ESTRO 2024 - Abstract Book

S2378

Clinical - Urology

ESTRO 2024

(60%) of the patients were taking medications for lower urinary tract symptoms pre-RT. In 38/40 patients, bladder constraints from PRIME trial were achieved (78% optimal, 20.5% acceptable). In only 2 patients (1.5%), the acceptable limit was not achieved for 28Gy and 31.5Gy. Total of 27.5% of patients experienced grade 2 acute GU toxicity and 1 (2.5%) patient had grade 3 GU toxicity (underwent TURP). The median simulation empty bladder volume was 81.4cc (IQR 61.7-114.5). The median (IQR) CBCT volume for each fraction is shown in Figure 1. The median CBCT bladder volume varied by 32.4cc (IQR 63-15) over 5 fractions. This is depicted for each patient in Figure 2. The overall median CBCT volume was 69cc (IQR 63-71), compared to 81.4cc at simulation.

Figure 1. Box-plot representing the median and IQR for bladder volumes at simulation and each fraction.

Figure 2. Jitter plot showing bladder volumes at simulation and every fraction for entire cohort.