ESTRO 2020 Abstract Book

S1101 ESTRO 2020

Session: Rectum, Skin & Breast

Edmonton, Canada ; 9 Postgraduate Institute of Medical Education and Research, Department of Radiotherapy and Oncology, Chandigarh, India ; 10 St James's University Hospital, Leeds Cancer Centre, Leeds, United Kingdom ; 11 Radiotherapiegroep Arnhem, Department of Radiotherapy, Arnhem, The Netherlands ; 12 UZ Leuven, Department of Radiation Oncology, Leuven, Belgium ; 13 Amsterdam University Medical Centers- Academic Medical Center- University of Amsterdam, Department of Radiation Oncology, Amsterdam, The Netherlands ; 14 Addenbrooke´s Hospital- Cambridge University Hospitals, Department of Oncology, Cambridge, United Kingdom ; 15 Erasmus MC, Department of Radiotherapy, Rotterdam, The Netherlands ; 16 University Medical Centre Utrecht, Department of Radiation Oncology, Utrecht, The Netherlands ; 17 EMBRACE Collaborative Group, EMBRACE Collaborative Group, EMBRACE Collaborative Group, Austria Purpose or Objective To report local outcome from the prospective observational multi-centre IntErnational study on MRI- guided BRAchytherapy in locally advanced CErvical Cancer (EMBRACE) Material and Methods Data from 1416 patients with locally advanced cervical cancer treated from 2008-2015 in 23 centres was prospectively collected. Treatment consisted of external beam radiotherapy with 45-50Gy (1.8-2.0 Gy per fraction), concomitant chemotherapy and MRI based image-guided adaptive brachytherapy. Brachytherapy target volumes, organs at risk contouring and dose volume parameter reporting were based on the GEC-ESTRO recommendations. Radiation doses for brachytherapy were according to institutional policy. A structured follow-up (FU) program with 3 months intervals for the first year, 6 months intervals for the second and third year and yearly intervals thereafter was applied. A local failure (LF) was defined as progressive or recurrent disease in the uterus, parametria or vagina. Local control and overall survival rates were calculated by the Kaplan-Meier method. Results 1318 patients with a median FU time of 51 months were available for this analysis. 98 patients were excluded because of wrong selection or missing data. 80 patients had persistent disease three months after end of treatment. Of those patients, 60 achieved local control at 6-9 months without further treatment (slow responders - SR), whereas 20 patients developed progressive disease. In addition, 78 patients developed a local recurrence after complete remission comprising a total number of 98 LF overall. The 3yr/5yr local control rate was 92%/92% (FIGO IB1: 98%/98% IB2: 93%,92% IIA: 90%/90%, IIB: 92%/91%, IIIA: 100%/100%, IIIB:91%/91%, IVA: 91%/91%, IVB: 92%/89%). 73% of LF were observed in a planned FU within 24 months after treatment. 48% of LF had simultaneous nodal or systemic disease. LFs were located inside the brachytherapy target volumes in 89% of the cases. Median survival after LF was 10 months (1yr/3yr overall survival: 48%/13%), whereas SR had a 3yr/5yr local control and overall survival rate of 98%/91% and 82%/75%, respectively. Conclusion MRI-based image guided adaptive brachytherapy leads to excellent local control among all stages. 75% of patients with persistent disease at three months achieve complete remission without further treatment and without impaired outcome in comparison to the overall cohort of patients. Patients with LF have poor outcome. Therefore, optimal primary treatment is of utmost importance.

OC-1053 Interstitial brachytherapy in non-melanoma skin cancer. Results of an expert center. G. Antelo-redondo 1 , J. Gonzalez Vigueras 2 , I. Visus Fernández de Manzanos 2 , D. Najjari Jamal 2 , A. Slocker Escarpa 2 , H. Pérez Montero 2 , I. Linares Galiano 2 , R. Gracia Lucio 2 , F. Guedea Edo 2 , C. Gutiérrez Miguélez 2 1 Institut Catalá de Oncologia- Hospital Germans Trias i Pujol, Oncologia radioterapica, Badalona, Spain ; 2 Institut Catalá de Oncologia, Radiation Oncology, Hospitalet de Llobregat, Spain Purpose or Objective To analise our experience with skin brachytherapy in our department. Since the beginning of our activity in 1989, more than 16,000 brachytherapies have been performed. 273 have been skin implants, about 20 patients per year. The procedures are done following the ACROP ESTRO guidelines and the recommendations of the Spanish A representative sample of patients diagnosed with non- melanoma skin cancer (squamous and basal cell carcinoma) treated at our brachytherapy unit between 2014 and 2017 have been reviewed. A series of 65 patients have been studied, most treated with interstitial brachytherapy (83.1%) and the minority with plesiotherapy (15.4%). Doses were 45-50 Gy in 10 fractions depending if the intention was radical (15.4%) or complementary to surgery (76.9%). 5 patients (7.7%) were treated for relapses. All patients except 1 were treated with HDR, 2- 3 times per day, with an interval of at least 6 hours between fractions. Statistical analysis was calculated by using the Kaplan-Meier method. brachytherapy group. Material and Methods Picture: Nose implant (left), after treatment (right). Results Descriptive data of the sample are described in the attached table. A median follow-up of 33 was reached, there were 11 local recivides and 3 ganglionar progression. Mean treated volume was 7,78 cc (0,95-47,31). Local control was 90.5% at 1 year and 84.9% at 2 years, with an average of local control of 50.2 months. Ganglionar progression-free survival was 95.2% at 1 and 2 years, with an average of 56.6 months of PFS. Overall survival was 83% at 2 years, and 68.4% at 5 years, an average of 48.16 months, without being able to reach the median of OS. The exclusion of intercurrent deaths allows to obtain the specific survival (SS) which was of 95,2% at 1 year, at 5 years it is estimated 91.4%, average 56.0 months, also, without having achieved a median SS. The toxicity reported does not show any grade 3 or 4 as to acute or chronic toxicity, the most frequent sequelae were achromia and telangiectasia, in 41.5% and 23.1% of the patients, respectively, and less frequent were alopecia in 9.2% of the patients, 7.7% showed hyperchromia and button hollow. Acute toxicity, as radiodermatitis, was observed in 43.1% of the patients.