How to follow a patient with brain mets after radiosurgery is becoming a more and more common question becasue treatments that control cancer in the rest of the boady are getting to be more and more effective and patients are living longer before cancer comes back in the brain or in the body. One does not want to overmonitor but also not to miss metastses when they come back. Many patietns remain disease free for many months even years after radiosurgery of the brain. For example, one study reported a median time of 8.8 months to new metastasis becoming visible after radiosurgery. Patients with 3 or more brain metasttses and cancers other than NSCLC were more likely to have future metastasis. Based on these facts, there was a published recommendation for close surveillance with a 3-month interval between magnetic resonance imaging (MRI), in order to identify new metastasis early enough to start treatment. However, much is not known about this. Clearly, more frequent imaigng is warranted soon after radiosurgery and less frequenlty as time goes on. As the most sensitive tests, MRI is the preferred surveillance tool, even though newer methods, such as spectroscopy, diffusion-weighted imaging, and perfusion-weighted imaging are coming to the fore.
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