Absorbable hydrogel spacer use in men undergoing prostate cancer radiotherapy: 12 month toxicity and proctoscopy results of a prospective multicenter phase II trial

Radiat Oncol. 2014 Apr 24;9:96. doi: 10.1186/1748-717X-9-96.

Abstract

Background: Radiation therapy is one of the recommended treatment options for localized prostate cancer. In randomized trials, dose escalation was correlated with better biochemical control but also with higher rectal toxicity. A prospective multicenter phase II study was carried out to evaluate the safety, clinical and dosimetric effects of the hydrogel prostate-rectum spacer. Here we present the 12 months toxicity results of this trial.

Methods: Fifty two patients with localized prostate cancer received a transperineal PEG hydrogel injection between the prostate and rectum, and then received IMRT to a dose of 78 Gy. Gastrointestinal and genitourinary toxicity were recorded during treatment and at 3, 6 and 12 months following irradiation by using the RTOG/EORTC criteria. Additionally, proctoscopy was performed 12 months after treatment and the results were scored using the Vienna Rectoscopy Scale (VRS).

Results: Of the patients treated 39.6% and 12.5% experienced acute Grade 1 and Grade 2 GI toxicity, respectively. There was no Grade 3 or Grade 4 acute GI toxicity experienced in the study. Only 4.3% showed late Grade 1 GI toxicity, and there was no late Grade 2 or greater GI toxicity experienced in the study. A total of 41.7%, 35.4% and 2.1% of the men experienced acute Grade 1, Grade 2 and Grade 3 GU toxicity, respectively. There was no Grade 4 acute GU toxicity experienced in the study. Late Grade 1 and Grade 2 GU toxicity was experienced in 17.0% and 2.1% of the patients, respectively. There was no late Grade 3 or greater GU toxicity experienced in the study. Seventy one percent of the patients had a VRS score of 0, and one patient (2%) had Grade 3 teleangiectasia. There was no evidence of ulceration, stricture or necrosis at 12 months.

Conclusion: The use of PEG spacer gel is a safe and effective method to spare the rectum from higher dose and toxicity.

Publication types

  • Clinical Trial, Phase II
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Follow-Up Studies
  • Gastrointestinal Tract / radiation effects*
  • Humans
  • Hydrogel, Polyethylene Glycol Dimethacrylate / administration & dosage*
  • Hydrogel, Polyethylene Glycol Dimethacrylate / adverse effects*
  • Male
  • Neoplasm Staging
  • Organs at Risk / radiation effects*
  • Proctoscopy
  • Prognosis
  • Prospective Studies
  • Prostatic Neoplasms / radiotherapy*
  • Radiation Injuries / etiology*
  • Radiotherapy Dosage
  • Time Factors
  • Urogenital System / radiation effects*

Substances

  • Hydrogel, Polyethylene Glycol Dimethacrylate