3D-Conformal Radiation Therapy is one of the most common forms of external radiation therapy. The delivery system uses a “multi-leaf collimator” to literally shape, or conform, the radiation beam to the tumor. This enables your Radiation Oncologist to prescribe a higher, more effective dosage amount while minimizing the risk of side effects.
3D-Conformal Radiation Therapy begins with a simulation. Your 21st Century Oncology team will use imaging, typically from computed tomography (CT) scans, to get a detailed view of your internal organs and tumor. They may also use magnetic resonance imaging (MRI), position emission tomography (PET) scans or ultrasound scans. They will then determine the number and angle of the radiation beams targeting the tumor, and a sophisticated computer calculates how much radiation dose will be delivered from each of the beams for your individual treatment plan.
During 3-D Conformal Radiation Therapy treatments, a device called a “multi-leaf collimator” will shape the individual radiation beams to “conform” to the shape of your tumor according to the data and instructions it receives from the system computer.
It is very important that you lie in exactly the same position for each treatment session. For this reason, 3D-Conformal Radiation Therapy often uses a custom-fit body mold to ensure you are correctly positioned on the treatment table during radiation delivery. You may also receive several small tattoos, each the size of a freckle, to make sure you are accurately positioned at each treatment session.
Once your mold is created, you can begin your treatment schedule. During each session you will lie in the mold on the treatment table and your Radiation Therapist will use sophisticated imaging to confirm your position. Minor adjustments may be made to the table to ensure exact targeting of the tumor. The radiation delivery system then moves in a circular motion around you; delivering beams from different directions and shaping them around the tumor. The external radiation delivery system then moves in a circular motion around you; delivering beams from different directions and shaping them around the tumor. Sessions last only a few minutes, require no sedation and are pain-free. The number of 3D-Conformal Radiation Therapy sessions you will need depends on the size of the tumor, its location and stage.