Incidence of Anterior Pituitary Deficiency after Radiotherapy at an Early Age: Study in Retinoblastoma

Abstract
Patients (31) treated for retinoblastoma in the first few years (3 mo.-3 yr and 6 mo.) of life were studied 2-15 yr later. Radiotherapy delivered 1300-6500 rads to the hypothalamo-pituitary area. Growth deficiency was documented in 30% of all cases. Other pituitary deficiencies were the exception. The critical dose for GH [Growth hormone] insufficiency is betwen 2000-3000 rad, as in older children or adults. The study does not support the hypothesis that the hypothalamo-pituitary area is more sensitive to radiation at an early age. Conservative therapy of retinoblastoma leads to double lateral irradiation and will increase the number of Gh deficient children after retinoblastoma.