Radiation Oncology: Top Questions from Patients

A Keck Medicine of USC radiation oncologist shares patients’ most-asked questions about radiation treatment for cancer.

Radiation therapy is a common, longstanding treatment for cancer — but one that patients have many questions about.

“There’s a lot of understandable fear,” says Elizabeth Zhang-Velten, MD, PhD, a radiation oncologist with the USC Norris Comprehensive Cancer Center, part of Keck Medicine of USC. “A patient once told me, ‘When I think of radiation, I think of Chernobyl.’”

Ahead, Dr. Zhang-Velten explains some of the top questions patients ask about radiation treatment.

How is radiation safely used to treat cancer?

Something many people don’t realize is how precisely targeted today’s radiation treatments can be.

“It used to be that you just treated the patient with a ‘box’ of radiation,” says Dr. Zhang-Velten, who provides radiation oncology services at Keck Medicine of USC – Newport Beach Radiation Oncology and Imaging and Keck Medicine of USC – Buena Park Radiation Oncology. “It would get the job done, but you’d also have a lot of what I’d call ‘friendly fire’ as a result, meaning high radiation doses and therefore toxicities in nearby tissues.”

Thankfully, this is no longer the case today. As Dr. Zhang-Velten explains, “Radiation oncology has changed significantly in the past 10 years. While it’s certainly possible to see toxicities today, we’ve come a long way in making sure that radiation is more precise. You can really limit the dose to nearby tissues. For instance, instead of delivering a ‘box’ of radiation, a linear accelerator can rotate 360 degrees around the patient, directing radiation to a tumor from various angles and strategically blocking critical tissues to limit dose. We also have the ability to do a real-time CT while the patient is on the radiation treatment machine to make sure that internal anatomy is accurately positioned, to the millimeter.”

In addition, she points out, physicians know a lot more about radiation tolerances and toxicities today. “We can calculate how much radiation each organ is exposed to and make sure it’s within safe limits,” she says. “That’s something that was very difficult to do 30 years ago.”

What are the side effects of radiation therapy?

This question is somewhat difficult to answer because it depends on which body areas are being treated, Dr. Zhang-Velten says.

“The only side effect that is pretty universal is fatigue,” she continues. “What I hear from my patients is that it feels like you had a longer day than you really did or like you might need an extra nap. It’s not typically the level of fatigue where you can’t get out of bed. In fact, I’ve had some patients continue to exercise and work throughout radiation treatment. They might notice that they get sleepier at their desk, though.”

Does radiation therapy cause nausea?

Again, this depends on the treatment site. “If we’re treating near the bowel or the brain, there’s a higher likelihood that the patient may get nauseated,” Dr. Zhang-Velten says. “In that case, we’d prescribe medication for nausea. But if I’m treating someone’s arm, for example, I wouldn’t typically expect them to get nauseated.”

Is radiation therapy painful?

One common question patients ask if whether radiation will cause burns on their body. This is also site-specific, Dr. Zhang-Velten says.

“It’s possible if we are targeting the skin with radiation,” she explains. “But, for instance, in pelvic radiation, our treatment target is typically deeper within the body, so burns aren’t likely.”

Does radiation therapy cause hair loss?

Another common question is whether patients will lose their hair. “Unless I’m treating the scalp, I don’t expect patients to lose their hair,” she says.

Who should not get radiation treatment?

Toxicity from radiation can adversely impact patients with certain genetic disorders, Dr. Zhang-Velten says. An example of this is the genetic disorder ataxia telangiectasia, which involves a defect in a gene that repairs DNA. For patients with these types of genetic disorders, their cells, compared to normal cells, are less able to repair DNA damage caused by radiation.

Meanwhile, for breast cancer patients carrying a BRCA gene mutation that heightens their likelihood of developing breast cancer again in the future, other cancer treatments might be preferable, Dr. Zhang-Velten says. “While some patients with early breast cancer can opt for a lumpectomy combined with radiation in lieu of getting a mastectomy,” she says, “in this particular case I might steer the patient away from lumpectomy and radiation and instead suggest she get bilateral mastectomies. That way, she gets the benefit of a prophylactic surgery to safeguard against future breast cancers developing, and in the case of an early-stage breast cancer, she is unlikely to need post-mastectomy radiation.”

Does radiation cause cancer to spread?

“I have heard some people say that radiation will make the tumor ‘angry’ and cause it to spread,” Dr. Zhang-Velten says. “That’s a myth. We’ve seen cases in which radiation is the only therapy for certain cancers. I wouldn’t want this unwarranted fear to keep someone from getting radiation they need.”

Is it safe to be around someone receiving radiation therapy?

It depends on the patient’s treatment type, Dr. Zhang-Velten says. For instance, if a patient received a specific type of brachytherapy called “low dose–rate” brachytherapy, which is when radiation sources are implanted inside the body to treat a targeted area from within, then it’s recommended they avoid contact of that implanted area with other people.

On the other hand, most radiation therapy is delivered with external beams which pass through the patient and are not retained. Patients who receive external beam radiation therapy do not retain the radioactivity, and it is safe for them to be near other people. Additionally, there are two types of brachytherapy, and the other type, called “high dose–rate” brachytherapy, doesn’t actually leave radioactive sources in the patient after the procedure is completed. Patients who have received high dose–rate brachytherapy are not radioactive after their procedures, and it’s safe for them to be around others.

Will a radiation machine cause claustrophobia?

Some patients worry they will feel claustrophobic during treatment. While the radiation treatment machine (linear accelerator) is an open machine which does not typically cause claustrophobia itself, some patients do struggle with the devices used by radiation oncologists to ensure immobilization and precise setup. For example, patients receiving radiation to the head and neck will typically have radiation delivered while they are secured to the table with a plastic mesh mask. This thermoplastic mask is attached to the table to keep the patient’s head and neck from moving.

“Wearing this can set off claustrophobia even in patients who didn’t think they were claustrophobic,” Dr. Zhang-Velten says. “They find out that they can’t tolerate having the mask on their face even for minutes at a time. I had a patient who recently asked me if he could quit radiation because of this. Because he had a laryngeal cancer that was curable with radiation, I really wanted to find a way to help him stay the course.”

She suggested a solution that helped him manage his fear and continue with treatment: music. “I told him to pick a playlist,” she says. “I tell patients to tell us what type of music we can play to make the experience less traumatic.”

Plus, she adds, “Playing music is nice because it lets the patient know how much time has passed and how long they’ve been on the table. They can get a sense of the time without necessarily having someone count down for them through a microphone.”

How can one stay motivated to follow through with radiation treatment?

Dr. Zhang-Velten says one tip she’s heard is for patients to ask different friends to give them a ride to and from radiation sessions. “Some patients had a rotating calendar among their friends,” she says. “It gives you something to look forward to: hanging out with your friends during the drive and in the waiting room.”

How to reduce side effects of radiation therapy

What is Dr. Zhang-Velten’s biggest tip for patients undergoing radiation therapy?

“Don’t be shy to tell your radiation oncologist how you’re doing,” she advises. “Even though I see patients at least once a week during radiation, I always tell them that if they start having an issue, don’t wait. Come find me so that we can address it and minimize the side effects. There are medicines we can administer to get them through it. I always tell patients, ‘I’m not trying to build character. Tell me what’s going on so that we can treat it together.’”

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