Analysis of seed loss and pulmonary seed migration in patients treated with virtual needle guidance and robotic seed delivery.
OBJECTIVE
To determine whether automated seed delivery system and real-time intraoperative (IO) virtual needle guidance reduce seed loss and pulmonary seed migration.


METHODS
We analyzed 279 patients with low and intermediate risk prostate cancer treated in our institution with radioactive iodine (I-125) permanent seed implants. Loose seeds were exclusively used. To account for lost seeds, pelvic fluoroscopic imaging from 3 different angles was done 30 days after the implant. Posteroanterior and lateral chest x-rays were done when seed loss was confirmed. Patients were compared using the χ(2) test and Fisher exact test.


RESULTS
At least 1 seed was lost in 31.5% of patients with a migration rate of 1.02%; 9.3% of patients had at least 1 seed in the lung with a migration rate of 0.22%. The population was divided into 3 groups according to the order in which they were treated. Seed loss (P=0.02) and pulmonary seed embolization (P=0.008) were significantly lower in the second hundred than in the first hundred patients. No difference was noted between groups 1 and 3 (patient, 201-279). Peri- or extracapsular seed placement was not correlated to seed loss (P=0.780 and P=0.092, respectively). No serious complications from seed migration were reported. Seed loss did not influence dosimetry parameters (V100, V150, and D90).


CONCLUSIONS
Our pulmonary seed migration and total seed loss rates are comparable to the ones reported in the literature. Virtual needle guidance and automated seed delivery system are in our hand as accurate as the manual technique.
Hathout
Lara
L
Department of Radiation Oncology, University of Montreal Medical, CHUM, Quebec, Canada.
Donath
David
D
Moumdjian
Camille
C
Tétreault-Laflamme
Audrey
A
Larouche
Renée
R
Béliveau-Nadeau
Dominic
D
Hervieux
Yannick
Y
Taussky
Daniel
D
D000368:Aged; D001918:Brachytherapy; D015331:Cohort Studies; D005500:Follow-Up Studies; D005548:Foreign-Body Migration / Q000150:complications*; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008168:Lung / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009339:Needles; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000532:radiotherapy*; D019736:Prostheses and Implants; D011655:Pulmonary Embolism / Q000209:etiology*; D012371:Robotics; D015996:Survival Rate; D016896:Treatment Outcome; D014463:Ultrasonography
D007457:Iodine Radioisotopes