Clinical Outcomes of γ-ray Stereotactic Body Radiation Therapy for Patients With Primary Hepatic Carcinoma of Stage I/II

Abstract

To evaluate the effects and radiation reaction of patients of primary hepatic carcinoma of I/II stage by the stereotactic body radiation therapy. Fifty-two patients of stage I/II primary hepatic carcinoma were treated with the γ-ray stereotactic body radiation therapy (γ-ray SBRT, stereotactic gamma ray body radiotherapeutic system , body γ-knife), including 10 patients of stage I and 42 patients of stage II. For γ-SBRT a stereotactic body frame for exact tumor localization, reproducible fixation, CT simulation, and 3-D treatment plan has been developed. A three dimensional margin of 1cm were added to GTV. Fifty percent isodose line was prescription dose line and covered 100% area of PTV and 70% isodose line covered more than 80% area of GTV. According to the tumors size, position and function of the liver, they were irradiated 3-5 Gy per fraction at 50% isodose line, 5 fraction per week and a total dose of 40-51 Gy at PTV margin, 60-70 Gy at GTV margin and 80∼102 Gy at tumor centrical area was delivered in 2∼3 weeks. The median follow-up duration was 48 months. The complete response rate (CR) and the overall response rate (CR+PR) were 46.2% and 80.8%, respectively, after 2-3months of the treatments. The 1-, 2-, 3-, 4- and 5-year overall survival rates were 82.7%, 75.0%, 58.3%, 42.8%and 34.3%, respectively. The major treatment-related acute gastrointestinal toxicities included nausea or vomiting. The incidence of Grade I/II gastrointestinal toxicities was 19.2%. The acute hematologic toxicities were 21.2% in Grade I, 11.5% in Grade II and 1.9% in Grade III. None of all patients was observed with acute hepatic toxicities during the treatment . Late hepatic toxicities were 13.5% in Grade I/II and 3.8% in Grade III. The whole process was bearable for all patients after allopathy. The γ-ray stereotactic body radiation therapy(γ-ray SBRT) is effective and safe which fraction schema of 3-5 Gy/fraction, 5 days a week with a total dose of 45∼51 Gy at 50% isodose line was delivered for patients with early stage primary hepatic carcinomas. It can improve the local control rate and survival rate for patients with stage I/II.