[Radiotherapy in the treatment of retinoblastoma: about 40 cases]

The aim of this study is to analyze the results and the complications of radiotherapy in the treatment of retinoblastoma.

Between 1994 and 2004, 40 children received radiotherapy for a retinoblastoma in Salah Azaiz Institute. The average age of the patients was 36 months (four to 132 months). There were 16 girls and 24 boys. Sixteen children presented a bilateral disease and 24 children a unilateral disease. Twenty eyes and thirty-six orbital cavities in 40 children with retinoblastoma were treated by radiotherapy. One child with a unilateral anterior retinoblastoma was treated with 106 ruthenium brachytherapy. External radiotherapy has been used to treat the 39 patients. In 20 cases the irradiation was conservative and in 36 cases postoperatively. The latter (n=36) presented at least one risk factor of relapses noted in the histological examination. The average dose was 44 Gy (1.8 to 2 Gy per fraction, five fractions weekly). This radiotherapy was associated with chemotherapy in 24 cases.

Thirty-five children were followed with an average follow-up of 53 months (3-108 months). The average delay of relapses was of 10 months (two to 26 months). We found four orbital relapses and seven metastasis in nine children. The conservation of the eye with a useful visual field was noted in 18 cases among the 20 conservative irradiated eyes. The major therapeutic complication was the growth defect of the bones face. A femoral bone sarcoma was noted five years after the end of the irradiation and chemotherapy in one case.

If the radiotherapy offers the advantage of the functional conservation and the improvement of the local control, its indications are more and more restricted in favor of the other therapeutic methods (chemotherapy, thermochemotherapy) and this considering the iatrogene risk. The development of new techniques of brachytherapy and the progresses of the conformational radiotherapy appear to reduce considerably this risk.