Prognostic significance of preoperative 18F-FDG PET/CT in uterine leiomyosarcoma

OBJECTIVE Uterine leiomyosarcoma (LMS) is a rare and aggressive disease with poor outcome. Due to its rarity and conflict of data, investigation on finding prognostic factor is challenging. The aim of the study was to investigate the prognostic significance of preoperative ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) in uterine LMS. METHODS This was a retrospective observational cohort study in 3 tertiary referral hospitals. We retrospectively evaluated data from patients with pathologically proven uterine LMS who underwent preoperative ¹⁸F-FDG PET/CT scans at 3 institutions. The prognostic implication of PET/CT parameters and other clinico-pathological parameters on disease-free survival (DFS) and overall survival (OS) was evaluated. RESULTS Clinico-patholgical data were reviewed for 19 eligible patients. In the group overall, median DFS and OS were 12 and 20 months, respectively. As for the recurrence, large tumor size, and high tumor maximum standardized uptake value (SUVmax) were demonstrated as risk factors of recurrence. As for the OS, high tumor SUVmax was demonstrated as the unique risk factor. There were significant differences in tumor size, mitotic count, SUVmax, and DFS between patients with and without recurrence. Also, there were significant differences in tumor size, SUVmax, DFS, and OS between 2 subgroups stratified by cut-off SUVmax. CONCLUSION SUVmax at preoperative ¹⁸F-FDG PET/CT was associated with worse outcome in patients with uterine LMS. In the preoperative setting, SUVmax can be a valuable non-invasive prognostic marker. Additionally, SUVmax can help identify highly aggressive uterine LMS and may help in adjusting standard treatment toward an individualized, risk-adapted treatment.