title: The effects of intraocular silicone oil placement prior to iodine 125 brachytherapy for uveal melanoma: a clinical case series.
abstract: OBJECTIVE
  To investigate the role of silicone oil as an adjunct to iodine 125 ((125)I) brachytherapy in attenuating radiation dose and reducing radiation retinopathy.
  
  
  METHODS
  A 16-mm COMS plaque loaded with (125)I seeds was simulated in vitro on an eye model containing silicone oil as a vitreous substitute using BrachyDose. The radiation dose ratio of silicone oil vs water to ocular structures was calculated at angles subtended from the centre of the eye. Silicone oil was then used in three choroidal melanoma patients who underwent 23-gauge vitrectomy, silicone oil placement, and (125)I brachytherapy.
  
  
  RESULTS
  Silicone oil reduced the ocular radiation dose in vitro to 65%. Radiation dose ratios on the retina increased from 0.45 to 0.99 when moving from points diametrically opposed to the plaque's central axis. In 10-24 months' follow-up, no patients have developed radiation retinopathy. Each patient required silicone oil removal and experienced cataract progression, and one also developed a retinal detachment.
  
  
  CONCLUSIONS
  This study confirms that silicone oil attenuates radiation dose in vitro, and may protect against radiation retinopathy clinically in patients, however it requires extensive surgical interventions. Further studies in only very selected populations using silicone oil as an adjunct to (125)I brachytherapy will best elucidate its role in shielding radiation retinopathy.
authors.affiliation: Department of Ophthalmology, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Ahuja
authors.forename: K G
authors.initials: KG
authors.lastname: Kapoor
authors.forename: R M
authors.initials: RM
authors.lastname: Thomson
authors.forename: K M
authors.initials: KM
authors.lastname: Furutani
authors.forename: R W
authors.initials: RW
authors.lastname: Shultz
authors.forename: S L
authors.initials: SL
authors.lastname: Stafford
authors.forename: S
authors.initials: S
authors.lastname: Dev
authors.forename: N E
authors.initials: NE
authors.lastname: Abu-Yaghi
authors.forename: D
authors.initials: D
authors.lastname: Reynolds
authors.forename: J S
authors.initials: JS
authors.lastname: Pulido
mesh_terms: D000368:Aged; D001918:Brachytherapy / Q000379:methods*; D002830:Choroid Neoplasms / Q000532:radiotherapy*; D004322:Drainage; D058450:Endotamponade; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008545:Melanoma / Q000532:radiotherapy*; D008875:Middle Aged; D011832:Radiation Injuries / Q000517:prevention & control*; D011837:Radiation-Protective Agents / Q000627:therapeutic use*; D011879:Radiotherapy Dosage; D012160:Retina / Q000528:radiation effects*; D012827:Silicone Oils; D014821:Vitrectomy
chemical_list: D007457:Iodine Radioisotopes; D011837:Radiation-Protective Agents; D012827:Silicone Oils