title: Long-term results and prognostic factors of fractionated strontium-90 eye applicator for pterygium.
abstract: OBJECTIVE
  To evaluate the long-term safety, effectiveness, and prognostic factors of fractionated postoperative beta-irradiation.
  
  
  METHODS
  Between 1993 and 2005, 623 patients with 737 pterygium lesions were treated with a strontium-90 eye applicator after surgical excision. The median follow-up period was 60 months (range, 6.7-139.5). Of the 737 lesions, 644 were primary and 93 were recurrences after surgical removal alone. Fractionated radiotherapy (RT) to a total dose of 35 Gy in five to seven fractions was used.
  
  
  RESULTS
  A total of 73 local pterygium recurrences (9.9%) were noted. Of the recurrent cases, 80% were noted within 3 years after treatment. The 5- and 10-year probability of local control was 90% and 88%, respectively. The multivariate analysis for all cases demonstrated that gender, age, total radiation dose, recurrent pterygia, and interval between surgery and RT affected the overall local control rate. Late toxicities that might have been associated with strontium-90 RT included scleromalacia (scleral thinning) in nine eyes, adhesion of the eyelids in eight, cataracts in six, and scleral ulcer in five eyes.
  
  
  CONCLUSIONS
  Fractionated strontium-90 RT to a total dose of approximately 35 Gy in five to seven fractions results in a similar local control rate as higher doses in other series, with an acceptable complication rate.
authors.affiliation: Department of Radiation Oncology, Marília Medicine School, São Paulo, Brazil. gusviani@gmail.com
authors.forename: Gustavo Arruda
authors.initials: GA
authors.lastname: Viani
authors.forename: Eduardo Jose
authors.initials: EJ
authors.lastname: Stefano
authors.forename: Ligia Issa
authors.initials: LI
authors.lastname: De Fendi
authors.forename: Ellen Carrara
authors.initials: EC
authors.lastname: Fonseca
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001938:Brazil / Q000453:epidemiology; D015897:Comorbidity; D019583:Dose Fractionation, Radiation; D005260:Female; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011625:Pterygium / Q000453:epidemiology* / Q000532:radiotherapy*; D011832:Radiation Injuries / Q000453:epidemiology*; D019275:Radiopharmaceuticals / Q000627:therapeutic use; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D013326:Strontium Radioisotopes / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D019275:Radiopharmaceuticals; D013326:Strontium Radioisotopes