ESTRO 2022 - Abstract Book

S806

Abstract book

ESTRO 2022

received concurrent chemotherapy with 82% (n=40) receiving ≥ 4cycles. Seven patients (11%) acquired COVID-19 infection. Median OTT was 56 days (38-131 days). Prolongation was either due to COVID infection (7.8%) or delay in referral for BT(42%). Overall 62.5% (n=40) patients received IC application and 37.5% (n=24) received IC+IS. The median HRCTV for IC application was 33 cc (IQR 25-44). Median point A dose, HRCTV D90, B2cc,R2cc and S2cc was 74 Gy (71-78), 80Gy (73-84),86 Gy (82- 89),70 Gy(65-74), 65 Gy (59-73) respectively. For those with IC+IS application the median HRCTV was 35 cc(27-45cc).The HRCTV D90, B2cc, R2cc and S2cc was 84 Gy (78-89 Gy), 89 Gy (86-92), 70 Gy (67-74),68 Gy (59-76). At a median follow-up of 12 (5 to 18 ) months, there were 6 pelvic relapses, 10 pelvic or distant events and 5 deaths (2 due to COVID or cardiac related mortality and 1 due to bowel late toxicity, 2 due to disease progression). The 12 month local control, disease free and overall survival was 90.6%, 82.8%, 92.2%. Three patients developed Grade III-IV rectal toxicity (4.6%) and 1 patient (1.6%) developed grade III bladder toxicity. Conclusion The 12-month oncological outcomes with abbreviated BT are comparable to previously published outcomes for cervix cancer. However, careful evolution of adverse events needs to be observed before routine recommendation of this as an alternative treatment option. 1 Faculty of Medicine Siriraj Hospital, Radiology, Bangkok, Thailand; 2 Faculty of Medicine Siriraj Hospital, Radiology, Bangkok , Thailand Purpose or Objective The outcome of concurrent chemoradiation in combination with high dose rate image guided adaptive brachytherapy (HDR- IGABT) for cervical cancer was favorable. However, the transformation of staging from FIGO2009 to FIGO2018 which incorporated nodal status into stage IIIC contributed the migration of patients among stages. The objective of this study was to compare the treatment outcomes and patterns of failure stratified by different FIGO staging in HDR-IGABT era. Materials and Methods 363 patients treated with definitive external beam radiation (EBRT) with/without concurrent chemotherapy followed by HDR-IGABT were retrospectively reviewed. Staging classification was based on FIGO2009 and FIGO2018. Kaplan-Meier estimates at 5 years were analyzed for local control, nodal control, distant metastasis-free survival, and overall survival. Pattern of failure including local, nodal, and distant failure stratified by FIGO staging was reported. Results The median follow-up time was 52 months. According to FIGO 2009, patients were mainly diagnosed as stage IIB (123 patients, 33.9%) and IIIB (175 patients, 48.2%). Among patients with FIGO2009 stage IIB and IIIB, 11 of 123 patients (8.9%) of stage IIB and 52 of 175 patients (29.7%) of stage IIIB were staged as FIGO2018 IIIC. The rates of 5-year local control, nodal control, distant metastasis-free survival, and overall survival for the whole cohort were 86.6%, 92.1%, 73.5% and 84.2%, respectively. After incorporating stage migration into FIGO2009 stage IIB, there were no significant different between FIGO2018 stage IIB and IIIC in terms of local control, nodal control, distant metastasis-free survival, and overall survival. For FIGO2009 stage IIIB, there was a significant difference between FIGO2018 stage IIIB and IIIC for distant metastasis-free survival (p = 0.010) but similar local control, nodal control, and overall survival. For pattern of failure among patients FIGO2009 stage IIB and IIIB, the primary site was distant failure (81 patients, 81%). After separating FIGO2018 stage IIIC, distant failure was still predominant. The most common sites for distant metastasis were lung (30.7%), bone (12.8%), and intraabdominal lymph node (12.1%). For locoregional failure among patients with FIGO2009 stage IIB and IIIB, the primary site was local which was found in 34 patients (68%). After separating FIGO2018 stage IIIC, paraaortic node (PAN) and pelvic node recurrence were more prevailing than FIGO2018 stage IIB and IIIB. PD-0911 Survival outcomes and patterns of failure from stage migration of FIGO staging in cervical cancer W. Sittiwong 1 , P. Dankulchai 1 , N. Chareonsiriwat 2 , S. Manopetchkasem 1 , T. Prasartseree 1