Early prediction of urinary retention following radical hysterectomy by 18F-FdG Pet/ct imaging

BACKGROUND: Radical hysterectomy for early cervical cancer is associated with postoperative bladder dysfunction. Postoperative imaging by 18F-FDG PET/CTscanning is often performed to rule out recurrence. Since women are instructed to empty the bladder before imaging, we aim to study if scanned abnormal residual bladder volume is associated with future urinary symptoms. METHODS: Women who underwent radical hysterectomy for cervical cancer between July 2010 and January 2019 were included in the study. Multi-Modality Tumor Tracking® (MMTT) was used to measure residual urinary volume on 18F-FDG PET/CTscans before and after hysterectomy. Demographic, clinical parameters, and urinary tract signs and symptoms, were evaluated among the cohort. RESULTS: Overall, 64 patients were included. Among those, in 24 (38%) the bladder volume reached ≥150 cm3 on postoperative 18F-FDG PET/CT scans. Of these, 9 (37.5%) had voiding difficulties of some degree. In 3 (12.5%) women, the 18F-FDG PET/CT scan has preceded their complaints of voiding difficulties by 2-4 months. Of the 40 women (62%) whose postoperative bladder volumes were <150 cm3, only 1 (2.5%) had urinary retention. Rate of symptomatic voiding difficulties was higher in the post-void volume ≥150 cm3 group; 13 (54.1%) vs. 6 (15.0%), P<0.002, Odds Ratio 95% Confidence Interval 6.6 (2.0-21.8), P=0.001. CONCLUSIONS: Measuring bladder volume on postoperative 18F-FDG PET/CT may facilitate early identification of urinary retention, possibly enabling early treatment and possibly preventing complications.