Seed migration after transperineal interstitial prostate brachytherapy with I-125 free seeds: analysis of its incidence and risk factors.
OBJECTIVE
The purpose of this study was to evaluate the incidence and predictors of seed migration after transperineal interstitial prostate brachytherapy.


METHODS
From March 2007 to March 2011, 121 patients with stage T1-T2 prostate cancer underwent transperineal interstitial prostate brachytherapy. Pre-planning was performed 3 weeks prior to implantation, and the implants were inserted using the standard parallel needle insertion technique. All patients underwent a series of radiographs [chest radiography, kidney-ureter-bladder (KUB) radiography, and a CT scan] to assess whether seed migration had occurred on postoperative days 1 and 30, and 12 months.


RESULTS
Seed migration occurred in 31 (25.6 %) of 121 patients. A total of 51 of 7,883 (0.65 %) implanted seeds migrated. Migration was detected on postoperative day 1 in 16 patients, day 30 in 13 patients and at 12 months in 4 patients (migration occurred at different times in 2 patients). The migrated seeds were found in the lungs, pelvis, heart, mediastinum, kidney, inguinal canal, liver and sacrum. The number of needles was a statistically significant factor in seed migration.


CONCLUSIONS
The seeds migrated to many organs. No decrease in the dose administered to the prostate or adverse effects associated with seed migration were noted.
Department of Urology, Kanazawa Medical University, Uchinada, Ishikawa 920-0293, Japan. miyazawa@kanazawa-med.ac.jp
Katsuhito
K
Miyazawa
Munetaka
M
Matoba
Hiroshi
H
Minato
Nobuyo
N
Morita
Ippei
I
Chikazawa
Kiyotaka
K
Ota
Kosuke
K
Tokunaga
Hisao
H
Tonami
Takayuki
T
Nojima
Koji
K
Suzuki
D000368:Aged; D000726:Androgen Antagonists / Q000627:therapeutic use; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods; D005500:Follow-Up Studies; D005548:Foreign-Body Migration / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000209:etiology; D006801:Humans; D015994:Incidence; D007457:Iodine Radioisotopes / Q000008:administration & dosage* / Q000009:adverse effects; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010502:Perineum; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D011859:Radiography; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
D000726:Androgen Antagonists; D007457:Iodine Radioisotopes