Prevention of pterygium recurrence by postoperative single-dose β-irradiation: A prospective randomized clinical double-blind trial

Purpose To affirm the effectiveness and complication rate of postoperative single-dose β-irradiation (RT) with ⁹⁰Sr in the case of primary pterygium in a clinical trial. Pterygium is a benign disease of the supporting orbital tissue that can cause impairment of visual function. Depending on the technique used for surgery, recurrence is described in up to 70% of cases - a reason to combine the initial treatment with radiotherapy or chemotherapy. Methods and materials This trial was designed as a prospective, randomized, multicenter, double-blind study. Surgery was performed in all cases according to the bare sclera technique. Ninety-one patients with 96 pterygia were postoperatively randomized to either β-RT or sham RT. In the case of β-RT, a ⁹⁰Sr eye applicator was used to deliver 2500 cGy to the sclera surface at a dose rate of between 200 and 250 cGy/min. Sham RT was given using the same type of applicator without the ⁹⁰Sr layer. After treatment, both an ophthalmologist and a radiation oncologist performed the follow-up examinations. The accumulated data were analyzed using a group sequential test. Results Between February 1998 and September 2002, 96 eyes with primary pterygium were operated on according to the trial protocol. Additional treatment was performed within 24 hours postoperatively. Ten patients were lost to follow-up, resulting in 86 patients who could be analyzed. In the 44 eyes randomized to receive β-RT, 3 relapses occurred compared with 28 recurrences in the 42 eyes that received sham RT, for a crude control rate of 93.2% vs. 33.3%, respectively. At a mean follow-up of 18 months, major treatment complications had not been observed. Conclusion Single-dose β-RT after bare sclera surgery is a simple, effective, and safe treatment that reduces the risk of primary pterygium recurrence.