BACKGROUND AND PURPOSE:The impact of the dose to the urethra and sources placed close to the urethra on urinary morbidity after permanent prostate brachytherapy (PPB) is not well known.
MATERIALS AND METHODS: Fifty-nine patients were surveyed prospectively before treatment (A), 1month after (B) and >1year after PPB (C) using a validated questionnaire (Expanded Prostate Cancer Index Composite). Computed tomography (CT) postimplant scans were performed at days 1 (Foley catheter in situ) and 30 after PPB and sources within 5mm of the urethra at day 1 were identified.
RESULTS: As opposed to the urethral dose-volume histogram, a larger number of sources within 5mm of the urethra at day 1 predicted significantly larger urinary bother score changes at times B and C - with an impact on incontinence and frequency (e.g. moderate/big problem with leaking urine in 25% vs. 3%, p=0.02; moderate/big problem with frequent urination in 33% vs. 7%, p< 0.01, at time C with vs. without ⩾3 sources in a single strand placed close to the urethra).
CONCLUSIONS: Placement of sources with a minimum distance of a few mm to the urethra should be a major aim to avoid urinary morbidity irrespective of the urethral dose-volume histogram.
Written by:
Pinkawa M, Holy R, Piroth MD, Klotz J, Pfister D, Heidenreich A, Eble MJ. Are you the author?
Department of Radiation Oncology, RWTH Aachen University, Aachen, Germany.
Reference: Radiother Oncol. 2012 Jan 31. Epub ahead of print.
doi: 10.1016/j.radonc.2011.12.011
PubMed Abstract
PMID: 22300607
