Detection of nodal metastases by 18F-FDG PET/CT in apparent early stage ovarian cancer: A prospective study Mauro Signorelli a, ⁎, Luca Guerra b , Cecilia Pirovano a , Cinzia Crivellaro b,c , Robert Fruscio a , Alessandro Buda a , Marco Cuzzucrea a , Federica Elisei b , Lorenzo Ceppi a , Cristina Messa b,c a Department of Obstetrics and Gynecology, San Gerardo Hospital, Monza; University of Milan-Bicocca, Milan, Italy b Nuclear Medicine Department, San Gerardo Hospital, Monza, University of Milan-Bicocca, Milan, Italy c Fondazione Tecnomed, University Milano-Bicocca, Monza Italy HIGHLIGHTS • Prospective evaluation of nodal staging by PET/CT in ovarian cancer grossly limited to the pelvis. • High sensitivity and NPV. • PET/CT scan have a great impact as pretreatment imaging technique. abstract article info Article history: Received 7 March 2013 Accepted 20 August 2013 Available online 27 August 2013 Keywords: PET/CT Lymphadenectomy Early stage Ovarian cancer Background. The rate of nodal metastases in ovarian cancer macroscopically confined to the pelvis is about 15%–20%. Systematic pelvic and aortic lymphadenectomy improves staging but it is associated with increased morbidity and costs. The purpose of this study was to evaluate the role of 18F-FDG PET/CT in the pre-operative nodal metastases detection in ovarian cancer grossly confined to the pelvis. Methods. From 2006 to 2012, 68 consecutive women with epithelial ovarian cancer confined to the pelvis underwent 18F-FDG PET/CT followed by surgery inclusive of systematic pelvic and aortic lymphadenectomy (SAPL). 18F-FDG PET/CT images were analyzed and correlated to histological examination. Results. Twenty-six women underwent bilateral and 42 unilateral SAPL with 3165 nodes removed and ana- lyzed. Median number of dissected nodes was 42 (range 16–91). Twelve women (17.6%) had nodal metastases. 18F-FDG PET/CT correctly identified 10 patients with nodal involvement. Sensitivity, specificity, accuracy, posi- tive and negative-predictive value of 18F-FDG PET/CT in detecting nodal metastases were 83.3%, 98.2%, 95.6%, 90.9% and 96.5%, respectively, on overall patient-based, and 75.5%, 99.4%, 98.1%, 87.5% and 98.6%, respectively, on nodal lesion site-based analysis. Conclusion. 18F-FDG PET/CT is an accurate tool for the detection of nodal metastases. Metabolic imaging could be used to select women who could benefit from systematic lymphadenectomy. The high negative predictive value allows avoidance of SAPL in the vast majority of women, minimizing operative and post surgical complica- tions. Further larger prospective investigation is required to confirm our data. © 2013 Elsevier Inc. All rights reserved. Introduction Epithelial ovarian cancer has the ninth highest incidence among all cancers and it represents the fifth highest cause of site-specific cancer deaths among women in the Western countries [1]. Almost 70% of cases are diagnosed at an advanced stage, with a 5-year overall survival (OS) of 35%–50%. Only 30% of all cases are diagnosed at an early stage and have a good prognosis, being the 5-year OS 85%–95% [2,3]. The optimal treatment of early stage ovarian cancer is currently based on surgery, in- cluding hysterectomy, bilateral salpingo-oophorectomy, omentectomy, peritoneal biopsies, systematic pelvic and aortic lymphadenectomy (SAPL) and adjuvant platinum-based chemotherapy according to risk fac- tors [2–4]. Lymphatic spread in ovarian cancer, even when the tumor is appar- ently limited to the ovaries or the pelvis, is not uncommon [5–9]. A re- cent meta-analysis by Kleppe and colleagues showed an overall incidence of nodal metastases of 14.2% (3.3% pelvic only, 6.7% aortic only and 4.3% both pelvic and aortic nodes). The risk of nodal metastases is very low in grade 1 and in mucinous histologic subtype, while it is about 15%–30% in undifferentiated or serous histologic subtypes and grade 2–3 cancers [10]. While in advanced-stage disease SAPL is part of the strategy of optimal debulking, in early-stage ovarian cancer, it is primarily a staging procedure, allowing selection of the appropriate Gynecologic Oncology 131 (2013) 395–399 ⁎ Corresponding author. Fax: +39 039 2333820. E-mail address: maurosignorelli78@gmail.com (M. Signorelli). 0090-8258/$ – see front matter © 2013 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.ygyno.2013.08.022 Contents lists available at ScienceDirect Gynecologic Oncology journal homepage: www.elsevier.com/locate/ygyno