Phase I Trial of Selective Internal Radiation Therapy for Chemorefractory Colorectal Cancer Liver Metastases Progressing After Hepatic Arterial Pump and Systemic Chemotherapy

IntroductionThis prospective study assessed the safety and outcomes of selective internal radiation therapy (SIRT) using yttrium-90 (90Y) resin microspheres as a salvage therapy for liver-predominant metastases of colorectal cancer in patients with documented progression after hepatic arterial chemotherapy (HAC) and systemic chemotherapy.Patients and MethodsWe recruited 19 patients who had received a mean of 2.9 prior lines of chemotherapy and ≥ 1 line of HAC. Dose-limiting toxicities (grade 3 or higher) were catalogued using Common Terminology Criteria for Adverse Events version 3.0. At 4 to 8 weeks and 3 to 4 months post SIRT, responses were assessed by carcinoembryonic antigen (CEA), and quantitative imaging using Response Evaluation Criteria in Solid Tumors (RECIST) and PET Response Criteria in Solid Tumors (PERCIST). Liver progression-free survival (LPFS), progression-free survival (PFS), and overall survival (OS) were calculated using Kaplan-Meier methodology.ResultsMedian follow-up was 31.2 months after SIRT. Within 6 weeks of SIRT, 3 patients (15.8%) experienced grade 3 toxicity. There was no incidence of radiation-induced liver disease. Responses by RECIST, PERCIST, and CEA were, respectively, 0%, 20%, and 32% at 4 to 8 weeks and 5%, 33%, and 21% at 3 to 4 months post SIRT; 53% of patients had stable disease (by RECIST) at 3 to 4 months. Of 19 patients, 4 (21.1%) had liver ablation, 9 (47%) received additional HAC, and 17 (89%) received systemic chemotherapy after SIRT. Median LPFS, PFS, and OS after SIRT were 5.2 months, 2.0 months, and 14.9 months, respectively.ConclusionSIRT was well tolerated and did not prohibit subsequent treatment, resulting in a median OS of 14.9 months in this heavily pretreated population.