Management of retinoblastoma with radiation.

ABSTRACT

OBJECTIVE: To evaluate the role of radiation therapy in the management of retinoblastoma. DESIGN: Retrospective analysis. METHOD: From January 1993 to March 1994, one hundred and eleven children (150 eyes) of retinoblastoma were referred for radiotherapy. The diagnosis was based on clinical examination and ocular ultrasonogram for both the eyes. The radiation treatment policy involved 40 Gy in 20 fractions over 4 weeks delivered with sedation for children under 1 year of age, 36 Gy in 9 fractions over 3 weeks under ketamine anesthesia for 1-4 years of age and for >4 years of age, a dose of 50 Gy in 25 fractions over 5 weeks. The initial tumor regression was evaluated by A and B mode ultrasonography and/or CT scan. RESULTS: The age distribution ranged from two months to six years (median - 20 months). Bilaterality was observed in 39 out of 111 cases (35%). The male to female ratio was 1.81. Eighty two of the 111 children were treated by definitive external beam radiation to one or both eyes. Fifteen cases received adjuvant radiotherapy after enucleation, and 14 had extensive disease for which palliative radiotherapy was offered. We observed a complete response in 54% of cases, partial response in 32%, and none in 14% of cases. Forty per cent (40%) eye survival was documented at the end of 28 months. The complication rate encountered was about 15%. CONCLUSION: Radiotherapy is an effective modality of treatment in significant number of patients with retinoblastoma. However, it requires appropriate fractionation, precise colimation and careful immobilization with general anesthesia.