ESTRO 38 Abstract book

S815 ESTRO 38

and centralized image guided high dose rate brachytherapy (IG-HDR BT). Material and Methods From 01/2012 to 06/2017, 96 (100%) pts with cervical cancer (FIGO IA2 - IVA) were treated with IG-EBRcT in 10 national institutions. 74% of pts were diagnosed with positive lymph nodes, 21% after complete or sentinel- lymphadenectomy and 53% via 18 FDG-PET/CT. 81% of pts were diagnosed with tumors larger than 4 cm in diameter. 82% of the tumors were squamous cell carcinomas, 10% adenocarcinomas and 7% other histologies. All pts were treated with IG-EBRcT. A dose of 50.4 Gy was prescribed to the elective pelvic nodal volume. Primary tumors smaller than 4 cm in diameter received an additional boost of 5.4 Gy, primary tumors larger than 4 cm in diameter received a boost of 9 Gy. Patients with positive lymph nodes detected with 18 FDG-PET/CT received a simultaneous integrated boost to a total dose of 64 Gy. Chemotherapy was administered according to institutional standards. After completion of IG-EBRcT all pts were centrally referred to our hospital for IG-HDR BT treatment (4 x 6-7 Gy). Median EQD2 dose for the primary tumor was 81.6 Gy (62.6 - 93.2 Gy). Adverse events were coded according to the CTCAE version 4.0. Results Survival data were available for 91 pts. During a median follow-up of 22 months (2-77 months) 28 (31%) pts developed disease relapse. 12 (13%) pts had loco-regional relapse, 7 (8%) local relapse and 5 (5%) nodal relapse. 22 (24%) pts developed systemic metastases. 13 (14%) pts died, 9 (10%) from cervical cancer. Median survival time was not reached. In total 89 acute adverse events (AE) were recorded (86 Gr. 1-2; 3 Gr. 3). Data on late AE were available for 83% of the pts. 68 late AE were recorded (37 Gr. 1; 26 Gr. 2; 5 Gr. 3). Conclusion Satisfactory treatment outcomes were achieved while treatment-related toxicities were kept reasonably low. EP-1507 Radical radiotherapy/brachytherapy for cervix cancer in Alberta: who are treated, how do they fare? N. Vawda 1,2 , S. Ghosh 1,3 , S. Menon 4 , A. Duimering 1,2 , J. Cuartero 1,2 , E. Wiebe 1,2 , C. Doll 4,5 , F. Huang 1,2 1 University of Alberta, Oncology, Edmonton, Canada ; 2 Cross Cancer Institute, Radiation Oncology, Edmonton, Canada ; 3 Cross Cancer Institute, Oncology, Edmonton, Canada ; 4 University of Calgary, Oncology, Calgary, Canada ; 5 Tom Baker Cancer Centre, Radiation Oncology, Calgary, Canada Purpose or Objective To explore patterns of disease and outcomes of cervix cancer (CC) patients treated with radical (chemo)radiotherapy (RT), including brachytherapy (BT), in the province of Alberta (AB), Canada. Material and Methods In this retrospective review, all patients with CC who received primary (chemo)RT (including BT) in AB were identified (by consultation date, January 1, 2013 - December 31, 2015). Descriptive statistics were performed on demographic and clinicopathologic data. The Kaplan Meier method was used to determine overall survival (OS) and cause-specific survival (CSS). Results Over 3 years, 146 women received radical RT including BT in AB (2 tertiary cancer centres, 2:1 spread). Annual caseload was 52 and 55 for 2013 and 2014, respectively; less (39) for 2015. Over half (54.5%) lived within 50 km of their treatment centre, with 20 women residing > 350 km (one > 1000 km) away. Among AB residents (n=140), 32.1% lived in areas designated rural and/or remote (AB Health community profile). Mean age at diagnosis was 52.4 years. Only 19.2% reported a routine Pap smear within 2 years of CC diagnosis; 8.2% had never had a Pap and 24.7%, not in

described in table 1, only differentiation grade differed significantly between AC and SCC. In 8 SCC patients, surgery was not performed due to remaining unresectable disease after NA-CRT, they were considered as lack of pathological complete response (pCR). Adenocarcinoma patients treated with NA-CRT showed significantly less pCR compared with SCC patients (AC=10.5%, SCC=39%, p=0.017) (table 1). Per FIGO stage, 5y OS and DSS was 100%/72%/50%/50% (p=0.012) and 100%/85%/57%/50% (p=0.005), for stage I/II/III/IV respectively. Per TNM stage, 5y-OS and DSS was 100%/75%/63%/69% (p=0.519) and 100%/90%/71%/69% (p=0.258) for stage I/II/III/IV respectively. Five-year OS and DSS were 80%/67% (p=0.285) and 80%/78% (p=0.816) for AC/SCC, respectively. Relapse pattern was not different between AC and SCC (table 1). Five-year locoregional relapse free survival (LRRFS) and DMFS (including distant nodal relapse) were 100%/83% (p=0.093) and 52%/81% (p=0.024) for AC/SCC, respectively. In AC, 2/6 patients metastasized in an oligometastatic way, 59m and 62m after treatment and were treated according to an oligometastasis protocol.

Conclusion Patients with AC responded significantly less to NA-CRT as evidenced by a significantly lower pCR rate. After surgery, however, this did not result in a worse LRRFS for AC. AC patients had a significantly lower DMFS but this did not translate into a worse OS or DSS. These findings imply a need for a paradigm shift in the treatment of AC patients. EP-1506 Multi-institutional treatment and management of cervical cancer patients A. Tsikkinis 1 , N. Cihoric 1 , E. Vlaskou Badra 1 , D. Aebersold 1 , K. Lössl 1 1 Inselspital- Universität Bern, Radiation-Oncology, Bern, Switzerland Purpose or Objective Evaluation of treatment outcome, toxicity and patterns of failure in cervical cancer patients (pts) treated with image guided external beam radio(chemo)therapy (IG-EBRcT)