Treatment of primary liver cancer using highly-conformal radiotherapy with kV-image guidance and respiratory control.

Abstract

To implement a reliable, practical and reproducible treatment procedure, based on in-room kV-image guidance and respiratory control, for liver cancer patients treated with high dose conformal radiotherapy using a commercially available treatment system. CT stimulation was conducted under voluntary breath hold or gating using the Varian Real-time Position Management™ (RPM) System. Treatments were delivered daily under kV image guidance to verify the diaphragmatic or lipiodol-defined tumor position. Thirty-three patients with liver confined hepatocellular carcinoma were treated between May 2006 and Dec 2009. After a median follow-up period of 16.5 months (range: 3.5-40.7), all but 2 patients demonstrated radiological tumor regression. Eight patients (24%) achieved complete remission. The median tumor shrinkage was 42% (27-100%). Subsequent in-field tumor progression was observed in only three patients (10%). For the 23 patients with abnormal alpha fetoprotein level, 22 of them showed biochemical response with a median AFP level drop of 78%. The treatment was well tolerated: Grade 3 toxicities occurred in 5 patients (1 leucopenia, 1 elevated liver enzyme and 3 elevated bilirubin level) but there was no grade 4 toxicity or treatment related death. The 1 year overall survival rate is 71.7% and median survival time is 17.2 months (3.5-40.7 months). Excellent treatment results with minimal toxicities could be achieved in a clinical environment with a commercially available highly sophisticated radiotherapy system.