Sightsaving therapy in retinoblastoma. Experience with external megavoltage radiotherapy

In Norway, sightsaving therapy in retinoblastoma has only been given to least affected eyes in bilaterally affected children. The results in 8 eyes given external high energy radiotherapy are reported. Additional focal therapy was given to 3 eyes for residual tumours and to one eye with new tumour at the ora serrata. Cataract was treated in 2 of the 3 eyes in which it developed. Vitrectomy was performed in 2 eyes with vitreous haemorrhage and persisting vitreous haze. Secondary enucleation has been avoided in all eyes 3-9 years after irradiation. One patient developed metastases in the temporal region at the enucleated side. Visual acuity is 6/12-6/6 if the macula has not been destroyed by tumour or focal therapy. Sightsaving therapy is presently also offered to unilateral cases and worst affected eyes in bilateral cases if the eyes belong to Reese-Ellsworth groups I-IV.