Retinoblastoma. The long-term appearance of radiated intraocular tumors.

A retrospective analysis of 50 patients with retinoblastoma was undertaken to determine the appearance of intraocular retinoblastoma that had received external beam radiation a minimum of 10 years previously. Of the 91 tumors found in 59 eyes, 76 (84%) continued to be ophthalmoscopically visible after 10 years. The most common ophthalmoscopic appearance was a Type III regression pattern. The type of radiation regression pattern correlated with the pretreatment volume of the tumor. The largest tumors (mean, 10.0 disc diameter [dd]) became Type I regression patterns, whereas the smallest tumors (mean, 1.0 dd) completely disappeared. This represents the first long-term follow-up of the intraocular status of radiated retinoblastoma.