What is Proton Therapy

Call Now For More Information

General Questions or
Schedule an Appointment

1-888-990-7782

Current Patients

1-206-306-2800

Physician Line

1-888-987-7782

Advantages & Benefits

Advantages and Benefits

When Your Tumor’s Two Inches From Your Spinal Cord, Precision Matters.

Both standard X-ray (photon) radiation therapy and proton therapy attack tumors by preventing cancer cells from dividing and growing. The difference between the two therapies is that protons can precisely target the tumor, allowing patients to receive higher, more effective doses, and reducing damage to healthy tissue near the tumor.

Research shows that proton therapy can cause fewer short- and long-term side effects than standard radiation therapy, reducing the occurrence of secondary tumors and improving quality of life for patients.

Benefits at a glance

  • Causes fewer short- and long-term side effects
  • Proven to be effective in adults and children
  • Targets tumors and cancer cells with precision, reducing the risk of damage to surrounding healthy tissues and organs
  • Reduces the likelihood of secondary tumors caused by treatment
  • Can be used to treat recurrent tumors even in patients who have already received radiation
  • Allows potential increase in treatment dose, thus reducing the number of treatment sessions
  • Improves quality of life during and after treatment

Comparison of proton therapy and X-rays/IMRT in breast cancer treatment

With proton therapy, more of the healthy tissue and critical organs are spared from radiation.

 

The science of proton therapy

X-rays are electronic waves that penetrate tissue, gradually losing energy as they move along. To penetrate deeply enough in the body to reach most tumors, higher doses of radiation must be used. With X-ray therapy, however, the highest radiation dose occurs shortly after entering the body. That means much of the radiation is deposited in the healthy tissue in front of the tumor. When the X-ray exits the tumor, it continues to affect healthy tissue as it leaves the body. That can cause a variety of short- and long-term side effects, some of which can seriously affect quality of life and health.

With X-ray radiation therapy (black line), the radiation dose peaks soon after entering the body and often, long before reaching the tumor, gradually decreases.  Healthy tissue surrounding the tumor receives much of the dose.  With proton therapy (blue lines), treatment conforms more closely to the tumor, so that less radiation is deposited in the healthy tissue in front of the tumor compared to X-ray therapy, and almost none is deposited in the healthy tissue behind the tumor

Protons are large particles that can be manipulated to release their energy at a precise point. The more energy, the deeper the protons can penetrate into the body. The amount of proton energy is calculated to release the proton radiation precisely at the tumor site. The peak of this radiation dose (called the Bragg Peak, named after William Henry Bragg who discovered it in 1903) is designed to conform to the back of the tumor. Immediately after that point, the radiation dose falls to zero. Less of the radiation affects the healthy tissue in front of the tumor, and virtually none of it affects the healthy tissue behind the tumor. That results in much less damage to healthy tissue or nearby organs and structures. It also means that a higher dose often can be delivered, leading to more effective treatment.

Proton therapy promotes fewer short and long term side effects.

Reduced tumor recurrence. Secondary tumors occurring later in life are a significant problem for children who are cancer survivors. Proton therapy greatly lessens the probability of this.

Less damage to healthy tissue versus X-ray radiation. X-ray (photon) radiation delivers substantial doses of radiation to tissues surrounding any tumor volume. For even the most energetic clinical X-ray beams available, the depth at which the maximum dose of radiation is delivered ranges between 0.5 cm and 3.5 cm. Because tumors are often located deeper than this range, a higher dose is invariably delivered to the normal tissue anterior to the tumor.

In contrast, the dose deposited by a proton beam increases gradually with depth until close to the maximum proton range, and then suddenly rises to a peak, known as the Bragg Peak. A proton beam can be directed so that the Bragg Peak occurs precisely within a volume of about a 3-5 mm radius. This spot can be moved anywhere in three-dimensional space within the body.

With proton therapy, the dose of radiation to healthy tissue surrounding the tumor volume is typically much less than to the tumor itself, sparing normal tissue in the area. The dose immediately beyond the Bragg Peak is essentially zero, which also spares normal tissue distal to the tumor volume. Side effects typically seen with X-ray therapy, both acute and long-term, can be markedly reduced with proton therapy.

State-of-the-Art Technology

The Cyclotron

The driving force behind proton therapy is the cyclotron. First, hydrogen gas is electrified, causing the atoms to eject protons. The cyclotron then spins these protons at speeds of up to 223 million miles per hour. Magnets then guide a beam of protons from the cyclotron to the treatment rooms.