Radiation response of the central nervous system

Journal Article · Thu Mar 30 04:00:00 EST 1995 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/0360-3016(94)00655-5· OSTI ID:90877

Schultheiss, T E ^[1]; Kun, L E ^[2]; Stephens, L C ^[3]

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1. Fox Chase Cancer Center, Philadelphia, PA (United States)
2. St. Jude`s Children`s Research Hospital, Memphis, TN (United States)
3. Anderson Cancer Center, Houston, TX (United States); and others

This report reviews the anatomical, pathophysiological, and clinical aspects of radiation injury to the central nervous system (CNS). Despite the lack of pathoGyomonic characteristics for CNS radiation lesions, demyelination and malacia are consistently the dominant morphological features of radiation myelopathy. In addition, cerebral atrophy is commonly observed in patients with neurological deficits related to chemotherapy and radiation, and neurocognitive deficits are associated with diffuse white matter changes. Clinical and experimental dose-response information have been evaluated and summarized into specific recommendations for the spinal cord and brain. The common spinal cord dose limit of 45 Gn in 22 to 25 fractions is conservative and can be relaxed if respecting this limit materially reduces the probability of tumor control. It is suggested that the 5% incidence of radiation myelopathy probably lies between 57 and 61 Gy to the spinal cord in the absence of dose modifying chemotherapy. A clinically detectable length effect for the spinal cord has not been observed. The effects of chemotherapy and altered fractionation are also discussed. Brain necrosis in adults is rarely noted below 60 Gy in conventional fractionation, with imaging and clinical changes being observed generally only above 50 Gy. However, neurocognitive effects are observed at lower doses, especially in children. A more pronounced volume effect is believed to exist in the brain than in the spinal cord. Tumor progression may be hard to distinguish from radiation and chemotherapy effects. Diffuse white matter injury can be attributed to radiation and associated with neurological deficits, but leukoencephalopathy is rarely observed in the absence of chemotherapy. Subjective, objective, management, and analytic (SOMA) parameters related to radiation spinal cord and brain injury have been developed and presented on ordinal scales. 140 refs., 3 figs., 6 tabs.

• OSTI ID: 90877
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 5 Vol. 31; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
56 BIOLOGY AND MEDICINE
APPLIED STUDIES
ATROPHY
BRAIN
CENTRAL NERVOUS SYSTEM
CHEMOTHERAPY
DOSE-RESPONSE RELATIONSHIPS
NECROSIS
PATHOLOGICAL CHANGES
RADIATION INJURIES
RADIOTHERAPY
SPINAL CORD