Feasibility and Safety of CT-Guided High-Dose-Rate Brachytherapy Combined with Transarterial Chemoembolization Using Irinotecan-Loaded Microspheres for the Treatment of Large, Unresectable Colorectal Liver Metastases

Abstract

To evaluate feasibility and safety of combined irinotecan chemoembolization and CT-guided high-dose-rate brachytherapy (HDRBT) in patients with unresectable colorectal liver metastases > 3 cm in diameter. This prospective study included 23 patients (age, 70 y ± 11.3; 16 men) with 47 liver metastases (size, 62 mm ± 18.7). Catheter-related adverse events were reported per Society of Interventional Radiology classification, and treatment toxicities were reported per Common Terminology Criteria for Adverse Events. Liver-related blood values were analyzed by Wilcoxon test, with P < .05 as significant. Time to local tumor progression, progression-free survival (PFS), and overall survival (OS) were estimated by Kaplan-Meier method. No catheter-related major or minor complications were recorded. Significant differences vs baseline levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT; both P < .001), γ-glutamyltransferase (GGT; P = .013), and hemoglobin (P=.014) were recorded. After therapy, 11 of 23 patients (47.8%) presented with new grade I/II toxicities (bilirubin, n = 3 [13%]; AST, n = 16 [70%]; ALT, n = 18 [78%]; ALP, n = 12 [52%] and hemoglobin, n = 15 [65%]). Moreover, grade III/IV toxicities developed in 10 (43.5%; 1 grade IV): AST, n = 6 (26%), grade III, n = 5; grade IV, n = 1; ALT, n = 3 (13%); GGT, n = 7 (30%); and hemoglobin, n = 1 (4%). However, all new toxicities resolved within 3 months after therapy without additional treatment. Median local tumor control, PFS, and OS were 6, 4, and 8 months, respectively. Combined irinotecan chemoembolization and CT-guided HDRBT is safe and shows a low incidence of toxicities, which were self-resolving.