Retrospective analysis of the 18F-FDG PET/CT cutoff value for metabolic parameters was performed as a prediction model to evaluate risk factors for endometrial cancer.

Abstract Purpose The study retrospectively analyzed the accuracy and predictive ability of preoperative integrated whole-body 18F-FDG PET/CT for the assessment of high-risk factors in patients with endometrial carcinoma (EC). Materials and methods A total of 205 patients with histologically curettage-confirmed endometrial cancer who underwent preoperative PET/CT at Shanghai General Hospital from January 2017 to December 2019 were retrospectively evaluated. 42 postmenopausal pathological confirmed endometrial atypical hyperplasia (EAH) were as control. Our study evaluated the ability and optimal cutoff values of three metabolic and volumetric parameters—standardized uptake value (SUV), metabolic tumor volume (MTV) and total lesion glycolysis (TLG)—to predict deep myometrial invasion (DMI), endocervical stroma invasion (ESI) and lymph node metastases (LNM) in endometrial cancer. The accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of PET/CT were used to assess the diagnostic performance for the prediction of the above risk factors. Results Our study demonstrated a significant relationship between SUVmax, SUVmean, MTV, and TLG on PET/CT and histologically confirmed DMI, ESI, and LNM in endometrial carcinoma (EC) (P < 0.01), with sensitivity, specificity, accuracy, PPV, and NPV of 100%/100%/100%, 96.53%/98.89%/87.14%, 97.56%/99.02%/91.22%, 92.42%/92.85%/78.31%, and 100%/100%/100%, respectively. The present study showed a risk model based on optimal cutoff values for MTV and TLG of 19.6 ml/126.3 g, 20.54 ml/84.80 g and 24 ml/49.83 g to preoperatively predict DMI, ESI, and LNM, respectively, in endometrial carcinoma (P  = 19.6 ml of MI and PET- positive LN with MTV cutoff > = 24 ml tended to predict poor OS and PFS. Conclusions These cutoffs of MTV and TLG in PET/CT assessment could be an independent prognostic factors to predict aggressive forms of EC.