Proton Therapy

Proton treatment requires planning. Before treatment, the patient undergoes a specialized computed tomography (CT) or magnetic resonance imaging (MRI) scan. During this scan, the patient is put in the exact same position that will be used for treatment. However, this requires that the doctor limits a person’s movement while having the scan.

To help keep the patient in one place, he or she may be fitted with a device that restricts movement. The type of device depends on where the tumor is located. For example, a patient may need to wear a custom-made mask for a tumor in the eye, brain, or head.

The patient will also need to wear this device later for the radiation planning scan. The table on which the patient lies for the radiation planning scan allows the scan to be referenced to the marks on the person’s body or the immobilization device. This helps ensure the patient’s position is accurate during each proton treatment.

The immobilization devices are designed to fit snugly so that there is no motion during the radiation treatment. However, the radiation oncology team wants each person to be as comfortable as possible during treatment. It is important for patients to communicate with the team to find a comfortable and reproducible position for treatment. Some patients, particularly with tumors around the head and neck region, feel somewhat anxious when they need to lie still in such an immobilizing device. It is important to let the members of the radiation oncology team know if this causes you anxiety. Your doctor can prescribe medication to help you relax for the treatment planning scan and the treatments.

Using the radiation treatment scan, a member of the radiation oncology team draws the tumor area(s) to be treated. He or she also draws the normal tissues to be avoided. This process is similar to the process for planning radiation therapy with x-rays.