A prospective randomized comparison of stranded vs. loose 125I seeds for prostate brachytherapy.
OBJECTIVE
To compare seed loss and dosimetric parameters between stranded and loose 125I seeds (LS) for prostate brachytherapy.


METHODS
Sixty-four patients with 1997 American Joint Commission on Cancer (AJCC) clinical stage T1c or T2a prostate carcinoma were prospectively randomized to brachytherapy (144Gy) with RAPID Strand 125I seeds (RS) vs. LS (Oncura, Plymouth Meeting, PA) The treatment plan for each patient was devised before randomization, and was not modified based on the randomization. Each patient underwent magnetic resonance, computed tomography, and plain film radiographs on the day of the implant (Day 0) and 30 days later (Day 30).


RESULTS
Overall, 21 of 62 patients (30%) experienced seed loss. Seed loss occurred in 15 of 32 of LS patients (47%) vs. 6 of 30 RS patients (23%; p=0.053). Mean seed loss was 1.09 in the LS patient vs. 0.43 in RS patients (p=0.062). Eight LS patients (25%) lost multiple seeds, compared to 3 stranded patients (10%). Despite the lesser degree of seed loss in patients who received stranded seeds, they had a paradoxical trend toward lower V100 and D90 values.


CONCLUSIONS
This prospective randomized trial showed a strong trend toward a decrease in postimplant seed loss with stranded seeds. Improved seed retention may be more advantageous in a setting of less generous periprostatic coverage. The lowered risk seed migration seen with stranded seeds would presumably also decrease the likelihood of lung or cardiac seed embolization.
Reed
Daniel R
DR
Scottsdale Radiation Oncology, Arizona Oncology Services, Phoenix, AZ 85260, USA. dreed@azoncology.com
Wallner
Kent E
KE
Merrick
Gregory S
GS
Arthurs
Sandra
S
Mueller
Amy
A
Cavanagh
William
W
Butler
Wayner B
WB
Ford
Eric
E
Sutlief
Steve G
SG
D000465:Algorithms; D001918:Brachytherapy / Q000379:methods; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes / Q000145:classification / Q000627:therapeutic use; D008279:Magnetic Resonance Imaging; D008297:Male; D009367:Neoplasm Staging; D011446:Prospective Studies; D011467:Prostate / Q000528:radiation effects; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy*; D011874:Radiometry; D012007:Rectum / Q000528:radiation effects; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D047368:Tumor Burden / Q000528:radiation effects; D014861:Washington
D007457:Iodine Radioisotopes