The utility of PET/CT in the management of patients with colorectal liver metastases undergoing laparascopic radiofrequency thermal ablation.

Background: There are scant data in the literature about the use of PET in the management of patients undergoing RFA of colorectal liver metastases (CLM). The aim of this study is to look at the use of PET versus contrast-enhanced CT (ce CT) scans on the initial assessment and follow-up of patients with CLM undergoing laparoscopic RFA.

Methods: The patients who had PET scans pre-RFA and post-RFA were identified from a prospective IRB-approved database within a 14-year period. The findings of PET scans were compared to those of ce CT. Kaplan-Meier survival, Cox proportional hazards, t test, and chi square analyses were performed.

Results: A total of 134 patients had PET scans prior to laparoscopic RFA and 104 (28%) had PET/CT scans in follow-up, with comparison ce CT done within a month in 82 patients. In follow-up, PET/CT findings were equivalent to ce CT in 55 patients (67%), superior in 22 (27%), and inferior in 5 (6%). Pre-RFA or post-RFA PET imaging did not affect overall survival. The patients in whom the benefit of PET/CT was most were those with multiple bilobar tumors.

Conclusions: Although, there was no survival benefit, PET/CT was superior to ce CT in demonstrating recurrence after RFA in about a quarter of the patients with CLM. The patients who would benefit most from a PET/CT seem to be those with multiple and bilobar tumors, who develop liver recurrence in follow-up after RFA.