Evaluating the Role of F-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Scanning in the Staging of Patients With Stage IIIB Cervical Carcinoma and the Impact on Treatment Decisions.

Abstract

FIGO (International Federation of Gynaecology and Obstetrics) staging is currently the most widely used clinical staging system for cervical cancer; however, this staging system has many shortcomings. One of these shortcomings is that lymph nodal status, specifically the para-aortic lymph nodal status, does not get taken into account. It is known that metabolic changes occur before changes are seen on anatomical imaging, and it is therefore possible to detect metastases earlier with the help of fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT). We hypothesized that by including an FDG PET/CT study as part of the staging investigations in patients with invasive cervical cancer, pretreatment staging would improve and management would change in a significant proportion of patients. Patients diagnosed with FIGO stage IIIB cervical cancer from September 2010 to December 2015 received an FDG PET/CT study as part of their staging workup. A whole-body FDG PET/CT was performed before initiation of treatment, and the results were interpreted by experienced nuclear medicine physicians and radiologists. We determined the percentage of patients in whom PET/CT changed the stage and/or altered management of the patient. There were 95 patients diagnosed with stage IIIB cervix cancer during the study period who received an FDG PET/CT as part of their staging workup. Eighty-eight patients were included in the final sample. Positron emission tomography/CT affected the management of 40% of patients, with 19% requiring a change in the radiation field due to identification of para-aortic nodal involvement and 21% upstaged to stage IVB. Fluorodeoxyglucose PET/CT is useful in assessing distant disease and evaluating nodal involvement in patients with invasive cervical cancer. Additional findings on the PET/CT that were missed by conventional imaging and clinical examination caused treatment change in a significant proportion of patients.