Does Radiation Therapy Hurt? What to Expect?

When learning that radiation therapy is needed, many people may feel anxious, imagining pain, intense heat, or large, intimidating equipment. In reality, external beam radiation therapy does not generally cause pain from the radiation itself. However, there are preparation steps and certain side effects you should be aware of so you can undergo treatment with greater confidence.

Does It Hurt During Radiation Therapy?

While the machine delivers radiation, you will not feel heat or burning from the beam, nor can you see or smell the radiation. You might hear the machine operating or see it moving around you, which is simply a routine part of the treatment.

However, some individuals may feel uncomfortable from lying still in the same position, keeping their arms raised, or having pre-existing pain. If you experience pain, discomfort, or anxiety, please inform the staff before starting so they can adjust your positioning and provide appropriate support.

This article refers to external beam radiation therapy, a service provided by the Radiation Oncology Center at Khon Kaen Ram Hospital.

What Needs to Be Done Before the First Radiation Session?

Before beginning treatment, the doctor will explain the goals, number of sessions, and potential side effects. Afterward, the treatment team will schedule a simulation and planning session to determine the exact position and radiation dose tailored to each individual. Steps may include:

1. Planning imaging scans, such as a computed tomography (CT) scan, taken while lying in the exact position to be used during actual treatment.
2. Marking the skin or immobilization devices to ensure precise and consistent positioning for every session. If ink marks are placed on your skin, follow the care instructions provided and notify staff if they begin to fade.
3. Fabricating immobilization devices, such as a specialized mesh mask for head and neck radiation. These masks are breathable; however, if you have claustrophobia or feel uneasy, let the treatment team know.

The planning day and the first treatment day are usually on different dates. Preparation depends on the treatment site, so be sure to ask in advance about any fasting, fluid intake, or bladder preparation instructions, and follow the hospital's specific guidance.

What to Expect Inside the Radiation Room?

1. The staff verifies your information and positions you carefully on the treatment table. You may need to change into a gown or uncover only the treatment area.
2. The team verifies your alignment according to the plan, which may include taking additional verification images and making fine table adjustments before starting.
3. The staff steps into the adjacent control room to operate the machine, but they continuously monitor you via cameras or a viewing window and can communicate with you via an intercom at all times.
4. The machine delivers the radiation as planned. You will need to stay still and follow any breathing instructions. Typically, you can breathe normally, though some plans may require brief breath-holds.

If you feel pain, nausea, discomfort, or urgently need to move, speak up through the intercom. The team can pause the machine at any moment to assist you; there is no need to endure it until the end.

How Long Does Each Session Take? Can You Go Home Afterward?

According to information from the Radiation Oncology Center at Khon Kaen Ram Hospital, the beam-on time is approximately 5–15 minutes, and the total appointment time including setup and positioning is about 30 minutes. Actual times may vary depending on the treatment plan and technique, excluding registration, waiting times, or doctor consultations.

Most patients receiving external beam radiation can return home immediately after their session without hospitalization. The total number of sessions varies depending on the condition, treatment goals, and technique used. Please attend every scheduled session; if you cannot make it, contact the care team promptly to reschedule.

If It Doesn't Hurt During Treatment, Why Do Some Feel Stinging or Pain Later?

Not feeling pain during the delivery of radiation does not mean there will be no side effects. Radiation can affect normal tissues within the treated area, leading to symptoms that develop during or after the course of treatment. Common symptoms depend on the area treated and the dose received, such as:

• Dry, itchy, discolored, or irritated skin in the treated area.
• Fatigue or feeling tired more easily.
• Mouth sores or difficulty swallowing when treating the head, neck, or esophagus.
• Nausea or diarrhea for certain abdominal/pelvic treatment sites.

Not everyone experiences the same symptoms. If you begin to feel pain, have trouble eating or drinking, develop skin breakdown, or find symptoms disrupting daily life, inform your care team early for prompt management, and always ask before applying any creams, ointments, or products to the treated area.

How Can You Prepare to Feel More at Ease?

• Wear comfortable, loose-fitting clothing that is easy to remove and does not bind or constrict the treatment area.
• Communicate any pain, anxiety, or claustrophobia before positioning begins.
• Follow your care team's instructions regarding diet, hydration, medications, and skin care.
• Ask clearly how to call for staff during treatment, and know whom to contact if symptoms occur after returning home.

Going through radiation therapy for the first time can feel unfamiliar and overwhelming, but you can share your feelings and request assistance at every step. Knowing what to expect in advance will help you prepare better and collaborate with your medical team with confidence.