Because of the high frequency of brain metastases in small cell lung cancer, especially in patients with prolonged survival, prophylactic radiation of the head is recommended by many physicians. This reduces the frequency of subsequent brain metastases, especially in patients who have a complete response to therapy. It has not, however, been shown to influence survival. There may be late complications of this type of treatment, with deterioration in mental function in some long-term survivors who were given high daily dose fractionation. It is generally recommended that the radiation to the brain be given in small daily doses, and not at the same time as chemotherapy .
It must also be emphasized that some physicians do not recommend the use of prophylactic brain irradiation because there is no proof of a survival benefit and there is a valid concern about late neurologic side effects of the treatment. If necessary, radiation therapy can be given when brain metastases occur.
