ESTRO 37 Abstract book

S633

ESTRO 37

EP-1123 Follow up on salvage radiotherapy for relapsed pilocytic astrocitoma J. Palma Delgado 1 , J. Andreescu Yagüe 2 , R. Alonso Gutiérrez 3 , X. Chen Zhao 3 , O. Hernando Requejo 3 , R. Ciérvide Jurió 1 , M. López González 1 , B. López Ibor 4 , M. Rubio Rodríguez 1 1 HOSP. Univ. Madrid Sanchinarro, Oncología Radioterápica, madrid, Spain 2 Hospital Universitario Marqués de Valdecilla, Radiation Oncology, Santander, Spain 3 Hospital Universitario HM Puerta del Sur, Oncología radioterápica, Madrid, Spain 4 Hospital Universitario HM Montepríncipe, Hematología y Oncología Radioterápica, Madrid, Spain Purpose or Objective Primary malignant central nervous system (CNS) tumors are the second most common childhood malignancies, after hematologic malignancies, and are the most common pediatric solid organ tumor. Pilocytic astrocitomas (P.A) are primary nervous system tumors classified in a broader group known as low grade astrocytomas. P.A has an incidence rate of 4.8 cases per 1 million per year. Radical neurosurgical resection remains the main therapeutic option for P.A. Radiation therapy provides a treatment option for patients with residual, recurrent, or unresectable P.A. We analyze the response of relapsed P.A to salvage radiotherapy treated in our centre. Material and Methods From 2006 to 2017, we treated 7 patients who had been diagnosed with relapsed P.A after surgery or chemotherapy. - 5 males and 2 females. - Mean age of diagnosis was 6.05 years old (2-10 years). - 5 (71.4%) were treated with subtotal resection. 2 (28.6%) were treated with chemotheraphy (the majority using the carboplatine based LGG protocol), and one patient had received previous neuroaxial radiotherapy (36Gy) in another centre. - After progression all the patients received salvage IMRT, with a mean dose of 52.5 Gy (50-54 Gy), averaging 27.5 fractions (25-30) and with daily IGRT with stereotaxic fractionated radiation therapy. - Follow up was performed by periodic cranial MRI. A retrospective and descriptive analysis of the cases was performed. Results Mean follow up was 45 months (10-126 months). - After salvage radiotherapy, local progression was observed in 1 patient (14.3%), who was submitted to salvage surgery. - At the end of the follow up period (01/2009-09/2017) overall survival in our series is 100%. 1 patient (14.3%) had complete radiological response, and 6 patients (85.7%) had local control with partial radiological response. -No evidence of neurological toxicity was observed. Conclusion Although we have a small series of patients (7 cases), with a long follow up (45 months), after analyzing our results, we can conclude that radiation therapy as a salvage treatment for relapsed P.A. achieves excellent local control, and no neurological toxicity. EP-1124 Delay of postoperative radiotherapy affected treatment outcomes of head and neck cancer Y. Hamamoto 1 , K. Nagasaki 1 , S. Tsuruoka 1 , N. Takata 1 , H. Ishikawa 1 , K. Makita 1 , T. Mochizuki 1 1 Ehime University, Radiology, Toon-city, Japan

Conclusion Treatment for OCSCC with definitive CCRT was comparable with PORT in terms of OS, LRC, DMFS, and toxicity. EP-1122 The value of the nutritional markers in predicting outcomes of RT-treated head and neck cancer J. Kim 1 , J. Lee 1 , K. Kim 1 , S. Jeong 1 , W. Jung 1 1 Ewha Womans University, Radiation Oncology, Seoul, Korea Republic of Purpose or Objective Patients with head and neck cancer commonly experience weight loss and malnutrition both before and during the course of treatment. This study aimed to investigate the prognostic value of body weight, body mass index (BMI), and nutritional markers in patients with radiotherapy (RT)-treated head and neck cancer (HNC). Material and Methods This study included 176 patients with non-metastatic HNC who underwent either postoperative or definitive RT from March 2000 to June 2016. Body weight and BMI were evaluated at baseline, 2 weeks, 2 months, 5 months, 8 months, and 1 year post-RT. Albumin and total protein were measured at baseline and after RT. Results The nadir of body weight and BMI were observed 5 months after RT. The median follow-up period was 61 months (range, 10 - 208). Five-year overall survival (OS), disease-free survival (DFS) and loco-regional recurrence- free survival (LRRFS) were 75.5%, 71.2% and 88.3%, respectively. In univariate analysis, patients with lower pretreatment body weight (<60 kg), lower pretreatment BMI (<22.9 kg/m²), pretreatment hypoalbuminemia (<4 g/dL), pretreatment hypoproteinemia (<6.5 g/L), failure to recover initial body weight within a year and larger BMI change (>3kg/m²) had inferior OS (p=0.021, p=0.019, p=0.008, p=0.003, p=0.026 and p=0.015 respectively). In multivariate analysis, patients with lower pretreatment body weight (<60 kg), pretreatment hypoalbuminemia (<4 g/dL), failure to recover initial body weight within a year, and larger BMI change (>3kg/m²) remained independent predictor for OS (p=0.025, p=0.023, p=0.010 and p=0.037 respectively). Conclusion Pretreatment body weight, pretreatment albumin, recovery of initial body weight and BMI change were significant predictors for survival in patients with RT- treated HNC in this study. Early nutrition assessment with intervention before treatment and weight change surveillance and care after RT might be needed to improve survival outcomes.