ESTRO 38 Abstract book

S431 ESTRO 38

between radiotherapy and hyperthermia is expected to influence treatment outcome. Therefore, we investigated the effect of the time interval on treatment outcome. In addition, we investigated the effect of thermal dose in a more recent cohort, including patients treated with image guided brachytherapy (IGBT). Material and Methods We included all primary cervical carcinoma patients treated with thermoradiotherapy at our institute between 1996 and 2005. For these patients, patient and follow-up data, but not the time interval, were collected previously. In addition, we included all primary cervical carcinoma patients treated between 2005 and 2016. Data on patients, tumors and treatments, including thermal dose parameter TRISE and the use of IGBT, were collected. Follow-up data on LC, disease free survival (DFS), DSS, OS and late toxicity were collected or updated. Kaplan Meier and Cox proportional hazards analyses were used for statistical analyses. Results 400 patients were included. Kaplan Meier and univariate Cox proportional hazard analysis showed no effect of the time interval (range 30-230 minutes) on any of the clinical outcome measures. In multivariate Cox analysis, the thermal dose parameter TRISE (HR 0,649; 95% CI 0.501– 0.840) and the use of IGBT (HR 0.432; 95% CI 0.214–0.972), but not the time interval, were significant predictors of LC. In a more recent cohort of 227 patients, treated since our previous analysis of the effect of thermal dose, the independent effect of TRISE on LC in multivariate analysis (HR 0.43; 95% CI 0.28 – 0.68) could be replicated. Moreover, in the 66 patients treated with IGBT from 2012 onwards, the thermal dose parameter TRISE remained to have a significant effect (HR 0,33; 95% CI 0,12 – 0,96) on LC in univariate analysis. The 17 patients having a higher than median radiation dose to the High-Risk CTV in combination with a higher than median thermal dose (TRISE), experienced an excellent 5-year LC, DFS and DSS of 100 percent. Conclusion The time interval between radiotherapy and hyperthermia, up to 4 hours, has no effect on clinical outcome. The positive association between thermal dose and clinical outcome is replicated in an independent, more recent, cohort of cervical carcinoma patients. Importantly, in patients receiving state-of-the-art IGBT, the additive effect of thermal dose on clinical outcome remains. PO-0824 Postoperative VBT vs EBRT/VBT in patients with early stage of uterine carcinoma - our update results A. Masarykova 1 , D. Scepanovic 1 , M. Pobijakova 1 , A. Hanicova 1 , M. Fekete 1 1 National Cancer Institute, Radiation Oncology, Bratislava, Slovakia Purpose or Objective Background. - In different trials, like PORTEC-2, Vaginal Brachytherapy (VBT) alone did not make a significant difference in the overall or disease-free survival when compared to patients treated with External Beam Radiotherapy ( EBRT) only. However, there are no randomized trials comparing VBT alone with EBRT plus VBT. Purpose/Objective. - The purpose was to show our update results of VBT alone versus EBRT plus VBT in preventing the vaginal recurrences in patients with early stage of uterine carcinoma, as well as disease-free survival and overall survival of these patients. Material and Methods Total of 307 patients with early stages of the uterine carcinoma have performed postoperative radiotherapy during the period from 2006 to 2010. There were two groups of patients: 55 patients with VBT alone and 252

Figure 1 Kaplan-Meier curve demonstrating overall survival and progression-free survival according to skeletal muscle radiodensity change groups. Conclusion SMD decreased significantly during treatment and was independently associated with poorer survival in patients with stage III endometrial cancer who underwent staging surgery and adjuvant chemoradiotherapy. Furthermore, SMD loss was occult and occurred independently of weight change. Future studies are required to devise interventions aimed at preserving muscle based on individual body composition phenotypes to improve outcomes in advanced endometrial cancer. PO-0823 Relevance of time interval and thermal dose for the clinical outcome of cervical carcinoma patients M. Kroesen 1 , T. Mulder 2 , N. Holthe 2 , A. Aangeenbrug 2 , J.W. Mens 2 , L. Van Doorn 3 , M. Paulides 4 , E. Oomen-de Hoop 2 , R. Vernhout 2 , L. Lutgens 5 , G. Van Rhoon 2 , M. Franckena 6 1 Erasmus MC- University Medical Center Rotterdam, Radiation Oncology, Rotterdam, The Netherlands ; 2 Erasmus MC- University Medical Center Rotterdam, Department of Radiation oncology, Rotterdam, The Netherlands ; 3 Erasmus MC- University Medical Center Rotterdam, Department of Obstetrics and Gynaecology, Rotterdam, The Netherlands ; 4 Eindhoven University of Technology, Department of Electrical Engineering, Eindhoven, The Netherlands ; 5 University Medical Centre Maastricht, Department of Radiation Oncology Maastro, Maastricht, The Netherlands ; 6 Erasmus MC- University Medical Center Rotterdam, Department of Radiation Oncology, Roterdam, The Netherlands Purpose or Objective Addition of deep hyperthermia to radiotherapy results in improved local control (LC) and overall survival (OS) compared to radiotherapy alone in locally advanced cervical carcinoma patients. Previously, we have shown that the thermal dose of hyperthermia significantly correlates with LC and disease specific survival (DSS). Besides thermal dose, the effect of the time interval