ESTRO 2021 Abstract Book

S1071

ESTRO 2021

study, 2 p presented disease progression; 1 p died from another cause, the rest are still alive in the sarcoma group; and 9 p presented disease progression and 7 p have died from a specific cause in the gynecologic group. Conclusion In the present series, salvage surgery and IOERT offered good long-term local control and with low rate of severe late complications, especially in patients with retroperitoneal sarcoma. PO-1303 FDG-PET/CT AND MRI in the radiotherapy treatment planning of locally advanced cervix cancer R. Autorino 1 , V. Lancellotta 1 , M. Campitelli 1 , A. Nardangeli 1 , M.G. Ferrandina 2 , N. Bizzarri 3 , B. Gui 4 , V. Rufini 5 , M. Ferioli 6 , L. Tagliaferri 1 , G. Macchia 7 , M.A. Gambacorta 1 1 UOC Radioterapia Oncologica, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario “A. Gemelli” IRCCS, Rome, Italy; 2 Ginecologia Oncologica, Department of Woman and Child Health and Public Health, Woman Health Area, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy; 3 Ginecologia oncologica, Department of Woman and Child Health and Public Health, Woman Health Area, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy; 4 Radiologia, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario “A. Gemelli” IRCCS, Rome, Italy; 5 Medicina Nucleare, Dipartimento di Diagnostica per Immagini, Radioterapia Oncologica ed Ematologia, Fondazione Policlinico Universitario “A. Gemelli” IRCCS, Rome, Italy; 6 Radiation Oncology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy; 7 Radiation Oncology Unit, Gemelli Molise Hospital, Università Cattolica del Sacro Cuore, Campobasso, Italy Purpose or Objective The established standard of care for advanced cervix cancer is cisplatin-based chemo-radiotherapy followed by interventional radiotherapy (brachytherapy). Pelvic magnetic resonance imaging (MRI) and 18- Fluorodeoxyglucose positron emission tomography (18F-FDG PET/CT) represent the most frequently used imaging techniques for thr staging: MRI for assessing the response of the primary tumor and 18F-FDG PET/CT for the assessment of the metastases. Our study assessed the impact of 18FDG-PET/CT and pelvic MRI on the radiotherapy contouring and the lymphatic spread detection resulting in the personalization of Clinical Target Volume (CTV) and dose prescription. Materials and Methods We retrospectively analyzed the clinical data of all patients with CC treated between January 2019 and December 2020. Eight-four patients with histologically proven squamous cell carcinoma of the cervix were analyzed. We discussed all patients in a multidisciplinary team composed of a radiation oncologist, medical oncologist, radiologist, gynecologist, and pathologist. Furthermore, we evaluated all patients with history, physical examination, biopsy, pelvic MRI and 18FDG-PET/CT, and we contoured on computed tomography (CT), MRI, and 18FDG-PET/CT fused images. Results The concordance between MRI and 18FDG-PET/CT in the definition of the positive lymph nodes was 65.5% (55 patients). The 18FDG-PET/CT showed positive lymph nodes not detected on MRI imaging (PET +, MRI-) in 15/84 patients (17.8%). Only in two cases (2.3%), MRI showed positive lymph nodes not detected by 18FDG-PET/CT (18FDG-PET/CT-, MRI+). In 12 patients (14.2%), 18FDG-PET/CT findings avoided a dose escalation of nodes considered positive on the MRI. The 18FDG-PET/CT led to changing the stage in 3/84 (3.6%) cases: 1 case from N0 to N1 and two patients from N1 to N0. Conclusion Present results showed that the combination of 18FDG-PET/CT and pelvic MRI in radiotherapy contouring is essential because of the relevant impact in staging and target volume delineation patients affected by advanced cervix cancer. Regarding lymph-nodes assessment, 18F-FDG PET/CT seems to be superior to pelvic MRI in the detection of the positive lymph-nodes. PO-1304 Acute hematological and metabolical side effects of chemoradiotherapy for inoperabl cervical cancer E.D. Nasuhbeyoglu 1 , S. Alanyali 2 , B.A. Aras 2 , Z. Ozsaran 2 1 Kahramanmaras Necip Fazıl City Hospital, Radiation Oncology, Kahramanmaras, Turkey; 2 Ege University Faculty of Medicine, Radiation Oncology, Izmir, Turkey Purpose or Objective Our aim for this study was to evaluate detailed acute hematological and acute metabolical side effects and toxicity associated risk factors of chemoradiotherapy (CRT) for inoperabl cervical cancer . Materials and Methods A total of 209 inoperabl cervical cancer patients were treated with CRT between 2005 and 2015 in Ege University Faculty of Medicine Department of Radiation Oncology were analyzed. Acute hematological and metabolical side effects were assesed according to Common Terminology Criteria of Advers Events Version 5 (CTCAEv.5) . Results Mean age was 55,9 years and elderly patients (≥65 years) were 43 (20,3%). Concurrent with radiotherapy weekly 40 mg/m 2 cisplatin was administered for 93% of patients and carboplatin 2AUC weekly was applied for 14 (7%) patients. The most common grade ≥3 acute side effects were found as hematological. Grade 3-4 leukopenia (37,8%) was the most common hematological side effect, followed by neutropenia (22%) , anemia (4,8%) and trombosytopenia (2,9%).Insidence of neutropenic fever was 1,9%. No grade 5 acute hematological side effect occured. Hemoglobin levels below 10 mg/dl, before the initiation of CRT , was associated with increased risk of neutropenic fever (p=0 .035; odds ratio [OR], 12.533 ;95% CI:1.647 to 95.361) and grade 3-4 hematotoxicity (p=0.022; [OR], 3.215 ;95% CI:1.139 to 9.075). The most common metabolic acute side effects was electrolyte abnormalities and hypomagnesemia was the most common abnormality (44,5%) followed by hypocalsemia(14,6%),hypocalemia (12,4%) and hyponatremia (11%). Grade ≥ 3 acute renal disorder not