Changes in Bladder Volume During Radiotherapy for Prostate Cancer.

Area of Science:

• Radiation Oncology
• Urology
• Medical Physics

Background:

• Prostate cancer radiotherapy can cause urinary toxicity, exacerbated by small bladder volumes.
• A mobile app intervention is proposed to help patients maintain adequate bladder volume.
• This study assesses bladder volumes during radiotherapy to inform future app-based trials.

Purpose of the Study:

• To evaluate the frequency of small bladder volumes (<200 ml) during prostate cancer radiotherapy.
• To identify risk factors associated with reduced bladder volumes.
• To provide data for designing a prospective trial of a bladder volume reminder app.

Main Methods:

• Retrospective analysis of 72 patients undergoing external beam radiotherapy for non-metastatic prostate cancer.
• Evaluation of bladder volumes (<200 ml) per fraction.
• Statistical analysis of seven potential risk factors, including pre-radiotherapy bladder volume and cancer risk level.

Main Results:

• A high number of radiation fractions (mean 17.8) had bladder volumes <200 ml.
• Pre-radiotherapy bladder volumes <200 ml were significantly associated with more fractions with small volumes (p<0.001).
• High-risk prostate cancer was also significantly associated with smaller bladder volumes during treatment (p=0.014).

Conclusions:

• The high incidence of small bladder volumes during prostate cancer radiotherapy necessitates intervention.
• Pre-treatment bladder volume and prostate cancer risk level are critical factors influencing bladder volume during treatment.
• Findings support the design of a prospective trial for a bladder volume management mobile application.