Radiation therapy is one of the most common and effective treatments for cancer, but for many patients, the process can feel like stepping into the unknown. The machines are large, the terminology is complex, and the thought of “radiation” naturally sparks fear. If you or a loved one are preparing for treatment, you may be asking yourself: What really happens during a session?
Let’s break it down step by step, so you know exactly what to expect when you walk in for your first treatment.
Step 1: Getting Checked In
When you arrive at the treatment center, you’ll check in just like a regular medical appointment. Radiation therapy is usually scheduled daily (Monday–Friday), and your team will try to keep your appointment time consistent. There will be a changing area with a place to secure your belongings and clothes, if you need to put a hospital gown on for your treatment.
Step 2: Positioning and Setup
A radiation therapist (RTT for short) will guide you to the treatment room and help you get into the exact position planned during your CT simulation appointment. Your treatment setup may use a mask, mold, or cushions created just for you. You also may have special instructions to follow, like “drink 20 ounces of water” or “you will need to hold your breath.” The goal is to keep your body as still as possible so the radiation can be delivered with pinpoint accuracy.
Step 3: Imaging for Precision
Before each treatment, the team may take quick scans (like X-rays or CT images) to confirm your position. It is totally normal if you aren’t exactly in the correct position, because the treatment table (or couch) can actually move you into the closest fit because of the images taken of you in that position that day. This ensures that the radiation beams are lined up correctly with your treatment plan, so we can hit the targeted areas as best we can.
Step 4: Delivering the Radiation
The machine, called a linear accelerator, will rotate around you to deliver radiation from different angles. Depending on the technique of treatment designed just for you, it may rotate continuously, or stop at several angles to deliver the planned radiation dose. The team takes extra precautions to make sure the machine won’t touch you or the devices used to position you for treatment, so you don’t have to worry about it hitting you! You won’t feel the radiation itself; no heat, no pain. The machine may make buzzing or clicking sounds, but you’ll just be lying still, breathing normally.
Pro tip: Ask for music to be played to help drown out the machine’s sounds that may make you uncomfortable.
Step 5: Finishing Up
A typical treatment lasts about 15–30 minutes from setup to beam off, with the actual radiation only taking a few minutes. Once it’s done, you can go about the rest of your day — you’re not radioactive afterward.
Pro tip: Ask your team how you did that day. If you were given preparation instructions each day, ask them if today was good enough, or if you need to do something different to make the positioning more like you were during your simulation. Never be afraid to ask questions!
Here’s a handy visual for the process described above as well:
Radiation Session Takeaways:
- Radiation therapy is painless and non-invasive.
- Each session is carefully planned and checked for safety.
- The process is routine and predictable, designed to minimize stress. Very often, the rooms where the machines are (referred to as vaults), have calming aspects and even music capabilities. Just ask your RTT for music you like!
A few caveats to remember here:
- There are several different types of machines that can deliver radiation. The most common one is the linear accelerator, or “linac” for short. That machine is like the one shown above.
- Other machine types will be covered in later blog posts though, like a Proton machine or brachytherapy machine. So don’t worry if your treatment is different than what you see here!
- Treatment times can range based on complexity, but every treatment is designed for safety and efficiency in mind. I know this, because it’s my job as a Medical Physicist to make sure of it!
Radiation therapy can sound intimidating, but once you know what to expect, it becomes a predictable and manageable part of your care. Remember: your treatment team is there to guide and support you every step of the way.
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