W. Onchan | Chiang Mai University (original) (raw)

Papers by W. Onchan

Research paper thumbnail of Adjuvant External Beam Radiotherapy ± Brachytherapy in Endometrial Cancer: A Retrospective Study from Faculty of Medicine, Chiang Mai University

Journal of Cancer Therapy, 2015

Purpose: To report the retrospective study of external beam radiotherapy (EBRT) ± intravaginal br... more Purpose: To report the retrospective study of external beam radiotherapy (EBRT) ± intravaginal brachytherapy (IVBT) as adjuvant treatment for endometrial cancer. Materials and Methods: From 2001-2009, 152 patients received complete surgical staging for endometrial carcinoma and were designed by a multidisciplinary team to receive EBRT ± IVBT. The treatment results and late toxicities were evaluated and recorded. Results: At the median follow-up time of 43 months, the disease-free survival, metastasis-free survival and overall survival rates were 96.9%, 96.9% and 96.9%, respectively. Stage and age showed the statistical significance with the p-value of less than 0.001. From five to ten percent of patients developed Grades 1-2 late gastrointestinal and genitourinary toxicities, respectively. Conclusion: The using of adjuvant EBRT ± IVBT for endometrial carcinoma yielded treatment results and acceptable toxicities.

Research paper thumbnail of The association of rectal equivalent dose in 2 Gy fractions (EQD2) to late rectal toxicity in locally advanced cervical cancer patients who were evaluated by rectosigmoidoscopy in Faculty of Medicine, Chiang Mai University

Radiation Oncology Journal, 2014

To evaluate association between equivalent dose in 2 Gy (EQD2) to rectal point dose and gastroint... more To evaluate association between equivalent dose in 2 Gy (EQD2) to rectal point dose and gastrointestinal toxicity from whole pelvic radiotherapy (WPRT) and intracavitary brachytherapy (ICBT) in cervical cancer patients who were evaluated by rectosigmoidoscopy in Faculty of Medicine, Chiang Mai University. Materials and Methods: Retrospective study was designed for the patients with locally advanced cervical cancer, treated by radical radiotherapy from 2004 to 2009 and were evaluated by rectosigmoidoscopy. The cumulative doses of WPRT and ICBT to the maximally rectal point were calculated to the EQD2 and evaluated the association of toxicities. Results: Thirty-nine patients were evaluated for late rectal toxicity. The mean cumulative dose in term of EQD2 to rectum was 64.2 Gy. Grade 1 toxicities were the most common findings. According to endoscopic exam, the most common toxicities were congested mucosa (36 patients) and telangiectasia (32 patients). In evaluation between rectal dose in EQD2 and toxicities, no association of cumulative rectal dose to rectal toxicity, except the association of cumulative rectal dose in EQD2 >65 Gy to late effects of normal tissue (LENT-SOMA) scale ≥ grade 2 (p = 0.022; odds ratio, 5.312; 95% confidence interval, 1.269-22.244). Conclusion: The cumulative rectal dose in EQD2 >65 Gy have association with ≥ grade 2 LENT-SOMA scale.

Research paper thumbnail of Image-Based Brachytherapy in Cervical Cancer: Review and Experiences in Faculty of Medicine, Chiang Mai University

Journal of Cancer Therapy, 2013

Cervical cancer is the one of the most common cancer in female patients in Thailand. Radiotherapy... more Cervical cancer is the one of the most common cancer in female patients in Thailand. Radiotherapy has the role for the treatment of cervical cancer by postoperative, radical and palliative treatments. For radical radiotherapy, the combination of external beam radiation therapy and brachytherapy will be used to increase the tumor dose to curative goal. With the new development of medical images (Computed tomography (CT), Magnetic Resonance Imaging (MRI) or Ultrasonography (US)), the treatment with brachytherapy will be developed from point-based to volume-based concepts. Many studies reported the benefit of image-based brachytherapy over conventional brachytherapy and clinical benefit of using image-based brachytherapy in the treatment of cervical cancer.

Research paper thumbnail of Real-world outcomes of postmastectomy radiotherapy in breast cancer patients with 1-3 positive lymph nodes: a retrospective study

Journal of Radiation Research, 2013

Objective: To assess the treatment outcomes and to explore the determinants of clinical outcome i... more Objective: To assess the treatment outcomes and to explore the determinants of clinical outcome in breast cancer patients with 1-3 positive nodes who did or did not receive postmastectomy radiotherapy (PMRT) in a tertiary care referral cancer center in Northern Thailand. Methods: We investigated a retrospective cohort of registered breast cancer patients at the Faculty of Medicine, Chiang Mai University, Thailand from 2001-2007. Analysis was performed using Cox regression models to identify factors affecting the overall survival (OS) and relapse-free survival (RFS) rates. Comparisons were made between two cohorts: women who received adjuvant PMRT (74 patients) and women who did not receive adjuvant PMRT (81 patients). Results: A total of 155 patients were included with a median follow-up period of 4.45 years. There was a statistically significant 4-year OS difference between the two groups of patients: 100% for the PMRT group and 93.1% for the non-PMRT group (P = 0.044). The 4-year RFS was 85.9% for patients receiving PMRT and 78.3% for patients who did not receive PMRT (P = 0.291). On multivariate analysis of OS, using hormonal treatment was the only significant independent factor associated with improved OS. On multivariate analysis of RFS, none of the variables were significantly associated with improved RFS. PMRT was notfound to be a prognostic variable related to the outcome of patients using a logistic regression model. Conclusion: Our retrospective, hospital-based analysis demonstrated that PMRT improved the treatment outcome in terms of OS for women with 1-3 node positive early-stage breast cancer.

Research paper thumbnail of The Associations for Vaginal Point Doses of Vaginal Stenosis in Image-Guided Brachytherapy

Journal of Cancer Therapy, 2014

Purpose: To evaluate the associations for vaginal dose points of vaginal stricture in image-guide... more Purpose: To evaluate the associations for vaginal dose points of vaginal stricture in image-guided brachytherapy. Materials and Methods: Twenty-six patients of locally advanced cervical cancer were treated with Image-Guided Brachytherapy (IGBT) with the dose at least 7 Gy per fraction to the D90 of High-Risk Clinical Target Volume (HR-CTV). The vaginal dose points of recommendations of the American Brachytherapy Society (ABS) were added into the plan and cumulative dose to these points was evaluated in Equivalent Dose of 2 Gy (EQD2) concepts. Results: The mean doses to right vaginal dose point (VR), left vaginal dose point (VL) and average dose of VR/VL ((VR + VL)/2) were 101.5 Gy, 98.2 Gy and 99.8 Gy in EQD2 concepts, respectively. Volume-based planning significantly reduced the cumulative dose in EQD2 concepts at vaginal points. At the median follow-up time of 22 months, grade-2 vaginal stricture was observed in two patients. The incidences of vaginal stricture were not differed between the cumulative dose to vaginal dose points in EQD2 concepts of ≤90 Gy versus >90 Gy (P = 1.000) and ≤100 Gy versus >100 Gy (P = 0.815). Conclusion: No association for cumulative vaginal doses and events of vaginal stricture was found.

Research paper thumbnail of Image-guided brachytherapy (IGBT) combined with whole pelvic intensity-modulated radiotherapy (WP-IMRT) for locally advanced cervical cancer: a prospective study from Chiang Mai University Hospital, Thailand

Journal of Contemporary Brachytherapy, 2013

Purpose: A report of preliminary results and toxicity profiles using image-guided brachytherapy (... more Purpose: A report of preliminary results and toxicity profiles using image-guided brachytherapy (IGBT) combined with whole pelvic intensity-modulated radiation therapy (WP-IMRT) for locally advanced cervical cancer. Material and methods: Fifteen patients with locally advanced cervical cancer were enrolled into the study. WP-IMRT was used to treat the Clinical Target Volume (CTV) with a dose of 45 Gy in 25 fractions. Concurrent cisplatin (40 mg/m 2) was prescribed during radiotherapy (RT) on weekly basis. IGBT using computed tomography was performed at the dose of 7 Gy × 4 fractions to the High-Risk Clinical Target Volume (HR-CTV). Results: The mean cumulative doses-in terms of equivalent dose of 2 Gy (EQD2)-of IGBT plus WP-IMRT to HR-CTV, bladder, rectum, and sigmoid colon were 88.3, 85.0, 68.2 and 73.6 Gy, respectively. In comparison with standard (point A prescription) dose-volume histograms, volume-based image-guided brachytherapy improved the cumulative doses for bladder of 67%, rectum of 47% and sigmoid of 46%. At the median follow-up time of 14 months, the local control, metastasis-free survival and overall survival rates were 93%, 100% and 93%, respectively. No grade 3-4 acute and late toxicities were observed. Conclusion: The combination of image-guided brachytherapy and intensity-modulated radiotherapy improved the dose distribution to tumor volumes and avoided overdose in OARs which could be converted in excellent local control and toxicity profiles.

Research paper thumbnail of The effect of central shielding in the dose reporting for cervical cancer in EQD2 era

Journal of Contemporary Brachytherapy, 2013

Purpose: To evaluate the cumulative dose at point A for three and four centimeters central shield... more Purpose: To evaluate the cumulative dose at point A for three and four centimeters central shielding. Material and methods: The plans of external beam radiotherapy plus conventional intracavitary brachytherapy were performed. Three or four centimeters central shieldings (after 44 Gy) were applied to the standard whole pelvis irradiation. Additional intracavitary brachytherapy 4 × 7 Gy at point A was prescribed, and the cumulative dose in EQD2 (α/b = 10) of 3 cm and 4 cm central shielding were evaluated. Results: The cumulative dose at point A in EQD2 (α/b = 10) of 3 cm central shielding were 95.7 Gy for AR and 95.5 Gy for AL, while the cumulative dose at point As in EQD2 (α/b = 10) of 4 cm central shielding were 90.8 Gy for AR and 91.2 Gy for AL. Conclusions: The 3 cm central shielding caused higher cumulative dose (in terms of EQD2 [α/b = 10]) than 4 cm central shielding.

Research paper thumbnail of The treatment outcome of radical radiotherapy in laryngeal cancer

Journal of the Medical Association of Thailand = Chotmaihet thangphaet, 2014

This study reports the treatment outcome of radiotherapy alone for laryngeal cancer A retrospecti... more This study reports the treatment outcome of radiotherapy alone for laryngeal cancer A retrospective analysis was performed on 138 patients with stage I to IV squamous cell carcinoma of larynx who received radiotherapy alone in Division of Therapeutic Radiology and Oncology, Faculty of Medicine, Chiang Mai University, Thailand between 2003 and 2009. The 4-year local control (LC) rate in all patients was 44.1%. The 4-year overall survival (OS) was 82.1%. The 4-year LC rates for stage I, II, III, and IV were 75.3%, 69.4%, 57.1%, and 36.9%,respectively (p = 0.0055). Finally, the 4-year OS rates for stage I, II, III, and IV were 85%, 78.6%, 91.1%, and 71.5%, respectively. The laryngeal preservation rate of all stages was 73%. In conclusion, the treatment outcome of radiotherapy alone in all stages of laryngeal cancer in our center was unsatisfactory when compared to other series.

Research paper thumbnail of PO-173: Ambulation status after emergency radiotherapy for metastatic spinal cord compression

Radiotherapy and Oncology, 2019

Research paper thumbnail of PO-146: Retrospective Analysis of Adjuvant Radiotherapy in Phyllodes Tumour: Single-Institute Study

Radiotherapy and Oncology, 2019

Research paper thumbnail of The effect of central shielding in the dose reporting for cervical cancer in EQD2 era

Journal of Contemporary Brachytherapy, 2013

To evaluate the cumulative dose at point A for three and four centimeters central shielding.

Research paper thumbnail of The association of rectal equivalent dose in 2 Gy fractions (EQD2) to late rectal toxicity in locally advanced cervical cancer patients who were evaluated by rectosigmoidoscopy in Faculty of Medicine, Chiang Mai University

Radiation Oncology Journal, 2014

Purpose: To evaluate association between equivalent dose in 2 Gy (EQD2) to rectal point dose and ... more Purpose: To evaluate association between equivalent dose in 2 Gy (EQD2) to rectal point dose and gastrointestinal toxicity from whole pelvic radiotherapy (WPRT) and intracavitary brachytherapy (ICBT) in cervical cancer patients who were evaluated by rectosigmoidoscopy in Faculty of Medicine, Chiang Mai University. Materials and Methods: Retrospective study was designed for the patients with locally advanced cervical cancer, treated by radical radiotherapy from 2004 to 2009 and were evaluated by rectosigmoidoscopy. The cumulative doses of WPRT and ICBT to the maximally rectal point were calculated to the EQD2 and evaluated the association of toxicities. Results: Thirty-nine patients were evaluated for late rectal toxicity. The mean cumulative dose in term of EQD2 to rectum was 64.2 Gy. Grade 1 toxicities were the most common findings. According to endoscopic exam, the most common toxicities were congested mucosa (36 patients) and telangiectasia (32 patients). In evaluation between rectal dose in EQD2 and toxicities, no association of cumulative rectal dose to rectal toxicity, except the association of cumulative rectal dose in EQD2 >65 Gy to late effects of normal tissue (LENT-SOMA) scale ≥ grade 2 (p = 0.022; odds ratio, 5.312; 95% confidence interval, 1.269-22.244). Conclusion: The cumulative rectal dose in EQD2 >65 Gy have association with ≥ grade 2 LENT-SOMA scale.

Research paper thumbnail of Image-guided brachytherapy (IGBT) combined with whole pelvic intensity-modulated radiotherapy (WP-IMRT) for locally advanced cervical cancer: a prospective study from Chiang Mai University Hospital, Thailand

Journal of Contemporary Brachytherapy, 2013

A report of preliminary results and toxicity profiles using image-guided brachytherapy (IGBT) com... more A report of preliminary results and toxicity profiles using image-guided brachytherapy (IGBT) combined with whole pelvic intensity-modulated radiation therapy (WP-IMRT) for locally advanced cervical cancer. Fifteen patients with locally advanced cervical cancer were enrolled into the study. WP-IMRT was used to treat the Clinical Target Volume (CTV) with a dose of 45 Gy in 25 fractions. Concurrent cisplatin (40 mg/m(2)) was prescribed during radiotherapy (RT) on weekly basis. IGBT using computed tomography was performed at the dose of 7 Gy × 4 fractions to the High-Risk Clinical Target Volume (HR-CTV). The mean cumulative doses - in terms of equivalent dose of 2 Gy (EQD2) - of IGBT plus WP-IMRT to HR-CTV, bladder, rectum, and sigmoid colon were 88.3, 85.0, 68.2 and 73.6 Gy, respectively. In comparison with standard (point A prescription) dose-volume histograms, volume-based image-guided brachytherapy improved the cumulative doses for bladder of 67%, rectum of 47% and sigmoid of 46%. At the median follow-up time of 14 months, the local control, metastasis-free survival and overall survival rates were 93%, 100% and 93%, respectively. No grade 3-4 acute and late toxicities were observed. The combination of image-guided brachytherapy and intensity-modulated radiotherapy improved the dose distribution to tumor volumes and avoided overdose in OARs which could be converted in excellent local control and toxicity profiles.

Research paper thumbnail of Adjuvant External Beam Radiotherapy ± Brachytherapy in Endometrial Cancer: A Retrospective Study from Faculty of Medicine, Chiang Mai University

Journal of Cancer Therapy, 2015

Purpose: To report the retrospective study of external beam radiotherapy (EBRT) ± intravaginal br... more Purpose: To report the retrospective study of external beam radiotherapy (EBRT) ± intravaginal brachytherapy (IVBT) as adjuvant treatment for endometrial cancer. Materials and Methods: From 2001-2009, 152 patients received complete surgical staging for endometrial carcinoma and were designed by a multidisciplinary team to receive EBRT ± IVBT. The treatment results and late toxicities were evaluated and recorded. Results: At the median follow-up time of 43 months, the disease-free survival, metastasis-free survival and overall survival rates were 96.9%, 96.9% and 96.9%, respectively. Stage and age showed the statistical significance with the p-value of less than 0.001. From five to ten percent of patients developed Grades 1-2 late gastrointestinal and genitourinary toxicities, respectively. Conclusion: The using of adjuvant EBRT ± IVBT for endometrial carcinoma yielded treatment results and acceptable toxicities.

Research paper thumbnail of The Associations for Vaginal Point Doses of Vaginal Stenosis in Image-Guided Brachytherapy

Journal of Cancer Therapy, 2014

Research paper thumbnail of The treatment outcome of radical radiotherapy in laryngeal cancer

Journal of the Medical Association of Thailand = Chotmaihet thangphaet, 2014

This study reports the treatment outcome of radiotherapy alone for laryngeal cancer A retrospecti... more This study reports the treatment outcome of radiotherapy alone for laryngeal cancer A retrospective analysis was performed on 138 patients with stage I to IV squamous cell carcinoma of larynx who received radiotherapy alone in Division of Therapeutic Radiology and Oncology, Faculty of Medicine, Chiang Mai University, Thailand between 2003 and 2009. The 4-year local control (LC) rate in all patients was 44.1%. The 4-year overall survival (OS) was 82.1%. The 4-year LC rates for stage I, II, III, and IV were 75.3%, 69.4%, 57.1%, and 36.9%,respectively (p = 0.0055). Finally, the 4-year OS rates for stage I, II, III, and IV were 85%, 78.6%, 91.1%, and 71.5%, respectively. The laryngeal preservation rate of all stages was 73%. In conclusion, the treatment outcome of radiotherapy alone in all stages of laryngeal cancer in our center was unsatisfactory when compared to other series.

Research paper thumbnail of 275PCombined chemoradiation of cisplatin versus carboplatin in cervical carcinoma for general condition patients: a single institution experience from Thailand

Research paper thumbnail of OP0005 Neoadjuvant chemotherapy plus chemoradiation (NACT-CCRT) versus chemoradiation plus adjuvant chemotherapy (CCRT-ACT) for locally advanced nasopharyngeal cancer: 3-Year results from a randomised trial

European Journal of Cancer, 2015

Research paper thumbnail of P0031 Use of FOLFOX4 regimen in stage IV cervical cancer: A pilot study

European Journal of Cancer, 2015

Research paper thumbnail of A dosimetric comparison of two-phase adaptive intensity-modulated radiotherapy for locally advanced nasopharyngeal cancer

Journal of radiation research, Jan 8, 2015

The purpose of this investigation was to evaluate the potential dosimetric benefits of a two-phas... more The purpose of this investigation was to evaluate the potential dosimetric benefits of a two-phase adaptive intensity-modulated radiotherapy (IMRT) protocol for patients with locally advanced nasopharyngeal cancer (NPC). A total of 17 patients with locally advanced NPC treated with IMRT had a second computed tomography (CT) scan after 17 fractions in order to apply and continue the treatment with an adapted plan after 20 fractions. To simulate the situation without adaptation, a hybrid plan was generated by applying the optimization parameters of the original treatment plan to the anatomy of the second CT scan. The dose-volume histograms (DVHs) and dose statistics of the hybrid plan and the adapted plan were compared. The mean volume of the ipsilateral and contralateral parotid gland decreased by 6.1 cm(3) (30.5%) and 5.4 cm(3) (24.3%), respectively. Compared with the hybrid plan, the adapted plan provided a higher dose to the target volumes with better homogeneity, and a lower dose...

Research paper thumbnail of Adjuvant External Beam Radiotherapy ± Brachytherapy in Endometrial Cancer: A Retrospective Study from Faculty of Medicine, Chiang Mai University

Journal of Cancer Therapy, 2015

Purpose: To report the retrospective study of external beam radiotherapy (EBRT) ± intravaginal br... more Purpose: To report the retrospective study of external beam radiotherapy (EBRT) ± intravaginal brachytherapy (IVBT) as adjuvant treatment for endometrial cancer. Materials and Methods: From 2001-2009, 152 patients received complete surgical staging for endometrial carcinoma and were designed by a multidisciplinary team to receive EBRT ± IVBT. The treatment results and late toxicities were evaluated and recorded. Results: At the median follow-up time of 43 months, the disease-free survival, metastasis-free survival and overall survival rates were 96.9%, 96.9% and 96.9%, respectively. Stage and age showed the statistical significance with the p-value of less than 0.001. From five to ten percent of patients developed Grades 1-2 late gastrointestinal and genitourinary toxicities, respectively. Conclusion: The using of adjuvant EBRT ± IVBT for endometrial carcinoma yielded treatment results and acceptable toxicities.

Research paper thumbnail of The association of rectal equivalent dose in 2 Gy fractions (EQD2) to late rectal toxicity in locally advanced cervical cancer patients who were evaluated by rectosigmoidoscopy in Faculty of Medicine, Chiang Mai University

Radiation Oncology Journal, 2014

To evaluate association between equivalent dose in 2 Gy (EQD2) to rectal point dose and gastroint... more To evaluate association between equivalent dose in 2 Gy (EQD2) to rectal point dose and gastrointestinal toxicity from whole pelvic radiotherapy (WPRT) and intracavitary brachytherapy (ICBT) in cervical cancer patients who were evaluated by rectosigmoidoscopy in Faculty of Medicine, Chiang Mai University. Materials and Methods: Retrospective study was designed for the patients with locally advanced cervical cancer, treated by radical radiotherapy from 2004 to 2009 and were evaluated by rectosigmoidoscopy. The cumulative doses of WPRT and ICBT to the maximally rectal point were calculated to the EQD2 and evaluated the association of toxicities. Results: Thirty-nine patients were evaluated for late rectal toxicity. The mean cumulative dose in term of EQD2 to rectum was 64.2 Gy. Grade 1 toxicities were the most common findings. According to endoscopic exam, the most common toxicities were congested mucosa (36 patients) and telangiectasia (32 patients). In evaluation between rectal dose in EQD2 and toxicities, no association of cumulative rectal dose to rectal toxicity, except the association of cumulative rectal dose in EQD2 >65 Gy to late effects of normal tissue (LENT-SOMA) scale ≥ grade 2 (p = 0.022; odds ratio, 5.312; 95% confidence interval, 1.269-22.244). Conclusion: The cumulative rectal dose in EQD2 >65 Gy have association with ≥ grade 2 LENT-SOMA scale.

Research paper thumbnail of Image-Based Brachytherapy in Cervical Cancer: Review and Experiences in Faculty of Medicine, Chiang Mai University

Journal of Cancer Therapy, 2013

Cervical cancer is the one of the most common cancer in female patients in Thailand. Radiotherapy... more Cervical cancer is the one of the most common cancer in female patients in Thailand. Radiotherapy has the role for the treatment of cervical cancer by postoperative, radical and palliative treatments. For radical radiotherapy, the combination of external beam radiation therapy and brachytherapy will be used to increase the tumor dose to curative goal. With the new development of medical images (Computed tomography (CT), Magnetic Resonance Imaging (MRI) or Ultrasonography (US)), the treatment with brachytherapy will be developed from point-based to volume-based concepts. Many studies reported the benefit of image-based brachytherapy over conventional brachytherapy and clinical benefit of using image-based brachytherapy in the treatment of cervical cancer.

Research paper thumbnail of Real-world outcomes of postmastectomy radiotherapy in breast cancer patients with 1-3 positive lymph nodes: a retrospective study

Journal of Radiation Research, 2013

Objective: To assess the treatment outcomes and to explore the determinants of clinical outcome i... more Objective: To assess the treatment outcomes and to explore the determinants of clinical outcome in breast cancer patients with 1-3 positive nodes who did or did not receive postmastectomy radiotherapy (PMRT) in a tertiary care referral cancer center in Northern Thailand. Methods: We investigated a retrospective cohort of registered breast cancer patients at the Faculty of Medicine, Chiang Mai University, Thailand from 2001-2007. Analysis was performed using Cox regression models to identify factors affecting the overall survival (OS) and relapse-free survival (RFS) rates. Comparisons were made between two cohorts: women who received adjuvant PMRT (74 patients) and women who did not receive adjuvant PMRT (81 patients). Results: A total of 155 patients were included with a median follow-up period of 4.45 years. There was a statistically significant 4-year OS difference between the two groups of patients: 100% for the PMRT group and 93.1% for the non-PMRT group (P = 0.044). The 4-year RFS was 85.9% for patients receiving PMRT and 78.3% for patients who did not receive PMRT (P = 0.291). On multivariate analysis of OS, using hormonal treatment was the only significant independent factor associated with improved OS. On multivariate analysis of RFS, none of the variables were significantly associated with improved RFS. PMRT was notfound to be a prognostic variable related to the outcome of patients using a logistic regression model. Conclusion: Our retrospective, hospital-based analysis demonstrated that PMRT improved the treatment outcome in terms of OS for women with 1-3 node positive early-stage breast cancer.

Research paper thumbnail of The Associations for Vaginal Point Doses of Vaginal Stenosis in Image-Guided Brachytherapy

Journal of Cancer Therapy, 2014

Purpose: To evaluate the associations for vaginal dose points of vaginal stricture in image-guide... more Purpose: To evaluate the associations for vaginal dose points of vaginal stricture in image-guided brachytherapy. Materials and Methods: Twenty-six patients of locally advanced cervical cancer were treated with Image-Guided Brachytherapy (IGBT) with the dose at least 7 Gy per fraction to the D90 of High-Risk Clinical Target Volume (HR-CTV). The vaginal dose points of recommendations of the American Brachytherapy Society (ABS) were added into the plan and cumulative dose to these points was evaluated in Equivalent Dose of 2 Gy (EQD2) concepts. Results: The mean doses to right vaginal dose point (VR), left vaginal dose point (VL) and average dose of VR/VL ((VR + VL)/2) were 101.5 Gy, 98.2 Gy and 99.8 Gy in EQD2 concepts, respectively. Volume-based planning significantly reduced the cumulative dose in EQD2 concepts at vaginal points. At the median follow-up time of 22 months, grade-2 vaginal stricture was observed in two patients. The incidences of vaginal stricture were not differed between the cumulative dose to vaginal dose points in EQD2 concepts of ≤90 Gy versus >90 Gy (P = 1.000) and ≤100 Gy versus >100 Gy (P = 0.815). Conclusion: No association for cumulative vaginal doses and events of vaginal stricture was found.

Research paper thumbnail of Image-guided brachytherapy (IGBT) combined with whole pelvic intensity-modulated radiotherapy (WP-IMRT) for locally advanced cervical cancer: a prospective study from Chiang Mai University Hospital, Thailand

Journal of Contemporary Brachytherapy, 2013

Purpose: A report of preliminary results and toxicity profiles using image-guided brachytherapy (... more Purpose: A report of preliminary results and toxicity profiles using image-guided brachytherapy (IGBT) combined with whole pelvic intensity-modulated radiation therapy (WP-IMRT) for locally advanced cervical cancer. Material and methods: Fifteen patients with locally advanced cervical cancer were enrolled into the study. WP-IMRT was used to treat the Clinical Target Volume (CTV) with a dose of 45 Gy in 25 fractions. Concurrent cisplatin (40 mg/m 2) was prescribed during radiotherapy (RT) on weekly basis. IGBT using computed tomography was performed at the dose of 7 Gy × 4 fractions to the High-Risk Clinical Target Volume (HR-CTV). Results: The mean cumulative doses-in terms of equivalent dose of 2 Gy (EQD2)-of IGBT plus WP-IMRT to HR-CTV, bladder, rectum, and sigmoid colon were 88.3, 85.0, 68.2 and 73.6 Gy, respectively. In comparison with standard (point A prescription) dose-volume histograms, volume-based image-guided brachytherapy improved the cumulative doses for bladder of 67%, rectum of 47% and sigmoid of 46%. At the median follow-up time of 14 months, the local control, metastasis-free survival and overall survival rates were 93%, 100% and 93%, respectively. No grade 3-4 acute and late toxicities were observed. Conclusion: The combination of image-guided brachytherapy and intensity-modulated radiotherapy improved the dose distribution to tumor volumes and avoided overdose in OARs which could be converted in excellent local control and toxicity profiles.

Research paper thumbnail of The effect of central shielding in the dose reporting for cervical cancer in EQD2 era

Journal of Contemporary Brachytherapy, 2013

Purpose: To evaluate the cumulative dose at point A for three and four centimeters central shield... more Purpose: To evaluate the cumulative dose at point A for three and four centimeters central shielding. Material and methods: The plans of external beam radiotherapy plus conventional intracavitary brachytherapy were performed. Three or four centimeters central shieldings (after 44 Gy) were applied to the standard whole pelvis irradiation. Additional intracavitary brachytherapy 4 × 7 Gy at point A was prescribed, and the cumulative dose in EQD2 (α/b = 10) of 3 cm and 4 cm central shielding were evaluated. Results: The cumulative dose at point A in EQD2 (α/b = 10) of 3 cm central shielding were 95.7 Gy for AR and 95.5 Gy for AL, while the cumulative dose at point As in EQD2 (α/b = 10) of 4 cm central shielding were 90.8 Gy for AR and 91.2 Gy for AL. Conclusions: The 3 cm central shielding caused higher cumulative dose (in terms of EQD2 [α/b = 10]) than 4 cm central shielding.

Research paper thumbnail of The treatment outcome of radical radiotherapy in laryngeal cancer

Journal of the Medical Association of Thailand = Chotmaihet thangphaet, 2014

This study reports the treatment outcome of radiotherapy alone for laryngeal cancer A retrospecti... more This study reports the treatment outcome of radiotherapy alone for laryngeal cancer A retrospective analysis was performed on 138 patients with stage I to IV squamous cell carcinoma of larynx who received radiotherapy alone in Division of Therapeutic Radiology and Oncology, Faculty of Medicine, Chiang Mai University, Thailand between 2003 and 2009. The 4-year local control (LC) rate in all patients was 44.1%. The 4-year overall survival (OS) was 82.1%. The 4-year LC rates for stage I, II, III, and IV were 75.3%, 69.4%, 57.1%, and 36.9%,respectively (p = 0.0055). Finally, the 4-year OS rates for stage I, II, III, and IV were 85%, 78.6%, 91.1%, and 71.5%, respectively. The laryngeal preservation rate of all stages was 73%. In conclusion, the treatment outcome of radiotherapy alone in all stages of laryngeal cancer in our center was unsatisfactory when compared to other series.

Research paper thumbnail of PO-173: Ambulation status after emergency radiotherapy for metastatic spinal cord compression

Radiotherapy and Oncology, 2019

Research paper thumbnail of PO-146: Retrospective Analysis of Adjuvant Radiotherapy in Phyllodes Tumour: Single-Institute Study

Radiotherapy and Oncology, 2019

Research paper thumbnail of The effect of central shielding in the dose reporting for cervical cancer in EQD2 era

Journal of Contemporary Brachytherapy, 2013

To evaluate the cumulative dose at point A for three and four centimeters central shielding.

Research paper thumbnail of The association of rectal equivalent dose in 2 Gy fractions (EQD2) to late rectal toxicity in locally advanced cervical cancer patients who were evaluated by rectosigmoidoscopy in Faculty of Medicine, Chiang Mai University

Radiation Oncology Journal, 2014

Purpose: To evaluate association between equivalent dose in 2 Gy (EQD2) to rectal point dose and ... more Purpose: To evaluate association between equivalent dose in 2 Gy (EQD2) to rectal point dose and gastrointestinal toxicity from whole pelvic radiotherapy (WPRT) and intracavitary brachytherapy (ICBT) in cervical cancer patients who were evaluated by rectosigmoidoscopy in Faculty of Medicine, Chiang Mai University. Materials and Methods: Retrospective study was designed for the patients with locally advanced cervical cancer, treated by radical radiotherapy from 2004 to 2009 and were evaluated by rectosigmoidoscopy. The cumulative doses of WPRT and ICBT to the maximally rectal point were calculated to the EQD2 and evaluated the association of toxicities. Results: Thirty-nine patients were evaluated for late rectal toxicity. The mean cumulative dose in term of EQD2 to rectum was 64.2 Gy. Grade 1 toxicities were the most common findings. According to endoscopic exam, the most common toxicities were congested mucosa (36 patients) and telangiectasia (32 patients). In evaluation between rectal dose in EQD2 and toxicities, no association of cumulative rectal dose to rectal toxicity, except the association of cumulative rectal dose in EQD2 >65 Gy to late effects of normal tissue (LENT-SOMA) scale ≥ grade 2 (p = 0.022; odds ratio, 5.312; 95% confidence interval, 1.269-22.244). Conclusion: The cumulative rectal dose in EQD2 >65 Gy have association with ≥ grade 2 LENT-SOMA scale.

Research paper thumbnail of Image-guided brachytherapy (IGBT) combined with whole pelvic intensity-modulated radiotherapy (WP-IMRT) for locally advanced cervical cancer: a prospective study from Chiang Mai University Hospital, Thailand

Journal of Contemporary Brachytherapy, 2013

A report of preliminary results and toxicity profiles using image-guided brachytherapy (IGBT) com... more A report of preliminary results and toxicity profiles using image-guided brachytherapy (IGBT) combined with whole pelvic intensity-modulated radiation therapy (WP-IMRT) for locally advanced cervical cancer. Fifteen patients with locally advanced cervical cancer were enrolled into the study. WP-IMRT was used to treat the Clinical Target Volume (CTV) with a dose of 45 Gy in 25 fractions. Concurrent cisplatin (40 mg/m(2)) was prescribed during radiotherapy (RT) on weekly basis. IGBT using computed tomography was performed at the dose of 7 Gy × 4 fractions to the High-Risk Clinical Target Volume (HR-CTV). The mean cumulative doses - in terms of equivalent dose of 2 Gy (EQD2) - of IGBT plus WP-IMRT to HR-CTV, bladder, rectum, and sigmoid colon were 88.3, 85.0, 68.2 and 73.6 Gy, respectively. In comparison with standard (point A prescription) dose-volume histograms, volume-based image-guided brachytherapy improved the cumulative doses for bladder of 67%, rectum of 47% and sigmoid of 46%. At the median follow-up time of 14 months, the local control, metastasis-free survival and overall survival rates were 93%, 100% and 93%, respectively. No grade 3-4 acute and late toxicities were observed. The combination of image-guided brachytherapy and intensity-modulated radiotherapy improved the dose distribution to tumor volumes and avoided overdose in OARs which could be converted in excellent local control and toxicity profiles.

Research paper thumbnail of Adjuvant External Beam Radiotherapy ± Brachytherapy in Endometrial Cancer: A Retrospective Study from Faculty of Medicine, Chiang Mai University

Journal of Cancer Therapy, 2015

Purpose: To report the retrospective study of external beam radiotherapy (EBRT) ± intravaginal br... more Purpose: To report the retrospective study of external beam radiotherapy (EBRT) ± intravaginal brachytherapy (IVBT) as adjuvant treatment for endometrial cancer. Materials and Methods: From 2001-2009, 152 patients received complete surgical staging for endometrial carcinoma and were designed by a multidisciplinary team to receive EBRT ± IVBT. The treatment results and late toxicities were evaluated and recorded. Results: At the median follow-up time of 43 months, the disease-free survival, metastasis-free survival and overall survival rates were 96.9%, 96.9% and 96.9%, respectively. Stage and age showed the statistical significance with the p-value of less than 0.001. From five to ten percent of patients developed Grades 1-2 late gastrointestinal and genitourinary toxicities, respectively. Conclusion: The using of adjuvant EBRT ± IVBT for endometrial carcinoma yielded treatment results and acceptable toxicities.

Research paper thumbnail of The Associations for Vaginal Point Doses of Vaginal Stenosis in Image-Guided Brachytherapy

Journal of Cancer Therapy, 2014

Research paper thumbnail of The treatment outcome of radical radiotherapy in laryngeal cancer

Journal of the Medical Association of Thailand = Chotmaihet thangphaet, 2014

This study reports the treatment outcome of radiotherapy alone for laryngeal cancer A retrospecti... more This study reports the treatment outcome of radiotherapy alone for laryngeal cancer A retrospective analysis was performed on 138 patients with stage I to IV squamous cell carcinoma of larynx who received radiotherapy alone in Division of Therapeutic Radiology and Oncology, Faculty of Medicine, Chiang Mai University, Thailand between 2003 and 2009. The 4-year local control (LC) rate in all patients was 44.1%. The 4-year overall survival (OS) was 82.1%. The 4-year LC rates for stage I, II, III, and IV were 75.3%, 69.4%, 57.1%, and 36.9%,respectively (p = 0.0055). Finally, the 4-year OS rates for stage I, II, III, and IV were 85%, 78.6%, 91.1%, and 71.5%, respectively. The laryngeal preservation rate of all stages was 73%. In conclusion, the treatment outcome of radiotherapy alone in all stages of laryngeal cancer in our center was unsatisfactory when compared to other series.

Research paper thumbnail of 275PCombined chemoradiation of cisplatin versus carboplatin in cervical carcinoma for general condition patients: a single institution experience from Thailand

Research paper thumbnail of OP0005 Neoadjuvant chemotherapy plus chemoradiation (NACT-CCRT) versus chemoradiation plus adjuvant chemotherapy (CCRT-ACT) for locally advanced nasopharyngeal cancer: 3-Year results from a randomised trial

European Journal of Cancer, 2015

Research paper thumbnail of P0031 Use of FOLFOX4 regimen in stage IV cervical cancer: A pilot study

European Journal of Cancer, 2015

Research paper thumbnail of A dosimetric comparison of two-phase adaptive intensity-modulated radiotherapy for locally advanced nasopharyngeal cancer

Journal of radiation research, Jan 8, 2015

The purpose of this investigation was to evaluate the potential dosimetric benefits of a two-phas... more The purpose of this investigation was to evaluate the potential dosimetric benefits of a two-phase adaptive intensity-modulated radiotherapy (IMRT) protocol for patients with locally advanced nasopharyngeal cancer (NPC). A total of 17 patients with locally advanced NPC treated with IMRT had a second computed tomography (CT) scan after 17 fractions in order to apply and continue the treatment with an adapted plan after 20 fractions. To simulate the situation without adaptation, a hybrid plan was generated by applying the optimization parameters of the original treatment plan to the anatomy of the second CT scan. The dose-volume histograms (DVHs) and dose statistics of the hybrid plan and the adapted plan were compared. The mean volume of the ipsilateral and contralateral parotid gland decreased by 6.1 cm(3) (30.5%) and 5.4 cm(3) (24.3%), respectively. Compared with the hybrid plan, the adapted plan provided a higher dose to the target volumes with better homogeneity, and a lower dose...