Urinary morbidity after permanent prostate brachytherapy - impact of dose to the urethra vs. sources placed in close vicinity to the urethra.
OBJECTIVE
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.


METHODS
Fifty-nine patients were surveyed prospectively before treatment (A), 1 month after (B) and > 1 year 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.
Department of Radiation Oncology, RWTH Aachen University, Aachen, Germany. MPinkawa@ukaachen.de
Michael
M
Pinkawa
Richard
R
Holy
Marc D
MD
Piroth
Jens
J
Klotz
David
D
Pfister
Axel
A
Heidenreich
Michael J
MJ
Eble
D001918:Brachytherapy / Q000009:adverse effects*; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008297:Male; D009017:Morbidity; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D014521:Urethra / Q000528:radiation effects*
D007457:Iodine Radioisotopes