The prognostic value of functional tumor volume and total lesion glycolysis in patients with colorectal cancer liver metastases undergoing ^sup 90^Y selective internal radiation therapy plus chemotherapy

Functional tumor volume (FTV) and total lesion glycolysis (TLG) are measures of metabolic activity of tumors determined by fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT images. These parameters could potentially have clinical value in response to treatment evaluation and disease prognostication. The objectives of this study were to investigate the relationship between functional tumor parameters (FTV and TLG) and clinical outcomes in patients with colorectal cancer liver metastases (CRCLM) undergoing ^sup 90^Y-resin microsphere selective internal radiation therapy (SIRT) (SIR-Spheres®, Sirtex Medical Limited, Lane Cove, NSW, Australia). FDG PET/CT studies of 20 patients with unresectable CRCLM who underwent ^sup 90^Y SIRT under a phase II clinical trial were analyzed. FTV and TLG were calculated using PET VCAR (GE Healthcare, Milwaukee, WI, USA) on pretreatment and 4-week posttreatment scans. The effects of pretreatment and posttreatment functional tumor activity on patient survival were evaluated using Kaplan-Meier survival curves. The median survival in the study group was 14.8 months (range 2.0-27.7 months). The median survival for patients with pretreatment FTV values of above and below 200 cc were 11.2 and 26.9 months, respectively (p