ekkasit tharavichitkul | Chiang Mai University (original) (raw)

Papers by ekkasit tharavichitkul

Research paper thumbnail of Survival outcome of cervical cancer patients treated by image-guided brachytherapy: a ‘real world’ single center experience in Thailand from 2008 to 2018

Journal of Radiation Research

The objective of our study was to evaluate the survival outcome of cervical cancer patients treat... more The objective of our study was to evaluate the survival outcome of cervical cancer patients treated using image-guided brachytherapy (IGBT). From 2008 to 2018, 341 patients with cervical cancer were treated by radical radiotherapy. IGBT (by computed tomography [CT] or transabdominal ultrasound [TAUS]) was used to treat all of these patients. The characteristic data and patient status after treatment were recorded. All data were evaluated for survival outcome analysis. From a total of 341 patients, 295 patients were analyzed and 46 patients were excluded due to data missing in the survival outcomes. At the median follow-up time of 48 months (IQR 30–80 months), The 4-year local control, progression-free survival and overall survival rates were 89.5%, 74.9% and 69.1%, respectively. For overall survival, the size (> 5 cm), pathology (non-SCCA), stage (stage III–IV by FIGO 2009), lymph node (LN) (presented) and overall treatment time (OTT) (> 56 days) showed statistical significanc...

Research paper thumbnail of Breast Cancer Subtypes in Northern Thailand and Barriers to satisfactory survival outcomes

BMC Cancer

Background: The incidence of breast cancer (BC) in Thailand has been rising at an alarming rate. ... more Background: The incidence of breast cancer (BC) in Thailand has been rising at an alarming rate. The annual incidence of BC in Thailand has doubled over a span of 15 years. A retrospective study was conducted with the primary objective of assessing and comparing survival rates of patients with BC, stratified by subtype of BC. Methods: A retrospective study was implemented for a cohort of women receiving a diagnosis of invasive BC with the objective of assessing and comparing their overall survival, stratified by BC subtype. Thai women receiving a diagnosis of their first primary invasive BC between January 2006 and December 2015 at Chiang Mai University Hospital were studied with 3,150 cases meeting the eligible criteria. Results: The median follow-up time was 4.9 years (Inter Quartile Range: 2.8–7.7). The most common diagnosed subtype was luminal B-like (n = 1,147, 36.4%). It was still the most prevalent subtype (35.8%) in women younger than 40 years and the 40–60 age-group, The pr...

Research paper thumbnail of Brachytherapy dose changes: comparing in-room and out-room image-guided brachytherapy. A randomized study

Journal of Contemporary Brachytherapy

Purpose: Image-based brachytherapy, involving an image machine and a brachytherapy unit in the sa... more Purpose: Image-based brachytherapy, involving an image machine and a brachytherapy unit in the same room (in-room brachytherapy [IRBT]), limits patient movements; however, this technique may not be feasible in high workload centers. In this study, we compared changes in the dose and volume of organs at risk (OARs) with out-room brachytherapy (ORBT) technique, in which patients musted be transferred to a waiting room and then transferred back for brachytherapy delivery. Material and methods: This was a randomized prospective study comparing changes in D 2cc doses and volume of OARs during IRBT and ORBT. Patients underwent CT for treatment planning (CT1) installed in brachytherapy loading room, and another CT immediately before brachytherapy (CT2) during each fraction. While patients remained on CT table after CT1 during treatment planning and delivery in IRBT arm, they were transferred out to waiting room and back to CT table in ORBT arm. CT2 was analyzed with CT1 to evaluate any changes in volumes and doses. Results: A total of 294 fractions of brachytherapy were considered. The findings indicated no significant differences in the mean D 2cc changes (Gy) (CT2 minus CT1) to the bladder, rectum, and sigmoid between IRBT and ORBT (mean

Research paper thumbnail of Salvage Treatment and Outcomes of Locally Advanced Cervical Cancer after Failed Concurrent Chemoradiation with or without Adjuvant Chemotherapy: Post Hoc Data Analysis from the ACTLACC Trial

Asian Pacific Journal of Cancer Prevention

Objectives: To evaluate the type of salvage treatment and outcomes of patients with locally advan... more Objectives: To evaluate the type of salvage treatment and outcomes of patients with locally advanced cervical cancer who failed treatment with concurrent chemoradiation with or without adjuvant chemotherapy. Methods: This was post hoc analyses of data from the randomized trial which included 259 patients who had FIGO stage IIB-IVA and had either pelvic radiation therapy concurrent with cisplatin followed by observation or paclitaxel plus carboplatin. Data of the patients who failed primary treatment were collected: type of salvage treatments, time to progress after salvage therapy, progression-free (PFS) and overall survivals (OS). Results: After primary treatment, 85 patients had either persistence (36.5%), progression (18.8%), or recurrences (44.7%). The sites of failure were loco/regional in 52.9%, systemic failure in 30.6%, and loco-regional and systemic in 16.5%. Chemotherapy was given in 51.8%, being the sole therapy in 34.1%. Majority were combination agents (31.8%), with paclitaxel/carboplatin as the most common regimen. Radiation to the metastatic sites along with chemotherapy was used in 14.1% whereas palliative radiation therapy or supportive care was used in approximately 10% of each. The median time from the start of salvage treatment to progression was 9.2 months (range 0.2-64.0 months) with median PFS of 11.2 months (95% CI, 7.2-15.3 months). Median overall survival 27.3 months (95% CI, 4.4-69.6 months). Conclusions: Chemotherapy, either alone or with radiation therapy, was the most common salvage treatment in LACC after failure from primary treatment. The time to progress and PFS were less than 1 year with OS of approximately 2 years.

Research paper thumbnail of Additional file 1 of Disparities in the change of cervical cancer mortality rate between urban and rural Chiang Mai in the era of universal health care and the Thai national screening program

Additional file 1: Supplementary Figure 1. Trend in age-standardized incidence rate (ASIR) of cer... more Additional file 1: Supplementary Figure 1. Trend in age-standardized incidence rate (ASIR) of cervical cancer in screening target women (aged 30–59 year) living in urban and rural areas, 1998–2012.

Research paper thumbnail of Dosimetric comparison between manual and inverse optimization in brachytherapy planning for cervical cancer

Background: For image-guided brachytherapy (IGBT) for cervical cancer, manual optimization is nor... more Background: For image-guided brachytherapy (IGBT) for cervical cancer, manual optimization is normally used in routine practice. However, to define the dwell position and dwell time, experiences of the planner is the key factor. The inverse optimization which dwell weight and dwell time were calculated by computer was introduced to improve planning quality. However, evaluation of the benefit of inverse optimization in comparison to manual optimization is controversial. Purpose: To compare dosimetric parameters between manual and inverse optimize planning for cervical cancer treated by IGBT. Materials and methods: Forty-four CT-images set with inserted applicator of 11 cervical cancer patients were used. All patients were treated by teletherapy 50 Gy in 25 fractions and intracavitary brachytherapy with the 4 fractions of 7 Gy to D90 of HR-CTV. Manual and inverse algorithm IPSA method were used for optimization in all CT images set. Dose parameters to HR-CTV and organs at risk and optimization time consuming from both plans were compared and paired t-test was used to evaluate the difference. Results: Inverse optimization plan significantly showed higher D90 of HR-CTV than manual method. For Organs at risk, inverse optimization showed higher dose of D2cc to bladder and rectum, but lower dose to sigmoid and bowel in comparison to manual method Moreover, the optimization time was lower for inverse planning. Conclusions: The inverse optimize planning showed better target coverage dose and lower dose to bowels and sigmoid in the intracavitary planning. The inverse optimization time is significantly faster than manual optimization.

Research paper thumbnail of Dose different between original treatment planning and planned adaptive calculation during helical tomotherapy in patients with nasopharyngeal cancer

Background: Changing anatomic and volumetric occur in nasopharyngeal cancer (NPC) patients during... more Background: Changing anatomic and volumetric occur in nasopharyngeal cancer (NPC) patients during fractioned radiotherapy cause the delivered dose considerably different from the original plan. Objectives: The study purpose was to evaluate dose difference between original plan and planned adaptive software calculation during the course of radiotherapy in NPC patients treated with Tomotherapy HiArtTM system. Materials and methods: Three NPC patients treated with helical tomotherapy underwent daily positional correction using megavoltage CT imaging. Both parotid glands and spinal cord of patients were recontoured on daily MVCT images. MVCT images were used to recalculate dose distribution for all 33 fractions by planned adaptive software. The original plan dose and recalculate dose were compared. Results: Percent dose difference between original plan and planned adaptive dose of PTV70 (D95%), left and right parotid glands (D50%) were 1.74%±0.32%, 35.19%±12.67% and 24.60%±15.21%, respectively. The structure dose difference were statistically significant ( p <0.05) after fraction number 2nd, 8th and 7th, respectively. Percentage of spinal cord dose (D2%) difference between original plan and planned adaptive was 8.76%±10.15% with no statistically significance. Volume reduction in percentage of PTV70, left and right parotid glands volumes compare to original plan were 9.43%, 29.00% and 27.29%, respectively. Volume of spinal cord was not change during the treatments. Conclusion: Anatomic and volumetric variations in nasopharyngeal cancer patients caused PTV70 and parotid glands in receiving treatment dose more than original plan. Adaptive planning should be considered to correct for delivery dose. Journal of Associated Medical Sciences 2017; 50(2): 286-292. Doi: 10.14456/jams.2017.28

Research paper thumbnail of MOESM2 of Conventional versus hypofractionated postmastectomy radiotherapy: a report on long-term outcomes and late toxicity

Additional file 2: Table S2. A comparison of late toxicity between CF-PMRT and HF-PMRT.

Research paper thumbnail of MOESM1 of Conventional versus hypofractionated postmastectomy radiotherapy: a report on long-term outcomes and late toxicity

Additional file 1: Table S1. A comparison of treatment outcomes between CF-PMRT and HF-PMRT.

Research paper thumbnail of Comparative dosimetry of brachytherapy treatment planning between a volume-based plan by CT and a point-based plan by TAUS in CT datasets for brachytherapy

Journal of Radiotherapy in Practice, 2021

Aim: To evaluate comparative dosimetry of brachytherapy treatment planning between a volume-based... more Aim: To evaluate comparative dosimetry of brachytherapy treatment planning between a volume-based plan by computed tomography (CT) and a point-based plan by transabdominal ultrasound (TAUS) in CT datasets for brachytherapy. Materials and methods: From 2019 to 2021, 59 different datasets of CT images were collected from 38 patients treated by intracavitary brachytherapy with tandem ovoid or tandem ring applicators. At that time, TAUS was performed to prevent uterine perforation and to evaluate topography of the cervix during application. In volume-based planning by CT, the target dose was used to keep the dose at 90% of high-risk clinical target volume (HR-CTV), to give a dose of at least 7Gy, while in the point-based plan by TAUS, the target dose was used to keep the minimum dose to eight cervix reference points (measured by TAUS), to give a dose of at least 7Gy. The doses to targets and organs at risk were evaluated and compared between volume-based planning by CT and the point-bas...

Research paper thumbnail of Optimising image-guidance frequency for patients treated with volumetric-modulated arc therapy for pelvic cancer

Journal of Radiotherapy in Practice, 2021

Aim:To determine the feasibility of non-daily image-guided radiotherapy (RT) with volumetric-modu... more Aim:To determine the feasibility of non-daily image-guided radiotherapy (RT) with volumetric-modulated arc therapy for pelvic cancer.Methods:Daily cone beam computed tomography (CBCT) images data of 21 patients (542 fractions) with pelvic cancer were used to simulate 5 non-daily imaging (DL) protocols (Alternate day: AD, First 5 + Weekly: FF+WL, Weekly: WL, First 5 fractions: FF and Alternate week: AW protocol). The residual errors in the lateral (X), longitudinal (Y), and vertical (Z) directions and 3D vector shifts of each non-DL protocol were explored. The planning target volume (PTV) margins were calculated using the van Herk’s formula according to population systematic and random error. Finally, the average time of each process from the start to stop of the treatment was used to calculate the number of patients treated per day to assess the treatment delivery capacity for different imaging protocols.Results:The 3D vector shift for the FF+WL protocol produced the greatest propor...

Research paper thumbnail of Comparison of helical tomotherapy treatment plan verification using ionization chamber, film and two-dimensional ionization chamber array

Objective To evaluate the performance of ionization chamber, film and two-dimensional ionization ... more Objective To evaluate the performance of ionization chamber, film and two-dimensional ionization chamber array used for the helical tomotherapy treatment plans verification. Methods The treatment plan of thirteen patients who were treated on Helical Tomotherapy in Division of Therapeutic Radiology and Oncology, Faculty of Medicine, Chiang Mai University were used to verify in this study. The verification point dose were measured by an ionization chamber and Octavius 2D array. The dose distribution were measured by film and Octavius 2D array. The point dose and dose distribution were compared using the percentage dose difference and gamma index passing rate, respectively. Results The treatment plan verification based on absorbed point dose measurement using ionization chamber and Octavius 2D array demonstrated the root mean square of the percentage dose difference obtained from measured values in comparison to calculation were 0.38 and 0.84 for ionization chamber and Octavius 2D arra...

Research paper thumbnail of Definitive Radiotherapy in Young Patients Newly Diagnosed with Nasopharyngeal Carcinoma

Study objectives : This is a retrospective, single institutional , review of the management and r... more Study objectives : This is a retrospective, single institutional , review of the management and results of locally advanced nasopharyngeal cancer in childhood and adolescents in Chiangmai Thailand

Research paper thumbnail of Radiotherapy for cervical carcinoma in human immunodefi ciency virus-infected patients: A retrospective study

This was a retrospective study on the results of curative radiotherapy (with or without chemother... more This was a retrospective study on the results of curative radiotherapy (with or without chemotherapy) for the treatment of cervical carcinoma patients who were infected with human immunodeficiency virus. This study was carried out in the Division of Therapeutic Radiology and Oncology, Department of Radiology, Faculty of Medicine, Chiang Mai University. Fifty-four patients were studied retrospectively from 2004 to 2009 and the CD4+ T cell count was assessed in 29 patients. According to FIGO staging, 25, 19, 9 patients and 1 patient were stage I, II, III and IV, respectively. The 2-year local control, disease-free survival and distant metastasis-free survival rates were 92.6%, 87% and 83.3%, respectively. During treatment, four (7.4%) and three (5.5%) patients developed grade 3-4 anemia and leucopenia, respectively. Serious late toxicity was observed in two patients with grade 3 hematuria.

Research paper thumbnail of Impact of universal health care and screening on incidence and survival of Thai women with cervical cancer: A population-based study of the Chiang Mai Province

Cancer Epidemiology, 2019

Universal Health Coverage (UHC) was implemented in Thailand in 2002. This study aims to compare c... more Universal Health Coverage (UHC) was implemented in Thailand in 2002. This study aims to compare cervical cancer incidence and survival before and after the implementation of UHC, including the national screening program, in the Chiang Mai population in Northern Thailand. Data of women diagnosed with in situ or malignant cervical cancer in Chiang Mai during 1998-2012 were used in our analysis. Annual age-standardized incidence rates (ASR) and age-adjusted relative survival (RS) were estimated for the following three diagnosis periods:

Research paper thumbnail of Intermediate-term results of trans-abdominal ultrasound (TAUS)-guided brachytherapy in cervical cancer

Gynecologic oncology, 2018

To report the intermediate-term results of trans-abdominal ultrasound (TAUS)-guided brachytherapy... more To report the intermediate-term results of trans-abdominal ultrasound (TAUS)-guided brachytherapy in cervical cancer. Ninety-two patients with cervical cancer (stage IB-IVA, according to FIGO staging), were treated by curative radiotherapy from February 2012 to June 2015. All patients were treated with whole pelvic radiotherapy to 50 Gy in 25 fractions and central shielding after 44 Gy, in combination with TAUS-guided brachytherapy, in order to escalate the total dose (EQD2) to the minimal dose at cervical points (in EQD2 concepts) defined by TAUS, while maintaining low doses to ICRU bladder and rectal points. The treatment results and toxicity profiles were reported. At median follow-up time of 41.2 months (range 8 to 61 months) the pelvic control, disease-free survival, and overall survival rates were 84.8%, 75%, and 88%, respectively. The mean applied doses to cervix, bladder, and rectal points were 83.5, 72.3, and 76.5 Gy, respectively. Eight patients developed grade 2 Gastroint...

Research paper thumbnail of Five-year results for image-guided brachytherapy (IGBT) for cervical carcinoma: a report from single institute of Thailand

Journal of Radiotherapy in Practice, 2016

Aim To report of long-term results and toxicity profiles using image-guided brachytherapy (IGBT) ... more Aim To report of long-term results and toxicity profiles using image-guided brachytherapy (IGBT) combined with whole pelvic radiation therapy (WPRT) for cervical carcinoma. Materials and Methods In total, 52 patients with locally advanced cervical carcinoma were enrolled into the study. WPRT was used to treat the clinical target volume (CTV) with a dose of 45–50·4 Gy in 23–28 fractions. IGBT using computed tomography was performed at the dose of 6·5–7 Gy×4 fractions to the minimum dose covering 90% of target volume (D90) of high-risk clinical target volume (HR-CTV). Results The mean cumulative dose in equivalent doses of 2 Gy for the D90 of HR-CTV, dose at 2% at refereed volume (D2cc) of bladder, D2cc of rectum and D2cc of sigmoid colon were 92·4, 87·9, 69·6, and 72 Gy, respectively. At the median follow-up time of 61 months, the 5-year local control, disease-free survival, and overall survival rates were 96·2, 75 and 84·6% respectively. Two patients (3·8%) developed grade 3–4 gastr...

Research paper thumbnail of Outcome of Image Guided Brachytherapy in Locally Advanced Cervical Cancer Within a Multi-institutional Retrospective Cohort

International Journal of Radiation Oncology*Biology*Physics, 2014

described in the Table. Patients' age, tumor histology, degree of differentiation, and chemothera... more described in the Table. Patients' age, tumor histology, degree of differentiation, and chemotherapy administration were all equally distributed between the four groups. The rate of spread to lymph nodes was significantly higher in Group 4 (37%, 31%, 54%, 74% in Groups 1-4, respectively; P < 0.001). The use of interstitial needles was significantly higher in Groups 3 and 4 (19%, 3%, 41%, 89% in Groups 1-4, respectively; P < 0.001). The mean HR CTV D90 in EQD2 was 93.4 Gy, 93.9 Gy, 89.2 Gy, and 87.4 Gy in Groups 1-4, respectively. Conclusions: FIGO stage IIB cervical cancer is a heterogenous group with significant variation in tumor size. Four different patterns of tumor response can be identified, with the majority of patients responding favorably to radiation therapy. IGABT has the potential to accommodate the different variants of tumor regression including those with major residual disease at time of BT.

Research paper thumbnail of The Effects of Two HDR Brachytherapy Schedules in Locally Advanced Cervical Cancer Treated with Concurrent Chemoradiation: A Study from Chiang Mai, Thailand

Journal of Radiation Research, 2012

Cervix carcinoma/HDR/Brachytherapy/Schedules. Efficacy of different schedules of HDR brachytherap... more Cervix carcinoma/HDR/Brachytherapy/Schedules. Efficacy of different schedules of HDR brachytherapy in concurrent chemoradiotherapy was evaluated. The study compared the effectiveness of the two HDR brachytherapy schedules which have the same Biological Effective Dose (BED) in locally advanced cervical carcinoma that was treated with concurrent chemoradiotherapy. Included in the study were 377 randomly selected patients with advanced carcinoma of the cervix uteri who were treated during the period 2004-2006. Patients were divided into Group I: 7.2 Gy × 3 fractions and Group II: 6 Gy × 4 fractions. With a median follow-up time of 35 months, local control, disease-free survival and overall survival rates were 80.8%, 63.4%, 98.8% in group I and 86.7%, 63.8%, 97.3% in group II, respectively. There was no statistical significance in terms of local control, disease-free survival, overall survival and complication rates between the two treatment schedules which could be observed. Seven patients in group I developed acute grade 2-4 GI toxicities and two patients in group II. In GU toxicities, there were three patients in group I and three patients in group II who developed grade 2-4 toxicities. In late toxicity, no patient developed grade 3-4 GU toxicities in group I while two patients developed grade 3-4 GU toxicities in group II. In GI toxicities, there were five and six patients in group I and group II, respectively, who developed grade 3-4 severity. Both HDR schedules seem to be safe and effective for the treatment of locally advanced cervical cancer.

Research paper thumbnail of Preliminary Results of Conformal Computed Tomography (CT)-based Intracavitary Brachytherapy (ICBT) for Locally Advanced Cervical Cancer: A Single Institution's Experience

Journal of Radiation Research, 2011

Cervical cancer/Intracavitary brachytherapy/Conformal CT-based planning. Intracavitary brachyther... more Cervical cancer/Intracavitary brachytherapy/Conformal CT-based planning. Intracavitary brachytherapy using tandem and ovoids is an important component of definitive treatment for cervical cancer. In the present study, we analyzed the dose-volume histograms (DVHs) of the tumor volume and organs at risk including the sigmoid colon by CT-based treatment planning for high dose rate (HDR) intracavitary brachytherapy (ICBT) in cervical cancer. Seventeen patients with carcinoma of the cervix uteri were treated with external beam radiotherapy plus concurrent chemotherapy. For brachytherapy, the planning procedure started by performing a conventional plan which prescribed a dose of 6.5-7 Gy per fraction to point A, then optimized the dose based on CT imaging. Volumes and DVHs were calculated for the HR-CTV, bladder, rectum and sigmoid colon. The mean BED2Gy total doses of post-optimized plans of HR-CTV, bladder, rectum and sigmoid colon were: 89.6, 94.1, 74.0 and 69.8 Gy, respectively. For conventional plans, the calculated mean BED2Gy total doses of HR-CTV, bladder, rectum and sigmoid colon were 92.2, 120.1, 75.7 and 78.3 Gy, respectively. This study showed statistical significant higher BED2Gy total doses for bladder and sigmoid colon (p < 0.001) using conventional plans versus post-optimized, CT-based plans, while no difference between HR-CTV and rectum BED2Gy total doses could be detected. After a median follow-up of nineteen months, all seventeen patients had a clinical complete response. Two patients developed distant metastasis. Compared with conventional treatment, CT based brachytherapy planning was very effective in reducing doses to OARs, especially bladder and sigmoid colon whilst maintaining a high therapeutic dose for tumor target volumes in the treatment of cervical carcinoma.

Research paper thumbnail of Survival outcome of cervical cancer patients treated by image-guided brachytherapy: a ‘real world’ single center experience in Thailand from 2008 to 2018

Journal of Radiation Research

The objective of our study was to evaluate the survival outcome of cervical cancer patients treat... more The objective of our study was to evaluate the survival outcome of cervical cancer patients treated using image-guided brachytherapy (IGBT). From 2008 to 2018, 341 patients with cervical cancer were treated by radical radiotherapy. IGBT (by computed tomography [CT] or transabdominal ultrasound [TAUS]) was used to treat all of these patients. The characteristic data and patient status after treatment were recorded. All data were evaluated for survival outcome analysis. From a total of 341 patients, 295 patients were analyzed and 46 patients were excluded due to data missing in the survival outcomes. At the median follow-up time of 48 months (IQR 30–80 months), The 4-year local control, progression-free survival and overall survival rates were 89.5%, 74.9% and 69.1%, respectively. For overall survival, the size (> 5 cm), pathology (non-SCCA), stage (stage III–IV by FIGO 2009), lymph node (LN) (presented) and overall treatment time (OTT) (> 56 days) showed statistical significanc...

Research paper thumbnail of Breast Cancer Subtypes in Northern Thailand and Barriers to satisfactory survival outcomes

BMC Cancer

Background: The incidence of breast cancer (BC) in Thailand has been rising at an alarming rate. ... more Background: The incidence of breast cancer (BC) in Thailand has been rising at an alarming rate. The annual incidence of BC in Thailand has doubled over a span of 15 years. A retrospective study was conducted with the primary objective of assessing and comparing survival rates of patients with BC, stratified by subtype of BC. Methods: A retrospective study was implemented for a cohort of women receiving a diagnosis of invasive BC with the objective of assessing and comparing their overall survival, stratified by BC subtype. Thai women receiving a diagnosis of their first primary invasive BC between January 2006 and December 2015 at Chiang Mai University Hospital were studied with 3,150 cases meeting the eligible criteria. Results: The median follow-up time was 4.9 years (Inter Quartile Range: 2.8–7.7). The most common diagnosed subtype was luminal B-like (n = 1,147, 36.4%). It was still the most prevalent subtype (35.8%) in women younger than 40 years and the 40–60 age-group, The pr...

Research paper thumbnail of Brachytherapy dose changes: comparing in-room and out-room image-guided brachytherapy. A randomized study

Journal of Contemporary Brachytherapy

Purpose: Image-based brachytherapy, involving an image machine and a brachytherapy unit in the sa... more Purpose: Image-based brachytherapy, involving an image machine and a brachytherapy unit in the same room (in-room brachytherapy [IRBT]), limits patient movements; however, this technique may not be feasible in high workload centers. In this study, we compared changes in the dose and volume of organs at risk (OARs) with out-room brachytherapy (ORBT) technique, in which patients musted be transferred to a waiting room and then transferred back for brachytherapy delivery. Material and methods: This was a randomized prospective study comparing changes in D 2cc doses and volume of OARs during IRBT and ORBT. Patients underwent CT for treatment planning (CT1) installed in brachytherapy loading room, and another CT immediately before brachytherapy (CT2) during each fraction. While patients remained on CT table after CT1 during treatment planning and delivery in IRBT arm, they were transferred out to waiting room and back to CT table in ORBT arm. CT2 was analyzed with CT1 to evaluate any changes in volumes and doses. Results: A total of 294 fractions of brachytherapy were considered. The findings indicated no significant differences in the mean D 2cc changes (Gy) (CT2 minus CT1) to the bladder, rectum, and sigmoid between IRBT and ORBT (mean

Research paper thumbnail of Salvage Treatment and Outcomes of Locally Advanced Cervical Cancer after Failed Concurrent Chemoradiation with or without Adjuvant Chemotherapy: Post Hoc Data Analysis from the ACTLACC Trial

Asian Pacific Journal of Cancer Prevention

Objectives: To evaluate the type of salvage treatment and outcomes of patients with locally advan... more Objectives: To evaluate the type of salvage treatment and outcomes of patients with locally advanced cervical cancer who failed treatment with concurrent chemoradiation with or without adjuvant chemotherapy. Methods: This was post hoc analyses of data from the randomized trial which included 259 patients who had FIGO stage IIB-IVA and had either pelvic radiation therapy concurrent with cisplatin followed by observation or paclitaxel plus carboplatin. Data of the patients who failed primary treatment were collected: type of salvage treatments, time to progress after salvage therapy, progression-free (PFS) and overall survivals (OS). Results: After primary treatment, 85 patients had either persistence (36.5%), progression (18.8%), or recurrences (44.7%). The sites of failure were loco/regional in 52.9%, systemic failure in 30.6%, and loco-regional and systemic in 16.5%. Chemotherapy was given in 51.8%, being the sole therapy in 34.1%. Majority were combination agents (31.8%), with paclitaxel/carboplatin as the most common regimen. Radiation to the metastatic sites along with chemotherapy was used in 14.1% whereas palliative radiation therapy or supportive care was used in approximately 10% of each. The median time from the start of salvage treatment to progression was 9.2 months (range 0.2-64.0 months) with median PFS of 11.2 months (95% CI, 7.2-15.3 months). Median overall survival 27.3 months (95% CI, 4.4-69.6 months). Conclusions: Chemotherapy, either alone or with radiation therapy, was the most common salvage treatment in LACC after failure from primary treatment. The time to progress and PFS were less than 1 year with OS of approximately 2 years.

Research paper thumbnail of Additional file 1 of Disparities in the change of cervical cancer mortality rate between urban and rural Chiang Mai in the era of universal health care and the Thai national screening program

Additional file 1: Supplementary Figure 1. Trend in age-standardized incidence rate (ASIR) of cer... more Additional file 1: Supplementary Figure 1. Trend in age-standardized incidence rate (ASIR) of cervical cancer in screening target women (aged 30–59 year) living in urban and rural areas, 1998–2012.

Research paper thumbnail of Dosimetric comparison between manual and inverse optimization in brachytherapy planning for cervical cancer

Background: For image-guided brachytherapy (IGBT) for cervical cancer, manual optimization is nor... more Background: For image-guided brachytherapy (IGBT) for cervical cancer, manual optimization is normally used in routine practice. However, to define the dwell position and dwell time, experiences of the planner is the key factor. The inverse optimization which dwell weight and dwell time were calculated by computer was introduced to improve planning quality. However, evaluation of the benefit of inverse optimization in comparison to manual optimization is controversial. Purpose: To compare dosimetric parameters between manual and inverse optimize planning for cervical cancer treated by IGBT. Materials and methods: Forty-four CT-images set with inserted applicator of 11 cervical cancer patients were used. All patients were treated by teletherapy 50 Gy in 25 fractions and intracavitary brachytherapy with the 4 fractions of 7 Gy to D90 of HR-CTV. Manual and inverse algorithm IPSA method were used for optimization in all CT images set. Dose parameters to HR-CTV and organs at risk and optimization time consuming from both plans were compared and paired t-test was used to evaluate the difference. Results: Inverse optimization plan significantly showed higher D90 of HR-CTV than manual method. For Organs at risk, inverse optimization showed higher dose of D2cc to bladder and rectum, but lower dose to sigmoid and bowel in comparison to manual method Moreover, the optimization time was lower for inverse planning. Conclusions: The inverse optimize planning showed better target coverage dose and lower dose to bowels and sigmoid in the intracavitary planning. The inverse optimization time is significantly faster than manual optimization.

Research paper thumbnail of Dose different between original treatment planning and planned adaptive calculation during helical tomotherapy in patients with nasopharyngeal cancer

Background: Changing anatomic and volumetric occur in nasopharyngeal cancer (NPC) patients during... more Background: Changing anatomic and volumetric occur in nasopharyngeal cancer (NPC) patients during fractioned radiotherapy cause the delivered dose considerably different from the original plan. Objectives: The study purpose was to evaluate dose difference between original plan and planned adaptive software calculation during the course of radiotherapy in NPC patients treated with Tomotherapy HiArtTM system. Materials and methods: Three NPC patients treated with helical tomotherapy underwent daily positional correction using megavoltage CT imaging. Both parotid glands and spinal cord of patients were recontoured on daily MVCT images. MVCT images were used to recalculate dose distribution for all 33 fractions by planned adaptive software. The original plan dose and recalculate dose were compared. Results: Percent dose difference between original plan and planned adaptive dose of PTV70 (D95%), left and right parotid glands (D50%) were 1.74%±0.32%, 35.19%±12.67% and 24.60%±15.21%, respectively. The structure dose difference were statistically significant ( p <0.05) after fraction number 2nd, 8th and 7th, respectively. Percentage of spinal cord dose (D2%) difference between original plan and planned adaptive was 8.76%±10.15% with no statistically significance. Volume reduction in percentage of PTV70, left and right parotid glands volumes compare to original plan were 9.43%, 29.00% and 27.29%, respectively. Volume of spinal cord was not change during the treatments. Conclusion: Anatomic and volumetric variations in nasopharyngeal cancer patients caused PTV70 and parotid glands in receiving treatment dose more than original plan. Adaptive planning should be considered to correct for delivery dose. Journal of Associated Medical Sciences 2017; 50(2): 286-292. Doi: 10.14456/jams.2017.28

Research paper thumbnail of MOESM2 of Conventional versus hypofractionated postmastectomy radiotherapy: a report on long-term outcomes and late toxicity

Additional file 2: Table S2. A comparison of late toxicity between CF-PMRT and HF-PMRT.

Research paper thumbnail of MOESM1 of Conventional versus hypofractionated postmastectomy radiotherapy: a report on long-term outcomes and late toxicity

Additional file 1: Table S1. A comparison of treatment outcomes between CF-PMRT and HF-PMRT.

Research paper thumbnail of Comparative dosimetry of brachytherapy treatment planning between a volume-based plan by CT and a point-based plan by TAUS in CT datasets for brachytherapy

Journal of Radiotherapy in Practice, 2021

Aim: To evaluate comparative dosimetry of brachytherapy treatment planning between a volume-based... more Aim: To evaluate comparative dosimetry of brachytherapy treatment planning between a volume-based plan by computed tomography (CT) and a point-based plan by transabdominal ultrasound (TAUS) in CT datasets for brachytherapy. Materials and methods: From 2019 to 2021, 59 different datasets of CT images were collected from 38 patients treated by intracavitary brachytherapy with tandem ovoid or tandem ring applicators. At that time, TAUS was performed to prevent uterine perforation and to evaluate topography of the cervix during application. In volume-based planning by CT, the target dose was used to keep the dose at 90% of high-risk clinical target volume (HR-CTV), to give a dose of at least 7Gy, while in the point-based plan by TAUS, the target dose was used to keep the minimum dose to eight cervix reference points (measured by TAUS), to give a dose of at least 7Gy. The doses to targets and organs at risk were evaluated and compared between volume-based planning by CT and the point-bas...

Research paper thumbnail of Optimising image-guidance frequency for patients treated with volumetric-modulated arc therapy for pelvic cancer

Journal of Radiotherapy in Practice, 2021

Aim:To determine the feasibility of non-daily image-guided radiotherapy (RT) with volumetric-modu... more Aim:To determine the feasibility of non-daily image-guided radiotherapy (RT) with volumetric-modulated arc therapy for pelvic cancer.Methods:Daily cone beam computed tomography (CBCT) images data of 21 patients (542 fractions) with pelvic cancer were used to simulate 5 non-daily imaging (DL) protocols (Alternate day: AD, First 5 + Weekly: FF+WL, Weekly: WL, First 5 fractions: FF and Alternate week: AW protocol). The residual errors in the lateral (X), longitudinal (Y), and vertical (Z) directions and 3D vector shifts of each non-DL protocol were explored. The planning target volume (PTV) margins were calculated using the van Herk’s formula according to population systematic and random error. Finally, the average time of each process from the start to stop of the treatment was used to calculate the number of patients treated per day to assess the treatment delivery capacity for different imaging protocols.Results:The 3D vector shift for the FF+WL protocol produced the greatest propor...

Research paper thumbnail of Comparison of helical tomotherapy treatment plan verification using ionization chamber, film and two-dimensional ionization chamber array

Objective To evaluate the performance of ionization chamber, film and two-dimensional ionization ... more Objective To evaluate the performance of ionization chamber, film and two-dimensional ionization chamber array used for the helical tomotherapy treatment plans verification. Methods The treatment plan of thirteen patients who were treated on Helical Tomotherapy in Division of Therapeutic Radiology and Oncology, Faculty of Medicine, Chiang Mai University were used to verify in this study. The verification point dose were measured by an ionization chamber and Octavius 2D array. The dose distribution were measured by film and Octavius 2D array. The point dose and dose distribution were compared using the percentage dose difference and gamma index passing rate, respectively. Results The treatment plan verification based on absorbed point dose measurement using ionization chamber and Octavius 2D array demonstrated the root mean square of the percentage dose difference obtained from measured values in comparison to calculation were 0.38 and 0.84 for ionization chamber and Octavius 2D arra...

Research paper thumbnail of Definitive Radiotherapy in Young Patients Newly Diagnosed with Nasopharyngeal Carcinoma

Study objectives : This is a retrospective, single institutional , review of the management and r... more Study objectives : This is a retrospective, single institutional , review of the management and results of locally advanced nasopharyngeal cancer in childhood and adolescents in Chiangmai Thailand

Research paper thumbnail of Radiotherapy for cervical carcinoma in human immunodefi ciency virus-infected patients: A retrospective study

This was a retrospective study on the results of curative radiotherapy (with or without chemother... more This was a retrospective study on the results of curative radiotherapy (with or without chemotherapy) for the treatment of cervical carcinoma patients who were infected with human immunodeficiency virus. This study was carried out in the Division of Therapeutic Radiology and Oncology, Department of Radiology, Faculty of Medicine, Chiang Mai University. Fifty-four patients were studied retrospectively from 2004 to 2009 and the CD4+ T cell count was assessed in 29 patients. According to FIGO staging, 25, 19, 9 patients and 1 patient were stage I, II, III and IV, respectively. The 2-year local control, disease-free survival and distant metastasis-free survival rates were 92.6%, 87% and 83.3%, respectively. During treatment, four (7.4%) and three (5.5%) patients developed grade 3-4 anemia and leucopenia, respectively. Serious late toxicity was observed in two patients with grade 3 hematuria.

Research paper thumbnail of Impact of universal health care and screening on incidence and survival of Thai women with cervical cancer: A population-based study of the Chiang Mai Province

Cancer Epidemiology, 2019

Universal Health Coverage (UHC) was implemented in Thailand in 2002. This study aims to compare c... more Universal Health Coverage (UHC) was implemented in Thailand in 2002. This study aims to compare cervical cancer incidence and survival before and after the implementation of UHC, including the national screening program, in the Chiang Mai population in Northern Thailand. Data of women diagnosed with in situ or malignant cervical cancer in Chiang Mai during 1998-2012 were used in our analysis. Annual age-standardized incidence rates (ASR) and age-adjusted relative survival (RS) were estimated for the following three diagnosis periods:

Research paper thumbnail of Intermediate-term results of trans-abdominal ultrasound (TAUS)-guided brachytherapy in cervical cancer

Gynecologic oncology, 2018

To report the intermediate-term results of trans-abdominal ultrasound (TAUS)-guided brachytherapy... more To report the intermediate-term results of trans-abdominal ultrasound (TAUS)-guided brachytherapy in cervical cancer. Ninety-two patients with cervical cancer (stage IB-IVA, according to FIGO staging), were treated by curative radiotherapy from February 2012 to June 2015. All patients were treated with whole pelvic radiotherapy to 50 Gy in 25 fractions and central shielding after 44 Gy, in combination with TAUS-guided brachytherapy, in order to escalate the total dose (EQD2) to the minimal dose at cervical points (in EQD2 concepts) defined by TAUS, while maintaining low doses to ICRU bladder and rectal points. The treatment results and toxicity profiles were reported. At median follow-up time of 41.2 months (range 8 to 61 months) the pelvic control, disease-free survival, and overall survival rates were 84.8%, 75%, and 88%, respectively. The mean applied doses to cervix, bladder, and rectal points were 83.5, 72.3, and 76.5 Gy, respectively. Eight patients developed grade 2 Gastroint...

Research paper thumbnail of Five-year results for image-guided brachytherapy (IGBT) for cervical carcinoma: a report from single institute of Thailand

Journal of Radiotherapy in Practice, 2016

Aim To report of long-term results and toxicity profiles using image-guided brachytherapy (IGBT) ... more Aim To report of long-term results and toxicity profiles using image-guided brachytherapy (IGBT) combined with whole pelvic radiation therapy (WPRT) for cervical carcinoma. Materials and Methods In total, 52 patients with locally advanced cervical carcinoma were enrolled into the study. WPRT was used to treat the clinical target volume (CTV) with a dose of 45–50·4 Gy in 23–28 fractions. IGBT using computed tomography was performed at the dose of 6·5–7 Gy×4 fractions to the minimum dose covering 90% of target volume (D90) of high-risk clinical target volume (HR-CTV). Results The mean cumulative dose in equivalent doses of 2 Gy for the D90 of HR-CTV, dose at 2% at refereed volume (D2cc) of bladder, D2cc of rectum and D2cc of sigmoid colon were 92·4, 87·9, 69·6, and 72 Gy, respectively. At the median follow-up time of 61 months, the 5-year local control, disease-free survival, and overall survival rates were 96·2, 75 and 84·6% respectively. Two patients (3·8%) developed grade 3–4 gastr...

Research paper thumbnail of Outcome of Image Guided Brachytherapy in Locally Advanced Cervical Cancer Within a Multi-institutional Retrospective Cohort

International Journal of Radiation Oncology*Biology*Physics, 2014

described in the Table. Patients' age, tumor histology, degree of differentiation, and chemothera... more described in the Table. Patients' age, tumor histology, degree of differentiation, and chemotherapy administration were all equally distributed between the four groups. The rate of spread to lymph nodes was significantly higher in Group 4 (37%, 31%, 54%, 74% in Groups 1-4, respectively; P < 0.001). The use of interstitial needles was significantly higher in Groups 3 and 4 (19%, 3%, 41%, 89% in Groups 1-4, respectively; P < 0.001). The mean HR CTV D90 in EQD2 was 93.4 Gy, 93.9 Gy, 89.2 Gy, and 87.4 Gy in Groups 1-4, respectively. Conclusions: FIGO stage IIB cervical cancer is a heterogenous group with significant variation in tumor size. Four different patterns of tumor response can be identified, with the majority of patients responding favorably to radiation therapy. IGABT has the potential to accommodate the different variants of tumor regression including those with major residual disease at time of BT.

Research paper thumbnail of The Effects of Two HDR Brachytherapy Schedules in Locally Advanced Cervical Cancer Treated with Concurrent Chemoradiation: A Study from Chiang Mai, Thailand

Journal of Radiation Research, 2012

Cervix carcinoma/HDR/Brachytherapy/Schedules. Efficacy of different schedules of HDR brachytherap... more Cervix carcinoma/HDR/Brachytherapy/Schedules. Efficacy of different schedules of HDR brachytherapy in concurrent chemoradiotherapy was evaluated. The study compared the effectiveness of the two HDR brachytherapy schedules which have the same Biological Effective Dose (BED) in locally advanced cervical carcinoma that was treated with concurrent chemoradiotherapy. Included in the study were 377 randomly selected patients with advanced carcinoma of the cervix uteri who were treated during the period 2004-2006. Patients were divided into Group I: 7.2 Gy × 3 fractions and Group II: 6 Gy × 4 fractions. With a median follow-up time of 35 months, local control, disease-free survival and overall survival rates were 80.8%, 63.4%, 98.8% in group I and 86.7%, 63.8%, 97.3% in group II, respectively. There was no statistical significance in terms of local control, disease-free survival, overall survival and complication rates between the two treatment schedules which could be observed. Seven patients in group I developed acute grade 2-4 GI toxicities and two patients in group II. In GU toxicities, there were three patients in group I and three patients in group II who developed grade 2-4 toxicities. In late toxicity, no patient developed grade 3-4 GU toxicities in group I while two patients developed grade 3-4 GU toxicities in group II. In GI toxicities, there were five and six patients in group I and group II, respectively, who developed grade 3-4 severity. Both HDR schedules seem to be safe and effective for the treatment of locally advanced cervical cancer.

Research paper thumbnail of Preliminary Results of Conformal Computed Tomography (CT)-based Intracavitary Brachytherapy (ICBT) for Locally Advanced Cervical Cancer: A Single Institution's Experience

Journal of Radiation Research, 2011

Cervical cancer/Intracavitary brachytherapy/Conformal CT-based planning. Intracavitary brachyther... more Cervical cancer/Intracavitary brachytherapy/Conformal CT-based planning. Intracavitary brachytherapy using tandem and ovoids is an important component of definitive treatment for cervical cancer. In the present study, we analyzed the dose-volume histograms (DVHs) of the tumor volume and organs at risk including the sigmoid colon by CT-based treatment planning for high dose rate (HDR) intracavitary brachytherapy (ICBT) in cervical cancer. Seventeen patients with carcinoma of the cervix uteri were treated with external beam radiotherapy plus concurrent chemotherapy. For brachytherapy, the planning procedure started by performing a conventional plan which prescribed a dose of 6.5-7 Gy per fraction to point A, then optimized the dose based on CT imaging. Volumes and DVHs were calculated for the HR-CTV, bladder, rectum and sigmoid colon. The mean BED2Gy total doses of post-optimized plans of HR-CTV, bladder, rectum and sigmoid colon were: 89.6, 94.1, 74.0 and 69.8 Gy, respectively. For conventional plans, the calculated mean BED2Gy total doses of HR-CTV, bladder, rectum and sigmoid colon were 92.2, 120.1, 75.7 and 78.3 Gy, respectively. This study showed statistical significant higher BED2Gy total doses for bladder and sigmoid colon (p < 0.001) using conventional plans versus post-optimized, CT-based plans, while no difference between HR-CTV and rectum BED2Gy total doses could be detected. After a median follow-up of nineteen months, all seventeen patients had a clinical complete response. Two patients developed distant metastasis. Compared with conventional treatment, CT based brachytherapy planning was very effective in reducing doses to OARs, especially bladder and sigmoid colon whilst maintaining a high therapeutic dose for tumor target volumes in the treatment of cervical carcinoma.