Excessive Bladder Filling at Simulation Correlates with Longer Treatment Times, More Interruptions, and Inferior...

Bladder filling during prostate radiotherapy (RT) helps displace bowel and reduce bladder dose but can be uncomfortable for patients. We hypothesized that overly full bladders at simulation (sim) are associated with longer treatments, more delays, and worse patient experience.

We retrospectively analyzed prostate cancer patients receiving fractionated RT over 9 months across 3 treatment centers within an academic network. Bladder diameter at sim was measured from dome to trigone on sagittal CT. We recorded average treatment duration, number of times patients were taken off the treatment table for bladder issues, and patient-reported experience via questionnaires in first and last weeks of RT (Likert scale 0-4). A separate group of patients with initially large bladders were coached to reduce bladder size ("Corrected bladders"). Two-sample t-tests were used for group comparisons on treatment times and times off table, while Wilcoxon rank sum test was used to compare the patient-reported outcomes.

Among 211 consecutive patients, those with large bladders (>10 cm diameter) at sim had longer average treatment times (498.5 sec vs 444.0 sec, p=0.01) and were taken off table more often (0.14 vs 0.04 times/week, p<0. 01). They also reported more worry about bladder filling (1.58 vs 0.90, p<0.01) and more frustration (1.06 vs 0.65, p=0.01) by the end of treatment. All 20 patients coached to correct their bladder size successfully did so and went on to have shorter treatment times (425.2 sec) than uncorrected large bladder patients (p=0.03).

Patients with prostate cancer simulated with very full bladders experience longer treatments, more interruptions, and worse RT-related anxiety. Coaching to reduce excessive bladder filling using a simple method is feasible, improves treatment efficiency, and improves patient quality of life.