Proton Therapy


What is Proton Therapy?

"Proton therapy potentially represents the best of both worlds – delivering a high dose of radiation to tumors, while at the same time limiting side effects to patients."

Proton therapy is a non–invasive, incredibly precise cancer treatment that uses a beam of protons moving at very high speeds to destroy the DNA of cancer cells, killing them and preventing them from multiplying.

The Benefits of Proton Therapy at Roberts Proton Therapy Center

Unlike conventional radiation that can affect surrounding healthy tissue as it enters the body and targets the tumor, proton therapy's precise, high dose of radiation is extremely targeted. This targeted precision causes less damage to healthy, surrounding tissue.

When aimed at cancer tumors, protons pack impressive power. Protons release their energy completely once they enter a tumor, limiting the radiation dose beyond the tumor, causing less damage to the healthy surrounding tissues and resulting in fewer side effects.

Even if you've already had a course of conventional radiation and are unable to receive more, you may still be able to receive proton therapy.

More facts about proton therapy:

  • Proton therapy offers fewer reported side effects and complications
  • Normal, healthy, surrounding tissues receive 50% to 70% less radiation
  • Proton therapy offers an increased safe dose delivered to tumors
  • Cure rates may be increased with proton therapy
  • Proton therapy can re–treat tumors after recurrences
Illustration of Photon Beam with exit dose
Photon Beam (X-Ray) - Exit Dose
Illustration of Proton Beam with no exit dose
Proton Beam - No Exit Dose

Increased Precision Close to Critical Organs

Thanks to its marvelous precision, proton therapy is perhaps the most advanced treatment for cancer tumors located close to critical organs and highly sensitive areas, such as the spinal cord, heart and brain.

Proton therapy, alone or in combination with other treatments, is a great choice for many specific types of cancers and benign conditions.

Proton therapy is also an important treatment option for cancers that cannot be completely removed by surgery.

How Proton Therapy Works

At the center of the cyclotron, protons from hydrogen gas are guided in a circular path by a powerful magnet and are accelerated to higher and higher energies. As the protons gain energy, they spiral outward to the edge of the cyclotron magnet where, traveling at close to two–thirds of the speed of light, a high voltage deflects them out of the cyclotron into a beamline. The beamline is an airless tube that runs for about the length of a football field in which the proton beam is guided by other magnets into the treatment rooms.

Inside the treatment room, the proton beam exits the beamline through the "nozzle" where the beam energy is adjusted and a multi–leaf collimator precisely shapes it to match the unique 3–D profile of the patient's tumor delivering the most effective dose exactly where it's needed.

Multi–Leaf Collimator (MLC)

Penn is one of the few centers in the world, and the only facility in the United States, to offer the additional precision of a multi–leaf collimator (MLC).

This tool enables us to deliver protons in the exact shape needed for your tumor, delivering optimum results, each and every time.

Pencil Beam Proton Therapy

The Roberts Proton Therapy Center is one of the few centers in the world that offers pencil beam scanning (PBS). Proton therapy delivered with PBS allows doctors to "paint" the tumor with a proton beam tuned to a precise range, as well as adjust the intensity of the beam to achieve the desired dose distribution.

Pencil beam scanning is ideal for complex cancers, in which the tumor is located near critical structures.

You'll find the world's largest, most advanced proton therapy capabilities in Philadelphia at the Roberts Proton Therapy Center at Penn Medicine.