FDG PET-CT in cervical cancer: relationship between primary tumor FDG uptake and metastatic potential

OBJECTIVEWe retrospectively evaluated the relationships between primary tumor F-fluorodeoxyglucose (FDG) uptake measured as the maximum standardized uptake value (SUVmax) and local extension, and nodal or distant metastasis in patients with cervical cancer on pretreatment FDG positron emission tomography–computed tomography (PET-CT). METHODSForty-three patients (mean age, 55.14 years; range, 34–90 years) with cervical cancer who underwent FDG PET-CT scans for staging before the initiation of treatment were included in the study. Primary tumor SUVmax was calculated; clinical tumor stages, presence of local extension, sites of lymph node and distant organ metastases were recorded. The patients were divided into low and high SUV groups by using the median primary tumor SUVmax. The low SUV group consisted of 21 patients with SUVmax less than 13.5, the high SUV group consisted of 22 patients with SUVmax ≥13.5. Their data were compared statistically. RESULTSThe average SUVmax was 9.6±2.6 and 19.9±4.9 in the low and high SUV groups, respectively. In the low SUV group, six patients (29%) had a local extension, eight (38%) had pelvic and/or para-aortic lymph node metastasis, and one had distant organ metastasis (4.7%). In the high SUV group, 10 patients (45%) had a local extension, 16 (73%) had pelvic and/or para-aortic lymph node metastasis, and two (9%) had distant organ metastases. There was a significant difference in the lymph node metastasis rate between the two groups (P0.05). In addition, there was a moderate correlation between SUVmax and clinical tumor stages (r=0.40, P=0.0075). CONCLUSIONHigher primary tumor FDG uptake predicts higher nodal metastatic potential in cervical cancer patients. Patients with higher SUVmax in cervical tumor may need a close follow-up because of their higher metastatic potential.