title: Radiation therapy for subretinal neovascularization.
abstract: OBJECTIVE
  To evaluate low-dose external beam irradiation and plaque radiotherapy for the treatment of subretinal neovascularization.
  
  
  METHODS
  The authors treated 137 patients with radiation therapy for subretinal neovascularization. Herein, they examine a subset of 75 patients with exudative age-related macular degeneration who were treated with (4- or 6-MV photons) external beam irradiation at a dose of 1200 to 1500 cGy to the affected macula. In addition, six patients were treated with palladium 103 ophthalmic plaque brachytherapy to an equivalent retinal apex dose of 1200 to 1500 cGy. The authors compared the intralesional, intraocular, and intracranial radiation dose distributions of each treatment modality. Early Treatment Diabetic Retinopathy Study-type visual acuity determinations, ophthalmic examinations, and angiography were performed before and after treatment. Clinical evaluations were performed in a nonrandomized and unmasked fashion.
  
  
  RESULTS
  Episcleral plaque brachytherapy was found to provide a higher average radiation dose within the neovascular tissues while delivering less radiation to most normal ocular (both eyes) and all intracranial structures. Both forms of radiotherapy were associated with decreased hemorrhages, exudates, and leakage of neovascular membranes. Ten (13 percent) patients receiving external beam radiotherapy had transient epiphora and ocular irritation.
  
  
  CONCLUSIONS
  Observation and laser photocoagulation of subfoveal neovascularization have been associated with poor visual outcomes. Pilot experience suggests that low-dose radiotherapy offers a method to treat subretinal neovascularization without destroying the overlying retina. Although the authors' radiation distribution studies favored plaque radiotherapy, additional factors such as relative efficacy, expense, convenience, and safety must be investigated.
authors.affiliation: Department of Ophthalmology, The New York Eye and Ear Infirmary, New York, USA.
authors.forename: P T
authors.initials: PT
authors.lastname: Finger
authors.forename: A
authors.initials: A
authors.lastname: Berson
authors.forename: D
authors.initials: D
authors.lastname: Sherr
authors.forename: R
authors.initials: R
authors.lastname: Riley
authors.forename: R A
authors.initials: RA
authors.lastname: Balkin
authors.forename: J L
authors.initials: JL
authors.lastname: Bosworth
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000379:methods*; D005260:Female; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D006801:Humans; D008268:Macular Degeneration / Q000150:complications; D008297:Male; D010165:Palladium; D011868:Radioisotopes; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy; D015861:Retinal Neovascularization / Q000209:etiology / Q000473:pathology / Q000532:radiotherapy*; D012171:Retinal Vessels / Q000473:pathology / Q000528:radiation effects*; D013819:Thermoluminescent Dosimetry; D014792:Visual Acuity
chemical_list: D011868:Radioisotopes; D010165:Palladium