2444 - Begin with the End in Mind: Assessing Symptom Index for Patients with Prostate Cancer to Select the Right Bladder Protocol for Radiotherapy

Purpose/Objective(s): Bladder filling (BF) is essential for treating pelvic tumors by moving the small bowel out of the treatment field. However, patients with prostate cancer often struggle with BF, causing discomfort. This study assessed an adapted hydration protocol (based on baseline symptom index), on effective BF and patients’ quality of life (QoL). The symptom index before radiotherapy will establish the right protocol for the right patient, improving BF efficiency, reducing patient discomfort, and enhancing patient-centered care in radiotherapy (RT) for prostate cancer.

Materials/Methods: A prospective multicenter study included 40 adult patients undergoing RT for prostate cancer receiving hypofractionated RT (60Gy/20 fractions) in 2024. Twenty patients (Group A) followed the standard hydration protocol of 660 mL of water, while the other 20 (Group B) received an adapted protocol based on their International Prostate Symptom Score (IPSS): those with high IPSS (20–35) received 330 mL, while those with medium or low IPSS received 660 mL. For both groups, outcomes were measured at multiple time points and included: 1) bladder volume measured on CT simulation images; 2) IPSS score; 3) occurrence and severity of gastrointestinal and genitourinary symptoms using the Common Terminology Criteria for Adverse Events (CTCAE); 4) tolerability of hydration protocol; and 5) perceived frustration. Hydration compliance and frustration were measured using a visual analog scale (VAS) of 1–10, where 1 represented "very tolerable / no frustration" and 10 represented "very intolerable / very high frustration," as applicable. Cone beam CT images were analyzed for both groups and were categorized into either a ‘pass’ or ‘fail’ status based on bladder compliance. Analysis was conducted using SPSS, Version 21.0 for Windows.

Results: Group B (Adapted protocol; mean ± SD = 67.35 ± 6.54) was significantly younger than the Standard group (72.45 ± SD, p = 0.019). IPSS scores showed no significant differences between groups at any time point. While both groups maintained high rates of adequate bladder filling over time, Group B showed a trend toward improved bladder filling, particularly in the earlier treatment phases. Acute gastrointestinal and genitourinary symptoms showed no significant differences between the two groups at most time points, except for bladder spasms at follow-up (p = 0.034), where the Group B had fewer persistent symptoms. Regarding QoL, the Adapted protocol led to significantly better tolerability across all four treatment weeks (p < 0.05) and lower frustration levels from week 2 onward (p = 0.004).

Conclusion: Individualized hydration protocol based on pre-treatment symptom assessment improves BF tolerability during radiotherapy for prostate cancer and reduces patient frustration. This approach may further enhance BF efficiency, overall treatment effectiveness, and patients' QoL.