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READ MOREPublished on April 28, 2025 in Educational Resources
For many people living with a brain tumor, radiation therapy is a critical part of care, but it might feel like stepping into a science fiction movie. With no prior understanding of this form of treatment, the machines, terminology, and even the daily routine may feel unfamiliar and overwhelming.
When patients know what radiation is and what to expect, they can feel more prepared and less anxious about the process before treatment begins. In the upcoming part two of our radiation therapy series, hear from patients and caregivers as they share tips on navigating radiation therapy and managing unwanted side effects.
Radiation treatment is a form of care for primary brain tumors (benign and malignant) as well as cancer that has metastasized to the brain. Radiation can follow brain surgery, or it can be the primary course of treatment if surgery is not possible.
Radiation treatment uses high-energy beams to target and destroy brain tumor cells. It’s a painless, non-invasive procedure that targets the DNA of tumor cells, preventing them from growing or spreading. The goal is to shrink the tumor or stop it from growing while protecting as much healthy brain tissue as possible and reducing the long-term effects of treatment.
Radiation therapy choices depend on the patient, the type of tumor, the tumor’s location, and the size of the tumor. Most patients receive either traditional radiation therapy, which uses X-ray beams (photons) that pass through the tumor and continue beyond it, or proton therapy, which uses proton particles that release their energy directly at the tumor and then stop.
Some patients may undergo stereotactic radiosurgery, which is not actual surgery– no incision is needed. However, the treatment delivers targeted, high-dose radiation that acts like the scalpel of a surgeon in the way it destroys the tumor. Because it is a one-time, highly targeted procedure, its preparation and experience differ significantly from traditional radiation therapy and therefore will not be addressed below. Mayo Clinic offers an online resource with information on what to expect before stereotactic radiosurgery.
Radiation offers localized delivery of treatment to a precise location, whereas chemotherapy is a systemic treatment (the drug travels through the bloodstream to reach tumor cells). Certain chemotherapy can make cancer cells more sensitive to radiation. Standard of care for some brain tumors includes both radiation and chemotherapy to treat the brain tumor from both a localized and systemic approach.
For example, temozolomide is an oral chemotherapy drug used to treat certain types of brain tumors in conjunction with radiation treatment.
“The reason it works is because temozolomide radiosensitizes [the tumor] — it makes radiation work better [and] be more effective,” said Erik Sulman, MD, PhD, New York University (NYU) Grossman School of Medicine. Dr. Sulman is a radiation oncologist and a member of NBTS’s DNA Damage Response Consortium.
Researchers today use clinical trials to explore the effectiveness of radiation taken in conjunction with innovative drug therapies. Learn more about clinical trials through NBTS’s MyTumorID campaign.
For most patients with brain tumors, standard radiation therapy is delivered a little bit per day (usually excluding weekends) so that the patient is receiving a fraction of the total dose over the course of 30 days.
“Typically, each day is the same dose, and we typically deliver it over a fixed number of days,” Dr. Sulman explained. “If we give too much radiation in a single day, even the normal tissues will be damaged. But if we give too little, not enough cancer cells will be damaged. So, we pick a point where we give enough radiation to kill the cancer cells but not too much to destroy or damage the normal tissue. After 30 treatments, it is our hope that we’ve destroyed all the cancer cells without causing significant damage to the normal tissue.”
Patients go through a three-step process before starting radiation treatment.
A patient’s first appointment will be a consultation with the radiation oncologist. In this meeting, they will:
Ideally, the patient should discuss any goals for treatment, as well as any questions or concerns they may have, to help prepare for treatment and feel more in control of the process.
“We had an opportunity to tour the facility, meet with social workers and case managers, and meet with the doctor who would oversee his care for the next six weeks,” said Kathryn D. about preparing for her son’s radiation treatment for grade 3 ependymoma. “They sat us down and talked about the experience and what to expect. They answered all of our questions.”
National Brain Tumor Society created a list of key questions to ask before starting any treatment. Here are some key questions to ask specifically ahead of radiation therapy:
NBTS recommends that patients and care partners bring their questions to the appointment either on their phones or as printouts.
Once the patient has agreed to move forward with radiation therapy, an appointment will be scheduled to help the care team map out exactly where the radiation should go. This appointment may be referred to as a CT simulation, mapping, or planning session.
The patient will not receive treatment at this appointment. Instead, the team will fit the patient with a radiation mask and then do a special scan using a CT simulation machine to ensure accurate positioning and consistency for future treatments.
“They make a mask, they put you in the scanner, they make sure that everything lines up to where the radiation oncologist would like it to line up to, they bring you out, and everything’s good,” said Stacy P., who has grade 3 astrocytoma.
To keep the patient’s head in one spot during treatment, people with brain tumors need to wear a custom-fitted radiation mask during each treatment, which is secured to the table to prevent individuals from moving.
The process to create this custom mask involves pulling the mask from a warm bath and gently stretching it over the patient’s face. The staff will use their fingers to lightly push the mask down so it forms to the patient’s facial features. They will then let it dry for 10-15 minutes in that position. OncoLink created an educational video to show the process of creating a mask, helping patients understand what to expect.
“Mask fitting was quick and painless to me,” said Tim P., who received radiation treatment for meningioma. “They position you on the table, pull the plastic mesh sheet from the warming oven, and drape it over your face so that it contours perfectly. The mask is a little bit hot at first, but I always found that part oddly therapeutic.”
For claustrophobic patients, the idea of getting fitted for a mask may cause some anxiety. Share these concerns with the radiation oncologist during the consultation to determine what the team can do to assist, which may include prescribing medication.
Once the mask has cooled and hardened, the patient will undergo a CT scan with the mask still in place. This scan is not intended for diagnostic purposes, but rather to capture the necessary imaging for planning radiation treatment.
In her book Let’s Talk Radiation Therapy, radiation therapist Margeaux Gregory writes, “What makes this scan unique for our planning purposes is that this image is acquired in the exact position you will be in for radiation treatment. This 3D picture will allow us to visualize the area we will be treating, along with the general anatomy directly surrounding it. We use this scan to design exactly where the radiation will be delivered, allowing us to conceive a fine-tuned and highly detailed radiation treatment plan that is completely geared to you.”
Upon completion of this scan, the patient will check out and schedule an appointment for the first treatment session, which is scheduled to take place approximately 1-2 weeks later.
Behind the scenes, the radiation oncologist collaborates with other specialized professionals, including dosimetrists and medical physicists, to carefully design a personalized treatment plan based on the patient’s unique brain tumor type. They will determine the total amount of radiation a patient will receive throughout their treatment and then decide the exact dose, angles, and number of sessions needed.
Once the treatment plan has been mapped out, it’s time for radiation therapy to begin. Typically, traditional and proton radiation take place every weekday until the 30 sessions have been completed. Each appointment, from start to finish, lasts approximately 15 to 30 minutes.
“The hard part about proton therapy was that it was every day,” said Melanie F., who has diffuse astrocytoma. “It’s pretty much a full-time job at that point.”
It can be helpful to map out the entire stretch of radiation appointments, using a care coordination app like CircleOf, to ensure someone can transport the patient to and from their appointment each day.
“The most challenging aspect of treatment for me was having to find different people to drive me to the hospital 45 minutes away every morning,” said Tommy M., who was diagnosed with astrocytoma.
At each session, a radiation therapist will position the patient in the exact location as during the simulation appointment to receive treatment. The radiation therapist is a great resource for asking questions about what to expect or any ongoing side effects. If they don’t have the answer, they can connect with the radiation nurse or oncologist.
A linear accelerator (LINAC) is a machine that rotates around the patient to deliver radiation treatment. Like an X-ray, radiation is painless.
“Luckily, the treatments are rather quick, in the scheme of medical treatments,” said Cheryl L., RN, who was diagnosed with grade 2 ependymoma. “The last snap of the face mask to the frame seems super loud, followed by a ‘here we go’ feeling. During the actual ‘zapping,’ I kept repeating to myself, ‘This is saving my life’ over and over again. It was my radiation mantra. The oddest thing was what I smelled during the actual treatments when the radiation was being applied. An electrical smell, maybe. I can still remember it.”
Some patients have described experiencing a different taste or even perceiving smells during radiation, but this experience is not representative of everyone.
“I learned that depending on the area of the brain being radiated, you smell different things,” said Kimberlee G., who has ependymoma. “Some people could smell roses, I smelled chlorine, like from a pool. It’s a smell I’ll never forget.“
While receiving radiation treatment, patients may be able to listen to music or an audiobook to help pass the time. Ask about what’s possible during the initial consultation or at the simulation appointment.
Especially at the beginning of treatment, some patients may feel overwhelmed and anxious about the process. In her book Let’s Talk Radiation Therapy, radiation therapist Margeaux Gregory writes, “When anxiety erupts like this, it can be challenging to find a way to quiet your mind so your body can relax. One method I’ve seen help people push past this anxiety in the treatment room is a shift in focus. Instead of trying to get answers for all the questions in your head, focus on one thing: getting through treatment today.”
Patients undergoing radiation therapy may experience a variety of side effects due to their treatment. The most common short-term side effects of radiation include fatigue, skin irritation, and hair loss.
For some, side effects may appear within a few days of starting treatment, while others may not experience side effects until several weeks into treatment or even after treatment concludes.
“Within two to four weeks of radiation being done, those side effects from the acute radiation irritation resolve,” said Martha Francis, a nurse practitioner in radiation oncology at the University of Maryland.
Long-term side effects may also occur well after treatment concludes. Patients and caregivers can ask their radiation oncologist about expected short-term and long-term side effects during the initial consultation.
Fatigue is a persistent sense of exhaustion that doesn’t go away with rest. It is a more intense form of tiredness that can significantly impact one’s ability to perform daily tasks.
Fatigue is common during radiation treatment because the high-energy beam can destroy or damage some of the healthy cells near the tumor. As the patient’s body works to repair the damaged tissue, it can cause fatigue. In Dr. Sulman’s experience, “the fatigue can last anywhere from four weeks to three or four months.”
A Neuro-Oncology article reports, “Although fatigue is prevalent throughout the disease trajectory, cranial radiation remains the most common and significant cause, with >80% of patients with primary brain tumor reporting fatigue during the course of radiation. Although fatigue has been reported to occur as early as the first week of treatment, the incidence and severity of fatigue markedly increases with cumulative radiation and often continues well into the post-radiation period.”
The National Comprehensive Cancer Network (NCCN) classified radiotherapy-induced fatigue (RIF) as a clinical subtype of cancer-related fatigue. An article in the Expert Review of Quality of Life in Cancer Care states, “There is a growing body of evidence that increasing physical activity during and following radiation therapy can reduce radiation-induced fatigue. The NCCN guidelines recommend a combination of endurance and resistance exercises to manage RIF.” NBTS recently shared seven tips for managing physical fatigue for people living with a brain tumor.
Patients and caregivers share some of their fatigue experiences during radiation treatment:
Melanie F. (diffuse astrocytoma): “We’d end on Friday, and I would just be so tired. Saturday was pretty useless. Sunday, I’d start coming around, and Monday, I was brand new. And so it was like following that cycle of knowing when the fatigue was going to hit.”
Joe M. (grade 4 astrocytoma with IDH mutation): “Plan for random fatigue because, for me, there were days where I’d come home, and I’d sleep for six hours, and there were days where I’m kind of tired but just sluggish.”
Lisa G. (infiltrative astrocytoma): “I was told a variety of side effects could happen — that extreme exhaustion would likely hit in the third week. They were pretty spot on. My schedule was taking radiation in the morning and then going to work afterward. It became very difficult, and I did have to take days off and would just sleep with naps lasting several hours.”
Mia M. (4-year-old son had DIPG): “As far as the radiation, it made him really tired afterward, and really groggy, because they had to put him under anesthesia.”
Within the first 2-3 weeks of treatment, patients may experience skin irritation at the site where radiation treatment is being administered. It may appear sunburned — discolored, with blisters, or peeling — and it may be itchy.
Patients should consult with their radiation therapist or oncologist before using any product or applying anything to the site to help reduce skin irritation, as it may interfere with radiation treatment. The provider can recommend products that will help and not cause further irritation.
In the book Let’s Talk Radiation Therapy, radiation therapist Margeaux Gregory cautions patients, “When you’re receiving radiation treatments, and even once treatments have been completed, your skin in the area that received treatment will be very sensitive to the sun. Please cover this skin up when you’re outside. If you’re still under treatment and receive a sunburn in the area we’re treating, we might need to delay treatment until your sunburn heals. You really don’t want to have an interruption like that for something as avoidable as a sunburn.”
Radiation to the brain can cause hair loss, as hair follicles are particularly sensitive to radiation. Hair loss may occur 1-3 weeks into radiation therapy. Hair often grows back 3-6 months after the patient completes treatment; however, it may return thinner, with a different texture, or even a different color. For example, it may be curlier than it once was. Depending on the location of the radiation site, patients may also experience loss of facial hair, such as their eyebrows.
Once hair starts falling out, patients may want to shave the remainder off. Patients are encouraged to consult with their radiation team to ensure that doing so won’t impact the fit of the custom radiation mask or cause further skin irritation. Patients often use scarves, hats, bandanas, or wigs to conceal hair loss.
Patients share some of their hair loss experiences during radiation treatment:
Sara P. (meningioma): “My hair began to thin out after treatment, and a small section of my eyebrow did not grow back.”
Joe M. (grade 4 astrocytoma with IDH mutation): “On my side, where they were doing the radiation, it got tender. Later that night, my hair just started coming out in clumps.”
Lisa G. (infiltrative astrocytoma): “You can’t see your cancer, but you can see when your hair is falling out and changing your physical appearance. My hair fell out on both sides, but left it on the top, as in some kind of punk rock survivor style — like a character from Mad Max.”
Some patients face cognitive or speech difficulties during or after radiation therapy as the brain works to repair the damage to the healthy cells.
“When I’m connecting with individuals undergoing radiation, I often hear about speech challenges,” said NBTS’s Patient Navigator, Katherine Pahler, RN. “Once there is a decline, it’s worth meeting with the care team to discuss what therapies are available.”
While the physical side effects are often discussed, the emotional toll of radiation can take patients by surprise.
“The most debilitating side effect was my emotions,” said Sara P., who has meningioma. “I became increasingly sad and melancholy. This is completely unlike me. After four weeks of treatment, it was bad. My feelings were easily hurt, I was easily overwhelmed, and I felt useless and upset.”
For some people living with a brain tumor, side effects can linger well after treatment. “Two years post-treatment, I have trouble with short-term memory and concentration in my daily life,” said Katrina S., who was diagnosed with astrocytoma. “When I am tired, I find I have issues with word recall, which is specific to where my tumor was located.”
Treatment affects everyone differently, so patients should consult with their radiation oncologist to learn about the potential side effects they may experience from treatment and to discuss ways to manage these effects.
In part two of our radiation therapy series, hear from patients and caregivers as they share valuable tips and strategies for managing some of the unwanted side effects based on their personal experiences with radiation therapy.
The content on this website is for informational and educational purposes only. It does not constitute medical advice. Always consult a professional for your particular needs and circumstances before making medical, professional, legal, or financial decisions.
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