Autologous fat transfer as prostate-rectal spacer: Technique description and early results

Abstract

Purpose: Several attempts have been made to increase the distance between the prostate and the rectum through injection of different synthetic compounds, generating space between organs. To report an original technique to increase the distance between the rectum and the prostate, by autologous fat implantation into the rectoprostatic space, with the aim of providing physical dosimetry protection and rectal dose sparing.

Methods: We prospectively evaluated twelve patients subjected to autologous fat implantation as recto-prostatic spacer subsequently receiving prostate either radical (n = 6), or salvage brachytherapy for local recurrence after external beam radiation therapy (EBRT) (n = 6). Standard permanent prostate brachytherapy seed implantation was performed through transperineal approach and under transrectal ultrasonography (TRUS) and template guidance. Prescribed D90 dose for Iodine - 125 monotherapy was 140 - 160 Gy, reduced by 30% for rescue cases to obtain a Rectum V100 under 1 cc.

Results: Lipo-transfer was completed in all 12 patients. Control CT scan at 1 month showed average distances of: 10.7 mm (range) (2.8 - 15.9 mm), 7.6 (1.8 - 11.6 mm) and 6.8 (4.2 - 8.3) mm at prostate base, middle and apex, respectively. Shortest separation distance observed was at apex and midline, while largest was observed the sides and at seminal vesicles level. Control CT at 3 months showed average distances of 9.6 mm (1.9 - 14.6 mm), 6.3 mm (1.8 - 10.2 mm) and 5.4 mm (3.8 - 7.2 mm) at prostate base, middle and apex, respectively. Most complications were minor.

Conclusion: Autologous fat transfer is a feasible and simple procedure for experienced practitioners with low complication rates, which allows dose escalation to the prostate.