van Son M, Peters M, Moerland M, van de Pol S, Eppinga W, Lagendijk J, van der Voort van Zyp J. Determining the safety of ultrafocal salvage high-dose-rate brachytherapy for radiorecurrent prostate cancer: A toxicity assessment of 150 patients.
Clin Transl Radiat Oncol 2020;
27:1-7. [PMID:
33364450 PMCID:
PMC7750686 DOI:
10.1016/j.ctro.2020.12.002]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 12/07/2020] [Accepted: 12/07/2020] [Indexed: 11/19/2022] Open
Abstract
Severe toxicity is as low as 3% (GU), 0% (GI) and 15% (ED).
Lower impact is predicted for patients with favorable function at baseline.
Lower dose to the urethra (D10% <17 Gy) may prevent urinary symptoms.
Background and purpose
Local re-treatment of radiorecurrent prostate cancer is potentially curative. However, the increased risk of severe toxicity may outweigh the opportunity of cancer control. This study aims to evaluate treatment-related toxicity from ultrafocal salvage high-dose-rate brachytherapy (HDR-BT) and to investigate potential risk factors.
Materials and methods
Toxicity data from 150 treated patients (July 2013–November 2019) was collected from a prospective registry. The treatment aim was to deliver a single dose of 19 Gy to the recurrent lesion as identified on multiparametric MRI and PET-CT. Treating physicians graded genitourinary (GU) and gastro-intestinal (GI) toxicity and erectile dysfunction (ED) using the Common Terminology Criteria for Adverse Events (CTCAE) 4.0, at baseline and during follow-up. Domains with substantial (≥10%) new-onset grade ≥ 2 toxicity were further evaluated using mixed effects logistic regression to find potential risk factors.
Results
Median follow-up time was 20 months (IQR 12–31). Over time, new-onset grade 2 and 3 toxicity was recorded in 41% and 3% (GU), 5% and 0% (GI) and 22% and 15% (ED). While GI toxicity remained stably low, grade ≥ 2 GU toxicity and ED were seen twice as frequent in the late phase (>3 months after treatment). Significant risk factors for grade ≥ 2 toxicity were baseline GU toxicity (grade ≥ 2), baseline ED (grade ≥ 2), IPSS (cut-off ≥ 14) and urethral dose (D10%, cut-off ≥ 17 Gy).
Conclusion
Ultrafocal salvage HDR-BT is a safe re-treatment option, especially in patients with a favorable symptom profile at baseline. Adherence to urethral dose constraints is important to avoid GU toxicity.
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