JMIR Publications

ABSTRACT

Background:

Many patients with non-metastatic prostate cancer receive radiotherapy, which may be associated with acute cystitis, particularly if the volume of the urinary bladder is small. Three studies showed bladder volumes <200 ml or <180 ml to be associated with increased urinary toxicity. Therefore, it appears important to achieve bladder volumes >200 ml at as many radiation fractions as possible. Several studies investigated drinking protocols, where patients were asked to drink a certain amount of water prior to radiotherapy sessions. This may require considerable discipline from the mainly elderly patients. Adherence to a drinking protocol may be facilitated by a mobile application (app) that reminds the patients prior to each radiation session to drink water. Our present study investigates the effect of such an app on the filling status of the bladder in prostate cancer patients receiving external beam radiotherapy alone (EBRT).

Objective:

The main goal of this study is to evaluate the impact of an app, which reminds patients irradiated for prostate cancer to drink 300 ml of water prior to each radiotherapy session, on the number of fractions with bladder volumes <200 ml during the radiotherapy course.

Methods:

This phase 2 study is ongoing and requires recruitment of 28 patients treated with EBRT alone for non-metastatic prostate cancer. Radiotherapy will be administered using normo-fractionation with 70-80 Gy in 35-40 fractions of 2.0 Gy, preferably with volumetric-modulated arc therapy (VMAT). Treatment volumes include the prostate with or without the seminal vesicles. A newly developed app will remind the patients to drink 300 ml of water 45 minutes prior to each fraction of radiotherapy. At the end of the radiotherapy course, patients will be asked to complete a questionnaire regarding their satisfaction with the app. In case of a dissatisfaction rate >40%, the app will be considered not useful. Patients will also be asked about the impact of the app on the general use of health technology. In addition, the phase 2 cohort will be matched and compared to a historical control group not supported by an app. The control group is considered appropriate for the comparison, since all patients were treated very recently (in 2022 or 2023) with EBRT alone.

Results:

This trial is the first study that evaluates the impact of a reminder app on the number of radiotherapy fractions with bladder volumes <200 ml in patients irradiated for localized prostate cancer.

Conclusions:

This study will help identify the potential benefit of a reminder app on the bladder filling status of prostate cancer patients during a course of radiotherapy. Clinical Trial: Clinicaltrials.gov NCT06653751; https://clinicaltrials.gov/show/NCT06653751