Radiation Therapy: What It Is and What to Expect
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 2, 2026.
What kind of doctor provides Radiation Therapy?
A radiation oncologist specializes in using high-energy beams to treat cancer, planning the treatment and checking on the patient throughout. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What it is
Radiation therapy, also called radiotherapy, uses strong energy beams to destroy abnormal cells, usually cancer cells. The energy is usually X-rays but can come from particles like protons. Normal cells can be affected too, which is why side effects happen.
Why a doctor might recommend it
Doctors recommend radiation to shrink a tumor before surgery, destroy remaining cancer cells after surgery, or treat cancer when surgery is not possible. It can also ease pain caused by a tumor, called palliative care.
How to prepare
Preparation usually starts with a planning visit. Patients may be asked to:
- Bring a list of all medicines and supplements they take.
- Tell the team about any implants, pacemakers, or past radiation treatments.
- Ask about skin care products, since some lotions can interfere with treatment.
The first visit often includes a scan to map the exact spot to treat, and patients may get small skin marks or a body mold to stay in position.
What happens during it
Most radiation therapy is given from a machine outside the body, called external beam radiation. The patient lies still while the machine moves around them. The treatment is painless and lasts only a few minutes. Some types are placed inside the body instead.
Recovery
Recovery depends on the body area treated and the radiation dose. Tiredness often builds up over weeks, and treated skin may get red or sore, like a sunburn. Most side effects improve after treatment ends.
Risks and side effects
Common side effects include fatigue, skin changes, and hair loss where the beams enter. Radiation to the belly can cause nausea or diarrhea; to the chest or neck, a sore throat or trouble swallowing.
Who performs it
A radiation oncologist leads the plan, with radiation therapists operating the machines and nurses and dietitians helping manage side effects.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Either can manage everyday health needs and side effects during cancer treatment, and will refer the patient to a radiation oncologist for the radiation itself.
Common questions
Will the radiation make me radioactive?
For external beam radiation, the answer is no. The energy passes through the body and does not stay there, so patients are safe around family and friends. Radiation placed inside the body is different. In that case, the care team will give clear safety instructions.
Does radiation therapy hurt?
The treatment itself does not hurt. Patients do not feel the beams at all. Some people feel discomfort from holding still or from side effects that build up over time.
How long does treatment last?
It varies widely. Some courses take a single session, while others involve short daily visits five days a week for several weeks. The radiation oncologist will explain the schedule before treatment starts.
Can I still see my regular doctor during treatment?
Yes, and many patients do. Your regular doctor and the cancer team can share updates and coordinate care. Always tell the radiation team about any new medicines or health changes during treatment.
Sources
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
