ESTRO 2020 Abstract Book

S602 ESTRO 2020

from 2004-2016. Factors which influenced survival were queried with Kaplan-Meier and log-rank test and multivariable analysis conducted via Cox proportional hazards. Factors which influenced the utilization of lymphadenectomy were explored with bivariate regression analysis. Significance was set at p<0.05. Results Six hundred and eighteen cases were identified. Lymphadenectomy was utilized in 195 (31.6%) of patients with the peak utilization occurring in 2008 with 47.5% of cases including lymphadenectomy and minimal utilization occurring in 2015 with only 12.5% of cases including lymphadenectomy. Of the 195 women undergoing lymphadenectomy, 56 (28.7%) had positive lymph nodes. Median follow up was 19.2 months. Median survival of women with negative nodes was 28.6 months, 17.9 months if nodes were positive and 18.9 months if lymphadenectomy was not performed (p<0.001). Factors that has a positive effect on the utilization of lymphadenectomy included: younger age, earlier year of diagnosis, private insurance, residing in well-educated and higher-income areas, smaller tumor size, and negative tumor margins. The only factor significant for lymphadenectomy on multivariable analysis was younger age (p<0.001). Predictors of overall survival on univariable analysis included: younger age, private insurance, better performance status, negative margins, node negativity, radiation therapy and lymphadenectomy. On multivariable analysis, the only factors influencing survival were: age (HR 1.015/year [95%CI 1.004-1.026], p=0.006), positive margins (HR 1.313 [95%CI 1.012-1.702], p=0.040), and lymphadenectomy (HR 0.763 [95%CI 0.588-0.989], p=0.041). Conclusion These data suggest that systematic lymphadenectomy improves survival in women with vaginal melanoma. These findings should be confirmed with institutional-level data. PO-1143 Temporal course of late toxicity in patients undergoing pelvic radiation for cervical cancer J. Shejul 1 , S. Chopra 1 , N. Ranjan 1 , P. Patil 2 , L. Naidu 1 , S. Mehta 2 , U. Mahantshetty 1 1 Tata Memorial Center, Radiation Oncology, Mumbai, India ; 2 Tata Memorial Center, Medical Gastroenterology, Mumbai, India Purpose or Objective Chemo-radiation (CRT) and brachytherapy (BT) for cervix cancer is associated with small percentage of moderate to severe late toxicities. While crude incidence of late events is often reported, there is a limited information on the temporal course. The present study reports on the temporal course of late toxicities, response to therapeutic interventions and direct costs. Material and Methods Women with cervical cancer who underwent CRT and BT and developed late rectal and bladder toxicities between Jan 2014 to June 2017 were included. Grade of toxicity (CTCAE version 4.03) and type of intervention performed was recorded at every 3-month interval. Proportion of patients with grade I-IV toxicity at presentation, 12 and 24 months and change in severity over a period of time was calculated. Number of clinical interventions, need for inpatient admissions, response to intervention and direct cost of intervention was calculated using hospital procedure billing codes. Results Ninety-two patients were identified with late radiation toxicity. With a median follow up of 31 months (10- 144) the median time to develop toxicity was 12 (3 to 111) months. Grade I, II, III, IV toxicity was observed in 54%, 36%, 8% and 2% patients at first reporting. On an average,

patient spent 12 (3-27) months with symptoms of toxicity. At 12 months 48/92 (52.2%) had complete resolution of toxicity however, 27/92 (29.3%) patients continued to have low grade (I-II) persistent toxicity. Only 6 patients (6.5%) who had grade III-IV toxicity had resolution to a lower grade whereas seven (7.6%) had persistent grade ≥ III toxicity despite interventions. Four patients (4.3%) died due to toxicity. At 24 months, 10% patients continued to have grade ≥ III toxicity. A median of 7 (2-24) interventions were required for clinical management. Apart from dietary modifications and medical treatment, blood transfusions were needed in 43% patients. Up to 60% patients also required argon plasma coagulation (average 2 sessions). Inpatient admission was needed for 60% patients for a median of 7 days (7-56 days). Hyperbaric oxygen therapy (HBOT) (25- 40 sessions) was needed for 21.7% of patients and was associated with 90% symptom resolution Average cost of toxicity management was 800 (10-4700) Euros which is almost equivalent or greater than the cost of primary treatment within our subsidized institutional healthcare system. Conclusion Late radiation toxicity resolves within 12 months in >50% of patients. Patients with residual symptoms of late toxicity at 12 months are likely to have persistent symptoms or progression to higher grade and symptoms are less likely to resolve even with multiple interventions. The direct financial impact is substantial. Structured strategies for management of persistent late toxicities should be developed and investigated. PO-1144 Adjuvant electronic brachytherapy for patients with endometrial cancer. M. Cerrolaza 1 , A. Campos 1 , A. Méndez 1 , M. Gascón 1 , A. Miranda 1 , S. Flamarique 1 , S. Lozares 2 , V. Navarro 1 , R. Ibañez 1 1 Hospital Universitario Miguel Servet, Servicio de Oncología Radioterápica, Zaragoza, Spain ; 2 Hospital Universitario Miguel Servet, Servicio de Radiofísica, Zaragoza, Spain Purpose or Objective Brachytherapy plays a fundamental role in the adjuvant treatment of endometrial cancer as almost every recurrence appears in the vaginal cuff. Traditionally HDR intracavitary brachytherapy with Iridium 192 had been used for this use, but the recent development of electronic brachytherapy based on X-ray emissions has important advantages over this one. Our main objective has been to know the local control of electronic brachytherapy (EBT) in endometrial cancer, to know the toxicity profile and to compare with series from the literature with HDR IR-192 brachytherapy. Material and Methods 193 patients with endometrial cancer were retrospectively analyzed from September 2015 to May 2019 treated with electronic brachytherapy at the Miguel Servet University Hospital. The total dose was 15 Gy in 3 fractions or 14 Gy in 2 for brachytherapy complementary to external radiotherapy; and 25 Gy in 5 fractions or 21 Gy in 3 fractions for exclusive brachytherapy. Acute and late toxicities were recorded by CTCAE v 4.0 criteria. Results The average age of the patients at diagnosis was 66.8 years and 74% diagnosed as endometrioid carcinoma (Type I). According to the FIGO classification, 38% were FIGO IB and the majority histopathological differentiation Grade was grade 2 with 40% observed. Some type of lymphadenectomy performed in 60% of the patients and 34% received adjuvant chemotherapy and 56% external radiotherapy. Mucosal toxicity was observed in 33.68% of the patients, urinary toxicity in 11.4% and rectal toxicity in 14%. All of them were Grade 1 toxicities except in 2 patients who presented Grade 2 acute mucosal toxicity