Apparent Diffusion Coefficient Can Predict Response to Chemotherapy of Liver Metastases in Colorectal Cancer

Abstract

The aim of this meta-analysis was to evaluate the suitability of apparent diffusion coefficient (ADC) as a predictor of response to systemic chemotherapy in patients with metastatic colorectal carcinoma (CRC). MEDLINE library, SCOPUS database, and EMBASE database were screened for relationships between pretreatment ADC values of hepatic CRC metastases and response to systemic chemotherapy. Overall, five eligible studies were identified. The following data were extracted: authors, year of publication, study design, number of patients, mean value ADC and standard-deviation, measure method, b-values, and Tesla-strength. The methodological quality of every study was checked according to the Quality Assessment of Diagnostic Studies-2 instrument. The meta-analysis was undertaken by employing RevMan 5.3 software. DerSimonian and Laird random-effects models with inverse-variance weights were used to account for heterogeneity. Mean ADC values including 95% confidence intervals were calculated. Five studies (n = 114 patients) were included. The pretreatment mean ADC in the responder group was 1.15 × 10-3 mm2/s (1.03, 1.28) and 1.37 × 10-3 mm2/s (1.3, 1.44) in the nonresponder group. An ADC baseline threshold of 1.2 × 10-3 mm2/s, below which no nonresponder was found, can distinguish both groups. The results indicate ADC can serve as a predictor of response to chemotherapy for CRC patients.