Stereotactic single-dose radiation therapy of liver tumors: Results of a phase I/II trial

Purpose: To investigate the feasibility and the clinical response of a ster eotactic single-dose radiation treatment for liver rumors. Patients and Methods: Between April 1997 and September 1999, a stereotactic single-dose radiation treatment of 60 liver tumors (four primary tumors, 5 6 metastases) in 37 patients was performed. Patients were positioned in an individually shaped vacuum pillow. The applied dose was escalated from 14 t o 26 Gy (reference point), with the 80% isodose surrounding the planning ta rget volume. Median tumor size was 10 cm(3) (range, 1 to 132 cm(3)). The mo rbidity, clinical outcome, laboratory findings, and response as seen on com puted tomography (CT) scan were evaluated. Results: Follow-up data could be obtained from 55 treated tumors (35 patien ts). The median follow-up period was 5.7 months (range, 1.0 to 26.1 months; mean, 9.5 months). The treatment was well tolerated by all patients. There were no major side effects. Fifty-four (98%) of 55 tumors were locally con trolled after 6 weeks at the initial follow-up based on the CT findings (22 cases of stable disease, 28 partial responses, and four complete responses ). After a dose-escalating and learning phase, the actuarial local tumor co ntrol rate was 81% at 18 months after therapy. A total of 12 local failures were observed during follow-up. So far, the longest local tumor control is 26.1 months. Conclusion: Stereotactic single-dose radiation therapy is a feasible method for the treatment of singular inoperable liver metastases with the potenti al of a high local tumor control rate and low morbidity. J Clin Oncol 19:16 4-170. (C) 2001 by American Society of Clinical Oncology.