Low value of [¹⁸F]-fluoro-2-deoxy-D-glucose positron emission tomography in primary staging of early-stage cervical cancer before radical hysterectomy

Purpose: The role of positron emission tomography (PET) with [ ¹⁸F]-fluoro-2-deoxy-D-glucose (FDG) in early-stage cervical cancer is unclear. We aimed to investigate the clinical benefit of FDG-PET in primary staging before radical hysterectomy and pelvic lymphadenectomy (RH-PLND). Patients and Methods: Patients with untreated stage IA2 to IIA adenocarcinoma (AD) or adenosquamous carcinoma (ASC) or nonbulky (≤ 4 cm) squamous cell carcinoma cervical cancer with magnetic resonance imaging (MRI) - defined negative nodal metastasis were enrolled onto a prospective study with a two-stage design. All patients had a preoperative dual-phase FDG-PET, technetium-99m-sulfur colloid lymphoscintigraphy, and intraoperative sentinel lymph node (LN) detection at RH-PLND. The gold standard of LN metastasis is histologic. A sample size of 120 patients was calculated to fit study aims (diagnostic efficacy of PET and sentinel LN sampling). An interim analysis was performed when 60 patients were accrued, which led to the current report. Results: There were 36 SCCs, 20 ADs, and four ASCs. Of the 60 patients, 10 (16.7%) had pelvic LN metastases, and one (1.7%) had para-aortic LN (PALN) metastasis histologically. FDG-PET detected the single PALN metastasis (one of one patient) but detected only one (10%) of the 10 pelvic LN metastases. The PET false-negative pelvic LN micrometastases measured a median of 4.0 X 3.0 mm (range, 0.5 X 0.5 to 7 X 6 mm). The second stage of this trial will be continued without PET. Conclusion: This study shows that dual-phase FDG-PET has little value in primary, nonbulky, stage IA2 to IIA and MRI-defined, LN-negative cervical cancer.