A prospective randomized trial to study the impact of pretreatment FDG-PET for cervical cancer patients with MRI-detected positive pelvic but negative para-aortic lymphadenopathy.

Abstract

This prospective randomized study was undertaken to determine the possible impact of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) on extrapelvic metastasis detection, radiation field design, and survival outcome for cervical cancer patients with enlarged pelvic nodes on MRI image. Inclusion criteria were patients with newly diagnosed Stage I-IVA cervical cancer and with positive pelvic but negative para-aortic lymph nodes (PALN) as detected by magnetic resonance image and good performance status for concurrent chemoradiotherapy. Eligible patients were randomized to receive either pretreatment FDG-PET (study group) or not (control group). Whole pelvis was the standard irradiation field for the control group and those with no extrapelvic findings on PET. The radiation fields for the rest of the study group were extended to include the PALN region or were modified according to the extrapelvic PET finding. From January 2002 to April 2006, 129 patients were included, and 66 of them were randomized to receive FDG-PET. PET detected seven extrapelvic metastases (11%, 6 PALN and 1 omental node), and four of them remained disease-free after treatment modification. For patients who underwent PET compared with those who did not, there were no differences in the 4-year rates of overall survival (79% vs. 85%, p = 0.65), disease-free survival (75 % vs. 77%, p = 0.64), and distant metastasis-free survival (82% vs. 78%, p = 0.83). Pretreatment FDG-PET in conjunction with magnetic resonance imaging can improve the detection of extrapelvic metastasis, mainly PALN, and help select patients for extended-field radiotherapy. However, the addition of FDG-PET may not translate into survival benefit, even though PALN relapses are reduced.