What is Proton Beam Therapy (PBT)?

Whereas other forms of radiation therapy use x-rays to kill cancer cells, proton beam therapy (PBT) uses particles called protons, which are easier to aim directly at a tumor, thus largely sparing healthy tissue.

This sophisticated type of treatment is often used to target cancers located in close proximity to vital parts of the body, and it can be combined with conventional photon treatments. PBT is mostly commonly used to treat cancers of the brain, head and neck, eye, lung, prostate, and spine.

Mount Sinai also offers a delivery technique called pencil beam proton therapy, which “sweeps” protons across the treatment area, thus maintaining conformity, eliminating an exit dose, and reducing the dose to normal tissues.

How Does Proton Therapy Work?

Proton therapy is done on an outpatient basis. The therapy begins by fitting the patient with a device that holds the part of the body where the cancer is located. Next, a CT or MRI scan is performed to “map” the specific area to be targeted. The treatment itself typically lasts 15-20 minutes.

Depending on the type of cancer, these treatments can be repeated over a period of 6-7 weeks.