ESTRO 2021 Abstract Book

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ESTRO 2021

(IQR: 76.9– 208.6 cc), respectively. After a median follow-up of 15 months from the end of reRT, a total number of 18 patients (78.2%) developed LR. Nine LR (39%) occurred inside previously irradiated targets. The local control (LC) rate and survival without LR at 18 months were: 29.3 CI95%[15-57] and 26.1%[13.1-51.9]. Most patients (74%) did not have grade 2 toxicity before the start of reRT. Acute toxicities of grade ≥ 2 were radiomucositis (43.5%), dysgeusia (27.3%), dysphagia (26%), and radiodermatitis (13%). Main late grade ≥ 2 toxicities were: dysphagia (34.8%), trismus (30.4%), xerostomia (26.1%), dysgeusia (26.1%), cranial nerve deficit (17.4%), osteoradionecrosis (13.4%), and temporal radionecrosis (8.7%). Carotid blowout occurred in three patients (13.4%). Dysgeusia was significantly more frequent in the photon than in the proton group (p=0.017).

Conclusion Curative reRT in HNC is possible for selected cases, but the LR rate in the irradiated field and the risk of toxicity grade ≥ 2 remain high. Improved selection criteria and definition of target volumes may improve the outcome of these patients. PO-0993 Malnutrition by GLIM criteria is a risk factor for survival of NPC patients undergoing radiotherapy M. Wan 1 , D. Zhao 2 , B. Zheng 2 , S. Xiao 2 , Y. Sun 3 1 Peking University Cancer Hospital and Institute, Beijing 100142, People’s Republic of China, Department of Radiation oncology , Beijing, China; 2 Peking University Cancer Hospital and Institute, Beijing 100142, People’s Republic of China, Department of Radiation Oncology, Beijing, China; 3 Peking University Cancer Hospital and Institute, Beijing 100142, People’s Republic of China, Department of Radiation Oncology,, Beijing, China Purpose or Objective Nutritional status of nasopharyngeal carcinoma (NPC) patients lying at a high risk of nutrition defect to a great extent determines the post-treatment outcomes, which deserves thorough observation. However, limited ever-conducted studies regarding the NPC patients’ malnutrition by effective methods like the Global Leadership Initiative in Malnutrition (GLIM) criteria heavily obstructed this prospect. Our study aimed to investigate the incidence of malnutrition in NPC cancer patients using GLIM criteria and explore the relationships between malnutrition and adverse effects, survival status. Materials and Methods A retrospective chart review of 113 patients with NPC from December 2016 to October 2019. The nutritional status of NPC undergoing radiotherapy (RT) was determined by GLIM criteria at three-time points: pre-RT, in the middle of RT, and at the end of RT. The adverse effects were graded according to the Radiation Therapy Oncology Group (RTOG) scoring criteria. Kaplan–Meier method was used to compare survival outcomes, and the differences were evaluated using the log-rank test. Results Nineteen cases (16.8%) were malnutrition before radiotherapy; overall stage (p=0.017) and induction chemotherapy(p=0.002) contributed to pre-radiotherapy malnourishment, and the nutritional status worsened with radiotherapy. Of the phenotypic GLIM criteria, low fat free mass index (FFMI) before radiotherapy was associated with mucositis and radiodermatitis (p<0.05). With a median follow-up of 28.3 months, the Kaplan- Meier curve indicated that malnutritional patients had significantly poorer Progress Free survival (PFS); 2-year PFS was 88.9% in the well-nourishment group vs. 62.1% in the malnutrition group (p=0.015). In multivariate analysis, nutritional status and gender were independent prognostic factors of poorer PFS (HR 3.387, 95%CI 1.299-8.834, p=0.013 and HR 5.698, 95%CI 1.290-25.168, p=0.022). Conclusion Malnutrition is common in NPC patients, and it increases significantly during radiotherapy. Malnutrition, according to GLIM criteria, is correlated with survival. Our study could justify the effectiveness and usability of GLIM for NPC patients undergoing RT. Appropriate nutritional guidance or nutritional support should be