ESTRO 38 Abstract book

S806 ESTRO 38

para-aortic lymph node had a non-significant trend towards worse OS (54.7% vs 91.3%, p=0.06) and DMFS (75% vs 90.8%, p=0.06)). Patients with a PET-CT MTV<24 cc had a better 3-y OS when comparing with MTV >24 cc (85% vs 56%, p=0.009). Pretreatment SUVmax did not influence outcome. Early 18 F-FDG PET/CT-based response assessment using the EORTC criteria was not correlated with disease control (3-y OS and LRFS), although patients with SUVmax < 5 had a non-significant trend towards better 3-y LRFS? ( 91% vs 78%, pNS). Conclusion In our series pretreatment PET-CT MTV was a good predictor of OS. Owing the high NPV observed in our study, a para-aortic lymphadenectomy can be avoided in patients with negative para-aortic 18F-FDG PET/CT. In our experience, early 18 F-FDG PET/CT-based response assessment before IGBT was not useful in predicting outcome. EP-1488 Treatment of early stage intermediate-risk endometrial cancer using MIS and adjuvant radiotherapy J. Song 1 , T. Le 2 , M. Gaudet 1 , C. Ee 1 , K. Lupe 1 , R. Samant 1 1 The Ottawa Hospital, Radiation Oncology, Ottawa, Canada ; 2 The Ottawa Hospital, Gynecologic Oncology, Ottawa, Canada Purpose or Objective Modern series of technical skills in minimally invasive surgery (MIS) using robotic arm for total abdominal hysterectomy and bilateral salpingo-oophorectomy (TAH- BSO) have resulted in improvement in patient outcome with less postoperative complications in patients with endometrial cancer. MIS has been increasingly used since its introduction in 2010 at our institution. Randomized prospective studies have shown that adjuvant radiotherapy (RT) following TAH-BSO significantly improves loco-regional control among stage I intermediate-risk patients. Our study aims to elucidate the current use and efficacy of MIS using robotic arm and adjuvant RT among these patients at our institution. Material and Methods A single-center retrospective study was conducted on patients with FIGO stage I endometrioid-type endometrial cancer with intermediate risk factors as defined by PORTEC-1 (<50% myometrial involvement and Grade 2-3, or >50% myometrial involvement Grade 1-2), who have undergone TAH-BSO and adjuvant RT at our institution between 2010 and 2015. Data on surgical and radiation treatments, as well as patient and tumor characteristics were collected and correlated with clinical outcomes. Statistical analysis was carried out using Kaplan-Meier method to compare clinical outcomes to previously reported studies. Results A total of 179 stage I intermediate-risk endometrial cancer patients were identified and 135 (75.4%) patients who received adjuvant RT were selected for study. Median age at diagnosis was 63 years (range 40-89 years) and median follow-up was 4.4 years. Surgical staging was performed with pelvic lymph node dissection on 107 (79.3%) patients, while 94 (69.6%) and 41 (30.4%) patients underwent MIS and traditional laparotomy, respectively. Twenty-eight (20.7%) patients received external beam radiotherapy (EBRT, 45Gy in 25 fractions) in the form of intensity- modulated radiotherapy (IMRT) and 107 (79.3%) patients received vaginal brachytherapy (VBT, 30Gy in 3 fractions). Five-year disease-free survival and overall survival rates were 92.8% and 94.8%, respectively. Estimated 5-year loco-regional relapse rate (vaginal, pelvic, or both) was 2.3%. Conclusion Clinical outcomes for stage I intermediate-risk endometrial cancer at our institution remain excellent with few loco-regional recurrences, and are comparable

Conclusion HPV genotype 16 positivity shows higher complete response in Cervical Carcinoma patients treated with Definitive Chemo Radiation compared to HPV 18 genotype. Further, HPV genotyping could potentially help to stratify cervical cancer patients for more effective therapeutic regimens EP-1487 Prognostic value of 18F-FDG PET/CT parameters in patients with locally advanced cervical carcinoma S. Cordoba Largo 1 , V. Garcia Jarabo 1 , D. Martinez 1 , M. Ramirez 1 , M. Gaztañaga Boronat 1 , C. De la Fuente 2 , G. Marquina 1 , A. Ortega 1 , R. Mendez 1 1 Hospital Clinico San Carlos, radiation Oncology, Madrid, Spain ; 2 Hospital Universitario Puerta de Hierro, radiation ONcology, Madrid, Spain Purpose or Objective To investigate the value of pretreatment intensity-based 18F-FDG PET/CT parameters as predictors of outcome and para-aortic lymph node involvement in patients with locally advanced cervical carcinoma (LACC) treated with concurrent external beam radiotherapy and chemotherapy (CRT) followed by image-guided brachytherapy (IGBT-MRI). Material and Methods From November 2010 to February 2016 we treated 65 patients with stages IB-III cervical carcinoma. Mean age: 54.6 y (30-88). TNM stage: I: 4 p, II: 54 p and III: 6 p. Histology: epidermoid: 49 p; adenocarcinoma: 15 p. All patients were treated with CRT and 3D-based planning intracavitary/interstiticial IGBT, using the GEC-ESTRO recommendations for defining high-risk clinical target volume (HR-CTV). Equieffective doses at 2 Gy (EQD2) were calculated, applying linear quadratic model. In 34 p. (45%) a laparoscopic para-aortic lymphadenectomy was performed before treatment. In all patients a pretreatment 18 F-FDG PET/CT was performed to determine the metabolic tumoral volume (MTV) and tumor standardized uptake value (SUVmax). In 56 p (87%) a second 18 F-FDG PET/CT before IGBT were used to classify patients as metabolic responders (MR) or non- metabolic responders (nonMR) according to the EORTC criteria. Statistics: Student´s T test for media comparison, chi- square test for comparing proportions and Kaplan Meier for survival analysis and log-rank for curve comparison. Results After median follow-up of 30 months (10-90), 3-year overall survival (OS), 3-year disease-free survival (DFS), local relapse-free survival (LCFS), pelvic relapse-free survival (PRFS) and distant metastases disease-free survival (DMFS) were 83.7%, 58%, 84.2%, 86.3% and 86.8%, respectively. Only 3/29 p with negative para-aortic PET/CT had pathologically involved nodes (negative predictive value, NPV: 89.6%). Treatment-related factors, D90/D98 HR-CTV and OTT, had no prognostic value. Patients with positive