Background: A transrectal ultrasound-guided prostate biopsy (TRUS) is the current gold standard for the diagnosis of prostate cancer. The standard analgesia for a TRUS biopsy is with periprostatic infiltration of local anaesthetic (PILA). However many men still experience significant pain. We hypothesise that the addition of methoxyflurane (Penthrox®) to PILA will improve the pain, discomfort and experience of the TRUS biopsy, thereby increasing men’s willingness to undergo repeat TRUS prostate biopsy.
Methods: This is a multi-centre, placebo-controlled, double-blinded, centrally randomised phase 3 trial. The target population is men scheduled to undergo their first TRUS biopsy of the prostate for a raised PSA or an abnormal digital rectal examination. Participants are randomised 1:1 to inhaled methoxyflurane or placebo and stratified by age and study site. All participants are treated with PILA (2% lignocaine), injected into and around the prostate prior to the biopsy. The primary objective is to determine the effects of inhaled methoxyflurane on pain rated by participants 15 minutes after biopsy. Secondary endpoints include other aspects of the biopsy experience rated by participants, willingness to undergo a biopsy in the future, Urologist’s ratings of the participant’s biopsy experience, biopsy completion, frequency of specified adverse events and frequency of hospitalisation. A sample size of 420 participants provides over 85% power at the two-sided 5% level of significance to detect a 0.80 point difference in mean pain scores (on scale from 0-10) assuming a standard deviation of 2.5 whilst allowing for missing data. Patients will complete a questionnaire to document their experience of the biopsy at 5-30 minutes following the procedure and at 7-35 days after the procedure. Urologists will also complete a questionnaire on the day of the procedure. Trial recruitment is scheduled to start by the last quarter of 2015.
Trial funded by a grant from Cancer Australia and Prostate Cancer Foundation of Australia. Methoxyflurane supplied by Medical Developments International. ANZUP is supported by Cancer Australia and Cancer Institute New South Wales.