Cancer
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The incidence of permanent damage to the spinal cord as a complication of radiation therapy generally correlates positively with total radiation dose. However, several reports have indicated that fraction size is also an important factor in the development of late damage in normal tissue. To determine the effect of fraction size on the incidence of radiation-induced spinal cord damage, the authors reviewed 176 cases of head and neck cancer treated at their department between 1980 and 1990 with radiation doses of 5500 cGy or greater to a portion of the cervical spinal cord. ⋯ Four of 72 (5.6%) patients had experienced permanent cervical spinal cord damage. The results of this study suggest that radiation damage to the cervical spinal cord correlates not only with total radiation dose, but also with fraction size. Low fraction sizes appear to decrease the incidence of such damage.