ESTRO 2022 - Abstract Book

S1100

Abstract book

ESTRO 2022

Materials and Methods This retrospective study included 125 patients who received RCTx between 01/10 and 01/19. Patients were irradiated with photons or protons to a total dose of 40-41.4 Gy in 20 to 23 fractions and received guideline-based concurrent chemotherapy. On FDG-PET/CT, acquired for staging and treatment planning, the lungs and heart were contoured as organs at risk. From the radiation treatment plans, the mean dose (Dmean) of the lungs and heart as well as the volume of the lungs receiving more than 20 Gy (lung V20Gy) were extracted. Absolute and differential values of blood samples [hemoglobin value (Hb), platelet and leukocyte counts] pre-treatment and in the 4th week of treatment were also included in the analysis. Univariate Cox regression was used to examine the impact of these variables on overall survival, with p-values ≤ 0.05 considered statistically significant. Results Most of the patients were male (90%), and the median age was 61 years (range: 40-79 years). Histologically, the majority of carcinomas were represented by squamous cell carcinomas (66%) as there were less adenocarcinomas (34%) amongst the patients. The median follow-up time of patients was 19.8 months (range: 0.8-91.9 months). Median overall survival measured from the start of RCTx was 37.4 months (95% confidence interval: 15.9-58.9 months). During the follow-up period, 35 patients died from esophageal cancer and 27 died for non-tumor related causes. In univariate analysis, higher normal tissue dose to lungs and heart were associated with decreased overall survival (Dmean lung: p<0.001; V20Gy: p<0.001; Dmean heart: p=0.002). None of the blood parameters was predictive of overall survival.

Conclusion In patients with locally advanced esophageal cancer treated with RCTx, the normal tissue dose to the heart and lungs was associated with overall survival. The influence of the cardiac dose on morbidity and mortality requires further analysis in this tumor entity.

PO-1305 Muscle Loss After Stereotactic Body Radiotherapy Predicts Worse Survival in Hepatocellular Carcinoma

J. Yang 1 , C. Lo 1 , M. Lee 2 , C. Lin 1 , P. Shen 1 , Y. Dai 1 , Y. Wang 1 , W. Huang 1

1 Tri-Service General Hospital, Department of Radiation Oncology, Taipei, Taiwan; 2 National Defense Medical Center, School of Public Health, Taipei, Taiwan Purpose or Objective The relationship between sarcopenia and treatment outcomes, especially in patients with hepatocellular carcinoma (HCC) undergoing stereotactic body radiotherapy (SBRT) has not been well-explored. This study aimed to investigate the effects of sarcopenia on the survival and toxicity after SBRT in patients with HCC. Materials and Methods We included 137 patients with HCC treated with SBRT at our institution between 2008 and 2018. Sarcopenia was defined as a skeletal muscle index (SMI) of < 49 cm 2 /m 2 for men and < 31 cm 2 /m 2 for women using pre- and post-SBRT computed tomography images at the mid-level of the third lumbar vertebra. The SMI change was presented as the standardized value (change per 90 days). The Kaplan–Meier method was used for survival estimation, and the Cox proportional hazards regression model was used to determine prognosticators for survival. Results Sarcopenia was present in 67 of 137 eligible patients. With the median follow-up of 14.1 months and 32.7 months in the entire cohort and in those alive, respectively, patients with pre-SBRT sarcopenia or SMI loss ≥ 7% after SBRT had worse overall survival than their counterparts (figure). Significant predictors associated with survival on Cox multivariate analysis were SMI loss ≥ 7% after SBRT, presence of extrahepatic metastasis, neutrophil-to-lymphocyte ratio, and multiple tumors. Separate Cox models according to the absence and presence of pre-SBRT sarcopenia showed that SMI loss ≥ 7% remained a significant survival predictor in patients with sarcopenia compared with those without sarcopenia. SMI loss ≥ 7% is also a predictor of the Child-Pugh score increase by ≥ 2 points after SBRT.