High-Dose proton beam radiotherapy of hepatocellular carcinoma: Preliminary results of a phase II trial

376 Background: Retrospective reports of PBT in hepatocellular carcinoma (HCC) demonstrate local control (LC) rates exceeding 85%. We prospectively replicate these findings and explore predictors of overall survival (OS) in pts with unresectable HCC receiving high dose, HF-PBT. Methods: Pts were enrolled on an NCI sponsored, multi-institutional, phase II study (NCT00976898). Key eligibility were unresectable HCC; Child’s A/B; ECOG PS 0-2; no extrahepatic disease; no prior RT. Maximum tumor size was 12 cm if solitary, 10 cm if 2 tumors, and 6 cm if 3. PBT was given in 15 fractions to a maximum total dose of 67.5 GyE. Sample size was calculated to demonstrate > 80% LC at 2 yrs (LC-2). Results: From 2009-2015, 44 patients were treated. Median age was 70 years (53-89) and 37 (84.1%) were male. 35 (79.5%) pts had Child A or no cirrhosis. 32 (72.7%) pts had 1 tumor, 12 (27.2%) had multiple tumors. Median longest tumor dimension was 5.0 cm (range 1.9-12.0). Median baseline AFP was 18.6 ng/mL (range 1.3-66081) and 29 pts (67.4%) had elevated AFP ( > 7.9 ng/mL). Median RT dose delivered was 58.0 GyE (range 40.5-67.5). 1 pt (2%) had grade 3 RT related toxicity (thrombocytopenia). With a median follow up 21.8 mo among 28 survivors, the LC-2 was 94.8% (95% CI 84.5-99.1%). mOS was 49.9 mo (95% CI 17.8 months- upper limit not reached) and mPFS was 13.9 mo (95% CI 8.4-49.9). OS did not differ by CLIP score, PS, prior treatment, vascular thrombus, baseline AFP, size, or dose. Median AFP change from baseline to 3 mo post treatment was a 32.8% reduction. Median time to AFP nadir in pts with elevated baseline levels was 3.9 mo (0-30.5). % decrease in AFP from baseline to 6 mo post-treatment was significantly associated with lower hazard of death. (HR = 0.993, p = 0.016). Conclusions: High dose hypofractionated proton beam therapy demonstrated a high local control rate for HCC with favorable safety profiles, supporting the ongoing evaluation of radiation in HCC in phase III studies. AFP decrease from baseline to 6 months post-radiation is associated with improved overall survival. Clinical trial information: NCT00976898.

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Multi-Institutional Phase II Study of High-Dose Hypofractionated Proton Beam Therapy in Patients With Localized, Unresectable Hepatocellular Carcinoma and Intrahepatic Cholangiocarcinoma

Journal of Clinical Oncology ◽

10.1200/jco.2015.64.2710 ◽

2016 ◽

Vol 34 (5) ◽

pp. 460-468 ◽

Cited By ~ 174

Author(s):

Theodore S. Hong ◽

Jennifer Y. Wo ◽

Beow Y. Yeap ◽

Edgar Ben-Josef ◽

Erin I. McDonnell ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Proton Beam ◽

Phase Ii ◽

Proton Therapy ◽

Intrahepatic Cholangiocarcinoma ◽

Performance Status ◽

Proton Beam Therapy ◽

Phase Iii ◽

High Dose ◽

Ecog Performance Status

Purpose To evaluate the efficacy and safety of high-dose, hypofractionated proton beam therapy for hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). Materials and Methods In this single-arm, phase II, multi-institutional study, 92 patients with biopsy-confirmed HCC or ICC, determined to be unresectable by multidisciplinary review, with a Child-Turcotte-Pugh score (CTP) of A or B, ECOG performance status of 0 to 2, no extrahepatic disease, and no prior radiation received 15 fractions of proton therapy to a maximum total dose of 67.5 Gy equivalent. Sample size was calculated to demonstrate > 80% local control (LC) defined by Response Evaluation Criteria in Solid Tumors (RECIST) 1.0 criteria at 2 years for HCC patients, with the parallel goal of obtaining acceptable precision for estimating outcomes for ICC. Results Eighty-three patients were evaluable: 44 with HCC, 37 with ICC, and two with mixed HCC/ICC. The CTP score was A for 79.5% of patients and B for 15.7%; 4.8% of patients had no cirrhosis. Prior treatment had been given to 31.8% of HCC patients and 61.5% of ICC patients. The median maximum dimension was 5.0 cm (range, 1.9 to 12.0 cm) for HCC patients and 6.0 cm (range, 2.2 to 10.9 cm) for ICC patients. Multiple tumors were present in 27.3% of HCC patients and in 12.8% of ICC patients. Tumor vascular thrombosis was present in 29.5% of HCC patients and in 28.2% of ICC patients. The median dose delivered to both HCC and ICC patients was 58.0 Gy. With a median follow-up among survivors of 19.5 months, the LC rate at 2 years was 94.8% for HCC and 94.1% for ICC. The overall survival rate at 2 years was 63.2% for HCC and 46.5% ICC. Conclusion High-dose hypofractionated proton therapy demonstrated high LC rates for HCC and ICC safely, supporting ongoing phase III trials of radiation in HCC and ICC.

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