Questions and answers on breast cancer

Question addressed to Dr. Charles B. Wilson, M.D., University of California, School of Medicine, San Francisco, California: Would you follow removal of a “¿ soli tar)' “¿ brain metastasis with whole brain irradiation on the assumption that there are multiple metastases? Dr. Wilson In general, I would recommend whole head irradiation following removal of a metastatic brain tumor believed to be a solitary lesion on the basis of current diagnostic techniques, e.g., brain scan and cerebral angiography. There are two reasons for this: First, approximately two thirds of metastatic brain tumors are accompanied by one or more ad ditional brain metastases although the latter may be occult. Consequently, odds are at least two to one that an apparent single lesion is associated with at least one additional brain metastasis. The odds are slightly higher with cer tain tumors such as melanomas and perhaps slightly lower in other tumors such as colon. Second, while metastatic tumors are characteristically circum scribed, they are often soft, friable and easily implanted at the operative site. Local recurrence at the site of a metastatic tumor thought to have been removed totally is common experience. Although postoperative radiation therapy does not exclude the possibility of local recurrence, certainly in the case of radiosensitive tumors this would seem a logical prophylactic step. One could cite exceptions to the foregoing generalization favoring postoperative radiation therapy. I would be inclined to withold post operative radiation therapy in the case of a patient with a metastatic tumor ap pearing several years after removal of a colon carcinoma, with no evidence of disease elsewhere if I had achieved a clear surgical removal. Other factors such as the patient's general condition, prior radiation to the head, etc., would also be factors modifying the desir ability of postoperative irradiation.