- Email: [email protected]
Current Practice of External Beam Radiation Therapy and Brachytherapy for Management of Endometrial Cancer in Ontario, Canada
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International Journal of Radiation Oncology Biology Physics
determined. SBRT dose and pre-SBRT tumor size were compared with response to determine potential associations. Results: Median follow-up was 12.8 months (range 0.6-67.5). 16/47 (34%) targets showed stable disease (SD), 15/47 (32%) partial response (PR), 8/ 47 (17%) complete response (CR), and 8/47 (17%) locally progressive disease (PD). Six of the failures were in pelvic soft tissue sites with three cases in a single patient with multiple local recurrences, while two failures were in liver sites. The overall mean tumor size was 24.4mm (range 5-95), and there was a significant difference between targets that responded (SD, PR, and CR) vs. progressed (PD) (17.2mm vs. 57.6mm, P Z 0.0044). Similarly, a trend of higher SBRT dose in SD/PR/CR vs. PD was seen, although non-significant (40.3 Gy vs. 33.3 Gy, P Z 0.08). 86% of patients were living at the time of analysis, and median PFS was 6.4 months. 16 patients (57%) had distant progression while 11 (39%) had no progression after SBRT. Median time to first failure (local/distant) was 3.8 months. 3 patients (10.7%) had acute grade 2 toxicity, with 2 cases of G2 pain and 1 case of G3 hemorrhagic cystitis that required early discontinuation of SBRT. Conclusion: SBRT results in high levels of local control with short-term follow-up and limited risks of serious toxicities. Larger lesions may require higher doses and the majority of patients will develop distant metastasis despite initially presenting with oligometastatic disease. Author Disclosure: S. Mesko: None. M. Kamrava: Honoraria; Elekta.
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2791 Nonmalignant Localized Ascites as a Late Response to Pelvic Irradiation for Uterine Cervix Cancer K. Kagawa, K. Tarutani, T. Hashimoto, and K. Yabuta; Department of Radiation Oncology, Kansai Rosai Hospital, Amagasaki, Hyogo, Japan Purpose/Objective(s): To clarify a pattern of appearance and fate of nonmalignant ascites after pelvic irradiation for uterine cervix cancer. Materials/Methods: Between 2010 and 2014, 49 patients with squamous cell carcinoma of the uterine cervix were treated with a curative intent by external beam radiation therapy (EBRT) and intracavitary radiation therapy (ICRT). Of these, 28 patients who showed no evidence of disease for more than 1 year were reviewed. Patients’ ages ranged from 39 to 84 years (median 62 years). There were 2 FIGO Stage IB, 16 Stage II, 8 Stage III, and 2 Stage IVA patients. All patients received 50 Gy/25 Fr of EBRT to the pelvis. Stage IIIB/IVA patients received additional 10 Gy/5 Fr boost to the parametrium. After a central shielding was placed at 20-40 Gy depending on stage, 20-24 Gy/4 Fr of high dose rate ICRT was delivered at point A according to ICRU Report #38. Concurrent chemotherapy with CDDP or CDGP was administered for Stage II-IVA patients unless patients’ ages exceeded 75 years or compliance was poor. All patients were followed by tumor marker, transvaginal US, and cervical and endometrial smear cytology every 3 months. CT or MRI examinations were performed at less than 6 months interval. Results: The median follow-up time was 43 months (range 14-68 months). Asymptomatic ascites was found in 17 patients (61%) without any sign of tumor recurrence. In most cases, the ascites was localized in the recto-uterine (Douglas) pouch in the pelvic region. Though concurrent chemotherapy was administered in 12 of 17 patients, no hepatic and renal dysfunction was observed in these patients. The median duration between the first day of radiation therapy and appearance of ascites was 13 months (range 3-26 months). In 8 patients with a small amount of ascites, the ascites spontaneously disappeared without any treatment. The median duration between its appearance and disappearance was 16 months (range 2-36 months). Conclusion: Non-malignant localized ascites was found in 61% of patients as a late response to pelvic irradiation for uterine cervix cancer. The ascites spontaneously disappeared within 2 years if the amount was small. No relation to hepatic or renal dysfunction was observed. Chylous ascites due to late peritoneal or mesenteric response is suspected. This should be cautiously discriminated from malignant ascites due to peritoneal tumor spread. Author Disclosure: K. Kagawa: None. K. Tarutani: None. T. Hashimoto: None. K. Yabuta: None.
A Canadian Experience: Current State and Challenges of Magnetic Resonance–Guided Cervical Cancer Brachytherapy in Ontario K.Y. Chan,1 Q. Benwell,2 K. Schneider,3 M. Ang,4 D.P. D’Souza,2 M. Milosevic,1 and L. Barbera5; 1Princess Margaret Cancer Centre, Toronto, ON, Canada, 2London Regional Cancer Program, London, ON, Canada, 3Windsor Regional Hospital Cancer Program, Windsor, ON, Canada, 4Cancer Care Ontario, Toronto, ON, Canada, 5Sunnybrook Health Sciences Centre, Odette Cancer Research Program, Toronto, ON, Canada Purpose/Objective(s): Magnetic resonance (MR) is considered the goldstandard imaging modality to guide cervical cancer brachytherapy (BT), however introducing MR-guided brachytherapy (MRgBT) into an existing BT process can be challenging. The Models of Care Working Group within Cancer Care Ontario’s Gynecological Community of Practice (GYN CoP) of the Radiation Treatment Program has a supportive role to help Ontario centers in developing strategies for patients to access this technology. The aim of this study is to identify current state and challenges of image-guided cervical cancer brachytherapy (ccBT) in Ontario (ONT). Materials/Methods: A qualitative phone interview was designed by the GYN CoP working group to determine the current state of ccBT in the province. Questions were developed to inquire about the use of imageguided ccBT and its associated referral process, the use of MR imaging in ccBT and the use of image-guided interstitial GYN BT. All ONT cancer centers offering radiation treatments to GYN cancers were included. Two group members conducted the interviews from May to November 2015 and all recordings were analyzed. Results: Thirteen (N Z 13) ONT cancer centers were interviewed. Of these, 3 centers do not offer ccBT, 5 centers offer CT-guided ccBT, 4 centers offer a combination of CT-MR-guided ccBT and 1 center offers strictly MR-guided ccBT. Of the 10 centers offering ccBT, 4 centers (all CT-guided) prescribe to ICRU point A and 6 centers prescribe to a target volume recommended by The Groupe Europe´en de Curiethe´rapie and the European Society for radiation therapy & Oncology (GEC-ESTRO) guideline. 9 of 10 ccBT centers use GEC-ESTRO guideline to quantify dose to organs at risk (bladder, rectum and sigmoid). Of the 5 centers that are equipped with MR-guided ccBT, only one center uses MR as the primary data set, 4 centers use CT and MR fusion to delineate target volume. The frequency of MR-guided planning during the course of ccBT ranges from once (first BT treatment) to five times (all BT treatments). Only 3 of 10 centers offer interstitial GYN BT, one center offers CT-guided and 2 centers offer MR-guided interstitial GYN BT. All CTguided ccBT centers except one have plans to develop MRgBT. Challenges to MRgBT indicated by the cancer centers were staff development (N Z 7), time share of MR scanner with the diagnostic department (N Z 4) and an increasing demand for operating room time and anesthesia support (N Z 3). Conclusion: The study demonstrated the variation in care models for MRgBT across the province. The identified areas of needed improvement are staff development and hospital infrastructure. More work is needed by the GYN CoP to address these challenges to help ONT cancer centers adapt current practice to MRgBT. This will ensure all cervical cancer patients in ONT have equitable access to this high quality of care. Author Disclosure: K.Y. Chan: None. Q. Benwell: None. K. Schneider: None. M. Ang: None. D. D’Souza: None. M. Milosevic: None. L. Barbera: None.
2793 Current Practice of External Beam Radiation Therapy and Brachytherapy for Management of Endometrial Cancer in Ontario, Canada N. Shahid,1 A. Ashworth,2 M. Ang,3 D.P. D’Souza,4 A. Di Tomasso,5 R. Sankreacha,6 R. Hunter,7 C.B. Shenfield,8 M. Milosevic,9 and I. Kong10; 1University of Toronto, Toronto, ON, Canada, 2Cancer Centre of Southeastern Ontario, Kingston, ON, Canada, 3Cancer Care Ontario, Toronto, ON, Canada, 4University of Western Ontario, London, ON, Canada, 5Princess Margaret Cancer Center/University of Toronto, Toronto, ON, Canada, 6Trillium Health Partners, Mississauga, ON,
Volume 96 Number 2S Supplement 2016 Canada, 7Juravinski Cancer Centre-McMaster University, Hamilton, ON, Canada, 8Cancer Centre of Southeastern Ontario, Kingston, ON, Canada, 9 Princess Margaret Cancer Centre/University of Toronto, Toronto, ON, Canada, 10McMaster University, Hamilton, ON, Canada Purpose/Objective(s): To document the practice of adjuvant brachytherapy (BT) and external beam radiation therapy (EBRT) for management of endometrial cancer in Ontario, Canada with a population of 13.6 million. Materials/Methods: An electronic survey including 83 questions focusing on general/demographic information, pre-treatment assessments, radiation therapy policies and EBRT/BT techniques was sent to all 14 regional cancer centers in 2014. Results: The response rate was 100%. The most frequently used dose/ fractionation scheme for EBRT was 45Gy in 25 fractions. The EBRT technique was 4-Field box in 46%, IMRT in 15%, VMAT in 31% and VMAT/4-Field box in 8% of the centers. Pelvic EBRT was recommended by all centers for stage II/IIIA/IIIC1 any grade, by 92% of the centers with stage IB grade 3 or serous-clear cell carcinoma/stage IIIC2 any grade and by 70% of the centers for stage IA serous-clear cell carcinoma. Combination of EBRT and BT was recommended by all centers for stage II any grade carcinoma, by 92% of the centers for stage IIIC1 with cervical stromal involvement, by 85% of the centers for stage IIIA/IIIB/IIIC2 with cervical stromal involvement and by 54% of the centers for stage IVB any grade with cervical stromal involvement. Adjuvant BT alone was recommended for stage 1A grade 3 or stage 1B grade 1-2 in 77% of the centers, for stage 1A serous-clear cell carcinoma in 31% of centers, for stage 1B grade 3 in 15% of centers. In 85% of centers, the cases were always peer reviewed. Half of the centers used image verification with x-ray/CT/fluoroscopy after each insertion of the applicator. Bladder and rectal doses were recorded in 8% of the centers using ICRU 38 point doses and in 25% using dose-volume metrics (D2cc). Seventeen percent of the centers treated the upper 3 cm of the vagina, 42% the upper 4 cm, 8% the upper 34 cm, 8% the upper 5cm, 17% the upper half and 8% the upper 3rd of the vagina. The dose was prescribed at the surface of the cylinder and at a depth of 5mm in 33% and 67% of the centers, respectively. The dose for BT alone prescribed to the surface varied from 6-10.5 Gy x 3-5 fractions. The dose was more uniform when prescribed at depth, with 87% using 7 Gy x 3 fractions. For combination EBRT-BT treatments, BT dose varied from 5-6 Gy x 3 fractions at the surface to 4-5.5 Gy x 2-3 fractions at depth. Conclusion: Practice patterns regarding the use of EBRT and BT appear to be fairly consistent across the province of Ontario, however, there is considerable heterogeneity in BT treatment planning practices, particularly with respect to length of vagina treated, prescription points, and dose/ fractionation. Further research is required to determine the reasons for this heterogeneity, to identify areas where harmonization of practice might lead to clinically significant benefits, and to generate evidenceebased practice recommendations for the use of EBRT and BT in the province of Ontario. Author Disclosure: N. Shahid: Fellow; University of Toronto. A. Ashworth: None. M. Ang: None. D. D’Souza: None. A. Di Tomasso: None. R. Sankreacha: None. R. Hunter: None. C.B. Shenfield: None. M. Milosevic: -; University of Toronto. -; Terry Fox Research Institute, Canadian Partnership Against Cancer. Chair; Canadian Partnership of Quality Radiotherapy. Past-President; Canadian Association of Radiation Oncology. I. Kong: Independent Contractor; Juravinski Cancer Center.
Poster Viewing E323 Japan, 3Central Radiology Department, Kobe University Hospital, Kobe, Japan, 4Department of Anesthesia, Kobe University Graduate School of Medicine, Kobe, Japan, 5Department of Gynecology, Kobe University Graduate School of Medicine, Kobe, Japan, 6Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan Purpose/Objective(s): Image guided adaptive brachytherapy (IGABT) for cervical cancer using magnetic resonance imaging (MRI) is not common in Japan and only several centers have been performing. In addition, Japanese technique of external beam radiation therapy (EBRT) is quite unique because central shielding (CS) is used after whole pelvic irradiation for all the patients. This study aims to compare dosimetric parameters in the 2 treatment plannings of intracavitary IGABT, one is the non-optimized planning (NOP) prescribed to point A and the other is optimized planning (OP), which is clinically used in combination of EBRT using Japanese CS technique. Materials/Methods: Treatment plannings of cervical cancer patients received MRI based IGABT at every implant were evaluated. NOP was at first created and then, OP was created considering the doses of organ at risks (OAR) and maintaining the dose that covers 90% (D90) of high risk clinical target volume (HRCTV) more than 7.0Gy per fraction. Our treatment aim of total HRCTV D90 in equivalent dose in 2Gy fractions (EQD2) is at least more than 70Gy in combination of whole pelvic irradiation, excluding the dose delivered by CS and IGABT. Dose constraints of OARs were determined using the dose that covers 2cc of them (D2cc) and limited less than 85Gy for bladder, 75Gy for rectum and sigmoid colon, respectively. HRCTV D90s in both planning were at first compared, and then D2cc of OARs were also compared. Wilcoxon’s signed rank test used for statistics. A P value < 0.05 was considered significant. Results: Treatment planning of 32 patients received intracavitary IGABT could be evaluated. The mean total HRCTV D90s of NOP and OP were 84.7 and 76.8Gy, respectively (P<0.001). The mean total bladder, rectum, and sigmoid colon D2cc were 88.4 / 77.1Gy, 63.0 / 57.9Gy, 54.1 / 49.9Gy, respectively (P<0.001, P Z 0.001, P Z 0.05). Dosimetric analyses were also performed according to the size of HRCTV (mean: 33.8, median: 28.8ml). In the smaller HRCTV group (less than 30ml, n Z 17)), the mean total HRCTV D90, bladder, rectum, and sigmoid colon D2cc of NOP and OP were 95.3 / 79.6Gy, 99.1 / 78.0Gy, 63.9 / 54.5Gy, and 54.5 / 47.5 Gy, respectively (P<0.001, <0.001, <0.001, and <0.001). In the larger HRCTV group (more than 30ml, n Z 15), the mean total HRCTV D90, bladder, rectum, and sigmoid colon D2cc were 72.6 / 73.1Gy, 76.3 / 73.6 Gy, 62.0 /61.9Gy, and 53.7 / 52.6Gy, respectively (P Z 0.65, 0.78, 0.82, and 0.43). Conclusion: NOP showed significantly higher HRCTV D90 even if CS was used. However, bladder D2cc was also significantly higher in NOP. In the smaller HRCTV group, although HRCTV D90 and D2cc of OARs were extremely high, using optimization achieved decreasing bladder D2cc keeping satisfactory HRCTV D90 up to 80Gy. In the larger HRCTV group, both NOP and OP could not achieve excellent HRCTV D90 (more than 80Gy). In such cases, more use of interstitial needles can solve this problem. Optimal treatment aim for HRCTV and dose constraints for OARs in IGABT under the use of CS must be defined in Japan. Author Disclosure: K. Yoshida: None. D. Miyawaki: None. R. Nishikawa: None. H. Akasaka: None. Y. Matsuo: None. M. Omoteda: None. K. Kyotani: None. H. Satoh: None. S. Osuga: None. Y. Shimizu: None. Y. Ebina: None. S. Takahashi: None. R. Sasaki: None.
2795 2794 Comparison of Dosimetric Parameters in the Treatment Planning of MRI-Based Intracavitary Image Guided Adaptive Brachytherapy With and Without Optimization Combined With EBRT Using Central Shield K. Yoshida,1 D. Miyawaki,1 R. Nishikawa,1 H. Akasaka,1 Y. Matsuo,1 M. Omoteda,2 K. Kyotani,3 H. Satoh,4 S. Osuga,1 Y. Shimizu,1 Y. Ebina,5 S. Takahashi,6 and R. Sasaki1; 1Division of Radiation Oncology, Kobe University Graduate School of Medicine, Kobe, Japan, 2Center for Radiology and Radiation Oncology, Kobe University Hospital, Kobe,
Weekly Cisplatin and Volumetric Modulated Arc Therapy With Simultaneous Integrated Boost for Radical Treatment of Advanced Cervical Cancer in Elderly Patients: Feasibility and Clinical Preliminary Results A. Fiorentino,1 N. Giaj Levra,1 F. Ricchetti,1 S. Fersino,1 R. Mazzola,1 U. Tebano,2 G. Sicignano,1 S. Naccarato,1 R. Ruggieri,1 and F. Alongi1; 1 Radiation Oncology Department Sacro Cuore Hospital, Negrar-Verona, Italy, 2Radiation Oncology School, University of Padova, Padova, Italy Purpose/Objective(s): To evaluate preliminary findings regarding local control (LC), overall survival (OS) and toxicity in a cohort of
International Journal of Radiation Oncology Biology Physics
determined. SBRT dose and pre-SBRT tumor size were compared with response to determine potential associations. Results: Median follow-up was 12.8 months (range 0.6-67.5). 16/47 (34%) targets showed stable disease (SD), 15/47 (32%) partial response (PR), 8/ 47 (17%) complete response (CR), and 8/47 (17%) locally progressive disease (PD). Six of the failures were in pelvic soft tissue sites with three cases in a single patient with multiple local recurrences, while two failures were in liver sites. The overall mean tumor size was 24.4mm (range 5-95), and there was a significant difference between targets that responded (SD, PR, and CR) vs. progressed (PD) (17.2mm vs. 57.6mm, P Z 0.0044). Similarly, a trend of higher SBRT dose in SD/PR/CR vs. PD was seen, although non-significant (40.3 Gy vs. 33.3 Gy, P Z 0.08). 86% of patients were living at the time of analysis, and median PFS was 6.4 months. 16 patients (57%) had distant progression while 11 (39%) had no progression after SBRT. Median time to first failure (local/distant) was 3.8 months. 3 patients (10.7%) had acute grade 2 toxicity, with 2 cases of G2 pain and 1 case of G3 hemorrhagic cystitis that required early discontinuation of SBRT. Conclusion: SBRT results in high levels of local control with short-term follow-up and limited risks of serious toxicities. Larger lesions may require higher doses and the majority of patients will develop distant metastasis despite initially presenting with oligometastatic disease. Author Disclosure: S. Mesko: None. M. Kamrava: Honoraria; Elekta.
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2791 Nonmalignant Localized Ascites as a Late Response to Pelvic Irradiation for Uterine Cervix Cancer K. Kagawa, K. Tarutani, T. Hashimoto, and K. Yabuta; Department of Radiation Oncology, Kansai Rosai Hospital, Amagasaki, Hyogo, Japan Purpose/Objective(s): To clarify a pattern of appearance and fate of nonmalignant ascites after pelvic irradiation for uterine cervix cancer. Materials/Methods: Between 2010 and 2014, 49 patients with squamous cell carcinoma of the uterine cervix were treated with a curative intent by external beam radiation therapy (EBRT) and intracavitary radiation therapy (ICRT). Of these, 28 patients who showed no evidence of disease for more than 1 year were reviewed. Patients’ ages ranged from 39 to 84 years (median 62 years). There were 2 FIGO Stage IB, 16 Stage II, 8 Stage III, and 2 Stage IVA patients. All patients received 50 Gy/25 Fr of EBRT to the pelvis. Stage IIIB/IVA patients received additional 10 Gy/5 Fr boost to the parametrium. After a central shielding was placed at 20-40 Gy depending on stage, 20-24 Gy/4 Fr of high dose rate ICRT was delivered at point A according to ICRU Report #38. Concurrent chemotherapy with CDDP or CDGP was administered for Stage II-IVA patients unless patients’ ages exceeded 75 years or compliance was poor. All patients were followed by tumor marker, transvaginal US, and cervical and endometrial smear cytology every 3 months. CT or MRI examinations were performed at less than 6 months interval. Results: The median follow-up time was 43 months (range 14-68 months). Asymptomatic ascites was found in 17 patients (61%) without any sign of tumor recurrence. In most cases, the ascites was localized in the recto-uterine (Douglas) pouch in the pelvic region. Though concurrent chemotherapy was administered in 12 of 17 patients, no hepatic and renal dysfunction was observed in these patients. The median duration between the first day of radiation therapy and appearance of ascites was 13 months (range 3-26 months). In 8 patients with a small amount of ascites, the ascites spontaneously disappeared without any treatment. The median duration between its appearance and disappearance was 16 months (range 2-36 months). Conclusion: Non-malignant localized ascites was found in 61% of patients as a late response to pelvic irradiation for uterine cervix cancer. The ascites spontaneously disappeared within 2 years if the amount was small. No relation to hepatic or renal dysfunction was observed. Chylous ascites due to late peritoneal or mesenteric response is suspected. This should be cautiously discriminated from malignant ascites due to peritoneal tumor spread. Author Disclosure: K. Kagawa: None. K. Tarutani: None. T. Hashimoto: None. K. Yabuta: None.
A Canadian Experience: Current State and Challenges of Magnetic Resonance–Guided Cervical Cancer Brachytherapy in Ontario K.Y. Chan,1 Q. Benwell,2 K. Schneider,3 M. Ang,4 D.P. D’Souza,2 M. Milosevic,1 and L. Barbera5; 1Princess Margaret Cancer Centre, Toronto, ON, Canada, 2London Regional Cancer Program, London, ON, Canada, 3Windsor Regional Hospital Cancer Program, Windsor, ON, Canada, 4Cancer Care Ontario, Toronto, ON, Canada, 5Sunnybrook Health Sciences Centre, Odette Cancer Research Program, Toronto, ON, Canada Purpose/Objective(s): Magnetic resonance (MR) is considered the goldstandard imaging modality to guide cervical cancer brachytherapy (BT), however introducing MR-guided brachytherapy (MRgBT) into an existing BT process can be challenging. The Models of Care Working Group within Cancer Care Ontario’s Gynecological Community of Practice (GYN CoP) of the Radiation Treatment Program has a supportive role to help Ontario centers in developing strategies for patients to access this technology. The aim of this study is to identify current state and challenges of image-guided cervical cancer brachytherapy (ccBT) in Ontario (ONT). Materials/Methods: A qualitative phone interview was designed by the GYN CoP working group to determine the current state of ccBT in the province. Questions were developed to inquire about the use of imageguided ccBT and its associated referral process, the use of MR imaging in ccBT and the use of image-guided interstitial GYN BT. All ONT cancer centers offering radiation treatments to GYN cancers were included. Two group members conducted the interviews from May to November 2015 and all recordings were analyzed. Results: Thirteen (N Z 13) ONT cancer centers were interviewed. Of these, 3 centers do not offer ccBT, 5 centers offer CT-guided ccBT, 4 centers offer a combination of CT-MR-guided ccBT and 1 center offers strictly MR-guided ccBT. Of the 10 centers offering ccBT, 4 centers (all CT-guided) prescribe to ICRU point A and 6 centers prescribe to a target volume recommended by The Groupe Europe´en de Curiethe´rapie and the European Society for radiation therapy & Oncology (GEC-ESTRO) guideline. 9 of 10 ccBT centers use GEC-ESTRO guideline to quantify dose to organs at risk (bladder, rectum and sigmoid). Of the 5 centers that are equipped with MR-guided ccBT, only one center uses MR as the primary data set, 4 centers use CT and MR fusion to delineate target volume. The frequency of MR-guided planning during the course of ccBT ranges from once (first BT treatment) to five times (all BT treatments). Only 3 of 10 centers offer interstitial GYN BT, one center offers CT-guided and 2 centers offer MR-guided interstitial GYN BT. All CTguided ccBT centers except one have plans to develop MRgBT. Challenges to MRgBT indicated by the cancer centers were staff development (N Z 7), time share of MR scanner with the diagnostic department (N Z 4) and an increasing demand for operating room time and anesthesia support (N Z 3). Conclusion: The study demonstrated the variation in care models for MRgBT across the province. The identified areas of needed improvement are staff development and hospital infrastructure. More work is needed by the GYN CoP to address these challenges to help ONT cancer centers adapt current practice to MRgBT. This will ensure all cervical cancer patients in ONT have equitable access to this high quality of care. Author Disclosure: K.Y. Chan: None. Q. Benwell: None. K. Schneider: None. M. Ang: None. D. D’Souza: None. M. Milosevic: None. L. Barbera: None.
2793 Current Practice of External Beam Radiation Therapy and Brachytherapy for Management of Endometrial Cancer in Ontario, Canada N. Shahid,1 A. Ashworth,2 M. Ang,3 D.P. D’Souza,4 A. Di Tomasso,5 R. Sankreacha,6 R. Hunter,7 C.B. Shenfield,8 M. Milosevic,9 and I. Kong10; 1University of Toronto, Toronto, ON, Canada, 2Cancer Centre of Southeastern Ontario, Kingston, ON, Canada, 3Cancer Care Ontario, Toronto, ON, Canada, 4University of Western Ontario, London, ON, Canada, 5Princess Margaret Cancer Center/University of Toronto, Toronto, ON, Canada, 6Trillium Health Partners, Mississauga, ON,
Volume 96 Number 2S Supplement 2016 Canada, 7Juravinski Cancer Centre-McMaster University, Hamilton, ON, Canada, 8Cancer Centre of Southeastern Ontario, Kingston, ON, Canada, 9 Princess Margaret Cancer Centre/University of Toronto, Toronto, ON, Canada, 10McMaster University, Hamilton, ON, Canada Purpose/Objective(s): To document the practice of adjuvant brachytherapy (BT) and external beam radiation therapy (EBRT) for management of endometrial cancer in Ontario, Canada with a population of 13.6 million. Materials/Methods: An electronic survey including 83 questions focusing on general/demographic information, pre-treatment assessments, radiation therapy policies and EBRT/BT techniques was sent to all 14 regional cancer centers in 2014. Results: The response rate was 100%. The most frequently used dose/ fractionation scheme for EBRT was 45Gy in 25 fractions. The EBRT technique was 4-Field box in 46%, IMRT in 15%, VMAT in 31% and VMAT/4-Field box in 8% of the centers. Pelvic EBRT was recommended by all centers for stage II/IIIA/IIIC1 any grade, by 92% of the centers with stage IB grade 3 or serous-clear cell carcinoma/stage IIIC2 any grade and by 70% of the centers for stage IA serous-clear cell carcinoma. Combination of EBRT and BT was recommended by all centers for stage II any grade carcinoma, by 92% of the centers for stage IIIC1 with cervical stromal involvement, by 85% of the centers for stage IIIA/IIIB/IIIC2 with cervical stromal involvement and by 54% of the centers for stage IVB any grade with cervical stromal involvement. Adjuvant BT alone was recommended for stage 1A grade 3 or stage 1B grade 1-2 in 77% of the centers, for stage 1A serous-clear cell carcinoma in 31% of centers, for stage 1B grade 3 in 15% of centers. In 85% of centers, the cases were always peer reviewed. Half of the centers used image verification with x-ray/CT/fluoroscopy after each insertion of the applicator. Bladder and rectal doses were recorded in 8% of the centers using ICRU 38 point doses and in 25% using dose-volume metrics (D2cc). Seventeen percent of the centers treated the upper 3 cm of the vagina, 42% the upper 4 cm, 8% the upper 34 cm, 8% the upper 5cm, 17% the upper half and 8% the upper 3rd of the vagina. The dose was prescribed at the surface of the cylinder and at a depth of 5mm in 33% and 67% of the centers, respectively. The dose for BT alone prescribed to the surface varied from 6-10.5 Gy x 3-5 fractions. The dose was more uniform when prescribed at depth, with 87% using 7 Gy x 3 fractions. For combination EBRT-BT treatments, BT dose varied from 5-6 Gy x 3 fractions at the surface to 4-5.5 Gy x 2-3 fractions at depth. Conclusion: Practice patterns regarding the use of EBRT and BT appear to be fairly consistent across the province of Ontario, however, there is considerable heterogeneity in BT treatment planning practices, particularly with respect to length of vagina treated, prescription points, and dose/ fractionation. Further research is required to determine the reasons for this heterogeneity, to identify areas where harmonization of practice might lead to clinically significant benefits, and to generate evidenceebased practice recommendations for the use of EBRT and BT in the province of Ontario. Author Disclosure: N. Shahid: Fellow; University of Toronto. A. Ashworth: None. M. Ang: None. D. D’Souza: None. A. Di Tomasso: None. R. Sankreacha: None. R. Hunter: None. C.B. Shenfield: None. M. Milosevic: -; University of Toronto. -; Terry Fox Research Institute, Canadian Partnership Against Cancer. Chair; Canadian Partnership of Quality Radiotherapy. Past-President; Canadian Association of Radiation Oncology. I. Kong: Independent Contractor; Juravinski Cancer Center.
Poster Viewing E323 Japan, 3Central Radiology Department, Kobe University Hospital, Kobe, Japan, 4Department of Anesthesia, Kobe University Graduate School of Medicine, Kobe, Japan, 5Department of Gynecology, Kobe University Graduate School of Medicine, Kobe, Japan, 6Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan Purpose/Objective(s): Image guided adaptive brachytherapy (IGABT) for cervical cancer using magnetic resonance imaging (MRI) is not common in Japan and only several centers have been performing. In addition, Japanese technique of external beam radiation therapy (EBRT) is quite unique because central shielding (CS) is used after whole pelvic irradiation for all the patients. This study aims to compare dosimetric parameters in the 2 treatment plannings of intracavitary IGABT, one is the non-optimized planning (NOP) prescribed to point A and the other is optimized planning (OP), which is clinically used in combination of EBRT using Japanese CS technique. Materials/Methods: Treatment plannings of cervical cancer patients received MRI based IGABT at every implant were evaluated. NOP was at first created and then, OP was created considering the doses of organ at risks (OAR) and maintaining the dose that covers 90% (D90) of high risk clinical target volume (HRCTV) more than 7.0Gy per fraction. Our treatment aim of total HRCTV D90 in equivalent dose in 2Gy fractions (EQD2) is at least more than 70Gy in combination of whole pelvic irradiation, excluding the dose delivered by CS and IGABT. Dose constraints of OARs were determined using the dose that covers 2cc of them (D2cc) and limited less than 85Gy for bladder, 75Gy for rectum and sigmoid colon, respectively. HRCTV D90s in both planning were at first compared, and then D2cc of OARs were also compared. Wilcoxon’s signed rank test used for statistics. A P value < 0.05 was considered significant. Results: Treatment planning of 32 patients received intracavitary IGABT could be evaluated. The mean total HRCTV D90s of NOP and OP were 84.7 and 76.8Gy, respectively (P<0.001). The mean total bladder, rectum, and sigmoid colon D2cc were 88.4 / 77.1Gy, 63.0 / 57.9Gy, 54.1 / 49.9Gy, respectively (P<0.001, P Z 0.001, P Z 0.05). Dosimetric analyses were also performed according to the size of HRCTV (mean: 33.8, median: 28.8ml). In the smaller HRCTV group (less than 30ml, n Z 17)), the mean total HRCTV D90, bladder, rectum, and sigmoid colon D2cc of NOP and OP were 95.3 / 79.6Gy, 99.1 / 78.0Gy, 63.9 / 54.5Gy, and 54.5 / 47.5 Gy, respectively (P<0.001, <0.001, <0.001, and <0.001). In the larger HRCTV group (more than 30ml, n Z 15), the mean total HRCTV D90, bladder, rectum, and sigmoid colon D2cc were 72.6 / 73.1Gy, 76.3 / 73.6 Gy, 62.0 /61.9Gy, and 53.7 / 52.6Gy, respectively (P Z 0.65, 0.78, 0.82, and 0.43). Conclusion: NOP showed significantly higher HRCTV D90 even if CS was used. However, bladder D2cc was also significantly higher in NOP. In the smaller HRCTV group, although HRCTV D90 and D2cc of OARs were extremely high, using optimization achieved decreasing bladder D2cc keeping satisfactory HRCTV D90 up to 80Gy. In the larger HRCTV group, both NOP and OP could not achieve excellent HRCTV D90 (more than 80Gy). In such cases, more use of interstitial needles can solve this problem. Optimal treatment aim for HRCTV and dose constraints for OARs in IGABT under the use of CS must be defined in Japan. Author Disclosure: K. Yoshida: None. D. Miyawaki: None. R. Nishikawa: None. H. Akasaka: None. Y. Matsuo: None. M. Omoteda: None. K. Kyotani: None. H. Satoh: None. S. Osuga: None. Y. Shimizu: None. Y. Ebina: None. S. Takahashi: None. R. Sasaki: None.
2795 2794 Comparison of Dosimetric Parameters in the Treatment Planning of MRI-Based Intracavitary Image Guided Adaptive Brachytherapy With and Without Optimization Combined With EBRT Using Central Shield K. Yoshida,1 D. Miyawaki,1 R. Nishikawa,1 H. Akasaka,1 Y. Matsuo,1 M. Omoteda,2 K. Kyotani,3 H. Satoh,4 S. Osuga,1 Y. Shimizu,1 Y. Ebina,5 S. Takahashi,6 and R. Sasaki1; 1Division of Radiation Oncology, Kobe University Graduate School of Medicine, Kobe, Japan, 2Center for Radiology and Radiation Oncology, Kobe University Hospital, Kobe,
Weekly Cisplatin and Volumetric Modulated Arc Therapy With Simultaneous Integrated Boost for Radical Treatment of Advanced Cervical Cancer in Elderly Patients: Feasibility and Clinical Preliminary Results A. Fiorentino,1 N. Giaj Levra,1 F. Ricchetti,1 S. Fersino,1 R. Mazzola,1 U. Tebano,2 G. Sicignano,1 S. Naccarato,1 R. Ruggieri,1 and F. Alongi1; 1 Radiation Oncology Department Sacro Cuore Hospital, Negrar-Verona, Italy, 2Radiation Oncology School, University of Padova, Padova, Italy Purpose/Objective(s): To evaluate preliminary findings regarding local control (LC), overall survival (OS) and toxicity in a cohort of