A pooled long-term follow-up after radiotherapy for prostate cancer with and without a rectal hydrogel spacer: impact of hydrogel on decline in sexual quality of life

Zachary A Seymour; Michael Pinkawa; Stephanie Daignault-Newton; Walter Bosch; Jeff M Michalski; Hiram Gay; Daniel A Hamstra

doi:10.3389/fonc.2023.1239104

A pooled long-term follow-up after radiotherapy for prostate cancer with and without a rectal hydrogel spacer: impact of hydrogel on decline in sexual quality of life

Front Oncol. 2023 Oct 11:13:1239104. doi: 10.3389/fonc.2023.1239104. eCollection 2023.

Authors

Zachary A Seymour^{1

2}, Michael Pinkawa^{3

4}, Stephanie Daignault-Newton⁵, Walter Bosch⁶, Jeff M Michalski⁶, Hiram Gay⁶, Daniel A Hamstra^{1

7}

Affiliations

¹ Department of Radiation Oncology, Beaumont Health, Dearborn, MI, United States.
² William Beaumont School of Medicine, Oakland University, Rochester, MI, United States.
³ Department of Radiation Oncology, Rheinisch-Westfälische Technische Hochschule (RWTH) Aachen University, Aachen, Germany.
⁴ Department of Radiation Oncology, Robert Janker Klinik, Bonn, Germany.
⁵ Department of Biostatistics, Michigan Medicine, Ann Arbor, MI, United States.
⁶ Department of Radiation Oncology and School of Medicine, Washington University, St. Louis, MO, United States.
⁷ Department of Radiation Oncology, Baylor College of Medicine, Houston, TX, United States.

Abstract

Purpose: The purpose of this study was to analyze the impact of prostate rectal spacers on sexual quality of life (QOL) following external beam radiation therapy (RT).

Methods and materials: Patient- reported QOL was evaluated using the Expanded Prostate Cancer Index Composite (EPIC). Patients were pooled from two sources: a randomized controlled trial and a non-randomized cohort of patients from a single institution. Both cohorts used the same spacing product and QOL instrument. Analysis was limited to those with good baseline pre-treatment sexual QOL (EPIC >/= 60). Differences in QOL summary score and individual items were assessed compared with baseline and between treatment arms.

Results: A total of 128 men had good baseline sexual function and were evaluated (64% with spacer and 36% without) with QOL data available for median 33 months (range: 2.5-69.4 months). Men without spacer were more likely to have declines in sexual function (p < 0.0001), bother (p = 0.0002), and sexual summary score (p < 0.0001). A minimally important difference of 10 points (1xMID) and 20 point (2xMID) was more likely without rectal spacer [10 points: odds ratio 3.53, (95% confidence interval 1.11-11.2), p = 0.032; 20 points: odds ratio 3.29, (95% confidence interval 1.16-9.33), p = 0.025]. Seven of 13 QOL items were statistically superior with hydrogel (six of nine functional and one of four bother), while no items were statistically superior for control. At baseline, more men treated with hydrogel had erections sufficient for intercourse; however, when analyzed only by the men with best baseline erectile potential and excluding those with worse function, the benefit of rectal spacing was maintained with a higher likelihood of preservation of erections sufficient for intercourse in those treated with hydrogel.

Conclusion: In this pooled analysis of QOL after prostate RT, the utilization of a hydrogel spacer was associated with better sexual QOL, less men with measurable declines in sexual QOL, and higher rates of adequate erectile function.

Keywords: prostate; quality of life; radiation; rectal spacer; sexual function.

Grants and funding

No funding was received for the performance of this secondary analysis. However, the phase 3 trial presented in this study was funded by Augmenix Inc. (now Boston Scientific). The funder was not involved in the study design, collection, analysis, interpretation of data, the writing of this article or the decision to submit it for publication. SD-N, WB, JM, HG, and DH received funding for part of this phase 3 trial outside the scope of the current work.