Long-term effects of radiotherapy administered in childhood for the treatment of malignant diseases.

Background: The use of radiotherapy for the treatment of childhood malignancy has improved long-term survival significantly, and many treated children now survive well into adulthood. As a consequence, long-term effects of childhood irradiation are being seen with increasing frequency.

Methods: The medical records of 236 patients who had been treated for malignant disease with radiotherapy during childhood were examined to determine the long-term effect of the radiation on their growth and development.

Results: Mean treatment dose was 35.5 Gy; mean age at treatment was 7.2 years; and mean follow-up was 14.5 years. Adjuvant chemotherapy was given to 82%. Some degree of bone deformity (usually with overlying soft-tissue hypoplasia) was seen in 40%; 21% developed some type of endocrine deficiency; 30% developed atrophic skin changes; and 7% developed second malignancies. The incidence of bone deformity and hormonal deficiency increased with the radiation dose; the incidence of second malignancy was independent of dose. Bone deformities were more common when radiation was administered before the age of 2 years.

Conclusions: The consequences of radiotherapy in childhood are significant and must be considered when planning treatment. Even when treatment is essential, families should be informed of the possibility of growth disturbance to prevent subsequent misunderstanding.