Conservative treatment of retinoblastoma. The use of plaque brachytherapy.

Retinoblastoma is the most common intraocular malignancy in childhood. The tumor arises from multipotential retinal cells. Treatment options include enucleation, external beam radiotherapy, episcleral plaque radiotherapy, photocoagulation, cryotherapy or a combination of these modalities. In retinoblastoma 10% have a positive family history and of the remaining 90%, 35% represent germinal chromosomal mutations while 65% represent somatic chromosomal mutations. Therefore, approximately 40% of all retinoblastomas are hereditary and are transmitted as a highly penetrant autosomal dominant trait. In the Wills Eye/Hahnemann University experience an analysis of 400 consecutive patients, 103 tumors in 103 eyes were treated with solitary plaque radiotherapy. Tumor regression was observed in all patients initially. After 40 months mean follow-up, persistent regression was observed in 89 cases (87%) and recurrences in 13 cases (13%). Of the 13 recurrences, five were in the group treated primarily (5/31) and eight in the group treated after failing other modalities (8/72). Plaque brachytherapy is an important tool in the management of retinoblastoma. Our preliminary data suggest that plaque brachytherapy is an effective treatment modality for primary treatment as well as after failure using other modalities.