What is Proton Therapy?
Proton therapy
may sound mysterious, but think back to high
school science class — protons are positively-charged
particles that are part of the nucleus of every
atom. When aimed at tumors, however, protons
are a particle with impressive power. Proton
therapy uses a beam of protons moving at very
high speeds — at about 100,000 miles per
second, near the speed of light — to pummel
and destroy the DNA of cancer cells, killing
them and preventing them from multiplying.
Conventional radiation uses X-rays or gamma rays, high-energy electromagnetic waves. As those rays pass into the body, they begin to scatter and lose much of their energy even before reaching the tumor, like a flashlight beam spreading out and becoming dimmer in the distance. After passing through the tumor, they continue through the body — affecting not only the cancer cells, but healthy tissues along their path, frequently resulting in side effects for the patient.
But protons act differently in tissue, in ways
that can help doctors treat tumors that are hard
to reach or close to vital organs like the heart: They
give up their energy completely once they enter
the tumor, so radiation dose is limited beyond
the tumor, causing less damage to healthy tissues.
"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," explains Stephen
Hahn, MD, chairman of the Department of
Radiation
Oncology at Penn Medicine.
Why Use Protons?
- Same
tumor killing properties as X-rays
- Decreased
dose to normal tissues by 50-70%
- Decreased
side-effects and complications
- Ability
to treat tumors close to critical organs like
the spinal cord
- With X-rays, 20% of
cancers come back because treatment dose was
too low to be effective
- Possibility
to increase the safe dose delivered to tumors
- Possibility
of increased cure rates
- The ability
to re-treat tumors after recurrences
- The
added ability to treat benign conditions
Applications
of Protons to Treat Cancers
Applications of Protons
to Treat Benign Conditions
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