs. 30.3 Gy, p ϭ 0.03). MU were reduced by 39.8 -49.2% with RapidArc (largest difference at DL3, 641 Ϯ 94 vs. 1261 Ϯ 118, p Ͻ 0.01). 18 F-FDG-PET-guided focal dose escalation in oropharyngeal cancer is feasible with RapidArc. Compared with conventional fixed-field IMRT, RapidArc can achieve better dose conformity, improve contralateral parotid sparing, and uses fewer MU.

2025, Applied sciences

Silently asymptomatic at an early stage and often painless, requiring only active surveillance, Prostate Cancer (PCa) is traditionally diagnosed by a Digital Rectal Examination (DRE) and a Prostate Specific Antigen (PSA) blood test. A histological examination, searching for pattern irregularities on the prostate glandular tissue, is performed to quantify the aggressiveness of PCa. The assigned Gleason Score (GS), usually combined with Transrectal Ultrasound Guided Biopsy (TRUS), allows the stratification of patients according to their risk group. Intermediate-risk patients may have a favourable (GS = 3 + 4) or unfavourable (GS = 4 + 3) prognosis. This borderline is critical for defining treatments and possible outcomes, while External Beam Radiotherapy (EBRT) is a curative option for localised and locally advanced disease and as a palliative option for metastatic low-volume disease; active surveillance or watchful waiting can also be an option for patients with a favourable prognosis. With radiomics, quantifying phenotypic characteristics in medical imaging is now possible. In the EBRT workflow, there are several imaging modalities, such as Magnetic Ressonance Imaging (MRI), Computed Tomography (CT), Positron Emission Tomography (PET), Ultrasound and Cone Beam Computed Tomography (CBCT). Most radiomic PCa studies focused on MRI and addressed tumour staging, GS, PSA or Biochemical Recurrence (BCR). This study intends to use CBCT radiomics to distinguish between favourable and unfavourable cases, with the potential of evaluating an ongoing treatment. Seven of the most used feature selection methods, combined with 14 different classifiers, were evaluated in a total of 98 pipelines. From those, six stood out with Area Under the Receiver Operating Characteristic (AUROC) values ≥ 0.79. To the best of our knowledge, this is the first work to evaluate a PCa favourable vs. unfavourable prognosis model based on CBCT radiomics.

2025, International Journal of Radiation Oncology*Biology*Physics

Purpose-To develop a novel 4-dimensional computed tomography (4D-CT) technique that exploits standard fast helical acquisition, a simultaneous breathing surrogate measurement, deformable image registration, and a breathing motion model to remove sorting artifacts. Methods and Materials-Ten patients were imaged under free-breathing conditions 25 successive times in alternating directions with a 64-slice CT scanner using a low-dose fast helical protocol. An abdominal bellows was used as a breathing surrogate. Deformable registration was used to register the first image (defined as the reference image) to the subsequent 24 segmented images. Voxel-specific motion model parameters were determined using a breathing motion model. The tissue locations predicted by the motion model in the 25 images were compared against the deformably registered tissue locations, allowing a model prediction error to be evaluated. A low-noise image was created by averaging the 25 images deformed to the first image geometry, reducing statistical image noise by a factor of 5. The motion model was used to deform the low-noise reference image to any user-selected breathing phase. A voxel-specific correction was applied to correct the Hounsfield units for lung parenchyma density as a function of lung air filling. Results-Images produced using the model at user-selected breathing phases did not suffer from sorting artifacts common to conventional 4D-CT protocols. The mean prediction error across all patients between the breathing motion model predictions and the measured lung tissue positions was determined to be 1.19 ± 0.37 mm. The proposed technique can be used as a clinical 4D-CT technique. It is robust in the presence of irregular breathing and allows the entire imaging dose to contribute to the resulting

2025, Medical Physics

In the past few years, innovations such as on-board imaging have made it possible to adjust each radiation beam on a daily basis to account for any changes in anatomical positions of target and normal tissues. This "adaptive radiotherapy" has made it possible to reduce margins so as to decrease the risk of normal tissue damage, enabling safe and effective delivery of higher doses/fraction (hypofractionation). It has been proposed that such technological advances will allow adaptive hypofractionation to become the most common form of radiotherapy within the next five years. This is the claim debated in this month's Point/Counterpoint.

2025, Medical physics

2025, Journal of the Egyptian National Cancer Institute

To compare the accuracy of 2D algorithm with an established 3D algorithm, and to define the number of CT-slices needed for treatment planning of intact breast irradiation. Twenty patients with breast cancer treated with conservative surgery were included in this study, ten of them had right breast cancer and the other 10 patients had cancer of the left breast. For each patient, 3-D calculations (HeLax-TMS) were performed using one CT-slice (central), 3 CT-slices (central, caudal, and cephalic) and full set CT-slices in addition to 2D calculations (Multidata System) on the digitized central cut. All calculations were done using 6MV-photon. When using 2D planning with lung correction, a large hot area of 105% was found at the medial and lateral subcutaneous (SC) regions. Comparison of 2D-treatment planning using Multidata System (2D-physics) and 2D-planning using HeLax System (3D-physics) showed that the 2D planning using Multidata System gave a large hot area of 105% compared with He...

2025, Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology

To evaluate long-term radiation toxicity and biochemical control of two moderately hypofractionated radiotherapy regimens for prostate cancer. Eligible men with localized prostate cancer received image-guided intensity modulated radiotherapy (IG-IMRT) to a dose of 60 or 66Gy in 3Gy fractions in a phase II trial. Endpoints included late gastrointestinal (GI) and genitourinary (GU) toxicity and biochemical failure (FFBF). Ninety-six men received 60Gy and 27 received 66Gy. Accrual to the 66Gy cohort terminated early due to excessive Grade 3-4 late toxicity. Median follow-up was 128months (60Gy) and 108months (66Gy). In the 60Gy cohort, cumulative late Grade ⩾2 GI and GU toxicity at 8years was 4% and 12% respectively. In the 66Gy cohort, late Grade ⩾2 GI and GU toxicity was 21% and 4% respectively at 8years. The 5- and 8-year FFBF for 60Gy was 81% and 66%, and for 66Gy was 88% and 80%. Moderate hypofractionation with IG-IMRT to 60Gy was associated with favorable late toxicity although l...

2025, Acta Oncologica

Background: A subset of patients experience a biochemical recurrence following radical prostatectomy. Radiotherapy can salvage those patients, provided that all disease is encompassed within the target volume. We hypothesized that this can be achieved more adequately with magnetic resonance imaging (MRI)-guided treatment planning. Material and methods: From January 2009 to April 2014, 183 patients were referred to our department for salvage radiotherapy (SRT). According to protocol, patients received a planning computed tomography (CT) as well as an MRI in treatment position. All MRI scans were retrospectively reviewed by an experienced uro-radiologist. Results: Median prostate-specific antigen (PSA) value at time of referral was 0.3 ng/ml (range 0.02-4.7 ng/ml). MRI did not show any suspected macroscopic disease in 137 patients (75%). In 46 (25%) patients, MRI did indicate a pelvic recurrence. The mean PSA level was significantly higher in patients with a suspected recurrence on MRI (0.4 vs. 1.4 ng/ml, p < .001) on a Student's t-test. The mean follow-up was 33 months (range 5-69 months). Biochemical disease-free survival (bDFS) was significantly worse in patients with suspected disease on MRI [hazard ratio (HR) 2.9, p < .0001]. bDFS was significantly worse in the subgroup where the macroscopic recurrences on MRI received a lower radiation dose (HR 3.4, p ¼ .01). Conclusion: MRI detects loco-regional disease in a substantial subset of patients with a biochemical recurrence after prostatectomy, especially in a PSA above 0.5 lg/l. Lack of MRI-based dose escalation on these macroscopic recurrences could explain some of the biochemical progression observed after SRT.

2025

This study investigates the use a 2D normalized cross-correlation (NCC)-based algorithm to estimate in vivo motion of liver features in 2D Bmode ultrasound (US) images. Datasets included 23 volunteer imaging sequences, each containing first frame annotated points of interest (POI). Images had a range of spatial (0.28 – 0.71 mm) and temporal (11 – 25 Hz) resolution. Image quality was also highly variable. A 2D block-matching algorithm was developed to track POI motion throughout the imaging sequence. A correlation and displacement thresholding tracking approach, which used knowledge of previous displacement and (1) linear extrapolation, (2) a regularizing sinusoidal breathing model or (3) hybrid fixed-reference / incremental tracking was use to account for potential tracking errors. The overall mean error in vessel tracking was 2.15 ± 2.7 mm. This approach to motion estimation shows promise for applications such as radiation therapy tumor tracking.

2025, Medical Physics

New technologies continue to be developed to improve the practice of radiation therapy. As several of these technologies have been implemented clinically, the Therapy Committee and the Quality Assurance and Outcomes Improvement Subcommittee of the American Association of Physicists in Medicine commissioned Task Group 147 to review the current nonradiographic technologies used for localization and tracking in radiotherapy. The specific charge of this task group was to make recommendations about the use of nonradiographic methods of localization, specifically; radiofrequency, infrared, laser, and video based patient localization and monitoring systems. The charge of this task group was to review the current use of these technologies and to write quality assurance guidelines for the use of these technologies in the clinical setting. Recommendations include testing of equipment for initial installation as well as ongoing quality assurance. As the equipment included in this task group continues to evolve, both in the type and sophistication of technology and in level of integration with treatment devices, some of the details of how one would conduct such testing will also continue to evolve. This task group, therefore, is focused on providing recommendations on the use of this equipment rather than on the equipment itself, and should be adaptable to each user's situation in helping develop a comprehensive quality assurance program.

2025, Tumori Journal

Aims and background. To evaluate the feasibility, toxicity and patient outcome of hypofractionated 3-dimensional conformal radiotherapy for low-and intermediate-risk prostate cancer, using daily an ultrasound targeting system (BAT TM ). Between May 2005 and October 2006, 25 patients (cT1-T2, GS ≤7, mean initial PSA = 7.06 ng/ml) received a dose of 72 Gy in 30 fractions. Only the prostate was included in the clinical target volume. Immediately before each radiotherapy session, BAT TM ultrasound alignment was performed. Acute and late toxicity was evaluated according to the Radiation Therapy Oncology Group criteria; the Phoenix definition (PSA = nadir + 2 ng/ml) was applied to define biochemical failure. BAT TM localization data were provided for 300 out of 750 procedures. No interruptions in 3-dimensional conformal radiotherapy due to toxicity were registered. There was no acute rectal toxicity in 52% of patients; 28% had G1, 16% had G2, and 1 patient had a G3 event. No acute urinary toxicity was observed in 28% of the patients. G1 toxicity occurred in 40%, G2 in 28%, and G3 in 1 patient; no G4 event was observed. With an average follow-up of 45 months, one biochemical relapse was observed; late toxicity showed an excellent profile: 78% of the patients had no rectal toxicity, 16% had G1, and 1 patient had G2 toxicity. Most of the patients (68%) had no late urinary complications, whereas 32% had G1 toxicity. Localization data showed systematic and random errors in relation to some procedure biases. Promising tumor control and toxicity profile were observed with this mildly hypofractionated BAT-based 3-dimensional conformal radiotherapy. Free full text available at www.tumorionline.it

2025, The British Journal of Radiology

Objectives: In radiotherapy, delineation uncertainties are important as they contribute to systematic errors and can lead to geographical miss of the target. For margin computation, standard deviations (SDs) of all uncertainties must be included as SDs. The aim of this study was to quantify the interobserver delineation variation for stereotactic body radiotherapy (SBRT) of peripheral lung tumours using a crosssectional study design. Methods: 22 consecutive patients with 26 tumours were included. Positron emission tomography/CT scans were acquired for planning of SBRT. Three oncologists and three radiologists independently delineated the gross tumour volume. The interobserver variation was calculated as a mean of multiple SDs of distances to a reference contour, and calculated for the transversal plane (SD trans ) and craniocaudal (CC) direction (SD cc ) separately. Concordance indexes and volume deviations were also calculated. Results: Median tumour volume was 13.0 cm 3 , ranging from 0.3 to 60.4 cm 3 . The mean SD trans was 0.15 cm (SD 0.08 cm) and the overall mean SD cc was 0.26 cm (SD 0.15 cm). Tumours with pleural contact had a significantly larger SD trans than tumours surrounded by lung tissue. Conclusions: The interobserver delineation variation was very small in this systematic cross-sectional analysis, although significantly larger in the CC direction than in the transversal plane, stressing that anisotropic margins should be applied. This study is the first to make a systematic cross-sectional analysis of delineation variation for peripheral lung tumours referred for SBRT, establishing the evidence that interobserver variation is very small for these tumours.

2025, Physics in Medicine and Biology

This work investigates the possibility of combining Monte Carlo (MC) simulations to a denoising algorithm for the accurate prediction of images acquired using amorphous silicon (a-Si) electronic portal imaging devices (EPIDs). An accurate MC model of the Siemens OptiVue1000 EPID was first developed using the PENELOPE code, integrating a non-uniform backscatter modelling. Two already existing denoising algorithms were then applied on simulated portal images, namely the iterative reduction of noise (IRON) method and the locally adaptive Savitzky-Golay (LASG) method. A third denoising method, based on a nonparametric Bayesian framework and called DPGLM (for Dirichlet Process Generalized Linear Model) was also developed. Performances of the IRON, LASG and DPGLM methods, in terms of smoothing capabilities and computation time, were compared for portal images computed for different values of the RMS pixel noise (up to 10%) in three different configurations, a heterogeneous phantom irradiated by a non-conformal 15 × 15 cm² field, a conformal beam from a pelvis treatment plan, and an IMRT beam from a prostate treatment plan. For all configurations, DPGLM outperforms both IRON and LASG by providing better smoothing performances and demonstrating a better robustness with respect to noise. Additionally, no parameter tuning is required by DPGLM, which makes the denoising step very generic and easy to handle for any portal image. Concerning the computation time, the denoising of 1024 × 1024 images takes about 1 h 30, 2 h and 5 min using DPGLM, IRON, and LASG, respectively. This paper shows the feasibility to predict within a few hours and with the same resolution as real images accurate portal images, combining MC simulations with the DPGLM denoising algorithm.

2025, Research Square (Research Square)

Background Although moderate hypofractionated radiotherapy were one of standard regimens for localized prostate cancer, the e cacy of moderated hypofractionated regimens has not been well validated in Asian countries. The aim of this multi-institutional phase II study was to con rm the safety and the potential e cacy of moderately hypofractionated intensity-modulated radiotherapy (IMRT) with prostate-based image-guidance for Japanese patients. Methods Patients with low-or intermediate-risk localized prostate cancer were eligible. Patients with a part of high risk (having only one of the following factors, cT3a, 20 < PSA ≤ 30, or GS = 8 or 9) were also included in this trial. Hypofractionated IMRT using daily image-guided technique with prostate matching was performed with a total dose of 70 Gy in 28 fractions. Neoadjuvant hormonal therapy for 4-8 months was mandatory for patients with intermediate or high-risk prostate cancer. The number of patients with low, intermediate, and high-risk prostate cancer was 20, 80, and 34, respectively. The 5-year overall, biochemical failure-free, and clinical failure-free survival was 94.5%, 96.0%, and 99.2%, respectively. The 5-year biochemical failure-free survival for patients with low-, intermediate-, and high-risk disease was 94.1%, 97.4%, and 93.9%, respectively. The incidences of grade 2 gastrointestinal and genitourinary late toxicities at 5 years were 5.3% and 5.3%, respectively. There are no acute or late toxicities ≥ grade 3. The safety and e cacy of moderately hypofractionated IMRT was con rmed in this trial among Japanese patients with prostate cancer.

2025, International braz j urol

To evaluate Lipiodol as a liquid, radio-opaque fiducial marker for image--guided radiation therapy (IGRT) for bladder cancer. Materials and Methods: Between 2011 and 2012, 5 clinical T2a-T3b N0 M0 stage II-III bladder cancer patients were treated with maximal transurethral resection of a bladder tumor (TURBT) and image-guided radiation therapy (IGRT) to 64.8 Gy in 36 fractions ± concurrent weekly cisplatin-based or gemcitabine chemotherapy. Ten to 15mL Lipiodol, using 0.5mL per injection, was injected into bladder submucosa circumferentially around the entire periphery of the tumor bed immediately following maximal TURBT. The authors looked at inter-observer variability regarding the size and location of the tumor bed (CTV boost ) on computed tomography scans with versus without Lipiodol. Results: Median follow-up was 18 months. Lipiodol was visible on every orthogonal two-dimensional kV portal image throughout the entire, 7-week course of IGRT. There was a trend towards improved inter-observer agreement on the CTV boost with Lipiodol (p = 0.06). In 2 of 5 patients, the tumor bed based upon Lipiodol extended outside a planning target volume that would have been treated with a radiation boost based upon a cystoscopy report and an enhanced computed tomography (CT) scan for staging. There was no toxicity attributable to Lipiodol. Conclusions: Lipiodol constitutes a safe and effective fiducial marker that an urologist can use to demarcate a tumor bed immediately following maximal TURBT. Lipiodol decreases inter-observer variability in the definition of the extent and location of a tumor bed on a treatment planning CT scan for a radiation boost.

2025, Annals of Surgical Oncology

Background.-Surgery is the only definitive therapy for gastro-entero-pancreatic neuroendocrine tumors (GEP-NETs), and achieving complete tumor resection is an important prognostic factor. Radiopharmaceuticals such as 68 Ga-DOTA peptides have been developed that offer superior accuracy for localization of GEPNETs. The study aim was to determine the feasibility of radio-guided surgery (RGS) using 68 Ga-DOTATATE in patients with primary and recurrent GEPNETs. Methods.-Fourteen patients with GEPNETs were enrolled onto a prospective study to determine the feasibility of RGS with 68 Ga-DOTATATE. Findings from preoperative imaging, intraoperative exploration, RGS, and pathology were analyzed. Results.-The median decay corrected target count rate was 172.6 (range 28.15-2341) for tumors, with a tumor-to-background ratio (TBR) of 4.46 (range 1.6-43.56). The median lesion size was 1.55 (range 0.5-15) cm. There was no significant correlation between preoperative imaging maximum standardized uptake value (SUV max ) of the lesions and TBR (Spearman r = -0.01, p = 0.9), TBR and tumor size (Spearman r = 0.29, p = 0.14), and SUV max and tumor size (Spearman r = 0.22, p = 0.28). The probe showed correct identification for gastric and small intestine neuroendocrine tumor (NET), including lymph node metastasis in 17 (81.0 %) of 21 cases, with a median TBR of 3.5 (1.6-40.2). For pancreatic NETs and lymph node metastasis, 16 (66.7 %) of 24 were correctly identified by RGS. Conclusions.-Our study shows that RGS with 68 Ga-DOTATATE is feasible and correctly confirms bowel NETs and metastatic mesenteric lymph nodes. Further studies are needed to determine the benefit of RGS with 68 Ga-DOTATATE.

2025, Physics in medicine and biology

Image-guided external beam radiotherapy (EBRT) allows radiation dose deposition with a high degree of accuracy and precision. Guidance is usually achieved by estimating the displacements, via image registration, between cone beam computed tomography (CBCT) and computed tomography (CT) images acquired at different stages of the therapy. The resulting displacements are then used to reposition the patient such that the location of the tumor at the time of treatment matches its position during planning. Moreover, ongoing research aims to use CBCT-CT image registration for online plan adaptation. However, CBCT images are usually acquired using a small number of x-ray projections and/or low beam intensities. This often leads to the images being subject to low contrast, low signal-to-noise ratio and artifacts, which ends-up hampering the image registration process. Previous studies addressed this by integrating additional image processing steps into the registration procedure. However, the...

2025, Journal of Medical Research and Surgery

Background: Prostate cancer remains a major health concern worldwide, and postoperative recurrences are a significant challenge in its treatment. Various treatment modalities have been studied, but consensus on optimal strategies has not yet been established. This case report examines the feasibility and toxicity of Stereotactic Body Radiation Therapy (SBRT) as a therapeutic option for postoperative recurrences of prostate cancer. Case presentation: A 68-year-old man with a history of prostate cancer, initially treated with radical prostatectomy, who presented biochemical recurrence. Diagnostic imaging revealed a 9 mm nodule in the prostate bed, which was treated by SBRT guided by ultrasound visualization. The patient tolerated the treatment well, experiencing minimal genitourinary and gastrointestinal discomfort. Discussion: Multiple treatment alternatives exist for post-prostatectomy recurrence. Retrospective studies have suggested the efficacy of SBRT, although they lack robust empirical evidence. Recent investigations have highlighted the safety profile of SBRT, emphasizing the need for further exploration, particularly in image-guided radiotherapy. Conclusion: SBRT guided by ultrasound visualization emerges as a promising option for ablative treatment of postprostatectomy recurrence, offering a favorable safety profile and encouraging oncologic outcomes. Further research is needed to further clarify its role in salvage radiotherapy for localized recurrences.

2025, Journal of Integrative Oncology

Objectives: To explore a simple and effective way to determine the total scatter of a C- Series linear accelerator.Methodology: Measurements for this study were acquired using a Varian C-Series linear accelerator, with a 6MV photon beam, a Blue water phantom, 2 IBA CC13 ion chambers and an IBA CCU electrometer. Measurements were acquired for field sizes ranging from 5cm x 5cm to 40cm x 40cm, increasing field size by an increment of 5cm. Three readings were collected for each field size and averaged. All readings were done at a depth of 10cm to reduce the probability of measuring electron contamination in the photon beam. Measurements for Sc calculation were acquired in air using a build-up cap with a 3cm diameter.Results: The average radiation dose measured increased as the field sizes increased. The maximum dose recorded for Sc was 2.33cGy while that for Scp was7.96cGy. There was a non-linear direct relationship between radiation dose measured, Scp and Sc calculated and field size....

2025

Purpose: There are no international guidelines for optimal needle insertion during interstitial intracavitary brachytherapy (IS-ICBT) for cervical cancer. We aimed to investigate the clinical feasibility and added value of computed to mography (CT) guidance to optimize needle insertion in IS-ICBT using the Utrecht appli cator and to evaluate needle shifts. Methods and Materials: We enrolled 24 patients who were treated with IS-BT . Two CT scans each were performed for every patient: 1) aft er applicator insertion without needles (CTpreneedle ); 2) after needle insertion (CT postneedle ). In addition to magnetic resonance imaging (MRI) after external-beam radiotherapy, CT preneedle was used to determine optimal needle locations and insertion lengths based on applicator nd organs at risk positioning on the day of treatment; CTpostneedle was used for IS-ICBT planning. The needle-channel axis was used as a reference to determine needle-shift evolution. Results: A total of 266 interstiti...

2025, The British journal of radiology

New linear accelerators can be equipped with a 6D robotic couch, providing two additional rotational motion axes: pitch and roll. These shifts in kV-CBCT image-guided radiotherapy (IGRT) were evaluated over the first 6 months usage of a 6D Robotic couch-top, ranking the treatment sites for which the two compensations are larger for patient setup. The couch compensations of 2945 fractions for 376 consecutive patients treated on the PerfectPitch™ 6D couch (Varian Medical System) were analyzed. Among these patients, 169 were treated for brain, 111 lung, 54 liver, 26 pancreas, and 16 prostate. During the setup, patient anatomy from planning CT was aligned to kV-CBCT and 6D movements were executed. Information related to pitch and roll were extracted by proper querying of the Microsoft SQL server ARIA database (Varian). Mean values and standard deviations were calculated for all sites. Kolmogorov-Smirnov (KS) test was performed. Considering all the data, mean pitch and roll adjustments w...

2025, Nature

The development of targeted anti-cancer therapies through the study of cancer genomes is intended to increase survival rates and decrease treatment-related toxicity. We treated a transposon-driven, functional genomic mouse model of... more

2025, Journal of Applied Clinical Medical Physics

The case of a 50-year-old man affected by a rhabdomiosarcoma metastatic lesion in the left flank Is reported. The patient was addressed to 50.4 Gy radiotherapy with concomitant chemotherapy in order to locally control the lesion. A Tri-60-Co magnetic resonance hybrid radiotherapy unit was used for treatment delivery and a respiratory gating protocol was applied for the different breathing phases (Free Breathing, Deep Inspiration Breath Hold and Final Expiration Breath Hold). Three intensity modulated radiation therapy (IMRT) plans were calculated and Final Expiration Breath Hold plan was finally selected due to the absence of PTV coverage differences and better organs at risk sparing (i.e. kidneys). This case report suggests that organs at risk avoidance with MRI-guided respiratory-gated Radiotherapy is feasible and particularly advantageous whenever sparing the organs at risk is of utmost dosimetric or clinical importance. adaptive radiotherapy, hybrid radiotherapy, MRI guided radiotherapy, respiratory gating ing (MRI) offers the unique possibility to directly detect and gate the treatment to a particular condition of the respiratory cycle eliminating the need for surrogate-based systems and imaging dose to patient. MRI-guided gated treatments can be performed during

2025, Journal of Applied Clinical Medical Physics

The case of a 50‐year‐old man affected by a rhabdomiosarcoma metastatic lesion in the left flank Is reported. The patient was addressed to 50.4 Gy radiotherapy with concomitant chemotherapy in order to locally control the lesion. A Tri‐60‐Co magnetic resonance hybrid radiotherapy unit was used for treatment delivery and a respiratory gating protocol was applied for the different breathing phases (Free Breathing, Deep Inspiration Breath Hold and Final Expiration Breath Hold). Three intensity modulated radiation therapy (IMRT) plans were calculated and Final Expiration Breath Hold plan was finally selected due to the absence of PTV coverage differences and better organs at risk sparing (i.e. kidneys). This case report suggests that organs at risk avoidance with MRI‐guided respiratory‐gated Radiotherapy is feasible and particularly advantageous whenever sparing the organs at risk is of utmost dosimetric or clinical importance.

2025, Nature

2025, Journal of Applied Clinical Medical Physics

We demonstrate a virtual pretreatment patient-specific QA (PSQA) procedure that is capable of quantifying dosimetric effect on patient anatomy for both intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT).A machine learning prediction model was developed to use linear accelerator parameters derived from the DICOM-RT plan to predict delivery discrepancies at treatment delivery (defined as the difference between trajectory log file and DICOM-RT) and was coupled with an independent Monte Carlo dose calculation algorithm for dosimetric analysis. Machine learning models for IMRT and VMAT were trained and validated using 120 IMRT and 206 VMAT fields of prior patients, with 80% assigned for iterative training and testing, and 20% for post-training validation. Various prediction models were trained and validated, with the final models selected for clinical implementation being a boosted tree and bagged tree for IMRT and VMAT, respectively. After validation, these models were then applied clinically to predict the machine parameters at treatment delivery for 7 IMRT plans from various sites (61 fields) and 10 VMAT multi-target intracranial radiosurgery plans (35 arcs) and compared to the dosimetric effect calculated directly from trajectory log files. Dose indices tracked for targets and organs at risk included dose received by 99%, 95%, and 1% of the volume, mean dose, percent of volume receiving 25%-100% of the prescription dose. The average coefficient of determination (r 2) when comparing intra-field predicted and actual delivery error was 0.987 ± 0.012 for IMRT and 0.895 ± 0.095 for VMAT, whereas r 2 when comparing inter-field predicted versus actual delivery error was 0.982 for IMRT and 0.989 for VMAT. Regarding dosimetric analysis, r 2 when comparing predicted versus actual dosimetric changes for all dose indices was 0.966 for IMRT and 0.907 for VMAT. Prediction models can be used to anticipate the dosimetric effect calculated from trajectory files and have potential as a "delivery-free" pretreatment analysis to enhance PSQA.

2025, Strahlentherapie und Onkologie

Purpose Evaluation of long-term outcome and toxicity of moderately hypofractionated radiotherapy using intensity-modulated radiotherapy (IMRT) with simultaneous integrated boost treatment planning and cone beam CT-based image guidance for localized prostate cancer. Methods Between 2005 and 2015, 346 consecutive patients with localized prostate cancer received primary radiotherapy using cone beam CT-based image-guided intensity-modulated radiotherapy (IG-IMRT) and volumetric modulated arc therapy (IG-VMAT) with a simultaneous integrated boost (SIB). Total doses of 73.9 Gy (n = 44) and 76.2 Gy (n = 302) to the high-dose PTV were delivered in 32 and 33 fractions, respectively. The low-dose PTV received a dose (D95) of 60.06 Gy in single doses of 1.82 Gy. The pelvic lymph nodes were treated in 91 high-risk patients to 45.5 Gy (D95). Results Median follow-up was 61.8 months. The 5-year biochemical relapse-free survival (bRFS) was 85.4% for all patients and 93.3, 87.4, and 79.4% for low-, intermediate-, and high-risk disease, respectively. The 5-year prostate cancer-specific survival (PSS) was 94.8% for all patients and 98.7, 98.9, 89.3% for low-, intermediate-, and high-risk disease, respectively. The 5-year and 10-year overall survival rates were 83.8 and 66.3% and the 5-year and 10-year freedom from distant metastasis rates were 92.2 and 88.0%, respectively. Cumulative 5-year late GU toxicity and late GI toxicity grade ≥2 was observed in 26.3 and 12.1% of the patients, respectively. Cumulative 5-year late grade 3 GU/GI toxicity occurred in 4.0/1.2%. Conclusion Moderately hypofractionated radiotherapy using SIB treatment planning and cone beam CT image guidance resulted in high biochemical control and survival with low rates of late toxicity.

2025, Medical Physics

Purpose: To identify achievable camera performance and hardware needs in a clinical Cherenkov imaging system for real-time, in vivo monitoring of the surface beam profile on patients, as novel visual information, documentation, and possible treatment verification for clinicians. Methods: Complementary metal-oxide-semiconductor (CMOS), charge-coupled device (CCD), intensified charge-coupled device (ICCD), and electron multiplying-intensified charge coupled device (EM-ICCD) cameras were investigated to determine Cherenkov imaging performance in a clinical radiotherapy setting, with one emphasis on the maximum supportable frame rate. Where possible, the image intensifier was synchronized using a pulse signal from the Linac in order to image with room lighting conditions comparable to patient treatment scenarios. A solid water phantom irradiated with a 6 MV photon beam was imaged by the cameras to evaluate the maximum frame rate for adequate Cherenkov detection. Adequate detection was defined as an average electron count in the background-subtracted Cherenkov image region of interest in excess of 0.5% (327 counts) of the 16-bit maximum electron count value. Additionally, an ICCD and an EM-ICCD were each used clinically to image two patients undergoing whole-breast radiotherapy to compare clinical advantages and limitations of each system. Results: Intensifier-coupled cameras were required for imaging Cherenkov emission on the phantom surface with ambient room lighting; standalone CMOS and CCD cameras were not viable. The EM-ICCD was able to collect images from a single Linac pulse delivering less than 0.05 cGy of dose at 30 frames/s (fps) and pixel resolution of 512 × 512, compared to an ICCD which was limited to 4.7 fps at 1024 × 1024 resolution. An intensifier with higher quantum efficiency at the entrance photocathode in the red wavelengths [30% quantum efficiency (QE) vs previous 19%] promises at least 8.6 fps at a resolution of 1024 × 1024 and lower monetary cost than the EM-ICCD. Conclusions: The ICCD with an intensifier better optimized for red wavelengths was found to provide the best potential for real-time display (at least 8.6 fps) of radiation dose on the skin during treatment at a resolution of 1024 × 1024.

2025, Medical Physics

Purpose: To demonstrate the feasibility of Tetrahedron Beam Computed Tomography (TBCT) using a carbon nanotube (CNT) multiple pixel field emission x-ray (MPFEX) tube. Methods: A multiple pixel x-ray source facilitates the creation of novel x-ray imaging modalities. In a previous publication, the authors proposed a Tetrahedron Beam Computed Tomography (TBCT) imaging system which comprises a linear source array and a linear detector array that are orthogonal to each other. TBCT is expected to reduce scatter compared with Cone Beam Computed Tomography (CBCT) and to have better detector performance. Therefore, it may produce improved image quality for image guided radiotherapy. In this study, a TBCT benchtop system has been developed with an MPFEX tube. The tube has 75 CNT cold cathodes, which generate 75 x-ray focal spots on an elongated anode, and has 4 mm pixel spacing. An in-house-developed, 5-row CT detector array using silicon photodiodes and CdWO 4 scintillators was employed in the system. Hardware and software were developed for tube control and detector data acquisition. The raw data were preprocessed for beam hardening and detector response linearity and were reconstructed with an FDK-based image reconstruction algorithm. Results: The focal spots were measured at about 1 Â 2 mm 2 using a star phantom. Each cathode generates around 3 mA cathode current with 2190 V gate voltage. The benchtop system is able to perform TBCT scans with a prolonged scanning time. Images of a commercial CT phantom were successfully acquired. Conclusions: A prototype system was developed, and preliminary phantom images were successfully acquired. MPFEX is a promising x-ray source for TBCT. Further improvement of tube output is needed in order for it to be used in clinical TBCT systems. V C 2011 American Association of Physicists in Medicine.

2025, World Conference on Interventional Oncology

Transarterial radioembolization (TARE) with yttrium-90 (Y-90) microspheres is a locoregional therapy for unresectable hepatocellular carcinoma (HCC) that delivers targeted radiation while sparing surrounding hepatic parenchyma. Advances in personalized dosimetry have improved treatment efficacy by optimizing radiation dose distribution within the tumor while minimizing non-target exposure. Quantitative imaging modalities, including positron emission tomography (PET) with Y-90 bremsstrahlung and technetium-99m macroaggregated albumin (Tc-99m MAA) single-photon emission computed tomography (SPECT), enable pretreatment dose planning and post-treatment verification of dose delivery. Refinements in computational models and artificial intelligence-assisted segmentation have further enhanced dose-response prediction. Ongoing research focuses on integrating personalized dosimetry with immunomodulatory approaches and combination therapies to enhance treatment outcomes in HCC and other liver malignancies.

2025, Medical physics

This report presents the methods and results of the Thoracic Auto-Segmentation Challenge organized at the 2017 Annual Meeting of American Association of Physicists in Medicine. The purpose of the challenge was to provide a benchmark dataset and platform for evaluating performance of auto-segmentation methods of organs at risk (OARs) in thoracic CT images. Sixty thoracic CT scans provided by three different institutions were separated into 36 training, 12 offline testing, and 12 online testing scans. Eleven participants completed the offline challenge, and seven completed the online challenge. The OARs were left and right lungs, heart, esophagus and spinal cord. Clinical contours used for treatment planning were quality checked and edited to adhere to the RTOG 1106 contouring guidelines. Algorithms were evaluated using the Dice coefficient, Hausdorff distance, and mean surface distance. A consolidated score was computed by normalizing the metrics against inter-rater variability and a...

2025, Radiotherapy and Oncology

2025, Strahlentherapie Und Onkologie

Results FFF-SBRT plans required more monitor units (MU) than conv-VMAT plans (2956.6 ± 885.3 MU for 12 Gy/fraction and 1148.7 ± 289.2 MU for 5 Gy/fraction vs. 608.4 ± 157.5 MU for 2 Gy/fraction). Total treatment and net beam-on times were shorter for FFF-SBRT plans than conv-VMAT plans (268.0 ± 74.4 s vs. 330.2 ± 93.6 s and 85.8 ± 25.3 s vs. 117.2 ± 29.6 s, respectively). Total slot time was 13.0 min for FFF-SBRT and 14.0 min for conv-VMAT. All modalities could be delivered accurately despite multiple beam-on/-off cycles and were robust against multiple interruptions. Conclusion Automatically gated CBCT-controlled fast DIBH SBRT in VMAT FFF technique and normofractionated lung DIBH VMAT can be applied with a low number of breath-holds in a short timeslot, with excellent dosimetric accuracy. In clinical routine, these approaches combine optimally reduced lung tissue irradiation with maximal delivery precision for patients with small and larger lung tumors. Imaging • Linear accelerators • Breathing • Cone-beam computed tomography • Quality assurance Automatisch gesteuerte, bildgestützte IMRT im Atemanhalt als schnelle, präzise und dosimetrisch stabile Therapie für Patienten mit Bronchialkarzinom Zusammenfassung Hintergrund Die Hochdosisstrahlentherapie des Bronchialkarzinoms ist eine Herausforderung. Bis zu 2 cm kann sich der Tumor in kraniokaudaler und anteroposteriorer Richtung bewegen -abhängig vom Atemzyklus. Die Tumorverschiebung nimmt mit der Behandlungsdauer zu, was also die Behandlungsunsicherheit vermehrt. Anna Simeonova-Chergou and Anika Jahnke contributed equally to this publication.

2025, International Journal of Radiation Oncology*Biology*Physics

Purpose/Objective(s): Bilateral cancer breast irradiation is a real challenge in the field of radiation therapy, especially in case of axillary nodes involvement. VMAT is an interesting technique to achieve suitable target volume coverage while sparing organs at risk (OAR) when compared to 3D-conformal radiation therapy. Here, we present results of treatment planning of 20 consecutive bilateral breast cancer patients treated in our institution. Materials/Methods: Twenty consecutive bilateral breast cancer patients were treated using VMAT technique from July 2011 to December 2013. Target volumes (CTV, GTV) were delineated according to RTOG guidelines. The prescribed doses were 63.2 Gy to PTV of boost (n Z 17), 52.2 Gy to PTV of whole breast (n Z 20) and of internal mammary chain (IMC) nodes (n Z 9) and 49.3 Gy to PTV of the supraclavicular (SC) nodes (n Z 9) in 29 fractions. The V95% for CTV breast should be larger or equal to 99% and V95% for all other CTVs larger or equal to95%. Values of PTV and OAR exposure were collected. Results: Main results are summarized in the following table.

2025, International cancer conference journal

Complete surgical resection is the potentially curative treatment for pancreatic cancer, but only fewer than 20% of those individuals will be found to be eligible for surgery. Here we report a 49-year-old man with locally advanced pancreatic cancer successfully treated with high-dose radiotherapy using helical tomotherapy (66 Gy/33 fractions, 2 Gy per day over 6.5 weeks). To our knowledge, this is the first reported case of locally advanced pancreatic cancer curatively treated with helical tomotherapy alone.

2025, Journal of oncology practice

To identify factors associated with a near-miss or safety incident (NMSI) in patients undergoing radiotherapy and identify common root causes of NMSIs and their relationship with incident severity. We retrospectively studied NMSIs filed between October 2014 and April 2016. We extracted patient-, treatment-, and disease-specific data from patients with an NMSI (n = 200; incident group) and a similar group of control patients (n = 200) matched in time, without an NMSI. A root cause and incident severity were determined for each NMSI. Univariable and multivariable analyses were performed to determine which specific factors were contributing to NMSIs. Multivariable logistic regression was used to determine root causes of NMSIs and their relationship with incident severity. NMSIs were associated with the following factors: head and neck sites (odds ratio [OR], 5.2; P = .01), image-guided intensity-modulated radiotherapy (OR, 3; P = .009), daily imaging (OR, 7; P < .001), and tumors st...

2025, Journal of Biomedicine and Biotechnology

Applying diffusive models for simulating the spatiotemporal change of concentration of tumour cells is a modern application of predictive oncology. Diffusive models are used for modelling glioblastoma, the most aggressive type of glioma. This paper presents the results of applying a linear quadratic model for simulating the effects of radiotherapy on an advanced diffusive glioma model. This diffusive model takes into consideration the heterogeneous velocity of glioma in gray and white matter and the anisotropic migration of tumor cells, which is facilitated along white fibers. This work uses normal brain atlases for extracting the proportions of white and gray matter and the diffusion tensors used for anisotropy. The paper also presents the results of applying this glioma model on real clinical datasets.

2025, Journal of Vascular and Interventional Radiology

Purpose: A new MWA device, the Emprint™ Microwave Ablation System, is purported to achieve spherical and predictable ablation zones. We aim to evaluate the clinical efficacy and shortterm safety profile this device in the percutaneous ablation of malignant liver tumors. Materials: This is a retrospective IRB-approved study of patients who underwent percutaneous MWA with the Emprint™ device from Jan 2015 to April 2017 in our institution. Patient demographics, technical success rates, as well as 30-day mortality and morbidity were examined. The presence of residual disease or recurrence was recorded after review of contrast-enhanced CT/ MRI up to 24 months post procedure. Results: A total of 119 ablations were performed in 102 patients, with a mean tumor diameter of 1.7 (1.0 -5.6) cm. Technical success rate was 99.2%. Residual disease rate at 6 weeks was 6.2%, while a recurrence rate of 2.7% was recorded. There was no procedural related mortality. One major complication of hemorrhage requiring angioembolization was recorded (0.8%), while minor complication rate was 17.6% (pneumothorax n ¼ 5, small subcapsular haematoma/haemoperitoneum n ¼ 5, over sedation n ¼ 5, pleural effusion n ¼ 4, transfusion reaction to platelets n ¼ 1, bacteremia n ¼ 1, focal portal vein thrombosis n ¼ 1). Conclusions: Our study suggests that the Emprint™ MWA device is a safe device that allows a high degree of technical success with a low rate of residual disease and short-term recurrence.

2025, Journal of Controlled Release

Radiation therapy is a major treatment regimen for more than 50% of cancer patients. The collateral damage induced on healthy tissues during radiation and the minimal therapeutic effect on the organ-of-interest (target) is a major clinical concern. Ultra-small, renal clearable, silica based gadolinium chelated nanoparticles (SiGdNP) provide simultaneous MR contrast and radiation dose enhancement. The high atomic number of gadolinium provides a large photoelectric cross-section for increased photon interaction, even for high-energy clinical radiation beams. Imaging and therapy functionality of SiGdNP were tested in cynomolgus monkeys and pancreatic tumor-bearing mice models, respectively. A significant improvement in tumor cell damage (double strand DNA breaks), growth suppression, and overall survival under clinical radiation therapy conditions were observed in a human pancreatic xenograft model. For the first time, safe systemic administration and systematic renal clearance was demonstrated in both tested species. These findings strongly support the translational potential of SiGdNP for MR-guided radiation therapy in cancer treatment.

2025, International Journal of Theoretical and Applied Research

The IMRT (Intensity Modulation Radiation Therapy) and rapid arc give uniform desired dose distribution to the target volume with adequate sparing of the nearby critical structures. The portal dosimetry system and 2-D array system are widely used as relative dosimetry detectors, because of their consistency in results, less time consumption, and ease of use. In the current work, twenty cases of dynamic IMRT plans were selected for the patient-specific QA (Quality Assurance) study using portal dosimetry and a 2-D(Two Dimensional) array set square pattern ,spaced 10 mm apart across the entire measurement area using Detectors Number 729 (Planar dose comparison was carried out with gamma criteria of 3% -3 mm (DTA)(Distance To Agreement). For the portal, dosimetry system area gamma, passing the 3%-3mm gamma was chosen. The current study Varian Linac Unique at El Hussein Hospital Electronic Portal Imager Device (EPID) is a flat panel X-ray imager with a large area active matrix readout structure, made up of phosphor or photoconductor. The 2-D array system consists of 1020 parallel plate ion chambers arranged in a 32x32 grid, with an interdetector spacing of 7.619 mm. Each detector has a diameter of 4.5 mm, a height of 5 mm, and a chamber volume of 0.02 cc. IMRT in pre-treatments to help select Pγ%< 1 point and relevant transition criteria to assess the reproducibility of treatment fractions. Compared to a 2D Array system., although the 2D array has limited sampling capabilities. The portal dosimetry soft for portal imager device (EPID) has a good result for breast cancer plan evaluation versus 2D array results and agreement with international publish data, in addition, reduces the time for calibration due to there is no need for extended cable for measurement is compared with a 2D array

2025, International Journal of Radiation Oncology Biology Physics

target and organs at risk (OARs) during breathing are not considered in this three-dimensional (3-D) planning system, because doses are calculated at the end-exhale computed tomography (CT) images. On the other hand, the four-dimensional (4-D) plans using CT images from all respiratory phases seem to be similar to the actual doses. To know the difference between the calculated doses and actual doses delivered to the target and OARs, doses were calculated using 4-D plans and compared with those of the 3-D plans. Materials/Methods: Fourteen patients with lung cancer were treated at our institution from December 2012 to June 2013. 4-D CT scans were performed using multi slice CT and respiratory gating system. 4-D CT images were categorized into 10 respiratory phases. CT images were imported to the treatment planning system and structures were delineated on the endexhale phase CT images. Monte-Carlo algorithm was used for the dose calculation. 48 Gy in four fractions were prescribed at D95 of the PTV. Doses were calculated by both 3-D and 4-D plans in each patient. Maximum doses of the GTV (D-Max), GTV-D99, PTV-D95, Lung-V20, Conformity Index (CI) and Homogeneity index (HI) were compared in each patient. Furthermore, maximum doses of the liver, stomach, esophagus, trachea and spinal cord were also evaluated. Results: The actual doses of 4708.09 cGy AE 91.62 in PTV-D95 calculated by 4-D plans were significantly decreased in comparison with the prescribed doses of 4800 cGy by 3-D plans (p Z 0.02). The maximum differences of the calculated doses between 3-D and 4-D plans in GTV-D99 and PTV-D95 were 400.0 cGy and 266.7 cGy, respectively. In 3-D plans, doses were overestimated at the average of 2% (max 7.5%). The differences of maximum doses between 3-D and 4-D plans were not statistically significant in each OAR. However, the differences of calculated doses between 3-D and 4-D plans were relatively high in liver (-110.82 cGy -454.28 cGy), esophagus (-86.31 cGy -344.27 cGy) and trachea (-972.89 cGy -536.14 cGy), respectively. Conclusions: Although Monte-Carlo calculation has 2% uncertainty, and deformations of both target and OARs during respiration are inevitable, it was conceivable that the difference of the calculated doses between 3-D plan and 4-D plan to the target tumor were negligible. In contrast, the maximum doses of the OARs varied widely in each case. The accurate margins of OARs were affected by respiratory motions especially in organs such as liver, esophagus, and trachea. 4-D planning should be employed in the treatment planning of the cases with tumor located near the liver, esophagus and trachea to avoid the unexpected overdose-radiation to OARs.

2024, Clinical Cancer Research

Background: Despite the use of prostate specific antigen (PSA), Gleason-score, and T-category as prognostic factors, up to 40% of patients with intermediate-risk prostate cancer will fail radical prostatectomy or precision image-guided radiotherapy (IGRT). Additional genetic prognosticators are needed to triage these patients toward intensified combination therapy with novel targeted therapeutics. We tested the role of the NKX3.1 gene as a determinant of treatment outcome given its reported roles in tumor initiating cell (TIC) renewal, the DNA damage response, and cooperation with c-MYC during prostate cancer progression. Methods: Using high-resolution array comparative genomic hybridization (aCGH), we profiled the copy number alterations in TIC genes using tumor DNA from frozen needle biopsies derived from 126 intermediate-risk patients who underwent IGRT. These data were correlated to biochemical relapse-free rate (bRFR) by the Kaplan–Meier method and Cox proportional hazards mode...