Stereotactic Radiosurgery for Brain Metastases
My sister, who is 51, was diagnosed with inflammatory breast cancer in August of 1997. It metastasized to her brain in August of 1998. The tumor was removed, thought to be totally encased, and radiation therapy followed. There is now new growth around the original removal site and stereotactic radiosurgery is being considered. How long has this procedure been around? How effective is it on IBC tumors? What is the standard number of treatments? How much radiation can a person tolerate before toxicity?
Thank you for your help.
Li Liu, MD, OncoLink Editorial Assistant, responds:
Thank you for your interest and question.
The first case of radiosurgery was reported in 1949 using multiple small and fixed semicircular radiation beams at different angles to treat an intracranial target (Leksell L, Acta Chir Scand, 1949, 99:231). This technique became more reliable and reproducible when the Gamma Knife was introduced in 1968, which uses Cobalt-60 to produce multiple, intersecting static beams (Leksell DG. Neurology Research, 1987; 9:60-68). Clinical studies using modified linear accelerator began in the early 1980s (Colombo F, et al. Neurosurgery, 1985, 16:154-159).
Stereotactic external beam irradiation (SEBI) has an important role in both the primary and secondary treatment of patients with metastatic brain malignancies. Dose and fractionation varies from patient to patient depending upon pathology, size, location, and prior treatments, including surgery and/or radiation. Also brain tolerance to radiation treatment varies in radiation volume, daily dose, total dose, and prior surgery, etc. It is always a challenge for both patients and physicians to weigh the risks and benefits of treatment to the brain with radiation. No radiosurgery treatments can be considered "standard" in this situation.
SEBI is considered by many investigators to be equivalent to surgical resection of solitary brain metastasis (Wronski M, et al. Journal of Neurosurgery, 1995; 83:605-616). Because of the relatively low incidence of inflammatory breast cancer, to my knowledge, SEBI for brain metastasis from inflammatory breast cancer has not been studied specifically. The outcome may be similar to other metastatic cancers if all other contributing factors are similar.
Your sister should discuss pros and cons of SEBI with her radiation oncologist.