Preoperative risk stratification of patients with endometrial cancer with F-18 FDG PET/CT

Objectives The aim of this study is to evaluate the usefulness of F-18 FDG PET/CT for the preoperative differential diagnosis of high-risk and low-risk carcinoma in patients with endometrial cancer.

Methods Between Jul 2006 and Sep 2009, forty-five women (mean age, 53.9±9.9 y) diagnosed histologically as endometrial cancer underwent F-18 FDG PET/CT for preoperative staging work-up, and were treated by total hysterectomy. Maximum standardized uptake values (SUVmax) of each endometrial carcinoma were measured, and compared with the clinical and the histologic findings after surgery. The tumor aggressiveness was classified as high-risk carcinoma (FIGO stage ≥ Ic or histologic grade ≥ 2) and low-risk carcinoma (FIGO stage ≤ Ib and histologic grade = 1).

Results Twenty-five patients were diagnosed postoperatively as high-risk and 20 patients as low-risk. Patients with high-risk (12.1±7.2) showed higher SUVmax than patients with low-risk carcinoma (6.9±3.5,P<0.01). The optimal SUVmax cutoff value of 8.8, determined by ROC analysis, revealed 68% sensitivity and 85% specificity for risk stratification. Postmenopausal patients (11.6±7.8) showed higher SUVmax than premenopausal patients (7.2±3.0,P=0.02). And, patients with histologic grade 3 (20.6±10.6) showed higher SUVmax than patients with histologic grade 1 (7.4±4.2,P<0.01) or 2 (10.3±3.4,P<0.01), respectively. There was no significant difference in SUVmax between patient groups accord to histopathologic type, T stage, myometrial invasion, estrogen receptor status, progesterone receptor status and p53 gene status.

Conclusions Patients with high-risk endometrial cancer show higher SUVmax than patients with low-risk endometrial cancer, therefore F-18 FDG PET/CT can be applied to stratify risk in patients with endometrial cancer preoperatively