Language Select
Varian Logo
What is IMPT?

Intensity-Modulated Proton Therapy (IMPT)

What is IMPT?

Intensity-modulated proton therapy (IMPT) is a highly precise type of radiation therapy using proton therapy. Intricate treatment planning and precise proton beam delivery results in modulating the intensity of the proton beam and shaping it to match the contours of the tumor. IMPT also provides the most conformal dose delivery technique for radiation therapy, “coloring” the tumor precisely within the lines prescribed by the physician. It also produces significantly fewer neutrons than other types of proton systems, and therefore delivers less radiation to healthy tissue adjacent to the tumor. This is especially important for pediatric patients who are at greater risk of developing neutron-induced secondary cancers later in life—and for patients with tumors in close proximity to critical structures that cannot be exposed to radiation.

Learn More

Beam Scanning Delivers True IMPT

Only Pencil Beam Scanning Delivers True IMPT

Not all proton therapy can deliver IMPT, only Pencil Beam Scanning (PBS) can. With its highly accurate targeting of tumors, IMPT focuses a narrow proton beam to “paint” the radiation dose, spot by spot and layer by layer, onto all parts of a tumor—even irregularly shaped tumors. IMPT is effective for tumors that wrap around critical structures (such as the brain or spinal cord) or are located adjacent to structures or organs (e.g., the frequent proximity of prostate tumors to the bladder or large intestine, or of breast tumors to the heart).

Learn More


XIX Congresso da Sociedade Brasileiro de Radioterapia
Rio de Janeiro, Brazil