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A Canadian Experience: Current State and Challenges of Magnetic Resonance--Guided Cervical Cancer Brachytherapy in Ontario
E322
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.
2792
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,
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.
2792
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,