Experience with stereotactic r adiation therapy for liver oligometastases of colorectal cancer

Abstract

Introduction: The problem of treating patients with unresectable liver metastases of colon cancer is currently far f rom being solved. One possible approach is the use of stereotactic body radiotherapy.The purpose of this study was to evaluate the immediate and long-term results of stereotactic radiotherapy in patients with colorectal cancer and oligometastatic liver metastases.Methods: This study was designed as a retro-prospective, open-label, controlled, non-randomized clinical trial. We assessed one-year local control, one-year overall survival, progression-free survival, and toxicity in 60 patients with oligometastatic liver disease from colorectal cancer who underwent stereotactic body radiotherapy, with median dose of 54 Gy.Results: The median follow-up was 20,1 months. One-year local control (LC) was 73,7 % (95 % CI = 62,7–86,6 %). Oneyear overall survival (OS) was 92,8 % (95 % CI = 86,3–99,9 %), one-year progression-free survival (PFS) was 31,3 % (95 % CI = 21,1–46,4 %) with a median of 8,1 months. Grade ≥ 3 toxicity was not noted. No cases of radiation-induced liver failure were observed. Radiation dose (HR = 0.88, 95 % CI = 0.81–0.95, p = 0.00087), metastasis size (HR = 1.51, 95 % CI = 1.07–2.12, p = 0.01858) and their number (HR = 1.8, 95 % CI = 1.01–3.22, p = 0.04669) are significant risk factors for LC. Metastasis size > 3 cm is a significant risk factor for LC (HR = 5.5, 95 % CI = 1.7–17.9, p = 0.005) and OS (HR = 3.8, 95 % CI = 1.3–11.7, p = 0.02).Conclusion: Stereotactic body radiotherapy is an effective and safe method of providing local control of oligometastatic liver metastases in colorectal cancer as part of a combined treatment approach. Further studies are required to individualize the indications for this treatment method.