Treatment planning Research Papers - Academia.edu (original) (raw)

A study of the performance of five commercial radiotherapy treatment planning systems (TPSs) for common treatment sites regarding their ability to model heterogeneities and scattered photons has been performed. The comparison was based on CT information for prostate, head and neck, breast and lung cancer cases. The TPSs were installed locally at different institutions and commissioned for clinical use based on local procedures. For the evaluation, beam qualities as identical as possible were used: low energy (6 MV) and high energy (15 or 18 MV) x-rays. All relevant anatomical structures were outlined and simple treatment plans were set up. Images, structures and plans were exported, anonymized and distributed to the participating institutions using the DICOM protocol. The plans were then re-calculated locally and exported back for evaluation. The TPSs cover dose calculation techniques from correction-based equivalent path length algorithms to modelbased algorithms. These were divided into two groups based on how changes in electron transport are accounted for ((a) not considered and (b) considered). Increasing the complexity from the relatively homogeneous pelvic region to the very inhomogeneous lung region resulted in less accurate dose distributions. Improvements in the calculated dose have been shown when models consider volume scatter and changes in electron transport, especially when the extension of the irradiated volume was limited and when low densities were present in or adjacent to the fields. A Monte Carlo calculated algorithm input data set and a benchmark set for a virtual linear accelerator have been produced which have facilitated the analysis and interpretation of the results. The more sophisticated

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- Algorithms, Biomedical Engineering, Monte Carlo, Brachytherapy

The purpose of this study was to establish the efficacy of standardized treatment planning for high dose rate (HDR) vaginal cuff brachytherapy in order to simplify and shorten the brachytherapy procedure. Two separate but related studies are presented. The first examined the reproducibility of treatment planning by assessing interoperator variability. This provided a baseline assessment of variability to evaluate standardized treatment planning in the second study. The second study examined interpatient variability in which the treatment plans of 20 patients were investigated by two different treatment methods. The first method used the dosimetry of the first insertion for the next insertion, while the other method utilized a standardized plan for all insertions dependent upon ovoid size. The dose was prescribed to the vaginal surface using either applicator points or dose points. Based on multiple calculations, a graph of distance vs. dose was generated to determine the dose to the bladder and rectum for a given implant. In the 6rst study, interoperator variability was acceptable with a standard deviation of 0.4% of the prescribed dose using dose points for the worst case. Applicator points were less reproducible with a worst-case standard deviation of 2.1% of the prescribed dose. In the second study, implementing initial dosimemc plans for the second implant for an individual patient yielded a worst-case standard deviation of 2.4% of the prescribed dose. The use of standardized treatment plans for all implants was also efficacious with a worst-case standard deviation of 1.7% of the prescribed dose. Treatment plans were always more reproducible when calculated to dose points rather than applicator points. Analysis of maximum bladder and rectal doses provided acceptable late tissue doses as predicted by the linear quadratic model. In conclusion, standardized dosimetry plans for vaginal cuff insertion are feasible and reliable in producing precise delivery of vaginal surface doses. The use of dose vs. distance curves facilitates rapid planning by providing a close approximation of the maximum bladder and rectal doses.

- by Timothy Kinsella
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- Treatment planning

A new treatment planning program was developed for the heavy-ion therapy facility at GS1. In addition, a concise quality standard for treatment planning has been set up. It covers acceptance and constancy checks of all critical aspects in treatment planning. Dose verification measurements done during the commissioning phase show an overall good agreement with the treatment planning calculations.

- by Michael P Kramer
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- Algorithms, Magnetic Resonance Imaging, Radiation Therapy, Quality Assurance

The feeding of young children is fundamentally a relational and multisystemic process. Successful treatment of clinically significant feeding problems involves careful assessment of the full range of influences on the feeding relationship and integrated treatment approaches. However, current diagnostic approaches to feeding disorders tend to be reductionistic, exclusively focused on the child as an individual, and overly concerned with exclusionary criteria. Criteria are proposed for "Feeding Disorder Between Parent and Child" that address these limitations and embrace the complexity of feeding problems. A multiaxial diagnosis that describes the child (including medical, developmental, and behavioral characteristics); the parent; the parent-child relationship; and the social and nutritional context of feeding will more accurately speak to treatment planning in this population. The proposed diagnostic criteria were developed and refined on the basis of the available literature and many years of treatment experience across the authors of this article. The proposed diagnosis will support the development and evaluation of treatment packages with components specifically targeted to issues of the child, parent, parent-child interaction, and the broader environment.

- by Kristoffer Berlin
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- Psychology, Eating Disorders, Family, Family Psychology

Cancer is a mass of abnormal and detrimental cells in a given part of the body. The main elucidated cause is the uncontrolled growth and proliferation of those cells after the corruption of the physiological processes responsible for normal development and functioning. The advantage of adjuvant therapy, therapy done after surgery, is to prevent the occurring of symptoms and not necessarily to make sure of the integrity of mechanisms that are crucial in preventing abnormal cell proliferation such cell cycle regulation, cell death, which include autophagy, necrosis, and apoptosis. The understanding of dysregulated cell death mechanisms combined with suitable alternative cancer therapies could lead to novel treatment modalities for cancer. Currently, breast cancer is the leading occurring cancer in sub-Saharan women after that of the cervix. This potentially curable condition kills more than half of the diagnosed group, which consists mainly of females aged between 35 and 49 years and with 77% being in stages III and IV. The social economic status of populations coupled with the limited access to proper control strategies and infrastructures in sub-Saharan regions accentuate the burden of the disease. Photodynamic therapy (PDT) has shown great potential in treating breast cancer and even greater therapeutic outcomes can be obtained when combining PDT with other therapies such as immunotherapy or nanomedicine.

- by Heidi Abrahamse
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- Chemistry, Cell Death, Programmed cell death, Treatment planning

Purpose: A dosimetric study was conducted to compare intracavitary brachytherapy using both a conventional and a custom loading intended to cover a positron emission tomography (PET)-defined tumor volume in patients with cervix cancer. Methods and Materials: Eleven patients who underwent an [ 18 F]-fluoro-deoxy-D-glucose (FDG)-PET in conjunction with their first, middle, or last brachytherapy treatment were included in this prospective study. A standard plan that delivers 6.5 Gy to point A under ideal conditions was compared with an optimized plan designed to conform the 6.5-Gy isodose surface to the PET defined volume. Results: A total of 31 intracavitary brachytherapy treatments in conjunction with an FDG-PET were performed. The percent coverage of the target isodose surface for the first implant with and without optimization was 73% and 68% (p ‫؍‬ 0.21). The percent coverage of the target isodose surface for the mid/final implant was 83% and 70% (p ‫؍‬ 0.02), respectively. The dose to point A was higher with the optimized plans for both the first implant (p ‫؍‬ 0.02) and the mid/last implants (p ‫؍‬ 0.008). The dose to 2 cm 3 and 5 cm 3 of both the bladder and rectum were not significantly different. Conclusions: FDG-PET based treatment planning allowed for improved dose coverage of the tumor without significantly increasing the dose to the bladder and rectum.

- by Daniel Low
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- Brachytherapy, Positron Emission Tomography, PET, Prospective studies
- by Chris Stout
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- Psychology, Cognitive Science, Treatment planning, Behavior Methods

Purpose: To evaluate uncertainties associated with treatment-planning computed tomography (CT) data obtained with the patient breathing freely. Methods and Materials: Patients with thoracic or abdominal tumors underwent a standard treatment-planning CT study while breathing quietly and freely, followed by CT scans while holding their breath at normal inhalation and normal exhalation. Identical treatment plans on all three CT data sets for each patient pointed out differences in: (a) radiation path lengths; (b) positions of the organs; (c) physical volumes of the lung, liver, and kidneys; (d) the interpretation of plan evaluation tools such as dose-volume histograms and normal tissue complication probability (NTCP) models; and (e) how well the planning CT data set represented the average of the inhalation and exhalation studies. Results: Inhalation and exhalation data differ in terms of radiation path length (nearly one quarter of the cases had path-length differences >l cm), although the free breathing and average path lengths do not exhibit large differences (O-9 mm). Liver and kidney movements averaged 2 cm, whereas differences between the free breathing and average positions averaged 0.6 cm. The physical volume of the liver between the free breathing and static studies varied by as much as 12%. The NTCP calculations on exhale and inhale studies varied from 3 to 43% for doses that resulted in a 15% NTCP on the free-breathing studies. Conclusion: Free-breathing CT studies may improperly estimate the position and volume of critical structures, and thus may mislead evaluation of plans based on such volume dependent criteria such as dose-volume histograms and NTCP calculations.

New Technologies in Radiation Oncology provides an excellent overview of recent technologic developments in the field of radiation oncology. This book is intended for physicians and medical physicists who are working in radiation oncology and those just entering the field. It encompasses a broad range of new technologies in radiation therapy-from image acquisition and processing to treatment planning to therapy-and helps the reader grasp the basic ideas of each new technology. If the reader wants more information than the book provides, each chapter includes a wealth of references for learning about a particular subject in detail.

- by dan dan
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- Nuclear medicine, New Technology, 3-D Imaging, Clinical Sciences

In reviewing the ABO case report in the September 2006 issue (Noble R, English J. Category 7: Anteroposterior skeletal discrepancy. Am J Orthod Dentofacial Orthop 2006: 130:403-8), we found several interesting issues that invite discussion of diagnosis and treatment planning, as well as how the ABO reviews and grades a submitted case. In presenting the treatment plan, the authors wrote, "Refer for an orthognathic surgical evaluation-expected to be a mandibular advancement with the possible need for midsymphyseal constriction." With contemporary diagnostic acumen and emphasis on facial esthetics, rather than referring a patient for evaluation, perhaps it would be more appropriate to meet personally with the surgeon to discuss all available options to achieve the maximum in a stable, functional, and esthetic occlusion. In reviewing the cephalometric analysis and the facial photographs, we noticed that the patient has maxillary and mandibular deficiency, short anterior facial height, and inadequate tooth display on smile. Contemporary orthodontic/ orthognathic surgery treatment planning would have concluded that the treatment of choice was 2-jaw surgery including a 2-piece LeFort I with expansion and advancement, and possibly clockwise rotation, mandibular advancement with no constriction, and genioplasty.

- by Jeryl English
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- Dentistry, Biomedical Engineering, Patient Participation, Dental Esthetics

§ Maryland Regional Cancer Care, Silver Spring, MD Purpose: To measure respiration-induced abdominal organ motion using four-dimensional computed tomography (4D CT) scanning and to examine the organ paths. Methods and Materials: During 4D CT scanning, consecutive CT images are acquired of the patient at each couch position. Simultaneously, the patient's respiratory pattern is recorded using an external marker block taped to the patient's abdomen. This pattern is used to retrospectively organize the CT images into multiple three-dimensional images, each representing one breathing phase. These images are analyzed to measure organ motion between each phase. The displacement from end expiration is compared to a displacement limit that represents acceptable dosimetric results (5 mm). Results: The organs measured in 13 patients were the liver, spleen, and left and right kidneys. Their average superior to inferior absolute displacements were 1.3 cm for the liver, 1.3 cm for the spleen, 1.1 cm for the left kidney, and 1.3 cm for the right kidney. Although the organ paths varied among patients, 5 mm of superior to inferior displacement from end expiration resulted in less than 5 mm of displacement in the other directions for 41 of 43 organs measured. Conclusions: Four-dimensional CT scanning can accurately measure abdominal organ motion throughout respiration. This information may result in greater organ sparing and planning target volume coverage.

- by Shalom Kalnicki and +1
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- Radiation Therapy, Spleen, Kidney, Liver

Methods and Materials: Between 1991 and 1998, 150 evaluable patients with Stage I-IIIB NSCLC were treated with three-dimensionally planned conformal radiotherapy and curative intent at Duke University Medical Center. On the treatment-planning CT, the primary tumor and nodal volumes were identified and subsequently combined to form the TTV. The TTV was compared with the stage and outcome with respect to OS, local progression-free survival, and distant failure-free survival using the Kruskall-Wallis analysis of variance and Kaplan-Meier actuarial method. To account for the potentially confounding effects of therapeutic and patientspecific covariates on survival, the Cox proportional hazard regression model was used.

- by Lawrence Marks
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- Clinical Sciences, Aged, Kaplan-Meier, Regression Model

A preliminary study on the possible use of the GEANT4 (GEometry ANd Tracking) toolkit and Grid technology, for the Monte Carlo simulation of a clinical beam line for proton therapy, has been investigated. We realized a GEANT4 application giving the possibility to simulate a typical proton therapy beam line (including all its elements and two dosimetric systems: an ionisation chamber and a radiochromic film). The application realized was tested simulating the proton therapy beam line operating at the Laboratori Nazionali del Sud of the Instituto Nazionale di Fisica Nucleare in Catania, Italy. Actually the main disanvatage of a Monte Carlo simulation are the long computation times. In order to overcome this problem and to obtain resonable computation times we decided to exploit the power of the Grid. We based our work on the local Grid installed at the Physics Department of the Catania University consisting of 20 machine, each one with two INTEL-Xeon at 2.8 GHz processors. The Grid approach, consisting in the distribution of a single big job in many CPUs, permitted us to decrease, in the actual configuration, of a factor 20 the time necessary for a complete simulation. Obtained results permit us to adfirm that GEANT4 toolkit, coupled with the Grid, can represent an answer for the routinary use of the Monte Carlo method for designing and simulating a clinical proton beam line. Moreover this can represent a first step for the use of Monte Carlo in proton treatment planning software development.

- by Giuseppe La Rocca
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- Monte Carlo Simulation, Monte Carlo, Software Development, Treatment planning

In this paper, we present a fully automatic, fast and accurate deformable registration technique. This technique deals with free-form deformation. It minimizes an energy functional that combines both similarity and smoothness measures. By using calculus of variations, the minimization problem was represented as a set of nonlinear elliptic partial differential equations (PDEs). A Gauss-Seidel finite difference scheme is used to iteratively solve the PDE. The registration is refined by a multi-resolution approach. The whole process is fully automatic. It takes less than 3 min to register two three-dimensional (3D) image sets of size 256 × 256 × 61 using a single 933 MHz personal computer. Extensive experiments are presented. These experiments include simulations, phantom studies and clinical image studies. Experimental results show that our model and algorithm are suited for registration of temporal images of a deformable body. The registration of inspiration and expiration phases of the lung images shows that the method is able to deal with large deformations. When applied to the daily CT images of a prostate patient, the results show that registration based on iterative refinement of displacement field is appropriate to describe the local deformations in the prostate and the rectum. Similarity measures improved significantly after the registration. The target application of this paper is for radiotherapy treatment planning and evaluation that incorporates internal organ deformation throughout the course of radiation therapy. The registration method could also be equally applied in diagnostic radiology.

Background: Practice guidelines recommend en bloc multivisceral resection (MVR) for all involved organs in patients with locally advanced adherent colorectal cancer (LAACRC) to reduce local recurrence and improve survival. We found that MVR was performed in onethird of eligible American patients in the Surveillance, Epidemiology and End Results cancer registry but that study could not identify factors amenable to quality improvement. This study was conducted to examine rates, and predictors of MVR among Canadian patients with LAACRC.

- by Calvin Law
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- Decision Making, Forecasting, Quality Improvement, Survival Analysis

The present study explores driving skills in a group of 50 media-recruited driving-fearful and 50 control drivers, all of whom were women. Participants completed an on-road practical driving assessment with a professional driving instructor. Diagnostic as well as pre-post self-report and instructor driving assessments were conducted. Fearful drivers made more errors on the driving assessment than controls. However, the pattern of errors was identical for both groups, indicating that fear and anxiety may be associated with the number rather than the type of driving errors made. These differences remained when factors such as driving history, current driving frequency, and diagnosis were controlled using case selection. More research is needed to replicate the findings in more diverse samples. Additional work should also aim to clarify the specific role of driving skills in driving fear, which will facilitate treatment planning for exposure-based treatments and help identify cases where driving skills assessment may be appropriate. r

- by Frank Deane
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- Psychology, Psychometrics, Fear, Anxiety

Purpose: Radiotherapy (RT) after conservative surgery for breast cancer involves part of the pulmonary parenchyma with a potential detrimental effect of reducing the normal functional reserve. Such an effect deserves to be studied in depth, considering the given long life expectancy of these women. We prospectively analyzed high-resolution computed tomography (HRCT) and pulmonary function tests (PFTs) with correlation with dosimetric data from RT. Methods and Materials: Lung HRCT and PFTs were performed in 41 women who had undergone conservative surgery for breast cancer before and 3 and 9 months after postoperative RT. The PFTs included forced vital capacity, forced expiratory volume in 1 s, total lung capacity, maximal expiratory flow at 50% and 25% of vital capacity, and the diffusion capacity of carbon monoxide. HRCT was matched with the RT treatment plan images to analyze the dosimetric correlation. Results: At 3 months after RT, the lung alterations were classified at HRCT as follows: 46.3% were Grade 1, 24.4% Grade 2, and 7.3% Grade 3, and at 9 months, 58.5% were Grade 1, 19.5% Grade 2, and 0% Grade 3. The PFTs showed a significant decrease at 3 months, with only partial recovery at 9 months. Chemotherapy, but not hormonal therapy, was associated with PFT changes. The grade of fibrosis increased with increasing lung volume treated to a dose 25Gy.Conclusion:Lungchanges,mainlyrelatedtodamagetothealveolar−capillarybarrierandsmallestairwayramifications,wereobservedat3months,withonlypartialrecoveryat9monthsafterRT.Minimizingthelungvolumereceiving25 Gy. Conclusion: Lung changes, mainly related to damage to the alveolar-capillary barrier and smallest airway ramifications, were observed at 3 months, with only partial recovery at 9 months after RT. Minimizing the lung volume receiving 25Gy.Conclusion:Lungchanges,mainlyrelatedtodamagetothealveolar−capillarybarrierandsmallestairwayramifications,wereobservedat3months,withonlypartialrecoveryat9monthsafterRT.Minimizingthelungvolumereceiving25 Gy could reduce pulmonary toxicity. Ó

- by Marco Krengli
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- Breast Cancer, Prospective studies, Carbon Monoxide, Life Expectancy

Purpose: The proliferation of various brachytherapy modalities for different anatomical sites necessitates the creation of standards for brachytherapy. Methods: A panel consisting of members of The American Brachytherapy Society (ABS), The American College of Medical Physics (ACMP) and The American College of Radiation Oncology (ACRO) developed standards for the clinical practice and quality assurance (QA) of brachytherapy. These were based upon their clinical experience and a review of the literature. Results: Recommended practice standards are presented for clinical processes, treatment planning, equipment, facilities, QA, dose evaluation, dose specification, dose reporting, the training, and credentialing of personnel, and radiation control/safety/protection. Safe and efficacious performance of brachytherapy requires a highly structured QA program and carefully designed treatment delivery processes, as well as a coordinated effort amongst the team members. Conclusion: Standards for clinical brachytherapy are proposed. Practitioners are encouraged to use these standards to design and implement a consistent and efficacious brachytherapy program.

- by Bruce Thomadsen
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- Brachytherapy, Quality Control, Clinical Practice, Quality Assurance

When treatment intent is to include breast and internal mammary lymph nodes (IMNs) in the clinical target volume (CTV), a significant volume of the heart may receive radiation, which may result in late morbidity. The value of conformal intensity-modulated radiation therapy (IMRT) to avoid heart dose was studied.Breast, IMNs, and normal tissues were contoured for 30 consecutive patients previously treated with RT after lumpectomy for left-sided breast cancer. Eleven-beam, conformal, inverse-planned IMRT plans were developed and compared with best standard plans. Conformity Index (CI), Homogeneity Index (HI), and doses to normal tissues were compared.Intensity-modulated RT significantly improved (two-sided paired t test) HI (0.95 vs. 0.74), CI (0.91 vs. 0.48), volume of the heart receiving more than 30 Gy (V30-heart) (1.7% vs. 12.5%), and volume of lung receiving more than 20-Gy (V20-left lung) (17.1% vs. 26.6%), all p < 0.001. The mean Healthy Tissue Volume (HTV = CT set – PTV) dose was similar between IMRT and best standard plans (6.0 and 6.9 Gy, respectively), but IMRT increased the volume of normal tissues receiving low-dose RT: V5-right lung (13.7% vs. 2.0%), V5-right breast (29.2% vs. 7.9%), and V5-HTV (31.7% vs. 23.6%), all p < 0.001. IMRT plans were generated in less than 60 min and treatment delivered in approximately 20 min, suggesting that this technique is clinically applicable.IMRT significantly improved conformity and homogeneity for plans when the breast + IMNs were in the CTV. Heart and lung volume receiving high doses were decreased, but more healthy tissue received low doses. A simple algorithm based on amount of heart included in the standard plan showed limited ability to predict the benefit from IMRT.

- by Carmen Popescu
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- Algorithms, Breast Cancer, Radiation Therapy, Low Dose

Avulsion of permanent teeth is the most serious of all dental injuries. The prognosis depends on the measures taken at the place of accident or the time immediately after the avulsion. Replantation is the treatment of choice, but cannot... more

- by mary gold flores
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- Dentistry, Emergency Management, Dental, Treatment planning
- by Lloyd H Robertson
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- Death Studies, Case Studies, Treatment Outcome, Adolescent
- by San Lon
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- Geriatrics, Typology, Mental Health, Depression
- by Joanna Cygler
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- Radiation, Brachytherapy, Computers, Quality Assurance

Purpose: To evaluate an infrared (IR) marker-based positioning system in patients receiving conformal radiotherapy for prostate cancer. Methods and Materials: During 553 treatments, the ability of the IR system to automatically position the isocenter was recorded. Setup errors were measured by means of orthogonal verification films and compared to conventional positioning (using skin drawings and lasers) in 184 treatments. Results: The standard deviation of anteroposterior (AP) and lateral setup errors was significantly reduced with IR marker positioning compared to conventional: 2 vs. 4.8 mm AP (p < 0.01) and 1.6 vs. 3.5 mm laterally (p < 0.01). Longitudinally, the difference was not significant (3.5 vs. 3.0 mm). Systematic errors were on the average smaller AP and laterally for the IR method: 4.1 vs. 7.8 mm AP (p ‫؍‬ 0.01) and 3.1 vs. 5.6 mm lateral (p ‫؍‬ 0.07). Longitudinally, the IR system resulted in somewhat larger systematic errors: 5.0 vs. 3.4 mm for conventional positioning (p ‫؍‬ 0.03). The use of an off-line correction protocol, based on the average deviation measured over the first four fractions, allowed virtual elimination of systematic errors. Inability of the IR system to correctly locate the markers, leading to an executional failure, occurred in 21% of 553 fractions. Conclusion: IR marker-assisted patient positioning significantly improves setup accuracy along the AP and lateral axes. Executional failures need to be reduced.

- by Vincent Vinh-Hung
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- Prostate Cancer, Standard Deviation, Measurement Error, Skin

This study examined teachers' implementation of treatment plans following consultation. Interventions were implemented for 45 elementary school students referred for consultation and intervention due to academic concerns, challenging behavior, or a combination of the two. The consultation follow-up procedures examined were brief weekly interviews, weekly interviews combined with an emphasis on the commitment to implement the treatment, and performance feedback. Performance feedback was associated with superior treatment implementation and child behavioral outcomes when compared to the two other conditions. Treatment implementation did not differ for the weekly follow-up meeting and the commitment emphasis conditions at a statistically significant level. Teacher ratings of consultants and treatment acceptability were similar across conditions. A moderate statistically significant correlation between treatment integrity and child behavioral outcome was obtained. The correlation between treatment acceptability and implementation was quite small and was not statistically significant. The implications of these findings for consultation and intervention are discussed.

- by Jennifer Resetar and +1
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- Psychology, Behavior Modification, School Psychology, Elementary Education

This study examined baseline characteristics associated with abstinence from tobacco 6 months after treatment for nicotine dependence. A total of 1224 cigarette smokers (619 females, 605 males) receiving clinical services for treatment of nicotine dependence between January 1, 1995 and June 30, 1997 were studied. The intervention involves a 45-min consultation with a nicotine dependence counselor. A treatment plan individualized to the patient's needs is then developed. The main outcome measure was the self-reported 7-day point prevalence abstinence from tobacco obtained by telephone interview 6-months after the consultation. A bootstrap resampling methodology for predictor variable selection was used to identify a set of multivariate predictors of 6-month tobacco abstinence. Five variables were multivariately associated with tobacco abstinence: male gender, no current psychiatric diagnosis, higher stage of change, longest duration of previous abstinence from tobacco of <1 or...

- by Christi Patten
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- Psychology, Tobacco, Adolescent, Counseling

The challenge in the field of sexual medicine is to develop evidence-based principles for clinical evaluation and create a uniform, widely accepted diagnostic and treatment approach for all sexual problems and dysfunctions, for both genders. Aim. To provide recommendations for the broad approach for assessing sexual problems in a medical practice setting; to develop an evidence-based diagnostic and treatment algorithm for men and women with sexual dysfunctions. Methods. The PubMed literature was reviewed. Expert opinion was based on the grading of evidence-based medical literature and the Delphi consensus process. Results. The Committee determined three principles for clinical evaluation and management: (i) adoption of a patient-centered framework, with emphasis on cultural competence in clinical practice; (ii) application of evidencebased medicine in diagnostic and treatment planning; (iii) use of a unified management approach in evaluating and treating sexual problems in both men and women. The International Consultation in Sexual Medicine-5 stepwise diagnostic and treatment algorithm was developed for that purpose. According to this algorithm, sexual, medical, and psychosocial history is mandatory, whereas physical examination and laboratory tests are highly recommended in most cases. Furthermore, the Brief Sexual Symptom Checklist (BSSC) for Men and BSSC for Women, and more recently the Sexual Complaints Screener (SCS) for Men and SCS for Women, were all endorsed for screening purposes. A classification system was also defined; clinically, sexual dysfunctions are categorized in three types according to their etiology (Type I: psychogenic; Type II: organic; Type III: mixed). Final recommendations on specialized diagnostic tests were based on level of evidence.

Background and purpose: The accuracy of dose calculation and delivery of a commercial serial tomotherapy treatment planning and delivery system (Peacock, NOMOS Corporation) was experimentally determined.Materials and methods: External beam fluence distributions were optimized and delivered to test treatment plan target volumes, including three with cylindrical targets with diameters ranging from 2.0 to 6.2 cm and lengths of 0.9 through 4.8 cm, one using three cylindrical targets and two using C-shaped targets surrounding a critical structure, each with different dose distribution optimization criteria. Computer overlays of film-measured and calculated planar dose distributions were used to assess the dose calculation and delivery spatial accuracy. A 0.125 cm3 ionization chamber was used to conduct absolute point dosimetry verification. Thermoluminescent dosimetry chips, a small-volume ionization chamber and radiochromic film were used as independent checks of the ion chamber measurements.Results: Spatial localization accuracy was found to be better than ±2.0 mm in the transverse axes (with one exception of 3.0 mm) and ±1.5 mm in the longitudinal axis. Dosimetric verification using single slice delivery versions of the plans showed that the relative dose distribution was accurate to ±2% within and outside the target volumes (in high dose and low dose gradient regions) with a mean and standard deviation for all points of −0.05% and 1.1%, respectively. The absolute dose per monitor unit was found to vary by ±3.5% of the mean value due to the lack of consideration for leakage radiation and the limited scattered radiation integration in the dose calculation algorithm. To deliver the prescribed dose, adjustment of the monitor units by the measured ratio would be required.Conclusions: The treatment planning and delivery system offered suitably accurate spatial registration and dose delivery of serial tomotherapy generated dose distributions. The quantitative dose comparisons were made as far as possible from abutment regions and examination of the dosimetry of these regions will also be important. Because of the variability in the dose per monitor unit and the complex nature of the calculation and delivery of serial tomotherapy, patient-specific quality assurance procedures will include a measurement of the delivered target dose.

- by Daniel Low
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- Algorithms, Radiotherapy, Quality Assurance, Standard Deviation

We report a methodology for comparing and combining dose information from external beam radiotherapy (EBRT) and interstitial brachytherapy (IB) components of prostate cancer treatment using the biological effective dose (BED). On a prototype early-stage prostate cancer patient treated with EBRT and low-dose rate I-125 brachytherapy, a 3-dimensional dose distribution was calculated for each of the EBRT and IB portions of treatment. For each component of treatment, the BED was calculated on a point-by-point basis to produce a BED distribution. These individual BED distributions could then be summed for combined therapies. BED dose-volume histograms (DVHs) of the prostate, urethra, rectum, and bladder were produced and compared for various combinations of EBRT and IB. Transformation to BED enabled computation of the relative contribution of each modality to the prostate dose, as the relative weighting of EBRT and IB was varied.

- by Gregory Zagaja
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- Algorithms, Brachytherapy, Prostate Cancer, Clinical Sciences

A new Monte Carlo (MC) algorithm, the "Dose Planning Method" (DPM), and its associated computer program for simulating the transport of electrons and photons in radiotherapy class problems employing primary electron beams is presented. DPM is intended to be a high accuracy Monte Carlo alternative to the current generation of treatment planning codes which rely on analytical algorithms based on approximate solution of the photon/electron Boltzmann transport equation. For primary electron beams, DPM is capable of computing 3D dose distributions (in 1 mm 3 voxels) which agree to within 1% in dose maximum with widely used and exhaustively benchmarked general purpose, public domain MC codes in only a fraction of the CPU time. A representative problem, the simulation of 1 million 10 MeV electrons impinging upon a water phantom of 128 3 voxels of 1 mm on a side, can be performed by DPM in roughly 3 minutes on a modern desktop workstation. DPM achieves this performance by employing transport mechanics and electron multiple scattering distribution functions which have been derived to permit long transport steps (on the order of 5 mm) which can cross heterogeneity boundaries. The underlying algorithm is a "mixed" class simulation scheme, with differential cross sections for hard inelastic collisions and Bremsstrahlung events described in an approximate manner to simplify their sampling. The continuous energy loss approximation is employed for energy losses below some predefined thresholds, and photon transport (including Compton, photoelectric absorption and pair production) is simulated in an analog manner. The δ-scattering method (Woodcock tracking) is adopted to minimize the computational costs of transporting photons across voxels.

- by Scott Wilderman
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- Algorithms, Biomedical Engineering, Public Domain, Monte Carlo

Three-dimensional imaging offers many advantages in making diagnoses and planning treatment. This article focuses on cone beam CT (CBCT) for making diagnoses and planning treatment in trauma-related cases. CBCT equipment is smaller and less expensive than traditional medical CT equipment and is tailored to address challenges specific to the dentoalveolar environment. Like medical CT, CBCT offers a three-dimensional view that conventional two-dimensional dental radiography fails to provide. CBCT combines the strengths of medical CT with those of conventional dental radiography to accommodate unique diagnostic and treatment-planning applications that have particular utility in dentoalveolar trauma cases. CBCT is useful, for example, in identifying tooth fractures relative to surrounding alveolar bone, in determining alveolar fracture location and morphology, in analyzing ridge-defect height and width, and in imaging temporomandibular joints. Treatment-planning applications include those involving extraction of fractured teeth, placement of implants, exposure of impacted teeth, and analyses of airways.

One of the newly introduced concepts in implant dentistry is computer-guided surgery.

- by Margareta Hultin
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- Dentistry, Biomedical Engineering, Computer Aided Design, Treatment Outcome

Objective: To evaluate the usefulness and accuracy of fine needle aspiration cytology in the diagnosis of parotid gland tumors. Methods: We reviewed files of all patients who underwent parotidectomy for various parotid pathologies at Aga Khan University Hospital. Study design included a comparison between results of preoperative FNAC with final histopathological diagnosis. Galen & Ganbino method was used to calculate sensitivity and specificity of FNAC. Results: Among 50 patients reviewed, there was one false positive and 3 false negative results reported on FNAC. This gives a sensitivity of FNAC for reporting malignancy to be 74% and specificity to rule out malignancy 97%. No significant complications were reported while performing the procedure. Conclusion: FNAC is a safe and effective modality in diagnosis and treatment planning of patients with parotid tumors (JPMA 54:617;2004).

- by zafar ahmad
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- Pakistan, Crystallization, Adolescent, Wildlife Diseases

Purpose: To present an automated technique for two-field tangential breast intensity-modulated radiotherapy (IMRT) treatment planning. Method and Materials: A total of 158 planned patients with Stage 0, I, and II breast cancer treated using wholebreast IMRT were retrospectively replanned using automated treatment planning tools. The tools developed are integrated into the existing clinical treatment planning system (Pinnacle 3 ) and are designed to perform the manual volume delineation, beam placement, and IMRT treatment planning steps carried out by the treatment planning radiation therapist. The automated algorithm, using only the radio-opaque markers placed at CT simulation as inputs, optimizes the tangential beam parameters to geometrically minimize the amount of lung and heart treated while covering the whole-breast volume. The IMRT parameters are optimized according to the automatically delineated whole-breast volume. Results: The mean time to generate a complete treatment plan was 6 min, 50 s ± 1 min 12 s. For the automated plans, 157 of 158 plans (99%) were deemed clinically acceptable, and 138 of 158 plans (87%) were deemed clinically improved or equal to the corresponding clinical plan when reviewed in a randomized, double-blinded study by one experienced breast radiation oncologist. In addition, overall the automated plans were dosimetrically equivalent to the clinical plans when scored for target coverage and lung and heart doses. Conclusion: We have developed robust and efficient automated tools for fully inversed planned tangential breast IMRT planning that can be readily integrated into clinical practice. The tools produce clinically acceptable plans using only the common anatomic landmarks from the CT simulation process as an input. We anticipate the tools will improve patient access to high-quality IMRT treatment by simplifying the planning process and will reduce the effort and cost of incorporating more advanced planning into clinical practice. Ó 2011 Elsevier Inc.

- by Daniel Letourneau
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- Algorithms, Breast Cancer, Clinical Practice, Automated Planning
- by Kaat Desloovere and +2
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- Pathology, Psychology, Biomechanics, Cerebral Palsy

We investigate whether IMRT optimization based on generalized equivalent uniform dose (gEUD) objectives for organs at risk (OAR) results in superior dosimetric outcomes when compared with multiple dose-volume (DV)-based objectives plans for patients with intact breast and postmastectomy chest wall (CW) cancer. Four separate IMRT plans were prepared for each of the breast and CW cases (10 patients). The first three plans used our standard in-house, physician-selected, DV objectives (phys-plan); gEUD-based objectives for the OARs (gEUD-plan); and multiple, "very stringent," DV objectives for each OAR and PTV (DV-plan), respectively. The fourth plan was only beam-fluence optimized (FO-plan), without segmentation, which used the same objectives as in the DV-plan. The latter plan was to be used as an "optimum" benchmark without the effects of the segmentation for deliverability. Dosimetric quantities, such as V 20Gy for the ipsilateral lung and mean dose (D mean ) for heart, contralateral breast, and contralateral lung were used to evaluate the results. For all patients in this study, we have seen that the gEUD-based plans allow greater sparing of the OARs while maintaining equivalent target coverage. The average ipsilateral lung V 20Gy reduced from 22 ؎ 4.4% for the FO-plan to 18 ؎ 3% for the gEUD-plan. All other dosimetric quantities shifted towards lower doses for the gEUD-plan. gEUD-based optimization can be used to search for plans of different DVHs with the same gEUDs. The use of gEUD allows selective optimization and reduction of the dose for each OAR and results in a truly individualized treatment plan.

- by Dimitris Mihailidis
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- Algorithms, Clinical Sciences, Reproducibility of Results, Treatment planning

Purpose: To identify a clinically relevant and available parameter upon which to identify non-small cell lung cancer (NSCLC) patients at risk for pneumonitis when treated with three-dimensional (3D) radiation therapy. patients were treated definitively for inoperable NSCLC. Patients were selected for good performance status (96%) and absence of weight loss (82%). All patients had full 3D treatment planning (including total lung dose-volume histograms [DVHs]) prior to treatment delivery. The total lung DVH parameters were compared with the incidence and grade of pneumonitis after treatment. Results: Univariate analysis revealed the percent of the total lung volume exceeding 20 Gy (V 20 ), the effective volume (V eff ) and the total lung volume mean dose, and location of the tumor primary (upper versus lower lobes) to be statistically significant relative to the development of > Grade 2 pneumonitis. Multivariate analysis revealed the V 20 to be the single independent predictor of pneumonitis. Conclusions: The V 20 from the total lung DVH is a useful parameter easily obtained from most 3D treatment planning systems. The V 20 may be useful in comparing competing treatment plans to evaluate the risk of pneumonitis for our individual patient treatment and may also be a useful parameter upon which to stratify patients or prospective dose escalation trials.

- by Carlos Avila Perez
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- Radiation Therapy, Risk assessment, Multivariate Analysis, Weight Loss

The mixture of gait deviations seen in patients following a stroke is remarkably variable. An objective system for classification of gait patterns for this population could be used to guide treatment planning. Quantitated gait analysis was conducted for 47 individuals at admission to in-patient rehabilitation and again at 6 months post-stroke for 42 subjects. Non-hierarchical cluster analysis was used to classify the gait patterns of patients based on the temporal Á/spatial and kinematic parameters of walking. Four clusters of patients were identified at both assessment intervals. At the admission test walking velocity, peak knee extension in mid stance and peak dorsiflexion in swing were the three factors that best characterized the groups. At 6 months the explanatory variables were velocity, knee extension in terminal stance, and knee flexion in pre swing. Differences in muscle strength and muscle activation patterns during walking were identified between groups. #

- by Sara Mulroy
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- Mechanical Engineering, Skeletal muscle biology, Muscle strength, Gait

The incidence, factor structure and scale item differences in anxiety-depression comorbidity were investigated in a sample of Australian university students defined according to the presence of anxiety and/or depression. The incidence of anxiety-depression comorbidity was over 32%, about four times that for anxiety or depression alone. Participants with comorbidity had significantly higher Selfrating Anxiety Scale (SAS) and Self-rating Depression Scale (SDS) total and factor scores than those with anxiety or depression alone. The major differences between the comorbid and unitary disordered subgroups were for self-disintegration and autonomic arousal. Comorbidity of anxiety and depression is a more serious disorder than either anxiety or depression alone, and appears to exist in large proportions among university students. Assessment and treatment plans might benefit from inclusion of this comorbidity.

- by Vicki Bitsika
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- Psychology, Social Work, University Student, Treatment planning

This questionnaire consists of items that describe various thoughts and experiences that individuals may have. Please read every item and respond whether or not you have recently had such thoughts and/or experiences. 1 P1 Sometimes I hear my thoughts inside my head. ○True ○ False 2 N1 People tell me that my tone of voice does not reflect my real feelings. ○True ○ False 3 X I need others to urge me to participate in activities; otherwise I keep to myself. ○True ○ False 4 N2 My train of thought is frequently interrupted. ○True ○ False 5 P2 I believe that others are capable of reading my thoughts. ○True ○ False 6 N3 Frequently, I do nothing. ○True ○ False 7 X I prefer that people do not visit me. ○True ○ False 8 N4 I feel that my sexual drive has decreased.

- by Amir Poreh
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- Psychometrics, Schizophrenia, Test Validation, Insight

Specialized treatment planning software systems are generally required for neutron capture therapy (NCT) research and clinical applications. The standard simplifying approximations that work well for treatment planning computations in the case of many other modalities are usually not appropriate for application to neutron transport. One generally must obtain an explicit three-dimensional numerical solution of the governing transport equation, with energy-dependent neutron scattering completely taken into account. Treatment planning systems that have been successfully introduced for NCT applications over the past 15 years rely on the Monte Carlo stochastic simulation method for the necessary computations, primarily because of the geometric complexity of human anatomy. However, historically, there has also been interest in the application of deterministic methods, and there have been some practical developments in this area. Most recently, interest has turned toward the creation of treatment planning software that is not limited to any specific therapy modality, with NCT as only one of several applications. A key issue with NCT treatment planning has to do with boron quantification, and whether improved information concerning the spatial biodistribution of boron can be effectively used to improve the treatment planning process. Validation and benchmarking of computations for NCT are also of current developmental interest. Various institutions have their own procedures, but standard validation models are not yet in wide use.

- by Manjeet Chadha
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- Monte Carlo, Treatment, Standardization, Neuro-Oncology

Purpose: The aim of this report was to present an integrated 3-dimensional (3D) virtual approach toward cone-beam computed tomography-based treatment planning of orthognathic surgery in the clinical routine. Materials and Methods: We have described the different stages of the workflow process for routine 3D virtual treatment planning of orthognathic surgery: 1) image acquisition for 3D virtual orthognathic surgery; 2) processing of acquired image data toward a 3D virtual augmented model of the patient's head; 3) 3D virtual diagnosis of the patient; 4) 3D virtual treatment planning of orthognathic surgery; 5) 3D virtual treatment planning communication; 6) 3D splint manufacturing; 7) 3D virtual treatment planning transfer to the operating room; and 8) 3D virtual treatment outcome evaluation. Conclusions: The potential benefits and actual limits of an integrated 3D virtual approach for the treatment of the patient with a maxillofacial deformity are discussed comprehensively from our experience using 3D virtual treatment planning clinically.

- by Filip Schutyser
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- Algorithms, Computer Graphics, Dentistry, Surgery
- by Denis Kinane
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- Dentistry, Obesity, Childhood Obesity, Adolescent

Three hundred and fifteen psychotherapists responded to a survey and provided information about clients who had failed to make progress in individual treatment. It was found that criteria for defining failure to progress varied with therapy orientation, and that social-cognitive factors, over the severity of patient symptoms, often guided therapists evaluations of client functioning. Preliminary estimates were that an average of 11% of each therapist's caseload were not making progress, and that the majority of therapists who were continuing to treat these clients had not developed alternative treatment plans. Both pragmatic and ethical concerns suggest the need for developing guidelines and criteria for use in determining when clients are failing to make sufficient progress and in providing recommendations for how such cases should be managed.

- by Laura Otto-salaj
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- Psychology, Cognitive Science, Treatment Outcome, Cognitive Therapy

Purpose: We describe a method of quantifying regional ventilation from the radiotherapy treatment planning computed tomography (CT) images, with the goal of developing functional images for treatment planning and optimization. Methods and Materials: A series of exhalation breath-hold (eBH-CT) and inhalation breath-hold (iBH-CT) CT images obtained using a feedback-guided breath-hold technique for radiotherapy treatment planning was selected. The eBH-CT was mapped on a voxel-by-voxel basis to the iBH-CT using a deformable image registration algorithm. By using the average CT number over a 3 mm 3 region surrounding each pair of mapped voxels, the change in fraction of air per voxel (i.e., regional ventilation) was calculated. This methodology was applied to a series of 22 patients. The calculated total ventilation was compared to the change in contoured lung volumes between the exhalation and inhalation CTs (measured tidal volume). Results: A significant correlation was found between the calculated and measured tidal volumes for the left (R ‫؍‬ 0.982) and right (R ‫؍‬ 0.985), and for both lungs combined (R ‫؍‬ 0.985). In the resulting images, the regional ventilation was highly variable and corresponded with the spatial distribution of differences in the CT values (Hounsfield units) between the eBH-CT and the iBH-CT images. Conclusions: A method of quantifying regional ventilation from radiotherapy treatment planning CT data sets was demonstrated. The ventilation images can be used in plan optimization to minimize injury to functioning lung.

- by Thomas Guerrero
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- Algorithms, Computed Tomography, Optical Flow, Movement
- by Ronald Steingard
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- Pharmacology, Psychology, Emotional/Behavioral Disorders, Clinical Practice
- by Karin Haustermans
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- Nuclear medicine, Risk assessment, Positron Emission Tomography, PET

Even if a clinician possesses basic knowledge in esthetic dentistry and clinical skills, many cases presenting in modern dental practices simply cannot be restored to both the... more

Even if a clinician possesses basic knowledge in esthetic dentistry and clinical skills, many cases presenting in modern dental practices simply cannot be restored to both the clinician&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s and the patient&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s expectations without incorporating the perspectives and assistance of several dental disciplines. Besides listening carefully to chief complaints, clinicians must also be able to evaluate the patient&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s physical, biologic, and esthetic needs. This article demonstrates the use of a smile evaluation form designed at New York University that assists in developing esthetic treatment plans that might incorporate any and all dental specialties in a simple and organized fashion.

- by Mitchell J Lipp and +2
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- Design, Phonetics, Smiling, Face