Posttherapy surveillance monitoring of cervical cancer by FDG-PET

Purpose: To evaluate the effect of irradiation and chemotherapy for carcinoma of the uterine cervix on posttreatment tumor uptake of the glucose analog ¹⁸F-fluorodeoxyglucose (FDG) imaged by positron emission tomography (PET) and to assess the utility of FDG-PET for surveillance monitoring. Methods and Materials: This was a retrospective review of 76 patients with a new diagnosis of carcinoma of the uterine cervix who underwent pre- and posttreatment whole-body FDG-PET. Posttreatment FDG-PET was performed 2.4-10.4 months (median 4.2) after irradiation completion. Results: After treatment, persistent abnormal FDG uptake in the cervix was found in 18% (14 of 76), in the pelvic lymph nodes in 16% (9 of 55), in the paraaortic lymph nodes in 45% (5 of 11), and in the supraclavicular lymph nodes in 75% (3 of 4). Eleven patients developed new sites of increased FDG uptake. In relation to the findings on posttreatment PET, the 2-year progression-free survival rate was 86% for patients with no abnormal FDG uptake at any site and 40% for those with persistent abnormal uptake; there were no survivors at 2 years among patients who developed new sites of abnormal FDG uptake (p <0.0001). A multivariate analysis of prognostic factors demonstrated that any posttreatment abnormal FDG uptake (persistent or new) was the most significant prognostic factor (p <0.0001) for death from cervical carcinoma. Conclusion: FDG-PET is a valuable tool to evaluate the response of primary cervical carcinoma and lymph node metastasis to treatment and for the surveillance of patients after initial therapy.