Radiation myelopathy

Journal Article · Sun Jan 01 04:00:00 EST 1961 · Brain (Journal of Neurology)

DOI:https://doi.org/10.1093/brain/84.3.460· OSTI ID:4780822

PALLIS, CHRISTOPHER A.; LOUIS, SYDNEY; MORGAN, ROWLAND L.

A survey was made of 38 cases of radiation myelopathy with regard to early symptoms and signs, differential diagnosis, prognosis, nature of the primary lesion irradiated, and latency between irradiation and the development of neurological symptoms. Death occurred in 17 of these cases, 1 month to 4 yr after the first neurologic symptoms, as a result of the myelopathy. In most instances the blood vessels and stroma appear to have been predominantly involved. The latent period of several months between irradiation and onset of myelopathic symptoms suggests that the effect is primarily on blood vessels. The findings indicate that new limits should be advised for the permissible dose of radiation to the spinal cord. For treatment times of 42 days the limit for fields greater than 10 cm long should be 3,300 rads, and for flelds less than 10 cm long, 4,300 rads. Idiosyncrasy is obviously a factor in the development of myelopathy, since the survey shows that many patients fail to develop the condition despite having received doses above 3,000 rads in 28 days (for large fields) or 4,300 rads in 42 days (for small fields). It is important to recognize the relative sensitivity of the spinal cord to irradiation, and to plan treatment accordingly. With conventional 240 kv machines (and with some Co/sup 60/ units) the radiation beam has a wide penumba, which sometimes makes it difficult to avoid irradiating the cord (e.g., in post-cricoid cancer, where the irradiated volume must include the anterior surface of the cervical vertebrae). Supervoltage machines however, such as the linear accelerator, produce a very much better collimated beam with little penumbra, and with such machines it is usually much easier to avoid irradiating the cord. With supervoltage radiation the energy absorbed in bone is very nearly equal to that absorbed in soft tissue, and the dose delivered to the spinal cord can therefore be estimated more accurately than with lower energy radiation. Thus, supervoltage radiation is probably the method of choice in the treatment of tumors adjacent to the spinal cord.

• Research Organization: Postgraduate Medical School, London
• Sponsoring Organization: USDOE
• NSA Number: NSA-16-032768
• OSTI ID: 4780822
• Journal Information: Brain (Journal of Neurology), Journal Name: Brain (Journal of Neurology) Journal Issue: 3 Vol. 84; ISSN 0006-8950
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
ABSORPTION
BLOOD VESSELS
BONES
CANCER
COBALT 60
DIAGNOSIS
EFFICIENCY
ENERGY RANGE
MEDICINE
NERVOUS SYSTEM
QUANTITATIVE ANALYSIS
RADIATION DOSES
RADIATION INJURIES
RADIATION SOURCES
RADIOSENSITIVITY
RADIOTHERAPY
SPINAL CORD
TISSUES
TUMORS