Lymph node staging by positron emission tomography in patients with carcinoma of the cervix

Purpose: The aim of this study was to compare the results of computed tomography (CT) and positron emission tomography (PET) with [¹⁸F]-fluoro-2-deoxy-D-glucose (FDG) for lymph node staging in patients with carcinoma of the cervix and to evaluate the relationship of the imaging findings to prognosis. Patients and Methods: We retrospectively compared the results of CT lymph node staging and wholebody FDG-PET in 101 consecutive patients with carcinoma of the cervix. Patients were treated with standard irradiation and chemotherapy (as clinically indicated) and observed at 3-month intervals for a median of 15.4 months (range, 2.5 to 30 months). Progression-free survival was evaluated by the Kaplan-Meier method. Results: CT demonstrated abnormally enlarged pelvic lymph nodes in 20 (20%) and para-aortic lymph nodes in seven (7%) of the 101 patients. PET demonstrated abnormal FDG uptake in pelvic lymph nodes in 67 (67%), in para-aortic lymph nodes in 21 (21%), and in supraclavicular lymph node in eight (8%). The 2-year progression-free survival, based solely on para-aortic lymph node status, was 64% in CT-negative and PET-negative patients, 18% in CT-negative and PET-positive patients, and 14% in CT-positive and PET-positive patients (P < .0001). A multivariate analysis demonstrated that the most significant prognostic factor for progression-free survival was the presence of positive para-aortic lymph nodes as detected by PET imaging (P = .025). Conclusion: This study demonstrates that FDG-PET detects abnormal lymph node regions more often than does CT and that the findings on PET are a better predictor of survival than those of CT in patients with carcinoma of the cervix.