Long-term results and prognostic factors of fractionated strontium-90 eye applicator for pterygium.
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.
Viani
Gustavo Arruda
GA
Department of Radiation Oncology, Marília Medicine School, São Paulo, Brazil. gusviani@gmail.com
Stefano
Eduardo Jose
EJ
De Fendi
Ligia Issa
LI
Fonseca
Ellen Carrara
EC
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
D019275:Radiopharmaceuticals; D013326:Strontium Radioisotopes