ESTRO 38 Abstract book

S804 ESTRO 38

IIA1, 6/67 stage IIA2 and 32/67 stage IIB. Mean SBRT V100 was 95.3% (range, 75.0-99.8%), and mean total equivalent effective doses (EQD2) to 2 cc of bladder and rectum were 72.91 and 64.86 Gy, respectively. Post-SBRT complete response rate was 94.0% at 3 months for all patients based on clinical assessment with or without biopsy; among patients who underwent planned biopsy at 3 months, 52 of 55 demonstrated complete pathologic response. At 5 years, estimated local control at the SBRT boost site is 90.8% for all patients. Estimated failure-free survival and overall survival at 5 years are 83.1% and 74.7%, respectively. Two patients suffered grade 3 toxicities (urinary frequency, vaginal stenosis), and no patient experienced ≥ grade 3 bowel toxicity. Post-treatment FACT-G scores were available for 82% of cases and were statistically superior at 2 and 5 years compared to pre- treatment assessments for the following studied domains: physical, emotional and functional well-being. Conclusion At a median followup of 5 years, SBRT appears to offer an effective and well-tolerated boost modality for selected stage IA-IIB cervix cancer patients who were otherwise contraindicated for brachytherapy. EP-1484 Neoadjuvant CT followed by chemoradiation in locally advanced cancer cervix : feasibilityand QOLstudy S. Singh 1 , S. Sadhan Sarangi 1 , P. Misra 2 , D. Kapoor 3 , A. Rani 3 , N. Rastogi 1 , S. Kumar 4 1 Sanjay Gandhi Postgraduate Institute of Medical Sciences, Dept. of Radiotherapy, Lucknow UP, India ; 2 Sanjay Gandhi Postgraduate Institute of Medical Sciences, Dept. of Biostatistics, Lucknow UP, India ; 3 Sanjay Gandhi Postgraduate Institute of Medical Sciences, Dept. of Gynecology- General Hospital, Lucknow UP, India ; 4 Sanjay Gandhi Postgraduate Institute of Medical Sciences, Dept. of Radiotherapy- Super Speciality Cancer Institute and Hospital, Lucknow UP, India Purpose or Objective To assess feasibility, response rate and qulaity of life (QOL) in locally advanced cervical cancer patient treated by 3 weekly neoadjuvant chemotherapy (NACT) followed by chemoradiation (CCRT). Material and Methods Between April 2016 – March 2017, 30 cervical cancer patients, FIGO stage IB2 to IVA, histopathogically proven, eligible and consented for the prospective study were included. Patients received 2 cycles of NACT using Inj. paclitaxel 175mg/m 2 and Inj. cisplatin 35mg/m 2 or carbpoplatin AUC5 as 3 weekly schedule followed by definitive radiation therapy along with concurrent weekly cisplatin 35mg/m 2 or carboplatin AUC2 chemotherapy The primary end point was to assess feasibility of NACT and overall response at 3months post NACT-CCRT, toxicities, and QOL (using EORTC C30, CX 24 and OV 28 questionaires). Analysis were intention to treat. Results The median age was 53 years. 53% had FIGO stage III followed by stage II 40% with >50% having bulky disease. One fifth of patients had both regional and para aortic lymph nodes at presentation based on imaging criteria. 27/30 patients (90%) received planned 2 cycles of NACT while 3 received 1 cycle either due to side effects (n= 2) or administrative error (n=1). The overall clinical response rate post NACT was 76% with complete disappearance of disease seen in 1 patient (3%). 29/30 completed planned radiation treatment with 90% receiving concurrent chemotherapy with a median number of 5 cycles. At 3 months, post completion of all planned treatment 25/30 (84%) of patients had clinically complete disappearance of disease and 3(10%) had partial response using clinical and imaging findings. NACT was well tolerated with only 11% experiencing any grade 3/4 toxicities and no treatment-

86.2%, respectively. BED10 > 50Gy was correlated with a better 12-months local control (91.7% versus 72.9%, p=0.034).

Conclusion Preliminary results on a population-level confirm that SBRT delivered in 1-10 consecutive fractions is safe and well tolerated notwithstanding several previous surgical and systemic treatments. Therefore, this treatment can be considered as a further resource in order to lengthen the free time of re-challege with platinum. EP-1483 Stereotactic Body Radiation Therapy Boost for Stage IA - IIB Cancers of the Cervix: 5-Year Results S. Dalwadi 1 , M. Ludwig 1 , N. Waheed 1 , D. Tran 1 , M. Bonnen 1 , C. Mantz 2 1 Baylor College of Medicine, Radiation Oncology, Houston, USA ; 2 21st Century Oncology, Radiation Oncology, Fort Myers, USA Purpose or Objective SBRT for cancers of the cervix may offer an alternative to brachytherapy for those patients who are not candidates for brachytherapy procedures. SBRT dose-fractionation schedules may be selected to approximate those of HDR in order to achieve similar radiobiologic dosing, while SBRT technique eliminates the need for applicator placement and sedation. Herein, we report health-related quality of life, toxicity and disease control outcomes of a multi- institutional series of SBRT for primary cervical cancers. Material and Methods Eligible patients included those with (1) pathologically confirmed cervical squamous cell carcinoma or adenocarcinoma; (2) FIGO stage IA, IB, IIA or IIB disease; and (3) medical or technical contraindication to brachytherapy or patient refusal of brachytherapy. Prior to SBRT, all patients received pelvic EBRT to a prescribed dose of 45.0-50.4 Gy; pelvic nodal boost (total EBRT dose, 55.9-66.0 Gy) was permitted. All patients received cisplatin-based chemotherapy concurrent with EBRT. SBRT boost treatment planning then followed, and HR-CTV delineation was aided by co-registration of the boost planning CT to a post-EBRT MRI. A boost dose of 14.0-40.0 Gy was prescribed to the post-EBRT HR-CTV and delivered over 4-5 fractions. Assessments included (1) disease response assessed through post-treatment surveillance per institutional protocol; (2) acute and chronic toxicities assessed using the U.S. National Cancer Institute's CTCAE v3 toxicity scales; and (3) quality-of-life scored using FACT-G measurements. Results Sixty-seven patients have been treated since June 2007 and have been followed for a median of 60 months (range, 5-120 months). Forty patients have been followed for a minimum of 5 years. Stage distribution was as follows: 2/67 stage IA, 6/67 stage IB1, 18/67 stage IB2, 3/67 stage