Long-term results of fractionated strontium-90 radiation therapy for pterygia

Purpose: The long-term safety and effectiveness of fractionated strontium-9 0 radiation therapy (RT) for pterygium were reviewed retrospectively. Methods and Materials: Between 1984 and 1996, 399 patients with 490 pterygi a were treated with a strontium-90 eye applicator following surgical remova l of the pterygium, The median follow-up period was 61 months (range 2-178) , Of the 490 pterygia, 452 were fresh, 17 were recurrences after surgical r emoval alone, and 21 were recurrences after surgical removal plus postopera tive RT. Fractionated RT of 31-42 Gy/4-5 fractions/22-29 days was given for 95.1% of the pterygia, Results: In total, 58 (11.8%) local recurrences of pterygia were noted. The median time of local recurrences was 10 months, ranging from 2 to 93 month s, and 16 recurrences (28%) were noted later than 24 months after treatment . The interval between surgery and the start of RT (1-3 days vs. > 3 days) and recurrent pterygia were significant variables for local control in the multivariate analysis, while total RT dose (7-29 Gy vs. 31-50 Gy) was a mar ginally significant. variable. Late toxicities that may be associated with strontium-90 RT were scleromalacia (scleral thinning) in 4 eyes, adhesion o f eyelids in 3 eyes, and scleral ulcer in 2 eyes. Conclusion: Fractionated strontium-90 RT of approximately 40 Gy/4-5 fractio ns was safe and effective for preventing recurrence of pterygia, when RT wa s started within 3 days of surgery. (C) 2000 Elsevier Science Inc.