Hypothesis The study's hypothesis is that vibration therapy, using the stimulation parameters
found in the pilot study, will have a beneficial effect on erectile function, orgasm
disturbances, penile shortening, and urinary incontinence, both generally and in connection
with sexual activity.
Methods The study is conducted as a randomized, controlled non-blinded study. Men undergoing
a nerve-sparing operation for prostate cancer are divided into two groups. A total of 100 men
will be included in the study. In case a surgery cannot be performed with nerve preservation
or if a participant experiences a recurrence of their prostate cancer requiring additional
treatment, the participant will be withdrawn from the study.
Randomization and Treatment Overall, we will investigate the effect of vibration stimulation
on erectile function, orgasm disturbances, penile shortening, and urinary incontinence, both
generally and in connection with sexual activity. In accordance with the hypotheses, this
study will offer vibration therapy for a longer duration than before. Both the vibration
group and the control group will be offered fixed post-operative treatment with
phosphodiesterase-5-inhibitors as per the standard protocol. Participants will be randomized
into the two groups through drawing lots for either vibration or no vibration. Randomization
will be done using block randomization via a computer-generated list. The "Ferticare 2.0"
vibrator (produced by the company Reflexonic LLC, Leesburg VA, USA) will be used in the
study, which is a modernized version of the previously used vibrator and is sold as a sexual
aid in Denmark. It is safety-approved with European CE marking as a "household appliance" and
is sold as a sexual aid in Denmark. Men in the vibration group will be instructed on the
stimulation before their prostate surgery. Subsequently, participants will be able to perform
the vibration therapy themselves at home. In both groups, participants must undergo a
standard pelvic floor training program, and both groups will be offered fixed PDE-5 inhibitor
treatment in the form of daily tadalafil, 5 mg, as the standard treatment for erectile
difficulties after the operation. In the vibration group, daily stimulation will be directed
towards the frenulum for a minimum of 5 minutes, with an amplitude of 1 mm and a frequency of
90 Hz, as found in the pilot study. Participants will start getting used to the vibration 1-4
weeks before the surgery and resume it within 14 days after the operation. The daily
stimulation will continue for a period of 9 months, along with the standard treatment. After
these 9 months, men in both groups will stop taking tadalafil during a 4-week wash-out
period, after which their spontaneous sexual function will be evaluated. This is necessary
due to the well-known positive effect of the medication. In comparison to the standard
treatment in the department, offering vibration to half of the participants is an addition.
Regarding pelvic floor training and medication for erectile difficulties for all study
participants, the current standard is to offer these to all men who have undergone
nerve-sparing radical prostatectomy. This will proceed as usual, and the only deviation from
usual practice is ensuring that the medication offer is consistent for all participants. The
mentioned 4-week period without tablet treatment (wash-out) is necessary to assess
spontaneous erections. This is a deviation from the normal standard, as such a wash-out is
not conducted for patients who do not participate in research, but it will not affect the
actual erectile function of the participants in either group.
Data Collection
Standard investigations related to prostate cancer will be conducted according to normal
guidelines, with the registration of:
Pre-operative PSA
Clinical and pathological tumor stage
Gleason score
Prostate size
Degree of nerve preservation during the surgery
Any complications during the surgery
Resection margin status (positive or negative)
PSA measurements at 3, 6, and 12 months after the operation. This information will be
obtained from the patient's medical records by the scientific staff after the study
participants have given their consent to participate. After providing consent, the study
organizers, sponsor, sponsor's representatives, and any regulatory authorities will have
direct access to obtain information from the patient's medical records, including
electronic records, for the purpose of reviewing information about the research
participant's health, as necessary for conducting the research project and for
monitoring, including self-monitoring, quality control, and oversight, as they are
obligated to perform.
Since potential participants are screened and informed about the project during their visits
to the outpatient clinic (see the section on Recruitment of Study Participants and Informed
Consent), there is no need to obtain information from the patient's medical records before
consent is given. At this stage, the research team only receives the name, social security
number, and contact information for patients who have expressed interest in the project.
Additional examinations are carried out before the surgery and at follow-ups at 3 months, 6
months, and 10 months (equivalent to the end of the wash-out period) after the surgery, with
the registration of the following for all participants in both the vibration group and the
control group:
Before the surgery and at follow-ups:
Validated symptom questionnaires for erectile function (IIEF-EF and EHS)
Specific questionnaire about orgasm disturbances, penile shortening, and urinary
incontinence during sexual activity.
Validated symptom questionnaire for incontinence symptoms (ICIQ-SF)
24-hour pad weighing test (only at follow-ups for men who are not fully continent)
Additional registrations at follow-ups: