Efficacy of PET/CT in the accurate evaluation of primary colorectal carcinoma

Aim: This study was performed to assess in the accurate evaluation of primary colorectal carcinoma using PET/CT. Methods: One hundred patients with primary colorectal carcinoma were evaluated during 2004. All patients underwent PET/CT when their preoperative serum carcinoembryonic antigen was ≥10 ng/mL or when CT showed equivocal findings. The appropriateness of PET/CT-induced changes was noted by subsequent operative findings and follow-up. Results: PET/CT more detected 15 intra-abdominal metastatic lesions than abdomino-pelvic CT scan. PET/CT showed true negative findings in 13 patients and false positive or negative findings in 10. Due to PET/CT results, management plans were altered in 27 patients; 9 had inter-modality changes, 10 received more extensive surgery, and 8 avoided unnecessary procedures. Conclusions: PET/CT altered management plan in 24% of patients with primary colorectal carcinoma in correct direction. These findings suggest that PET/CT should be considered a part of standard work up for preoperative evaluation in a subset of patients with colorectal carcinoma.