title: Prostate implant dosimetric outcomes and migration patterns between bio-absorbable coated and uncoated brachytherapy seeds.
abstract: OBJECTIVE
  To evaluate the lung and pelvic seed migration and intraprostatic dose variability for prostate seed implant (PSI) using bio-absorbable polymer "coated" seeds for intraoperative planning.
  
  
  METHODS
  A total of 100 PSI patients were initially implanted with uncoated I-125 (STM 1251 or I125-SL, N = 85) or Pd-103 (mod 200, N = 15) seeds, and 105 PSI patients were implanted subsequently with coated seeds using inverse optimization with real-time planning. Implant technique, average number of needles, and dose objectives remained identical among the cohorts.
  
  
  RESULTS
  Day 30 postimplant comparison of seed migration demonstrated a significant reduction in overall lung and pelvic seed migration from 25% (uncoated) to 4% (coated) (p < 0.0001). A measurable reduction in intraprostatic dose variability was observed in patients with the coated seeds when comparing 30 days dosimetry results for V100, V150, and D90 for prostate, and V110 for the rectum. A statistically significant reduction in the standard deviation from Day 0 to Day 30 for the above parameters for the prostate as well as for V110 of rectum was also observed. A significant improvement in implant quality at Day 30 was demonstrated using Radiation Therapy Oncology Group (RTOG) evaluation criteria range with the coated seeds cohort.
  
  
  CONCLUSIONS
  PSI using coated seeds shows lower lung and pelvic seed migration compared with those using uncoated seeds and compares favorably to pelvic stranded seed migration reports. A higher concordance was observed with less dose variability in dosimetric parameters on Day 30 dosimetry compared with that on Day 0. Improvement in the implant quality was also observed using the RTOG criteria, suggesting reduced intraprostatic migration.
authors.affiliation: Department of Radiation Oncology, Helen F. Graham Cancer Center, Christiana Care Health System, Newark, DE.
authors.forename: Abhirup
authors.initials: A
authors.lastname: Sarkar
authors.forename: Viroon
authors.initials: V
authors.lastname: Donavanik
authors.forename: Isabella
authors.initials: I
authors.lastname: Zhang
authors.forename: Hungcheng
authors.initials: H
authors.lastname: Chen
authors.forename: Christopher
authors.initials: C
authors.lastname: Koprowski
authors.forename: Alex
authors.initials: A
authors.lastname: Hanlon
authors.forename: Firas
authors.initials: F
authors.lastname: Mourtada
authors.forename: Jon
authors.initials: J
authors.lastname: Strasser
authors.forename: Adam
authors.initials: A
authors.lastname: Raben
mesh_terms: D001918:Brachytherapy / Q000009:adverse effects* / Q000379:methods*; D005548:Foreign-Body Migration; D006801:Humans; D007457:Iodine Radioisotopes; D008168:Lung; D008297:Male; D010165:Palladium; D010388:Pelvis; D011108:Polymers; D011471:Prostatic Neoplasms / Q000532:radiotherapy*; D019736:Prostheses and Implants / Q000009:adverse effects*; D011868:Radioisotopes; D011879:Radiotherapy Dosage; D012007:Rectum; D013997:Time Factors
chemical_list: D007457:Iodine Radioisotopes; D011108:Polymers; D011868:Radioisotopes; D010165:Palladium