Hydrogel injection reduces rectal toxicity after radiotherapy for localized prostate cancer

Abstract

Purpose: Injection of a hydrogel spacer before prostate cancer radiotherapy (RT) is known to reduce the dose to the rectal wall. Clinical results from the patient's perspective are needed to better assess a possible benefit.

Methods: A group of 167 consecutive patients who received prostate RT during the years 2010 to 2013 with 2‑Gy fractions up to 76 Gy (without hydrogel, n = 66) or 76-80 Gy (with hydrogel, n = 101) were included. The numbers of interventions resulting from bowel problems during the first 2 years after RT were compared. Patients were surveyed prospectively before RT, at the last day of RT, and at a median of 2 and 17 months after RT using a validated questionnaire (Expanded Prostate Cancer Index Composite).

Results: Baseline patient characteristics were well balanced. Treatment for bowel symptoms (0 vs. 11 %; p < 0.01) and endoscopic examinations (3 vs. 19 %; p < 0.01) were performed less frequently with a spacer. Mean bowel function scores did not change for patients with a spacer in contrast to patients without a spacer (mean decrease of 5 points) >1 year after RT in comparison to baseline, with 0 vs. 12 % reporting a new moderate/big problem with passing stools (p < 0.01). Statistically significant differences were found for the items "loose stools", "bloody stools", "painful bowel movements" and "frequency of bowel movements".

Conclusion: Spacer injection is associated with a significant benefit for patients after prostate cancer RT.

Keywords: Prostate neoplasm; Quality of life; Questionnaires; Radiotherapy, image-guided; Radiotherapy, intensity-modulated; Spacer.