Long‐term effects of radiation for medulloblastoma on intellectual and physical development. A case report of monozygotic twins

Abstract

Background. Recent advances in treatment have improved the prognosis for medulloblastoma. Although postoperative radiation of the central nervous system (CNS) is widely practiced, late radiation sequelae, especially in long‐term survivors, pose a constant risk. Methods. To assess the long‐term effects of CNS radiation, a monozygotic twin girl with medulloblastoma was compared with her normal twin. Treatment included total removal of the mass, postoperative chemotherapy, and CNS radiation with 47.8 Gy directed to the posterior fossa, 30.2 Gy to the cerebral hemispheres, and 20 Gy to the whole spine. Results. Not only the radiated patient's spine but also the unradiated upper and lower limbs were shorter than the control subject's. The patient's thyroid hormone level was within normal range; however, thyroid‐stimulating hormone was higher than normal. The patient's intellectual ability deteriorated, and cognitive dysfunction has not improved as of 6 years after treatment. Conclusions. Treatment systems that do not cause late sequelae affecting physical and intellectual development should be pursued. Copyright © 1994 American Cancer Society