ESTRO 2020 Abstract Book

S595 ESTRO 2020

Material and Methods From April 2014 to May 2019 63 patients were treated with post-operative IMRT for gynecological neoplasms. 44 had endometrial carcinoma (EC), with the following FIGO Staging: IB in 20, II in7, IIIC in 14, 21 patients had cervical cancer (CC); according to FIGO staging they were: IB2 in 9 cases, IIB in 6, IIIC in 6 cases. The most frequent histological subtypes were for EC: adenocarcinoma in 42, serous cells carcinoma in 1 and carcinosarcoma in 1; for CC squamous cell was detected in 13, while adenocarcinoma in 8. A median total dose of 50 Gy (range, 45-50.4 Gy) was delivered with IG-IMRT (VMAT or Helical Tomotherapy), including the para-aortic field in 6 patients (respectively 3 EC and 3 CC). Platinum-based chemotherapy was sequentially administered in 15 EC cases, and concurrently in 18 CC patients. Acute and late toxicity was assessed using CTCAE v4.0, time-to-event data was analysed using Kaplan-Meier and log-rank test. Chi-squared test was used to evaluate potential associated risk factors for late G≥2 adverse events. Results Median age was 60 years (33-86). All patients completed the treatment as planned, with acute G2 toxicity rates of 22% and 14% respectively for gastrointestinal (GI) and genitourinary (GI), and no evidence of G3 events. Median follow-up was 19 months (6-47). Late G≥2 toxicity incidence was 1.5% for GI and 3.1% for GU at 1 year, while 2.3% and 2.7% at 2 years. Only one case of G3 late adverse event was observed, consisting of a hemorrhagic cystitis requiring hospitalization after 27 months from the end of RT. At statistical analysis we investigated the following dosimetric parameters as potential predictors of late G≥2 toxicity: bowel V15Gy, V25Gy and V40Gy, and for both rectum and bladder Dmax, Dmean, Davg. No significant correlation was found. Concerning clinical outcomes, our progression free survival rates were both 73% at 2- and 3- years for EC and of 74% and 68% for CC. The most frequent site of progression was the lung. 10 patients died by progressive disease, with 2- and 3-years overall survival (OS) rates of 76% and 72% for EC and of 72% and 62% for CC. For both EC and CC the log-rank test revealed no factors significantly related to PFS or OS. Conclusion Our experience supports the use of IG-IMRT for the post- operative treatment of EC and CC, since it leads to a very low incidence of severe adverse events. Furthermore, our preliminary results in terms of clinical outcomes are promising and long-term updates are warranted. PO-1128 Oncologic outcomes of cervical cancer using FIGO 2018 staging in the era of modern radiation therapy R. Dejean 1 , M. Nourmoussavi 2 , H. Bahig 1 , T. Warkus 2 , V. Samouelian 2 , B. Cormier 2 , M. Beauchemin 1 , M. Barkati 1 1 Centre Hospitalier de l'Université de Montréal, Radiation Oncology, Montréal, Canada ; 2 Centre Hospitalier de l'Université de Montréal, Gynecologic Oncology, Montréal, Canada Purpose or Objective Imaging was recently incorporated in the new FIGO 2018 cervical cancer staging, which now includes nodal disease (IIIC). We sought to evaluate the outcomes and patterns of recurrence using FIGO 2018 staging in a cohort of patients treated in an era of high precision image-guided radiotherapy. Material and Methods We carried out a retrospective database review of 196 patients treated at a single institution from 2011 to 2018. All had pre-treatment MRI and PET scans and were treated with concurrent chemoradiation using intensity-modulated radiotherapy and 3D-image guided brachytherapy. Previously assigned 2009 FIGO staging and all imaging were reviewed for FIGO 2018 reclassification. Kaplan-Meier survival curves and Log-Rank test were performed.

performed for such cases in almost half of the institutes in Japan because of rare severe toxicities. Therefore, this study was meaningful, although it was a retrospective single institute experience. Material and Methods Consecutive patients who were treated with pelvic radiotherapy using VMAT for postoperative uterine cervical cancer in our institute were enrolled in this study. Patients treated with cervical conization or patients who had already relapsed before radiotherapy were not regarded as patients in a postoperative setting. Time to an event was calculated from the day of surgery. Relapse-free survival (RFS) and overall survival (OS) were calculated using the Kaplan–Meier estimator and Cox proportional hazard model was used to evaluate prognostic factors. Results Sixty-two patients were identified. Fifty-eight patients received radical hysterectomy, 4 patients received total hysterectomy and 19 patients received ovarian transposition. The pathology was squamous cell carcinoma in 44 patients, adenocarcinoma in 11 patients and other pathology in 7 patients. Thirty-four patients had high-risk prognostic factors: parametrial invasion in 15 patients, positive pelvic lymph nodes in 28 patients and positive surgical margins at the virginal cuff in 2 patients. Twenty- seven patients had only intermediate-risk factors. The prescribed radiation doses were 50 Gy in 25 fractions for 58 patients and 50.4 Gy in 28 fractions for 4 patients. Only one patient received a virginal cuff boost using intracavitary brachytherapy with 12 Gy in 2 fractions. Chemotherapy (typically weekly cisplatin at 40 mg/m2) were administered in 36 patients. The median follow-up period was 50.9 months and one patient died of primary disease. There was no loco- regional failure. Six patients in the high-risk group relapsed, but none of the patients in the intermediate-risk group relapsed (p=0.02). The 3-year OS and RFS rates were 98.2% and 90.9%, respectively, and the 5-year OS and RFS rates were 98.2% and 87.7%, respectively. Prognostic factors of RFS were squamous cell carcinoma pathology (HR: 0.080, p=0.02), multiple pelvic lymph node metastases (HR: 14.8, p=0.02) and positive surgical margin (HR: 230, p<0.01). Grade 3 or more toxicity occurred in 6 patients. Four patients had obstruction of the intestine and 2 patients had stenosis of the urinary tract. Ovarian function was maintained in 8 of 19 patients who received ovarian transposition. Conclusion In clinical practice, pelvic radiotherapy for postoperative uterine cervical cancer using the VMAT technique showed perfect loco-regional control and a good RFS rate with a relatively low rate of severe toxicity. The maintenance of ovarian function needs further investigation. PO-1127 Acute and late toxicity report of post- operative IG-IMRT for gynecological malignancies M. La Vecchia 1 , F. Cuccia 1 , G. Ferrera 2 , G. Mortellaro 2 , D. Cespuglio 2 , L. Ognibene 3 , G. De Gregorio 1 , N. Luca 1 , G. Trapani 1 , E. Quartuccio 1 , A. Gioia 1 , A. Palmeri 1 , G. Terranova 1 , G. Napoli 1 , A. Sanfratello 1 , C. Lotà 1 , M. Torchia 1 , V. Venuti 1 , V. Valenti 1 , A. Tripoli 1 , G. Evangelista 2 , A. Lo Casto 4 1 University of Palermo, Radiation Oncology School, Palermo, Italy ; 2 ARNAS Civico Hospital, Radiation Oncology Unit, Palermo, Italy ; 3 San Gaetano Radiotherapy and Nuclear Medicine Center, Radiotherapy Unit, Bagheria- Palermo, Italy ; 4 University of Palermo, Radiation Oncology School- Section of Radiology - Di.Bi.Med., Palermo, Italy Purpose or Objective To retrospectively investigate acute and late toxicity of post-operative image-guided/intensity modulated radiotherapy (IG-IMRT) for the treatment of endometrial and cervical cancer.