Radiation management of bilateral retinoblastoma: the need to preserve vision

Thirty-four patients with retinoblastoma were treated in the Radiation Therapy Department of the University of Oregon Health Sciences Center from 1944 to 1978. Twenty-five of these patients had bilateral disease. Most patients were treated with megavoltage equipment and received doses of 5000 rad in 5 weeks. According to the lifetable method, five year survival was 67.6%; it increased to 85.7% if patients who were treated with orthovoltage equipment were excluded. Seventy-one percent of evaluable patients had useful vision at 5 years; an additional two patients had useful vision for two years after radiation therapy. The value of even limited vision during this critical time of sensorimotor and psychological development is discussed. Orthovoltage equipment should not be used to irradiate patients with retinoblastoma.