Published online Oct 15, 2009. doi: 10.4251/wjgo.v1.i1.55
Revised: February 17, 2009
Accepted: February 24, 2009
Published online: October 15, 2009
AIM: To evaluate the value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in the restaging of resected rectal cancer.
METHODS: From January 2007 to Sep 2008, 21 patients who had undergone curative surgery resection for rectal carcinoma with suspicious relapse in conventional imaging or clinical findings were retrospectively enrolled in our study. The patients underwent 28 PET/CT scans (two patients had two scans, one patient had three and one had four scans). Locoregional recurrences and/or distant metastases were confirmed by histological analysis or clinical and imaging follow-up.
RESULTS: Final diagnosis was confirmed by histopathological diagnosis in 12 patients (57.1%) and by clinical and imaging follow-up in nine patients (42.9%). Eight patients had extrapelvic metastases with no evidence of pelvic recurrence. Seven patients had both pelvic recurrence and extrapelvic metastases, and two patients had pelvic recurrence only. 18F-FDG PET/CT was negative in two patients and positive in 19 patients. 18F-FDG PET/CT was true positive in 17 patients and false positive in two. The accuracy of 18F-FDG PET/CT was 90.5%, negative predictive value was 100%, and positive predictive value was 89.5%. Five patients with perirectal recurrence underwent 18F-FDG PET/CT image guided tissue core biopsy. 18F-FDG PET/CT also guided surgical resection of pulmonary metastases in three patients and monitored the response to salvage chemotherapy and/or radiotherapy in four patients.
CONCLUSION: 18F-FDG PET/CT is useful for evaluating suspicious locoregional recurrence and distant metastases in the restaging of rectal cancer after curative resection.