How long does stereotactic radiosurgery take to work for brain metastases?

The treatment delivers focused radiation to selected deposits in the brain. Its effect develops over time, so a treated spot may not shrink immediately and can sometimes look temporarily different on imaging.

Your team compares later scans with the planning scan and considers symptoms, neurological examination and medicines such as steroids. The appearance of treated tissue can be affected by swelling or treatment-related change, so scan findings are interpreted in context.

The timing also depends on the number, size and position of the metastases, the cancer outside the brain and any other treatment being given.

Attend the scan and oncology appointments even if you feel well. Keep a simple note of headaches, nausea, balance, vision, speech, strength, sensation and seizure-like events.

Use prescribed medicines as directed. Steroids may be used to reduce swelling, but their dose should only be changed with the treating team. Tell the team about every medicine or supplement you take.

Ask how the brain scan fits with scans of the rest of the body and whether another treatment is planned.

Call the oncology or radiation team promptly if headaches are worsening, vomiting keeps returning, balance deteriorates, or you notice new weakness, numbness, speech or vision changes.

Get emergency help for a seizure, fainting, severe confusion, sudden one-sided weakness or inability to stay awake. Do not drive yourself if neurological symptoms are severe.

What changes on my next scan would suggest treatment response?

How will you distinguish swelling from tumour change?

Which symptoms mean I should call the team the same day?