Article Text
Abstract
Introduction/Background The objective of this study was to analyse the utility of pretreatment 18F-FDG-PET/CT metabolic parameters to predict non-complete cytoreduction in patients with epithelial ovarian cancer.
Methodology Transversal study on 50 patients with epithelial ovarian cancer at Clínica Universidad de Navarra who underwent pretreatment 18F-FDG-PET/CT and subsequent debulking surgery (R0 = complete, R1 = non-complete). The supra- and infradiaphragmatic metabolic active disease (primary tumor, peritoneal carcinomatosis and lymph nodes) visualized in the 18F-FDG-PET/CT was segmented using Syngo.via (automatic thresholding at 40% SUVmax and manual corrections). The extent and distribution of the peritoneal carcinomatosis was evaluated globally and throughout abdominopelvic regions. The presence of pathological 18F-FDG uptake of the ascites was also evaluated. Metabolic parameters studied were metabolic active tumor volume (MTV) and total lesion glycolysis (TLG, defined as MTVxSUVmean), calculated for each segmented region and for the whole disease. Other variables studied were age, FIGO and histological tumor type. The dependent variable was non-complete cytoreduction. Data were described by median (IQR) and frequency (%). Chi-squared and median test were used to compare groups and ROC analysis to dichotomize continuous variables. Predictors of non-complete cytoreduction were analysed by multiple logistic regression.
Results Patient´s characteristics are listed in table 1. Eleven patients (22%) showed non-complete cytoreduction, mostly associated to pathological uptake in ascites (60 vs 12,5%; OR= 10.5 95%CI: 2.2–50.7; p= 0.004), total MTV >192 (45.0 vs 6.7%; OR=11.5; 95%CI: 2.1–61.7; p=0.007; AUC=0.818) and MTV value of the whole infradiaphragmatic disease >209 (56.3 vs 5.9%; OR= 20.6; 95%CI: 3.6–116.8; p=0.010; AUC=0.818). Only the MTV of the whole infradiaphragmatic disease retains signification in the adjusted model.
Conclusion Despite the small sample size, this initial study highlights the possible role of some 18F-FDG-PET/CT metabolic parameters as predictors of non-complete cytoreduction in patients with epithelial ovarian cancer. Further validation in larger series is needed.