PET-CT accurately predicts the pre-operative characteristics of colorectal hepatic metastases

BackgroundSince 2002, Positron Emission Tomography (PET-CT) has been considered to be an essential pre-operative investigation in the management of colorectal liver metastases (CRLM) in our institution. This study aimed to compare characteristics of hepatic metastases on PET-CT with post-operative histological findings and pathology of the primary tumour.MethodsAll patients with CRLM, who underwent surgical intervention from 2002 to 2008, were reviewed. PET-CT and pathology reports of hepatic resections and original colorectal resections were retrieved. Patient demographics, colorectal staging, number of metastases and their maximum diameter from both PET-CT and pathology reports were recorded. Values were expressed as mean (±SD).Results141 patients were identified. The maximum diameter on PET-CT (4.2 ± 2.6) was similar to pathology (4.8 ± 3.6; p = 0.39), with significant correlation (r = 0.72, p < 0.0001). The number of lesions on PET-CT (1.6 ± 1.0) was similar to pathology (1.7 ± 1.3; p = 0.43) with significant correlation (r = 0.80, p < 0.0001). Mean SUV max was 9.22 (±4.39), with no correlation to lesion diameter (r = 0.25, p = 0.045), but significantly increased with decreasing differentiation (p = 0.01).ConclusionsPET-CT scanning accurately detected the number of lesions and their maximum diameter, with radiological evidence of poorer differentiation. Further studies of non-surgical patients are required to assess its overall accuracy.