ESTRO 2023 - Abstract Book

S742

Monday 15 May 2023

ESTRO 2023

Results Between Jan 2017 till May 2022, 318 consecutive HCC with PVT patients were screened and 219 patients were accrued [male 92%, CP score 5-7 90%, mean age 63 years (38-85yrs), CLIP 2 mo follow up). At mean follow up of 10.2 mo (SD 8.43), 88 (63%) patients expired and 51 (36%) were alive. 82 (59%) patients had recanalization of PVT (response), 57 (41%) pts did not recanalize, 28 (17%) had progressive disease had progressive/ metastatic disease prior to response evaluation (<2 months). Mean overall survival in responders and non-responders were 18.4 (SE 2.52) and 9.34 month (SE 0.81) respectively (p<0.001). Mean survival in patients with PS0, PS1 and PS2 were 17, 11.7 and 9.7 months (p- 0.019) respectively. Overall survival in partial recanalization, bland thrombus and complete recanalization was 12.4, 14.1, 30.3 months respectively (p- 0.002). Adjuvant sorafenib, BCLC stage, gender, age, RT dose did not influence response to treatment. Recanalization rate was higher in good PS patients (p-0.019). OS in patients with response to treatment, no response to treatment, fit but not accrued and not suitable patients were 18.4, 9.34, 5.9, 2.6 months respectively (p-<0.001). 36/139 patients (24%) had RILD [10 (7.2%) had Classic RILD & 26 (19%) had non-classic RILD]. Derangement in Child Pugh Score (CP score change) by more than 2 was seen in 30 (24%) within 2-month period after CK. 18 (13%) had unplanned admissions, two patients required embolization due to fiducial related bleeding, 20 (14%) had ascites of which 9 (6%) patients required abdominocentesis. Conclusion PVT response or recanalization after SBRT is a statistically significant prognostic factor for survival function in HCC-PVT. PD-0896 Definitive SBRT in early-stage HCC: an Australian multi-institutional review of outcomes H. Liu 1 , Y.Y. Lee 1 , S. Sridharan 2 , W. Wang 3 , R. Khor 4 , J. Chu 5 , A. Oar 6 , E.S. Choong 7 , H. Le 8 , M. Shanker 1 , A. Wigg 9 , K. Stuart 10 , D. Pryor 1 1 Princess Alexandra Hospital, Radiation Oncology, Brisbane, Australia; 2 Calvary Mater Newcastle, Radiation Oncology, Newcastle, Australia; 3 The Crown Princess Mary Cancer Centre, Radiation Oncology, Sydney, Australia; 4 Olivia Newton- John Cancer Wellness and Research Centre, Radiation Oncology, Melbourne, Australia; 5 Peter MacCallum Cancer Centre, Radiation Oncology, Melbourne, Australia; 6 ICON Cancer Centre, Radiation Oncology, Gold Coast, Australia; 7 Chris O'Brien Lifehouse, Radiation Oncology, Sydney, Australia; 8 Royal Adelaide Hospital, Radiation Oncology, Adelaide, Australia; 9 Flinders Medical Centre, Hepatology and Liver Transplantation Medicine Unit, Adelaide, Australia; 10 Princess Alexandra Hospital, Department of Gastroenterology and Hepatology, Brisbane, Australia Purpose or Objective Management of HCC is challenging as liver cirrhosis, comorbidities and tumor location can limit the choice of treatment modality. The majority of patients will be ineligible for resection or transplantation and several factors including tumor size and location impact on the feasibility and efficacy of thermal ablation or transarterial therapies. SBRT has demonstrated high rates of local control in multiple series, however, few studies have reported on SBRT specifically in the treatment naïve, curative intent setting. We report the outcomes of patients with solitary early-stage HCC treated with SBRT as first line definitive therapy. Materials and Methods This is a multi-institutional retrospective study between 2010 and 2019 of patients with a new diagnosis of BCLC stage 0/A HCC and a single ≤ 5cm lesion, Child-Pugh (CP) A compensated liver function who underwent SBRT as first line, curative intent therapy. The primary end point was freedom from local progression (FFLP). Secondary end points were progression- free survival (PFS), overall survival (OS) and treatment related toxicity. Results 68 patients met inclusion criteria with a median follow-up of 20 months (range, 3-58). Median age was 68 years (range, 50- 86), 54 (79%) were male, 62 (91%) had cirrhosis and 50 (74%) patients were ECOG 0. The predominant etiologies of liver cirrhosis were NAFLD (48%), HCV (35%) and ALD (34%). Median HCC diameter was 2.6cm (range, 1.3-5) and serum AFP was 5.1 (range, 1.5-2275). Median prescription BED10 dose was 93Gy (range, 48-125Gy). The 2-year FFLP, PFS and OS were 94%, 60% and 88%, respectively. Two patients had local failures and did not undergo further treatment due to decline in general and hepatic function unrelated to SBRT. The predominant cause of disease progression was out-of-field intrahepatic relapse, occurring in 16 patients. Of those patients, 13 (81%) patients underwent additional liver directed therapy, 1 patient commenced systemic therapy and 2 patients received best supportive care in light of co-morbidities. Grade 2 and 3 clinical toxicity (excluding asymptomatic biochemical and hematological) was reported in 9 (13.2%) and 0 (0%) patients, respectively. A rise of ≥ 2 in CP-score was observed in six patients with cirrhosis (9.6%) within 3 months of SBRT.