Peri-urethral calcifications as a potential biomarker for acute genitourinary toxicity following prostate stereotactic body radiotherapy
Year: 2026
Type: article
Study design: Observational Study
Abstract: Background and Objectives: Peri-urethral calcifications (PUCs) are readily identifiable on planning computed tomography (CT) and may reflect chronic inflammation, fibrosis, and reduced peri-urethral tissue compliance. We evaluated whether baseline PUCs are associated with acute genitourinary (GU) toxicity following prostate stereotactic body radiotherapy (SBRT). Methods: We retrospectively analyzed 60 consecutive patients with localized prostate adenocarcinoma treated with definitive SBRT between June 2023 and February 2026. PUCs were assessed on non-contrast planning CT using predefined criteria by blinded observers. The primary endpoint was acute grade ≥ 2 GU toxicity occurring during treatment or within 90 days, graded according to CTCAE v5. Associations with toxicity were evaluated using logistic regression, with Firth penalized regression used for multivariable analysis. Results: PUCs were identified in 17 patients (28.3%). Interobserver agreement was high (93.3%; Cohen's κ = 0.84). Overall, 21 patients (35%) developed acute grade ≥ 2 GU toxicity, including three (5%) with grade ≥ 3 toxicity. Acute grade ≥ 2 GU toxicity occurred significantly more frequently in patients with PUCs than in those without PUCs (64.7% vs 23.3%; OR 6.05, 95% CI 1.78–20.51; P = 0.006). After adjustment for baseline International Prostate Symptom Score (IPSS), PUCs remained independently associated with toxicity (adjusted OR 6.90, 95% CI 1.97–27.96; P = 0.002). Baseline IPSS was also independently associated with toxicity (adjusted OR 1.13 per point; P = 0.008). Conclusion: PUCs on routine planning CT were independently associated with acute grade ≥ 2 GU toxicity after prostate SBRT. If externally validated, PUC assessment may provide a simple, cost-neutral imaging biomarker for pretreatment urinary toxicity risk stratification.
Institution: Rebecca Sieff Hospital
Language: English
Subfield: Urology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,430
OpenAlex ID: W7222093679