Use of strontium-90 beta irradiation as an adjunctive therapy for the management of squamous cell carcinoma of the conjunctiva

Full text: To evaluate the effectiveness of strontium-90 beta irradiation in management of squamous cell carcinoma of the conjunctiva. A retrospective analysis of the medical records of 5 patients treated with strontium-90 beta irradiation was done. Squamous cell carcinoma of the conjunctiva was histologically proved in all patients who had initial surgery to remove the major part of the lesion. This was followed by beta radiation within 48 hours with Sr -90 contact applicator obtained from Amersham International. The hand held Sr- 90 eye applicator was used after appropriately instilling the eyes with local anesthetics and a total of 5000cGy was delivered in seven fractions. Follow-up period was from 6 to 12 months. Clinical response and side effects to the therapy were used as outcome measurements. Three patients showed good response with no evidence of tumor within 6 to 12 months of the follow-up period. One patient was lost to follow-up and one patient showed local recurrence within 4 months. In this patient the tumor was more extensive involving the limbal conjunctiva and the cornea. The early side effects of beta radiation reported by all five patients were temporary local irritation of the eyes with additional mild chemosis in four patients. None of the other three potentially cured patients showed any long-term adverse reactions. There were no incidence of late radiation induced complications such as corneal ulcerations, damage to cornea, eye pain, cataract or any other serious effects in these patients within the follow-up period. In conclusion, beta irradiation is an effective post-surgical therapy for local control of superficial conjunctival squamous cell carcinoma. The very low and minimum side -effects of Sr-90 irradiation is an advantage, which makes it a good alternative to external beam radiation, which has serious side effects. (author)