Health-Related Quality of Life and Toxicity After Definitive High-Dose-Rate Brachytherapy Among Veterans With Prostate Cancer
Purpose: High-dose-rate (HDR) brachytherapy (BT) is a well-tolerated and effective treatment for prostate cancer. There is limited research, however, investigating toxicity outcomes with HDRBT treatment among veterans. The objective of this study is to assess the impact on health-related quality of life (hrQOL) and physician-graded toxicities associated with HDRBT as monotherapy among veterans treated at Edward Hines, Jr. Veterans Affairs Hospital in Hines, Illinois.
Methods: Between 2016 and 2019, 74 veterans with low- or intermediate-risk prostate cancer were treated with HDRBT as monotherapy with 27 Gy in 2 fractions, delivered over 2 implants. Veteran-reported hrQOL in the genitourinary (GU), gastrointestinal (GI), and sexual domains was assessed using the International Prostate Symptoms Score (IPSS) and Expanded Prostate Cancer Index Composite (EPIC-26) questionnaire. Mixed linear effect models were used to assess differences in the hrQOL scores at follow-up compared with baseline scores. Statistically significant differences in hrQOL scores from baseline were further assessed for clinical significance, using minimal clinically important difference (MCID) evaluations.
Results: Median follow-up was 18 months. Veterans reported declines in GU, GI, and sexual hrQOL scores immediately after treatment, with the IPSS and EPIC-26 hrQOL scores all displaying significant decrease from baseline over time. The majority of the declines in hrQOL scores met criteria for MCID. These hrQOL scores trended toward a return to baseline, with the EPIC-26 urinary obstruction score returning to baseline at the 18-month follow-up assessment and the EPIC-26 bowel score returning to baseline at the 12-month follow-up. The IPSS, urinary incontinence, and sexual scores did not return to baseline at 18 months. The grade 2 maximum physician-graded GU, GI, and sexual toxicity rates were 65%, 5%, and 53%, respectively. There was 1 incidence of grade 3 GU toxicity but no grade 3 GI or sexual toxicity.
Conclusions: HDRBT as monotherapy is a well-tolerated treatment option for veterans with low- or intermediate-risk prostate cancer, with favorable veteran-reported and physician-graded toxicities. Veterans should be educated about HDRBT as an option when counseled regarding treatment for localized prostate cancer.
Our results mirror this experience, with similar rates of patient-reported hrQOL scores and physician-graded toxicities. Patients reported similar rates of decline in GU, GI, and sexual hrQOL after treatment. The patient-reported GU and GI hrQOL scores worsened immediately after treatment, with a return toward baseline over time. However, the patient-reported sexual hrQOL dropped after treatment and had a subtle trend toward a return to baseline. Our data show higher rates of maximum physician-graded GU toxicity rates of 23%, 65%, and 1% grade 1, 2, and 3, respectively. This is likely due in part to our prophylactic use of tamsulosin. Patients who continued tamsulosin after the implant out of preference were technically grade 2 based on CTCAE v5.0 criteria. GI and sexual toxicity were substantially lower with rates of 15% and 5% grade 1 and grade 2 bowel toxicity with no grade 3 events, and 15% and 52% grade 1 and grade 2 sexual toxicity, respectively.
Contreras and colleagues also reported on treating civilian patients with HDRBT as monotherapy for PC.17 They, too, found similar results as in our veteran study, with a rapid decline in GU, GI, and sexual hrQOL scores immediately after treatment. They also found a gradual return to baseline in the GU hrQOL scores. Contrary to our results, they reported a return to baseline in sexual hrQOL scores, while their patients did not report a return to baseline in the GI hrQOL scores.
Limitations
To the authors’ knowledge, there are no other studies exploring HDR prostate BT toxicity in a veteran-specific population, and our study is novel in addressing this question. One limitation of the study is the relatively short median follow-up time of 18 months. With this limitation, our data were not yet sufficiently mature to perform biochemical control or overall survival analyses. The next step in our study is to calculate these clinical endpoints from our data after longer follow-up.
An additional limitation to our study is the single institutional nature of the design. While veterans from neighboring VA hospitals were included in the study by way of referral and treatment at our center, the only VA hospital in the state to provide radiation therapy, our patient population remains limited. Further multi-institutional and prospective data are needed to validate our findings.
Conclusions
HDR prostate BT as monotherapy is feasible with a favorable veteran-reported hrQOL and physician-graded toxicity profile. Veterans should be educated about this treatment modality when considering the optimal treatment for their localized prostate cancer.
