Randomized Clinical Trial of Postoperative Strontium-90 Radiation Therapy for Pterygia

Postoperative adjuvant treatment with strontium-90 radiation therapy (RT) is a proven technique for reducing the recurrence of pterygium. This randomized trial was conducted to evaluate whether a total dose of 40 Gy provides a better local control rate than a total dose of 30 Gy for surgically resected pterygia. A single institutional randomized trial was conducted. Between 1999 and 2003, 74 pterygia in 71 patients were randomly allocated to 30 Gy/3 fractions/15 days (arm A) or to 40 Gy/4 fractions/22 days (arm B). Only primary pterygia for which RT could be started within 3 days of surgical resection were included. Postoperative RT was given by a strontium-90 eye applicator, and a dose of 10 Gy per fraction was delivered in weekly fractions (day 1, 8, 15, 22). Of the 74 pterygia treated, 73 in 70 patients were analyzed. Of the 73 pterygia, 41 were allocated to arm A, and the remaining 32 to arm B. The 2-year local control rates for arm A and arm B were 85% and 75%, respectively, without significant difference. No serious acute and late complications were noted in either arm. Our new standard fractionation for postoperative RT for pterygia is 30 Gy/3 fractions.