Trial Title:
Reminder App to Optimize Bladder Filling During Radiotherapy for Prostate Cancer
NCT ID:
NCT06653751
Condition:
Prostate Cancer Patients Treated by Radiotherapy
Conditions: Official terms:
Prostatic Neoplasms
Conditions: Keywords:
Prostate cancer
Radiotherapy
Mobile application
Study type:
Interventional
Study phase:
N/A
Overall status:
Not yet recruiting
Study design:
Allocation:
N/A
Intervention model:
Single Group Assignment
Primary purpose:
Prevention
Masking:
None (Open Label)
Intervention:
Intervention type:
Device
Intervention name:
Reminder App
Description:
he purpose of the app is to remind patients irradiated for prostate cancer in an
intuitive, unobtrusive and supportive way to drink 300 ml of water 45 minutes prior to
each radiation session.
Arm group label:
Support by a reminder app
Summary:
The primary goal of this study is to assess the impact of an app that reminds patients
irradiated for prostate cancer to drink water prior to each radiotherapy session on the
number of bladder volumes <200 ml during the radiotherapy course and to demonstrate that
this number is lower than without using an app (historical control group).
Detailed description:
Prostate cancer is one of the most common solid malignancies worldwide. Most patients
with non-metastatic disease receive either prostatectomy or radiotherapy. Radiotherapy of
prostate cancer may be associated with significant acute urinary toxicity such as
cystitis, particularly if the volume of the urinary bladder is small. Three studies
showed that bladder volumes <200 ml or <180 ml, respectively, were associated with
increased acute or late urinary toxicity. Therefore, it appears important to achieve
bladder volumes >200 ml at as many radiation fractions as possible. Several studies
investigated the role of drinking protocols. However, drinking a certain amount of water
at a specific point in time may require considerable discipline from the mainly elderly
or very elderly patients. These considerations led to the idea of developing a mobile
application (app) that reminds the patients prior to each radiation session to drink a
certain amount of water. The present study investigates the number of radiation fractions
with bladder volumes <200 ml in a prospective cohort of patients using a such a reminder
app. In addition, the study evaluates whether the use of the reminder app leads to a
significant reduction of the proportion of fractions with bladder volumes <200 ml when
compared to a historical control group not supported by an app. The app reminds the
patients to drink 300 ml of water 45 minutes prior to each radiotherapy session.
Endpoints: The primary endpoint is the number of radiation fractions with bladder volumes
<200 ml after 35 fractions of radiotherapy. In addition, the following endpoints will be
evaluated: Number of radiation fractions with bladder volumes <200 ml at the end of
radiotherapy, patient satisfaction with the reminder app: Evaluation at the end of
radiotherapy, and impact of the reminder app on the use of health technology: Evaluation
at the end of radiotherapy.
General trial design: This is a single-arm prospective study, which will investigate the
effect of a reminder app on the number of radiation fractions with bladder volumes <200
ml during a course of radiotherapy for definitive treatment of prostate cancer in
comparison to a historical control group of 35 patients [8]. The historical control group
is considered appropriate for the comparison to the cohort of the present study, since
all patients of the control group were treated very recently (in 2022 or 2023) with
external beam radiotherapy alone in three of the five centers participating in the
present study and received a Cone Beam Computed Tomography prior to each radiation
fraction, which allowed assessment of the bladder volume as precisely as in the present
study. To ensure comparability of total number of fractions administered in the
prospective study with those in the historical control group, the primary endpoint is
restricted to the first 35 fractions administered.
The recruitment of all 28 patients is planned to be completed within 20 months. The
follow-up period will end directly after the radiotherapy course, which is scheduled to
take 7 to 8 weeks. This equals a total running time for the study of 22 months. In
accordance with the previous study assessing the number of radiation fractions with
bladder volumes <200 ml during a course of radiotherapy for definitive treatment of
prostate cancer, the following characteristics will be recorded to allow adequate
comparison with the historical control group: Initial (pre-radiotherapy) bladder volume,
body-mass index (BMI), age, prostate volume prior to radiotherapy, Karnofsky performance
score, risk group of prostate cancer, and antihormonal therapy.
Sample size calculation: The primary goal of this study is to assess the impact of an app
that reminds patients irradiated for prostate cancer to drink water prior to each
radiotherapy session on the number of fractions with bladder volumes <200 ml during the
radiotherapy course and to demonstrate that this number is lower than without using an
app (historical control group). To allow for a skewed distribution of the primary
endpoint, the Wilcoxon-Mann-Whitney test will be applied for confirmatory statistical
analysis. In the external historical control group consisting of 35 patients, the mean
number of radiation fractions with bladder volumes <200 ml was 26.7 (SD 8.5), and the
median number was 30 fractions (IQR 22-34). A decrease of this mean value by roughly 30%
(to 18.7 fractions) is considered clinically relevant. For illustrative purposes,
translating this decrease into a non-parametric effect size framework (assuming for
simplicity normal distribution) leads to a probability of roughly 0.25 that the number of
fractions <200 ml with the reminder app is larger than without the app. Based on this
effect size, a sample size of 25 patients in the prospective trial is required for the
comparison with the historical control group to ensure 90% power to reach statistical
significance with a two-sided Wilcoxon Mann-Whitney-U-test and a 5% significance level.
Assuming that roughly 10% of the enrolled patients will not be eligible for the primary
analysis, since they have received less than 35 fractions, a total number of 28 patients
should be enrolled in this study.
Statistical analyses: All data recorded in the case report forms describing the study
population (demographic and clinical characteristics recorded at baseline), efficacy,
safety and quality of life will be analyzed descriptively. Categorical data will be
presented in contingency tables with frequencies and percentages and their 95% confidence
intervals. Continuous data will be summarized with at least the following: frequency (n),
median, quartiles, mean, standard deviation (standard error), minimum and maximum. Number
of subjects with protocol deviations during the study and listings describing the
deviations will be provided. In general, chi-square tests will be used to compare
percentages in a two-by-two contingency table, replaced by Fisher´s exact test if the
expected frequency in at least one cell of the associated table is less than 5.
Stratified two-by-two contingency tables will be analyzed using Cochran-Mantel-Haenszel
tests. Logistic regression models serve as multivariable methods for binary endpoint
data. Comparison of ordinal variables between treatment arms will be performed using the
asymptotic Wilcoxon-Mann-Whitney test, replaced by its exact version in case of ordinal
categories with small number of categories and/or sparse data within categories. Any
shift in location of quantitative variables between study groups will be performed with
the Wilcoxon-Mann-Whitney tests as well. All patients who have started the radiotherapy
and provide data on the primary endpoint will be analyzed (Full Analysis Set). The data
analysis will be performed according to the statistical analysis plan (SAP), and which
will be finalized prior to database lock and prior to any statistical analysis.
Primary Endpoint: The primary study endpoint is defined as the number of radiation
fractions with bladder volumes <200 ml after 35 fractions of radiotherapy. Descriptive
measures of location and dispersion will be used to describe the results of the
prospective study. The impact of patient characteristics on the primary endpoint will be
assessed by means of Wilcoxon-two sample tests. These factors include age (<75 vs. ≥75
years), Karnofsky performance score (70-80 vs. 90-100), body-mass index (<30 vs.
≥30=obesity), prostate volume prior to radiotherapy (<60 vs. ≥60 mL), risk group of
prostate cancer (low to intermediate vs. high), and antihormonal therapy prior to and/or
during the course of radiotherapy (no vs. yes). For confirmatory analysis, the
prospective study will be compared with the historical control group by means of a
two-sided Wilcoxon-Mann-Whitney two sample test and significance level of 5%. A high
degree of comparability of patient population is expected between the prospective trial
data and the retrospective patient data set. However, potential heterogeneity of study
populations will be identified by comparing the patient characteristics listed above with
Wilcoxon-Mann-Whitney tests. Homogeneity is assumed if all resulting p-values are above
20%. Any factor indicating a tendency towards heterogeneity (i.e. p<0.20) will be
included in a multivariable count data Poisson regression model with the number of
radiation fractions with bladder volumes < 200 ml as dependent variable and including the
respective factors and the binary factor (prospective study vs historical control) as
independent variables. In case of evidence of overdispersion the Poisson model will be
replaced by a negative binomial model.
Secondary Endpoints: In addition to the primary study endpoint, secondary endpoints will
be subjected to statistical analysis. Since no comparison with historical data is
possible, these analyses focus on descriptive statistical analysis only. The results of
patient satisfaction will be used to decide whether the app needs modification: In case
of a dissatisfaction rate >20%, the reminder app needs modifications. In case of a
dissatisfaction rate >40%, it will be considered not useful.
Criteria for eligibility:
Criteria:
Inclusion Criteria:
1. Histologically proven prostate cancer
2. Indication for definitive normo-fractionated radiotherapy
3. Possession of a smart phone and the ability to use it
4. Bladder volume at CT-simulation <200 ml
5. Male gender
6. Age ≥18 years
7. Written informed consent
8. Capacity of the patient to contract
Exclusion Criteria:
1. Radiotherapy of pelvic lymph nodes
2. Expected non-compliance
Gender:
Male
Minimum age:
18 Years
Maximum age:
N/A
Healthy volunteers:
No
Locations:
Facility:
Name:
Vejle Hospital, University Hospital of Southern Denmark
Address:
City:
Vejle
Zip:
7100
Country:
Denmark
Contact:
Last name:
Charlotte Kristiansen, MD
Phone:
0045-7940
Phone ext:
6094
Email:
charlotte.kristiansen@rsyd.dk
Facility:
Name:
Medical Practice for Radiotherapy and Radiation Oncology
Address:
City:
Hannover
Zip:
30161
Country:
Germany
Contact:
Last name:
Stefan Janssen, Prof. Dr. med.
Phone:
0049-511-220
Phone ext:
60420
Email:
stefan.janssen@uksh.de
Facility:
Name:
Medical School Hamburg, Schwerin Campus
Address:
City:
Schwerin
Zip:
19055
Country:
Germany
Contact:
Last name:
Marciana N Duma, Prof. Dr. med.
Phone:
0049-385-520
Phone ext:
5070
Email:
Marciana.Duma@helios-gesundheit.de
Facility:
Name:
Malteser Hospital St. Franziskus
Address:
City:
Flensburg
Zip:
24939
Country:
Germany
Contact:
Last name:
Carmen Timke, Dr. med.
Phone:
0049-461-816
Phone ext:
2518
Email:
carmen.timke@malteser.org
Contact backup:
Last name:
Julia Köck, Dr. med.
Phone:
0049-461-816
Phone ext:
2518
Email:
julia.koeck@malterser.org
Facility:
Name:
Department of Radiation Oncology, University of Lübeck and University Medical Center Schleswig-Holstein
Address:
City:
Lübeck
Zip:
23562
Country:
Germany
Contact:
Last name:
Dirk Rades, Prof. Dr. med.
Phone:
0049-451-500
Phone ext:
45400
Email:
dirk.rades@uksh.de
Contact backup:
Last name:
Jan-Dirk Küter, Dr. med.
Phone:
0049-451-500
Phone ext:
45420
Email:
Jan-Dirk.Kueter@uksh.de
Investigator:
Last name:
Michael von Staden, Dr. med.
Email:
Sub-Investigator
Investigator:
Last name:
Ahmed Al-Salool, Dr. med.
Email:
Sub-Investigator
Start date:
January 15, 2025
Completion date:
October 31, 2026
Lead sponsor:
Agency:
University Hospital Schleswig-Holstein
Agency class:
Other
Collaborator:
Agency:
University of Southern Denmark
Agency class:
Other
Collaborator:
Agency:
Medical School Hamburg
Agency class:
Other
Source:
University Hospital Schleswig-Holstein
Record processing date:
ClinicalTrials.gov processed this data on November 12, 2024
Source: ClinicalTrials.gov page:
https://clinicaltrials.gov/ct2/show/NCT06653751
