Clinical Performance of Whole-Body 18F-FDG PET/Dixon-VIBE, T1-Weighted, and T2-Weighted MRI Protocol in Colorectal Cancer

Abstract

Purpose The aim of this study was to investigate the clinical performance of whole-body F-18-FDG PET/Dixon-volume-interpolated breath-hold examination (Dixon-VIBE), T1-weighted, and T2-weighted MRI protocol in patients with colorectal cancer. Patients and Methods A total of 59 patients with colorectal cancer were enrolled in this study. Each patient had one of the following clinical conditions: initial stage before therapy, stage after neoadjuvant therapy, suspicious colorectal liver metastases, and colorectal liver metastases after chemotherapy. Fourteen patients had primary colorectal cancer, whereas 38 patients had a total of 132 hepatic lesions, 53 lesions existed before chemotherapy, and 79 lesions appeared after chemotherapy. The primary stage and metastases images were obtained using our PET/Dixon-VIBE/T1/T2 MRI protocol and were analyzed by 2 nuclear medicine physicians. Diagnostic accuracy was compared with contrast-enhanced MRI images, which were based on surgical pathology results. Results The sensitivity of our imaging protocol for primary colorectal cancer was 100% (14/14). T and N stage both showed 92.9% (13/14) accuracy. Of all 132 hepatic lesions, 115 metastatic lesions were analyzed, and 17 benign lesions were excluded (6 were during pretreatment cases, and 11 were during posttreatment cases). In pretreatment metastatic lesions (n = 47), the sensitivities of our protocol and dedicated MRI were 95.7% (45/47) and 100% (47/47), respectively. In posttreatment lesions (n = 68), sensitivities of our protocol and dedicated MRI were 75% (51/68) and 91.2% (62/68), respectively. Conclusions Whole-body PET/Dixon-VIBE/T1/T2 MRI protocol is clinically useful for TNM staging and chemonaive hepatic metastasis in colorectal cancer.