Preoperative imaging with positron emission tomography and computed tomography (18F-FDG PET/CT) or contrast-enhanced computed tomography (CECT) scan in operable cervical cancer: a prospective study

Abstract

We evaluated the accuracy of preoperative PET/CT and CECT for lymph node staging in cervical cancer, which is relevant in the context of recently revised staging. Patients with International Federation of Gynaecology and Obstetrics (FIGO) 2009 stage IB1–IB2 cervical cancer underwent preoperative 18F-FDG PET/CT and CECT abdomen and pelvis. Lymph nodes in various anatomical stations (paraaortic, various right and left pelvic regions) were scored separately as involved or not involved on both imaging modalities and compared with histopathology. The sensitivity and specificity of PET/CT and CECT were estimated for each lymph node station, and all lymph node stations combined, per patient. The study population comprised 57 patients (stage IB1 37, IB2 19) with median age of 45 (32–64) years, 39 (68.7%) with squamous carcinoma, median tumor size of 3.1 (0.5–9.0) cm, mean (range) lymph node harvest of 23.5 (8–46), and 13 (22.8%) patients with histopathologically positive lymph node(s). The sensitivity and specificity of PET/CT for various pelvic lymph node stations were 22.2–100% and 96.3–100%, respectively, and of CECT were 22.2–100% and 96.2–100%, respectively. At patient level, for all lymph node stations combined, the sensitivity and specificity of PET/CT and CECT were 53.9% (95% confidence interval (CI), 26.8%–80.9%) and 90.5% (95% CI, 81.6%–99.4%), and 69.2% (95% CI, 44.1%–94.3%) and 95.0% (95% CI, 88.3%–100%), respectively. Primary tumor maximum standardized uptake value (SUVmax) was the only independent prognostic factor for overall survival. The sensitivity of PET/CT and CECT for lymph node staging in operable cervical cancer is modest, and these modalities can miss lymph node involvement, but they have high specificity and, when indicative of lymph node involvement, may be clinically useful in triaging patients for primary chemoradiation therapy.