Hepatocellular carcinoma patients with portal vein thrombosis treated with robotic radiosurgery: Interim results of a prospective study

Background This is a prospective study evaluating the role of stereotactic body radiotherapy (SBRT) with CyberKnife (CK) in Indian patients suffering from hepatocellular carcinoma with portal vein thrombosis (HCC-PVT). Methods Patients with inoperable HCC-PVT, good performance score (PS), and liver function are accrued for treatment on CK (version M6) and planned with Multiplan (iDMS V2.0). Triple-phase contrast computed tomography (CT) scan was done for contouring, and the gross tumor volume (GTV) included contrast-enhancing mass within main portal vein and adjacent parenchymal disease. Dose prescription was as per-risk stratification protocol (22–50 Gy in 5 fractions) while achieving the constraints of mean liver dose <15 Gy, 800 cc liver <8 Gy, and the duodenum max of ≤24 Gy). Results Seventy-two HCC-PVT accrued till date (mean age 63 years [38–76 years], 96% male; Child-Pugh [CP] A 84%, B 9%; Barcelona-Clinic Liver Cancer [BCLC] C 96%; PS0-1: 80%, Karnofsky performance score [KPS]>70: 88%; co-morbidities 42%; infective 12%, alcohol intake 31%, adjuvant sorafenib 39%). CP scores 5, 6, 7, and 8 were in 35%, 32%, 8%, and 18%, respectively. Focal disease with portal vein thrombus (PVT) in 21%, liver involvement >50% and <50% in 46% and 32%. Liver cancer study group of Japan staging–based portal vein invasion VP2, VP3, and VP4 in 22%, 29%, and 40%. Cancer of the Liver Italian Programm (CLIP) scores 1, 2, 3, 4, and 5 were in 8%, 26%, 31%, 26%, and 7%, respectively. Mean follow-up was 7.3 months (median 6 months, standard deviation [SD] 6; range 3–30 months). Mean actuarial overall survival (OS) was 11.4 months (SE 1.587; 95% CI: 8–14.2 months). Six months and 12 months actuarial OS 55% and 38%, respectively. At last follow-up, 25/69 (36%) were alive and 44/69 (64%) were dead. Among 54 patients evaluated for response assessment, 23 (30%) had radiological confirmed PVT response, 1 (3%) had response of IVC thrombus, and 30 (42%) had no or minimal response to SBRT. Actuarial OS in responders and non-responders were 14.4 months (95% CI 9.4–19.2) and 7.4 months (95% CI 4.9–9.7), p -value: 0.022. Six and 12 months survival in responders and non-responders were 65.7% and 37% and 49% and 24.6%, respectively. Post-SBRT, 4 (12%) patients underwent transarterial chemoembolization (TACE) 3 patients (8%) and 1 patient (4%) transarterial radioembolization (TARE). Post-CK, (<4 weeks) 2 patients (4%) had decompensation. Conclusions PVT response or recanalization after SBRT is a statistically significant prognostic factor for survival function in HCC-PVT.