The long-term effects of cranial irradiation on the central nervous system

Abstract

Cranial irradiation and chemotherapy may have significant long-term deleterious effects on children with brain tumors. Intellectual deterioration, endocrinopathies, leukoencephalopathy, extraneural metastases, and oncogenesis may all complicate the treatment of central nervous system neoplasia. These long-term effects of therapy have important implications, as some are amenable to treatment and others may be prevented by the careful monitoring of drug and radiation administration. Until recently, the survivals of children with brain tumors were limited, so that concerns over long-term effects of therapy were unnecessary. As children with certain types of brain tumors now have a better prognosis, these long-term and possibly remediable effects have important implications. This article emphasizes radiation effects on intellect, endocrine function, and oncogenesis. Recommendations for baseline and longitudinal evaluations of children with brain tumors are suggested.Cancer 561841-1846, 1985.HE SURVIVAL of children with certain types of brain T tumors has increased over the last two decades.Recent data from the Surveillance Epidemiology End Results (SEER) registries suggested that 5-year survival rates of children with medulloblastomas, low-grade supratentorial astrocytomas, and cerebellar astrocytomas ranged from 40% to 90%. Eight hundred sixty-five children with brain tumors diagnosed from 1973 through 1981 from this registry had an overall 40% 5-year survival rate.' Pari pussu with these prolonged survivals has come the recognition of the potential long-term consequences of this therapy on the surviving children. Intellectual deterioration, endocrine deficiencies, leukoencephalopathy, and oncogenesis are areas of concern.The two most remarkable long-term sequelae of cranial irradiation with or without chemotherapy are the adverse effects on intelligence and endocrine function. Unfortunately, prospective evaluations of children with brain

Survival outcomes in atypical teratoid rhabdoid tumor for patients undergoing radiotherapy in a Surveillance, Epidemiology, and End Results analysis

“…It should be noted that there are significant side effects associated with radiation in young children and that these side effects are particularly significant in the youngest patients treated. 26 These side effects include cognitive delay and endocrine dysfunction, although the extent of side effects depends on the dose and size of RT fields delivered. 5 In addition, chemotherapy and progression of the tumor in the absence of RT also can contribute to neurocognitive delay, complicating the decision to use RT in the very young.…”

Lack of benefit of spinal irradiation in the primary treatment of intracranial germinoma

“…3,[5][6][7][8] Cranial irradiation leads to late adverse effects, including intellectual deficits, hormonal abnormalities, arterial obstruction, and secondary malignancies. 5,11,19,[27][28][29][30] Diabetes insipidus, panhypopituitarism, and delayed gonadal function are observed frequently in patients with intracranial germinoma at initial evaluation. 4,7,8,25,28 Few authors have evaluated the frequency of radiation-induced adverse effects correctly by comparing intellectual status and hormonal abnormalities before and after treatment.…”

Pre‐radiation chemotherapy with response‐based radiation therapy in children with central nervous system germ cell tumors: A report from the Children's Oncology Group

“…The biologic disparity between pure germinomas and nongerminomatous tumors is also supported by the difference in mean age at diagnosis (adolescent versus middle school years), with nongerminomatous tumors having a more heterogeneous appearance with spread to distant structures [1][2][3][4][5]. With the goal of reducing potential late sequelae of cranial radiation [6][7][8][9][10][11], platinum-based regimens have sought to decrease radiation dose by administering chemotherapy before reduced radiation [12][13][14][15][16]. It is not yet known whether this approach will lead to similar cure rates with decreased toxicity.…”