ESTRO 2020 Abstract Book

S553 ESTRO 2020

Purpose or Objective Prospective study evaluating role of Radiosurgery (CK) in Indian patients suffering from hepatocellular carcinoma with portal vein thrombosis. Material and Methods Inoperable HCC with PVT with good PS (0-1), preserved liver function (Bi <4, CHILD B7) were accrued after radiological diagnosis for CK (M6). Fiducial placement (3 number) done as per protocol. Triple phase contrast CT scan, planning done with Multiplan. PVT categorized as Chen classification. GTV is gross contrast enhancing mass within the main portal vein, involved tributaries and adjacent parenchymal disease. PTV margin was 2-3 mm. Dose prescribed as per established risk stratification protocol (22-50Gy/5fr). Mean liver dose <15Gy & 800 cc liver <8Gy. Prognostication done with Chen, Child Pugh (CP), AFP, CLIP score, BCLC classification, RT dose and response to treatment. Results 41 HCC with PVT accrued in the study till date [mean age 61.4 yrs (38-76 yrs), 98% male; Child Pugh A 61%, B 34%; BCLC C 95% & D 5%; PS0-1: 71%, KPS>80: 83%; co- morbidities 39%; infective 15%, Alcohol intake 24%]. Patients presented with abdominal pain (39%), ascitis (17%), fatigue (7%), and melena (7%). CP Score 5,6,7 & 8 was in 27%,34%,20% & 10% respectively. Focal disease with PVT in 15%, liver involvement >50% & <50% in 51% and 34%. 44% received adjuvant sorafinib after SBRT. PVT Chen classification VP2, VP3 & VP4 were in 34%, 32%, 32% respectively. CLIP score 1, 2, 3, 4, 5 in 3%, 29%, 34%, 27% & 5% respectively. Mean follow up was 30.8 weeks (SD 25.8; range 2-107 weeks). Mean actuarial OS was 52.1 wks (95%CI: 38.4-65.5 wks). 6 month & 12 months actuarial OS 65% and 48% respectively. At last follow up, 22/41(54%) were alive and 19/41(46%) expired with disease progression. Among 34 patients evaluable for response assessment, 18(45%) had complete PVT response 1 (3%) had response of IVC thrombus, 15 (36%) had no response to RT. One (3%) patient each had partial PVT response and bland thrombus. At last follow up, among 22 alive patients 9 (22%) had stable disease and 13 (32%) had progressive disease. Among 19 patients expired, 15 (85%) due to local progression, 4 (15%) due to metastasis. No death due to classical RILD. 19/41 (46%) pts had radiologically confirmed re-canalization [18 in PVT & 1 in IVC]. Post-CK, 3 (8%) patient underwent TACE and one (4%) had TARE. Mild GI toxicities (Gr-1-II) in 12 (29%), fatigue(Gr II-III) in 20(48%) and grade III GI toxicity in 2 (5%) patient. Two (5%) pt had decompensation (<4wk) after treatment. Actuarial OS in responders and non-responders were 70.5 wks (95%CI 50.7-90.2) and 35.4 (95%CI 21.7-49.1); p-value: 0.007. CLIP and RT dose predicts OS benefit (OS in CLIP Score 1-2 Vs 3- 6: 35.6 Vs 27.6 wks; p-value 0.058 and RT dose <39Gy Vs >39Gy: 25.5 Vs 39.2 wks; p-value 0.245). Conclusion CyberKnife is safe & effective option in Indian HCC with PVT patients. Good PVT response, CP score, CLIP Score and RT dose have prognostic significance. RT dose and PVT response may be included in response assessment scoring system. PO-1039 Lymphopenia and worse OS are associated with GTV and fraction in patients with HCC treated with EBRT H. Zhang 1,2 , J. Sun 1 , S. Du 1 , Z. Zeng 1 1 Zhongshan Hospital- Fudan University, Department of Radiation Oncology, Shanghai, China ; 2 Luoyang Central Hospital affiliated to Zhengzhou University, Department of Radiation Oncology, Luoyang- Henan, China Purpose or Objective We investigated lymphocyte nadir induced by radiation was associated with survival and explored its underlying risk factors in patients with hepatocellular carcinoma (HCC).

Material and Methods Total lymphocyte counts were collected from 184 HCC patients treated by radiotherapy (RT) with complete follow-up. Associations between gross tumor volumes (GTVs) and radiation-associated parameters with lymphocyte nadir were evaluated by Pearson/Spearman correlation analysis and multiple linear regression. Kaplan- Meier analysis, log-rank test, as well as univariate and multivariate Cox regression were performed to assess the relationship between lymphocyte nadir and overall survival (OS). Results GTVs and fractions were negatively related with lymphocyte nadir ( p < 0.001 and p =0.001, respectively). Lymphocyte nadir and Barcelona Clinic Liver Cancer (BCLC) stage were independent prognostic factors predicting OS of HCC patients (all p < 0.001). Patients in the GTV ≤ 55.0cc and fractions ≤ 16 groups were stratified by lymphocyte nadir, and the group with the higher lymphocyte counts (LCs) showed longer survival than the group with lower LCs ( p < 0.001 and p = 0.006, respectively). Patient distribution significantly differed among the RT fraction groups according to BCLC stage, p < 0.001. However, stratification of patients in the same BCLC stage by RT fractionation showed that the stereotactic body RT (SBRT) group achieved the best survival. Furthermore, there were significant differences in lymphocyte nadir among patients in the A lower lymphocyte nadir during RT was associated with worse survival among HCC patients. Smaller GTVs and fractions reduced the risk of lymphopenia. PO-1040 Peritreatment peripheral blood cells predict progression hazard in esophageal cancer after treatment J. Chen 1,2 , L. Xu 1,3 , H. Guo 1 , R. Huang 1 , L. Guo 1 , Y. Yu 1 , F. Wu 1 , Z. Chen 1,4 , D. Li 1 , C. Chen 1 1 Cancer Hospital of Shantou University Medical College, Radiation Oncology, Shantou, China ; 2 University of Oxford, Oncology, Oxford, United Kingdom ; 3 Tungwah Hospital of Sun Yat-Sen University, Radiation Oncology, Dongguan, China ; 4 Cancer Hospital-Chinese Academy of Medical Sciences, Radiation Oncology, Shenzhen, China Purpose or Objective Prediction of response to chemoradiotherapy is critical for the optimal management of esophageal cancer, yet it is still an unmet clinical need. The prognostic implication of peripheral blood cell (PBC) parameters in esophageal cancer patients suggests that they may help address this issue, though their predictive capacity was often moedest. The majority of previous studies relies solely on pretreatment PBC parameters, while emerging data suggest that changes of PBC parameters after radiotherapy may provide substantial inputs to their predictive capacity for patient outcomes. This study aims to evaluate the predictive potential of peri-treatment PBC in evaluation of disease progression hazard in esophageal cancer following definitive chemoradiotherapy. Material and Methods 87 patients with primary esophageal squamous cell carcinoma were subjected to definitive concurrent chemoradiotherapy with radiation dose escalation in a phase II trial. PBC parameters (hemoglobin, neutrophils, platelets, lymphocytes and monocytes) were collected at 7 time points through the course of radiotherapy. The values of peri-treatment PBC parameters in predicting 3- year cumulative hazard of tumor progression (local, regional or distant) were evaluated by using receiver operating characteristic curves, univariate analysis and multivariate cox regression. Time-to-event curves were generated using the Kaplan-Meier method and compared using the log-rank's test. SBRT group. Conclusion