What is 3D Conformal Radiation Therapy?
3D treatment planning for a patient with a lung tumor
Three-dimensional (3D) conformal radiation therapy is a technique where the beams of radiation used in treatment are shaped to match the tumor.
Previously, radiation treatment matched the height and width of the tumor, meaning that healthy tissue was exposed to the beams. Advances in imaging technology have made it possible to locate and treat the tumor more precisely.
Conformal radiation therapy uses the targeting information to focus precisely on the tumor, while avoiding the healthy surrounding tissue. This exact targeting makes it possible to use higher levels of radiation in treatment, which are more effective in shrinking and killing tumors.
Three-dimensional conformal therapy is, in many ways, similar to intensity-modulated radiation therapy (IMRT); both are used to target cancer while sparing healthy tissue.
The radiation oncologist will determine which therapy is best for you, depending on your tumor’s shape and location.
How is 3D conformal radiation therapy done?
The radiologist will take a 3D image of your tumor, often using one of the following imaging technologies:
Then, a computer program analyzes the 3D image and designs radiation beams that follow the shape of the tumor.
What can I expect during my 3D radiation session?
Prior to treatment, you will have a simulation (or planning) session, where a custom-fit mold is created. Learn more about planning sessions for radiation.
A 3D radiation therapy session typically takes about 30 minutes.
The therapist sets up the treatment according to the 3D images of the tumor and the information obtained from the simulation.
- You lie in the mold on the x-ray table.
- During treatment, beams from several directions precisely match the tumor’s height, width, and depth.
- The linear accelerator moves in a circular fashion around the tumor area.
- The actual treatment lasts only a few minutes.
Your oncologist will determine your treatment schedule and how often you will need to repeat the treatment process.
What are the benefits of 3D conformal radiation therapy?
Three-dimensional conformal therapy has been shown to improve outcomes for a number of cancer types, including: