ESTRO 2023 - Abstract Book

S19

Saturday 13 May

ESTRO 2023

of Medicine and Surgery and Translational Medicine, Roma, Italy; 8 Alma Mater Studiorum - Bologna University, Department of Experimental, Diagnostic and Specialty Medicine-DIMES, Bologna, Italy; 9 University Hospital Udine, Department of Radiation Oncology, Udine, Italy; 10 Ospedale degli Infermi, Radiation Oncology Department, Biella, Italy; 11 University of Florence, Radiation Oncology Unit, Oncology Department, Firenze, Italy; 12 Ospedale "Vito Fazzi", Radiotherapy Unit, Lecce, Italy; 13 Azienda Ospedaliera Universitaria Ospedali Riuniti, Radiation Oncology Unit, Ancona, Italy; 14 Fondazione "Casa Sollievo della Sofferenza", IRCCS, S. Giovanni Rotondo, UOC Radioterapia, Foggia, Italy; 15 Università Cattolica del Sacro Cuore, Istituto di Radiologia, Roma, Italy; 16 Università Cattolica del Sacro Cuore, Istituto di Radiologia, Roma, Italy; 17 Fondazione Policlinico Universitario Agostino Gemelli IRCCS, UOC Ginecologia Oncologica, Dipartimento Scienze della Salute della Donna e del Bambino, Roma, Italy Purpose or Objective This retrospective, multicenter study analyzes the efficacy and safety of stereotactic body radiotherapy in a large cohort of patients with oligometastatic/persistent/recurrent uterine cancer. Materials and Methods A standardized data collection from several radiotherapy centres that treated patients by stereotactic body radiotherapy between March 2006 and February 2022 was set up. Clinical and stereotactic body radiotherapy parameters were collected. The objective response rate was defined as a composite of complete and partial response, while clinical benefit included objective response rate plus stable disease. Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer and Common Terminology Criteria for Adverse Events scales were used to grade toxicities. The primary endpoints were the rate of complete response to stereotactic body radiotherapy, and the 2-year actuarial local control rate on a 'per lesion' basis. The secondary endpoints were progression-free survival and overall survival, as well as toxicity. Results A total of 157 patients with oligometastatic/persistent/recurrent uterine cancer-bearing 272 lesions treated by stereotactic body radiotherapy at 14 different centers were selected for analysis. Of the sites of metastatic disease, lymph node metastases (137, 50.4%) were most common, followed by parenchyma lesions (135, 49.6%). The median total dose was 35 Gy (range 10-75.2), in five fractions (range 1-10). Complete and partial responses were found in 174 (64.0%), and 54 (19.9%), respectively. Stable disease was registered in 29(10.6%), while 15 (5.5%) lesions progressed. Patients achieving complete response on a 'per lesion' basis experienced a 2-year actuarial local control rate of 92.4% versus 33.5% in lesions not achieving complete response (p<0.001). There was not a statistically significative difference in terms of actuarial local control rate between nodal and parenchymal lesions. There were 58 acute toxicities reported, the most of which were minor (Grade 1 and Grade 2), and four of which were severe (two Grade 3 pain, one Grade 4 pain, and one toxic death due to gastric perforation). Conclusion Our analysis confirmed the efficacy of stereotactic body radiotherapy in oligometastatic/persistent/recurrent uterine cancer patients. The low toxicity profile and the high local control rate in complete responder patients encourage the wider use of stereotactic body radiotherapy in this setting. MO-0052 Vulvar cancer exclusive radiotherapy (OLDLADY 1.1): AIRO GYN, MITO AND MaNGO GROUPS Cooperation L. Tagliaferri 1,1 , V. Lancellotta 1 , M. Ferioli 2 , C. Casà 3 , B. Pappalardi 4 , C.T. Delli Curti 5 , C. Laliscia 6 , M. Boccardi 7 , F. Tortoreto 3 , G. Garganese 8 , G. Ferrandina 9 , M.A. Gambacorta 1 , A.G. Morganti 2 1 Fondazione Policlinico Universitario A. Gemelli IRCCS, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Rome, Italy; 2 Alma Mater Studiorum University of Bologna, Department of Experimental, Diagnostic and Specialty Medicine – DIMES, Bologna, Italy; 3 Fatebenefratelli Isola Tiberina - Gemelli Isola, U.O.C. di Radioterapia Oncologica, Rome, Italy; 4 Fondazione IRCCS Istituto Nazionale dei Tumori, Radiotherapy Unit, Milan, Italy; 5 Fondazione IRCCS Istituto Nazionale dei Tumor, Radiotherapy Unit, Milan, Italy; 6 University of Pisa, Department of New Technologies and Translational Research, Division of Radiation Oncology, Pisa, Italy; 7 Gemelli Molise Hospital – Università Cattolica del Sacro Cuore, Radiation Oncology Unit, Campobasso, Italy; 8 Università Cattolica del Sacro Cuore, Dipartimento Universitario Scienze della Vita e Sanità Pubblica - Sezione di Ginecologia ed Ostetricia , Rome, Italy; 9 Università Cattolica del Sacro Cuore, Dipartimento Universitario Scienze della Vita e Sanità Pubblica - Sezione di Ginecologia ed Ostetricia , Rome, Italy Purpose or Objective Vulvar cancer (VC) is a relatively uncommon type of gynaecologic cancer. VC patients require multidisciplinary evaluation for primary surgery and inguinal lymph node assessment, and potentially adjuvant radiation and/or chemotherapy [4-7]. Radiotherapy (RT) and/or chemotherapy may be considered for primary treatment instead of surgery in cases that would otherwise require radical surgery such as abdominal-perineal resection or exenterative procedures. The aim of this study was to define efficacy and safety of exclusive radiotherapy (RT) +/- chemotherapy in a large, real-world data set of patients Data was obtained retrospectively from VC patients treated with RT in seven Italian Radiation Oncology Centers between January 2010 and December 2021. All patients underwent radiotherapy (45 Gy external-beam radiotherapy/1.8 Gy per fraction) +/- chemotherapy on the pelvic area plus overdosage on gross tumor volume (GTV) and positive nodes. The primary study endpoint was the local control (LC), secondary endpoints were metastases free survival (MFS), overall survival (OS), and the rate and severity of acute toxicities. Results A total of 80 patients were included in the analysis, with a median age of 73.5 years (range 32-89). Thirty-five patients received a total dose ≥ 70Gy and 45 patients a total dose <70Gy (range 60-66Gy) on the GTV. On positive nodes, 44 patients got a total dose > 65 Gy and 27 patients received a total dose ranging between 45-60 Gy. Nine, twelve, forty-five and fourteen patients were Stage I, II, III and IV, respectively. Sixty-six patients (82.5%) and sixty (87.5%), respectively, achieved tumor and nodal full remission. With a median follow-up of 11 months (range 1-114 months), the 24-month actuarial LC rate, MFS and OS were 49%, 79.8%, and 53.8%, respectively. Acute toxicity was registered in 69 patients, with sixteen and ten cases of proctitis G1 and G2, respectively; twelve, eighteen, and one case of cystitis G1, G2, and G3; and five, forty- one, and twenty cases of skin toxicity G1, G2, and G3, respectively. Three and five patients, respectively, had lymphedema G1 and G2. with vulvar cancer (VC). Materials and Methods