HF 7913

Radiation Therapy Imaging – Common Questions

Imaging is used to study and confirm your position before we start your treatment. The type and rate of imaging depends on the unique types of your treatment plan. There may be a delay between when you are imaged and when your treatment begins while your treatment team reviews your imaging.

What does imaging mean?

Imaging is a term for any type of x-ray image. We may also call it a “picture,” “image” or “x-ray.”

Why do I have imaging some days and not on other days?

The rate of imaging varies from one day per week to every day. This depends on many factors such as your treatment site, your setup and the doctor’s orders. We use a set of rules to figure out when you need imaging. 

Why do some patients require more imaging than others?

Some treatment setups are more difficult than others. It depends on the location and size of the region being treated. Our goal is to get you in the same position as you were at the time of simulation. This can be hard because the body can move in so many ways. 

What does it mean if my image “looks good” or “lines up well”?

This means that your treatment image shows that your body is in the correct spot for treatment. Treatment images are always checked for correctness before starting the treatment.  

Should I be worried about the extra radiation dose from images?

The radiation dose that you receive from imaging is very small compared to the dose you receive from your treatment. While we strive to limit the extra dose from imaging, our first goal is always to make sure you are in the correct position. 

What can I do to help make the setup more accurate?

Your most important job during your treatment is to hold still. Please let us know if at any time you feel discomfort, or you feel like you cannot hold still. We can always see and hear you during your treatment and will watch for any signs of discomfort or motion.

When you have other x-rays (like at the dentist) they use a lead shield. Why don’t you use a shield?

We do not use a shield because of what we need to see in our images. We use stronger (higher energy) x-rays than your dentist. This means that a lead apron would not work well as a shield.

Can you tell if my tumor is changing from imaging?

These x-rays are not used to diagnose. We can rarely see your tumor on the image. The purpose of the images is to make sure you are in the correct position for treatment. Your doctor is looking at your images throughout your treatment. You can talk with your doctor about their meaning.

What if I have more questions about my treatment imaging?

Please let your treatment therapists know and they can help, or they can refer you to a member of your treatment team to give you more information. We always welcome your feedback.