ESTRO 36 Abstract Book

S690 ESTRO 36 2017 _______________________________________________________________________________________________

Oncology, Vienna, Austria 2 Medical University of Vienna, Department of Radiotherapy, Vienna, Austria

patient counselling and deciding on follow-up strategies

EP-1300 Stereotactic radiotherapy for oligometastatic ovarian cancer patients: preliminary results. S. Ronchi 1 , R. Lazzari 2 , A. Surgo 2 , S. Volpe 1 , S. Comi 3 , F. Pansini 3 , E. Rondi 3 , C. Fodor 2 , R. Orecchia 4 , B.A. Jereczek-Fossa 1 1 Istituto Europeo di Oncologia - IEO - University of Milan, radiotherapy - Oncology and Hemato-oncology, MIlan, Italy 2 Istituto Europeo di Oncologia - IEO, radiotherapy, MIlan, Italy 3 Istituto Europeo di Oncologia - IEO, Medical Physics, MIlan, Italy 4 Istituto Europeo di Oncologia - IEO -University of Milan, Scientific Directorate - Oncology and Hemato-oncology, MIlan, Italy Purpose or Objective To retrospectively evaluate response and toxicity of stereotactic radiotherapy (SRT) for oligometastatic ovarian cancer patients (pts). Material and Methods Between May 2012 and October 2015 we enrolled 57 adult oligometastatic ovarian cancer pts to SRT. Indication criteria were: 1)low tumor burden (1–5 lesions); 2)contraindication to salvage surgery; 3)localized persistent disease after chemotherapy (CT); 4)no CT indication due to ematological toxicity (tox); 5)no more CT lines available or refusal of the patient. Toxicity and tumor response were evaluated using CTCAE and RECIST criteria. CT or PET was performed at 2-3 months (mo.). Results 57 patients/96 lesions underwent SRT. We treated 65 nodal metastases (mets) and 31 visceral mets ¸72 and 24 lesions were treated with VERO™ and Cyberknife™ respectively. Median age was 60.3 years (range 45.7-81). All pts had previously received CT and/or ormonotherapy (OT). Concomitant systemic therapy was performed in 10 cases (4 CT, 6 OT). SRT consisted in re-irradiation for 8 lesions. Mean GTV was 13.2 cm3 (range 0.5 - 90.05). Median dose was 24 Gy (range 16–45 Gy) in 3 fractions (range 2-5). Median follow-up (FU) was 20.9 months (mo.) (range 3.2 - 48.7). Radiological response at first FU (evaluable for 87 lesions) was: complete response, partial response, stabilization and progressive disease (PD) in 52 (59.8%), 18 (20.7%), 12 (13.8%) and 5 (5.7%) lesions, respectively. At last FU (available for 55 pts), 16 pts were alive with no evidence of disease, 26 alive with disease, 13 pts died of disease. Acute and late tox were low: 13 G1 and 12 G1-events (predominantly gastrointestinal), respectively. Pattern of failure was mainly out field (PD out field, in field, in and out field in 41, 3, and 1 cases respectively). Local control at last FU was observed in 76/87 evaluable lesions (87.4%). Median local progression free survival was 10.6 mo. (range 3.1 - 33.4). Median progression free survival was 3.9 mo. (range 1,5 – 29). Conclusion In our experience, SRT in oligometastatic ovarian cancer pts has shown excellent local control and toxicity profile. It might be a good alternative to other more invasive local therapies in order to delay systemic therapy especially when temporaneously contraindicated, not tolerated, or in chemorefractory disease. The evaluation of site and volumes treated is ongoing. Longer FU and further studies are needed to identify which subgroup of patients may most benefit from this treatment. EP-1301 Early toxicity for image guided adaptive radiochemotherapy including brachytherapy in cervix cancer K. Majercakova 1 , D. Najjari 2 , M. Buschmann 1 , A. Sturdza 2 , E. Dörr 1 , R. Pötter 2 , D. Georg 2 , Y. Seppenwoolde 1 1 Medical University of Vienna, Christian Doppler Laboratory for Medical Radiation Physics for Radiation

Purpose or Objective Advanced treatment for locally advanced cervical cancer consists of external beam radiotherapy (EBRT), concurrent Cisplatin combined with Image Guided Adaptive Brachytherapy (IGABT). Recently EBRT adaptive radiotherapy (ART) based on library of plans was implemented in our department for patients with large cervix-uterus motion. Acute side effects associated with chemo start usually in the first stage of EBRT when the full dose is not yet reached. In the last stage of treatment, combination with IGABT may accelerate toxicity. Material and Methods The objective of this study was to evaluate sensitivity, variability and dose-volume correlations of several general, gastrointestinal (GI) and genitourinary (GU) symptoms. These were assessed weekly during treatment and at 3 time points after treatment. A prospective study was performed on 21 non-adaptive EBRT (two 3D-CRT and 19 VMAT) and 5 VMAT ART patients. GI and GU symptoms were evaluated according to CTCAE 4.03. Results Most parameters did not show much variation throughout treatment and between patient groups. Weight loss showed a slow onset in the first 3-4 treatment weeks and increased after the first IGABT. The most sensitive GI parameters were stool consistency and diarrhea that were worst in the 3 rd and 4 th week of treatment for non-adaptive EBRT patients and had a little later onset for ART patients. For patients treated with Cisplatin, weight loss in the 3-4 th week of treatment correlated with the irradiated volume to 43Gy (±1 kg weight loss for every 500cc irradiated to more than 1250cc) in combination with severity of vomiting and diarrhea as secondary multivariate components. From the GU toxicity only nighttime micturition seemed to be less for the ART patients. This might be confounded by the coincidence that those patients had a better baseline function to start with and had on average 100 ml more volume in their bladder during the treatment course. Bladder incontinence was worst 6 weeks after treatment and did not correlate with planned EBRT dose volumes. Bladder volumes varied largely throughout the EBRT treatment. The incidence of other side effects like proctitis and cystitis was limited. More patient data is needed to assess the time course.