Radioactive seed migration after prostate brachytherapy with iodine-125 using loose seeds versus stranded seeds.
OBJECTIVE
To assess the incidence and clinical parameters that could influence migration of seeds in localized prostate cancer patients treated by stranded versus loose sources by Iodine-125 brachytherapy.


METHODS
100 patients were treated from January/1998 until December/2006. Age, PSA, clinical stage, Gleason, prostate volume, number of seeds, activity of radioactive seeds, and dosimetric parameters, such as V100, V150 and D90 were evaluated.


RESULTS
Mean follow-up was 79 months (18 - 120. CI 95%: 72 - 85). Overall, 6 of 100 patients experienced seed migration. Seed migration was found in 4/50 (8%) patients using loose seeds and in 2/50 (4%) treated by stranded seeds. Mean value dosimetric parameters for stranded seeds were greater than those for loose seeds (V100(%): 88.7/82, D90(Gy): 149.2/140.3, D90(%): 104.2/93.8, V150 (%): 53.8/47, respectively). No significant difference in migration of seeds was detected between loose and stranded seeds considering age (p = 0.33), PSA (p = 0.391), prostate volume (p = 0.397), activity of radioactive seeds (p = 0.109), number of seeds (p = 0.338), V100 (p = 0.332), although significant differences were measured in the values of D90(% and Gy) (p = 0.022 and 0.011) and V150 (p = 0.023).


CONCLUSIONS
Seed migration after brachytherapy might occur and it does affect post-implant dosimetry.
Franca
Carlos A S
CA
Brazilian Institute of Oncology and Radioterapia Botafogo, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. carlosfranca@cremerj.org.br
Vieira
Sergio L
SL
Carvalho
Antonio C P
AC
Bernabe
Antonio J S
AJ
Penna
Antonio B R
AB
D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011471:Prostatic Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D012189:Retrospective Studies; D016896:Treatment Outcome
D007457:Iodine Radioisotopes