Botulinum Toxin Injection With Prostate Brachytherapy: A Randomized, Placebo-controlled Study Monitoring Urinary Symptoms and PSA
Brachytherapy is a popular treatment modality for localized prostate cancer, where
radioactive seeds are implanted through 18 gauge needles into the prostate via a perineal
template with rectal ultrasound guidance. The radioactivity is delivered over several
months, depending on the isotope used. During this time, there can be exacerbation of
urinary voiding symptoms from early edema of the prostate gland due to the implantation
procedure, then later from the inflammatory reaction of the radiation. Because the initial
acute inflammation may persist for many months despite steadily declining doses of
radiation, attempts are made to minimize urinary symptoms prior to brachytherapy with
pharmacologic therapy (alpha-blockers) or minimally invasive surgical therapy (transurethral
incision or limited transurethral resection to avoid significant distortion of the prostate
parenchyma for future seed implantation). Even with these precautions, around 30-40% of
brachytherapy patients will still develop voiding symptoms. With such bothersome symptoms,
intervention is deferred for at least 8-10 months to avoid distorting the planned field of
radiation. Once symptoms develop, various additional pharmacologic measures are employed,
such as increased doses of alpha-blockers, medrol steroid taper, and non-steroidal
anti-inflammatory agents. Some patients require intermittent self-catheterization or
suprapubic catheter for urinary diversion.
Botulinum toxin has been used for cosmetic uses, and has been successfully used for
treatment of overactive bladder, external sphincter dyssynergia, and benign prostatic
hyperplasia (BPH). The studies with BPH show reduction in symptoms scores, PSA, and prostate
volume, the latter from atrophy due to the denervation effect. The response lasts for 6-9
months.
We propose to study botox intraprostatic injection during brachytherapy to see whether this
improves urinary symptoms or avoids need for urinary tract instrumentation over this 6-8
month post-operative period when one wants to avoid manipulating the radioactive seeds. We
will also monitor PSA, and see if there is any measurable augmentation of PSA decline with
botox + Brachytherapy vs Brachytherapy alone. We will randomize patients to botox (100
units for < 30 cc prostate; 200 units for > 30 cc prostate) vs saline injection,
administering 2 transperineal injections into both lateral lobes of the prostate (25-50 mg
per injection), just 5-10 mm proximal to the bladder neck.
Study design:
N= 60 (30 receive Botox, 30 receive saline)
Followup:
AUA Symptoms scores weekly for 4 weeks, monthly thereafter Medications for urinary symptoms
Need for catheterization PSA checked at 1 mo, 3 mo, 6 mo, 9 mo, 1 year, 15 mo, 18 mo, 24 mo
Interventional
Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Investigator), Primary Purpose: Treatment
Urinary symptoms
Weekly for 4 weeks, monthly thereafter until 1 year
No
Peter T Nieh, MD
Principal Investigator
Emory University SOM
United States: Institutional Review Board
IRB0009836
NCT00681148
July 2012
Name | Location |
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Emory Clinic, Emory University Hospital | Atlanta, Georgia 30322 |