The Role Of Prophylactic Urethral Stenting With Memokath® 028SW in Patients Undergoing Prostate 125I Seed Implants For Prostate Carcinoma: A Phase I/II Study
Image-guided transperineal permanent prostate brachytherapy (PI) is an accepted curative
treatment option for patients with early stage prostate cancer. Multiple reports have
defined its efficacy and shown it to be superior to antecedent trans-abdominal techniques.
In addition, the efficacy of PI has been shown to be similar to radical retropubic
prostatectomy (RRP) and external beam radiotherapy (EBRT). These positive results, however,
are gained at the expense of toxicity. The most notable toxicity is associated with the
urinary system. The most severe side effect of PI is urinary retention requiring
intermittent self-catheterization (ISC).
The reported rate of severe urinary retention following PI is ~10%. Most of these patients
can be managed with ISC and alpha-blockers for a few weeks. Although this is generally a
temporary phenomenon, a small percentage will eventually require surgical intervention to
permit urinary flow. This is a major concern for patients undergoing PI, but should not be
a reason to avoid this form of curative treatment.
The use of implantable stents has been successful in BPH. The Memokath® device has been
shown to decrease the International Prostate Symptom Score from a mean of 20.3 to 8.2 in the
first 3 months after stent placement in patients with bladder outlet obstruction unable to
undergo TURP. Few experience side-effects with pain in 3%, hematuria in 3%, incontinence in
6%, and infection in 6%. A multicenter randomized control trial is currently underway
assessing the use of this device in patients with recurrent urethral strictures.
Urethral stents have been used with some success in patients with post-brachytherapy bladder
outlet obstruction. Five patients, who could not tolerate alpha-blockers or clean
intermittent catheterization, received UroLume urethral stents following one or more
episodes of urinary retention. All patients were able to void immediately after stent
placement. No patients developed incontinence after the stent placement. The main
complaints following UroLume® stent placement were urethral bleeding, referred pain at the
head of the penis, and dysuria. These symptoms required stent removal in 2 out of the 5
patients. In another study, five patients received SpannerTM urethral stents following
significant urinary symptoms after prostate brachytherapy. All patients were able to void
spontaneously with no post-void residual volume of urine. Flow rates increased and the
International Prostate Symptom Score decreased from a mean of 25.2 to 10 (p=0.03). However,
two patients experienced pain, which required removal of the stent.
Given that few patients have experienced side effects with the Memokath® urethral stent in
bladder outlet obstruction, we wish to assess the toxicity associated with this stent in a
post-brachytherapy setting. In addition, we would like to assess its efficacy when used
prophylactically in reducing bladder outlet obstruction following prostate brachytherapy and
its impact on the AUA score.
Allocation: Non-Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment
Morbidities assessed on RTOG Morbidity Scale weekly for 12 weeks after PI then biweekly for next 12 weeks
Jay P Ciezki, MD
The Cleveland Clinic
United States: Food and Drug Administration
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