Prospective Analysis of Hydrogel Spacer for Patients With Prostate Cancer Undergoing Radiotherapy

BJU Int. 2018 Sep;122(3):427-433. doi: 10.1111/bju.14192. Epub 2018 Apr 10.


Objective: To report on the dosimetric benefits and late toxicity outcomes after injection of hydrogel spacer (HS) between the prostate and rectum for patients treated with prostate radiotherapy (RT).

Patients and methods: In all, 76 patients with a clinical stage of T1-T3a prostate cancer underwent general anaesthesia for fiducial marker insertion plus injection of the HS into the perirectal space before intensity-modulated RT (IMRT) or volumetric-modulated arc RT (VMAT). HS safety, dosimetric benefits, and the immediate- to long-term effects of gastrointestinal (GI) toxicity were assessed.

Results: There were no postoperative complications reported. The mean (range) prostate size was 66.0 (25.0-187.0) mm. Rectal dose volume parameters were observed and the volume of rectum receiving 70 Gy (rV70 ), 75 Gy (rV75 ) and 78 Gy (rV78 ) was 7.8%, 3.6% and 0.4%, respectively. In all, 21% of patients (16/76) developed acute Grade 1 GI toxicities, but all were resolved completely by 3 months after treatment; whilst, 3% of patients (2/76) developed late Grade 1 GI toxicities. No patients had acute or late Grade ≥2 GI toxicities.

Conclusion: Injection of HS resulted in a reduction of irradiated rectal dose volumes along with minimal GI toxicities, irrespective of prostate size.

Keywords: #PCSM; #ProstateCancer; hydrogel spacer; intensity-modulated RT; volumetric-modulated arc RT.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Fiducial Markers / adverse effects*
  • Follow-Up Studies
  • Humans
  • Hydrogels / administration & dosage*
  • Hydrogels / adverse effects
  • Male
  • Middle Aged
  • Prospective Studies
  • Prostate / pathology
  • Prostate / radiation effects
  • Prostatic Neoplasms / radiotherapy*
  • Radiation Injuries / epidemiology
  • Radiation Injuries / etiology
  • Radiometry
  • Radiotherapy Dosage
  • Radiotherapy Planning, Computer-Assisted / adverse effects
  • Radiotherapy Planning, Computer-Assisted / methods
  • Radiotherapy, Intensity-Modulated / adverse effects
  • Radiotherapy, Intensity-Modulated / methods*
  • Rectum / radiation effects


  • Hydrogels