title: Dosimetric and late radiation toxicity comparison between iodine-125 brachytherapy and stereotactic radiation therapy for juxtapapillary choroidal melanoma.
abstract: OBJECTIVE
  To compare the dose distributions and late radiation toxicities for (125)I brachytherapy (IBT) and stereotactic radiation therapy (SRT) in the treatment of juxtapapillary choroidal melanoma.
  
  
  METHODS
  Ninety-four consecutive patients with juxtapapillary melanoma were reviewed: 30 have been treated with IBT and 64 with SRT. Iodine-125 brachytherapy cases were modeled with plaque simulator software for dosimetric analysis. The SRT dosimetric data were obtained from the Radionics XKnife RT3 software. Mean doses at predetermined intraocular points were calculated. Kaplan-Meier estimates determined the actuarial rates of late toxicities, and the log-rank test compared the estimates.
  
  
  RESULTS
  The median follow-up was 46 months in both cohorts. The 2 cohorts were balanced with respect to pretreatment clinical and tumor characteristics. Comparisons of radiation toxicity rates between the IBT and SRT cohorts yielded actuarial rates at 50 months for cataracts of 62% and 75% (P=.1), for neovascular glaucoma 8% and 47% (P=.002), for radiation retinopathy 59% and 89% (P=.0001), and for radiation papillopathy 39% and 74% (P=.003), respectively. Dosimetric comparisons between the IBT and SRT cohorts yielded mean doses of 12.8 and 14.1 Gy (P=.56) for the lens center, 17.6 and 19.7 Gy (P=.44) for the lens posterior pole, 13.9 and 10.8 Gy (P=.30) for the ciliary body, 61.9 and 69.7 Gy (P=.03) for optic disc center, and 48.9 and 60.1 Gy (P<.0001) for retina at 5-mm distance from tumor margin, respectively.
  
  
  CONCLUSIONS
  Late radiation-induced toxicities were greater with SRT, which is secondary to the high-dose exposure inherent to the technique as compared with IBT. When technically feasible, IBT is preferred to treat juxtapapillary choroidal melanoma.
authors.affiliation: Department of Ocular Oncology, Princess Margaret Hospital/University Health Network, University of Toronto, Toronto, Ontario, Canada. htmkrm19@yahoo.com
authors.forename: Hatem
authors.initials: H
authors.lastname: Krema
authors.forename: Mostafa
authors.initials: M
authors.lastname: Heydarian
authors.forename: Akbar
authors.initials: A
authors.lastname: Beiki-Ardakani
authors.forename: Daniel
authors.initials: D
authors.lastname: Weisbrod
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.forename: Normand J
authors.initials: NJ
authors.lastname: Laperriere
authors.forename: Arjun
authors.initials: A
authors.lastname: Sahgal
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000009:adverse effects* / Q000379:methods; D002386:Cataract / Q000209:etiology; D002830:Choroid Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D005260:Female; D015355:Glaucoma, Neovascular / Q000209:etiology; D006801:Humans; D007457:Iodine Radioisotopes / Q000009:adverse effects* / Q000627:therapeutic use; D008297:Male; D008545:Melanoma / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery*; D008875:Middle Aged; D009898:Optic Disk / Q000528:radiation effects; D011832:Radiation Injuries / Q000209:etiology*; D016634:Radiosurgery / Q000009:adverse effects* / Q000379:methods; D011879:Radiotherapy Dosage; D012164:Retinal Diseases / Q000209:etiology; D012189:Retrospective Studies; D018709:Statistics, Nonparametric
chemical_list: D007457:Iodine Radioisotopes