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

Abstract

Objective: We retrospectively evaluated the relationships between primary tumor F-fluorodeoxyglucose (FDG) uptake measured as the maximum standardized uptake value (SUV(max)) and local extension, and nodal or distant metastasis in patients with cervical cancer on pretreatment FDG positron emission tomography-computed tomography (PET-CT).

Methods: Forty-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 SUV(max) 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 SUV(max). The low SUV group consisted of 21 patients with SUV(max) less than 13.5, the high SUV group consisted of 22 patients with SUV(max) > or = 13.5. Their data were compared statistically.

Results: The average SUV(max) 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 (P<0.05), but differences in local extension and distant organ metastasis were not statistically significant (P>0.05). In addition, there was a moderate correlation between SUV(max) and clinical tumor stages (r=0.40, P=0.0075).

Conclusion: Higher primary tumor FDG uptake predicts higher nodal metastatic potential in cervical cancer patients. Patients with higher SUV(max) in cervical tumor may need a close follow-up because of their higher metastatic potential.