Role of Integrated PET-CT in Pelvic Lymph Node Staging of Cervical Cancer Before Radical Hysterectomy

Abstract

Integrated positron emission tomography-computed tomography (PET-CT) with fluoro-2-deoxy-D-glucose (FDG) is a noninvasive technique that can depict different primary and metastatic tumor types on the basis of the increased glucose metabolism of malignant tissue. Some investigators believe that FDG PET is useful in detecting metastatic pelvic lymph nodes (LNs) especially in locally-advanced cervical cancer. The results of clinical studies, however, have been controversial, and the predictive value of PET-CT for the assessment of pelvic LNs in early-stage cervical cancer is unclear. This retrospective study examined the accuracy and feasibility of preoperative FDG PET-CT for primary pelvic LN staging in patients with operable cervical cancer. Between 2003 and 2007, the investigators identified through medical records 34 patients with invasive International Federation of Gynecology and Obstetrics (FIGO) stage IA2-IIB cervical cancer who underwent preoperative FDG PET-CT before type II or III radical hysterectomy and pelvic lymphadenectomy. The sensitivity, specificity, accuracy, and positive and negative predictive values for metastasis detection with PET-CT were calculated in relation to results of histological analysis following surgery. Seventeen of the 34 patients (50.0%) had pelvic LN metastases. The median number of harvested LNs was 29. Analysis of the accuracy of PET-CT scan in cervical cancer showed that overall region-specific sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of PET-CT were 36.4, 98.8, 85.7, 88.9, and 88.7%, respectively. The recurrence rates among patients with positive preoperative PET-CT scans were significantly higher than those with negative scans (3/8 versus 1/26, respectively, P = 0.03). These data show that preoperative integrated PET-CT has limited sensitivity, but high specificity in predicting pelvic LN metastasis in the staging of invasive cervical cancer, and may be useful for identifying patients at higher risk for cervical cancer recurrence.