S169
Brachytherapy - Urology
ESTRO 2026
GU toxicity was similar (32.4% vs 20.9%), nocturia being the most frequent symptom. Six patients (three per arm) developed G3 events. Acute GI toxicity ocurred in 21% (19% vs 25%), all grade ≤ 2. The most common symptom was proctitis. Late GI toxicity was 17.7% (16.2% vs 20.9%), with one G3 rectal bleeding in HDR-SBRT group.A transient, non-significant QOL decline was noted one month post-radiotherapy in both arms across all domains, with full recovery thereafter. In patients without ADT, sexual QOL was slightly lower in the SBRT group (Figure 1).Ten patients (4.8%) developed biochemical failure (five per arm), seven with metastatic progression and one with regional recurrence. One prostate cancer-related death ocurred during follow-up.
Voet, William Chu, Andrew Loblaw, Daniel Ford, et al. 2022 “Intensity-modulated radiotherapy versus stereotactic body radiotherapy for prostate cancer (PACE-B): 2-year toxicity results from an open-label, randomised, phase 3, non-inferiority trial” The Lancet Oncology October Volume 23, Issue 10 p1308-1320.
Poster Discussion 3481
SBRT with HDR boost vs SBRT alone: a prospective comparative analysis of side effects, quality of life and disease control. Laura Zaragoza 1 , David Büchser 2 , Libe Del Castillo 2 , Ana Hompanera 2 , Uxue Ruiz-Epelde 2 , Carlos Mascarell 2 , Jon Cacicedo 2 , Alfonso Gomez-Iturriaga 2 1 Radiation Oncology, Hospital la Paz, Madrid, Spain. 2 Radiation Oncology, Hospital de Cruces, Bilbao, Spain Purpose/Objective: To compare tolerance, disease control and impact on Quality of life (QOL) between two treatment modalities for localized prostate cancer (PCa): exclusive stereotactic body radiotherapy (SBRT) and a combination of high-dose-rate brachytherapy boost (HDR-BT) followed by SBRT. Material/Methods: A total of 209 patients with localized PCa were enrolled in two prospective series to receive either HDR- BT (15Gy) followed by SBRT (25Gy in 5 daily fractions) or exclusive SBRT (36.25-40 Gy in 5 every-other-day fractions). Short- or long-term androgen deprivation therapy (ADT) was prescribed according to risk stratification. Acute and late genitourinary (GU) and gastrointestinal (GI) side effects were graded (CTCAE v5). Patient-reported outcomes (PROMS) were assessed following ICHOM (international consortium for health outcomes measurement) methodology. Biochemical and metastatic failures, PCa-specific deaths, and PSA kinetics in patients treated without ADT were analyzed. Results: Among 209 patients, 142 received HDR-BT + SBRT and 67 SBRT alone. Median follow-up was 53.7 (IQR 39-63) for HDR-SBRT and 46.8 months (IQR 36-57) for SBRT.Most patients had intermediate-risk disease (71.1% in HDR-SBRT vs 86.9% in SBRT), while HDR- SBRT arm included more high-risk cases (28.1% vs 11.5%). Short-term ADT was administered to 24% of HDR-SBRT and 14.5% og SBRT patients; long-term ADT in 44.4% and 11.6% respectively. The remaining patients did not received ADT.No significant differences were found in acute or late GU toxicity between groups. Acute G2 GU events were lower in HDR-SBRT vs SBRT (14.1% vs 23.8%; p=0.1). The most common symptom was dysuria. One patient experienced grade 3 toxicity, in the SBRT arm.Late G2
Conclusion: HDR-BT boost combined with SBRT allowed safe dose escalation without additional toxicity or impact on QOL compared with SBRT alone.Both strategies achieved excellent biochemical and metastatic disease control in localized prostate cancer. Keywords: Prostate Cancer, HDR-Brachytherapy Musunuru HB, Cheung P, Vesprini D, Liu SK, Morton G, Deabreu A, Davidson M, Ravi A, Helou J, Ho L, Zhang L, Loblaw A. Gantry-based 5-fraction elective nodal irradiation in unfavorable-risk prostate cancer: outcomes from 2 prospective studies comparing SABR boost, SBRT References: boost with MR dose-painted HDR brachytherapy boost. Int J Radiat Oncol Biol Phys. 2023;116(1):157– 167. doi:10.1016/j.ijrobp.2022.10.009Hennequin C, et al; French Genito-Urinary Tumors Study Group (GETUG). Long-term results of dose escalation (80 vs 70 Gy) combined with long-term androgen deprivation
in high-risk prostate cancers: GETUG-AFU 18 randomized trial. J Clin Oncol. 2024;42(suppl 4):LBA259.
Made with FlippingBook - Share PDF online