Radiation is an effective glioma treatment, and knowing its side effects in advance helps you prepare and manage them. Side effects fall into those that appear during and shortly after treatment and those that can develop later.
During and shortly after radiation
- Fatigue — the most common effect, often building over the weeks of treatment and sometimes lingering for a while afterward. It's a deep tiredness, not just sleepiness.
- Hair loss in the treated area — usually where the beams enter and exit. It may be partial or patchy, and regrowth varies (sometimes hair returns thinner or doesn't fully return in heavily treated areas).
- Scalp and skin changes — redness, irritation, dryness, or tenderness in the treated area, similar to a sunburn.
- Headache or nausea — sometimes related to temporary swelling; often managed with medication, including steroids if needed.
Later effects Months to years after treatment, some people experience:
- Cognitive effects — changes in memory, attention, or processing speed. This is one of the most important long-term concerns and a key reason radiation is used thoughtfully, especially in younger patients and children. (Cognitive changes have their own article.)
- Radiation necrosis — an area of damaged tissue at the treatment site that can look like tumor on scans and sometimes causes symptoms; distinguishing it from tumor regrowth can require advanced imaging.
Managing side effects Strategies include pacing activity and prioritizing rest for fatigue, gentle skin care as advised by your team, anti-nausea medication, and steroids for significant swelling. Cognitive rehabilitation and support exist for thinking changes. Modern radiation techniques are designed to minimize damage to healthy brain, and approaches like proton therapy may further spare tissue in some cases.
It helps to remember that side effects vary widely — many people get through radiation while maintaining much of their routine. Tell your team about any side effect; most can be eased, and reporting them early usually makes them easier to manage.
Note: This is a sensitive topic. If long-term effects on memory or function are weighing on you, your team can connect you with rehabilitation and counseling support.