MEDICINE

MMRI will treat cancer patients with Protron Beam Therapy (PBT) Technology--the most advanced molecular medicine technology in the world.

MMRI will offer cancer patients Proton Beam Therapy (PBT), Positron Emission Tomography (PET), Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) for effective cancer treatment and treatment planning.

PROTON THERAPY

History of Proton Beam Therapy

The idea to use accelerated protons to treat cancer is not new. In 1946, physicist Robert R. Wilson suggested the use of protons in medical treatment. The first attempts to use proton radiation to treat patients began in the 1950’s in facilities whose main purpose was conducting nuclear physics research.

Only in the last decade has it become possible to develop proton beam facilities in conjunction with established medical centers. Nonetheless, the early success of proton beam treatments led the way for their use in an integrated manner with other cancer treatments. More then 40,000 patients at about 25 centers worldwide have been treated using proton therapy.

Proton Definition

A proton is a positively charged particle found in the nucleus of an atom. The protons used in proton therapy are derived from stripping a hydrogen atom of its electron.

Proton Radiation Definition

It is a form of external-beam radiation treatment, delivered by generating beams that penetrate the body from the outside.

Difference between protons and x-rays

Protons deposit their radiation differently than x-rays do. Compared to an x-ray beam, a proton beam has a low “entrance dose” (the dose delivered from the surface of the skin to the front of the tumor), a high dose designed to cover the entire tumor and no “exit dose” beyond the tumor.

If proton beam therapy has been around for a half century, why has it taken so long to offer it to patients on a significant scale?

Although the precision of proton beam therapy has been known for decades, applications were limited to a few anatomic sites (e.g., uveal melanomas and tumors of the brain and head & neck) because accelerators were not designed for treating patients (their energies were not sufficiently high to treat tumors found deep in the body), and because many tumors could not be visualized with sufficient precision.

However, in the late 1970s, imaging modalities, such as computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET), greatly advanced the diagnosis and visualization of cancerous tumors. This, coupled with the advent of sophisticated computers and improved accelerator and treatment delivery technology, made proton therapy more available for routine medical applications.

How proton beams destroy cancer cells?

When protons interact with electrons in the atoms of cancer cells, they impart energy to the electrons, causing them to leave the atom and undergo a series of interactions (ionizing events) that result in damage to the DNA of the cancer cell. Damaging the DNA destroys specific cell functions, which include the ability to divide or proliferate. A cancer cell's ability to repair molecular injury is frequently inferior to that of cells in normal tissues. As a result, cancer cells accumulate permanent damage and subsequent cell death occurs. As the cell dies, so does the tumor.

Proton therapy vs. traditional radiation therapy

Traditional radiation therapy affects everything in its path, so doctors have to limit the dose delivered to the tumor in order to minimize damage to surrounding healthy tissue.  With proton therapy, however, the beam is accelerated to specific energies that determine how deeply in the body protons will deposit their maximum energy. Protons enter the body with a low dose of radiation, which increases when the beam slows down within the designated target tumor and then protons stop. The combined effect is greater precision in targeting the tumor with a more potent dose of radiation.

Proton therapy accuracy

The accuracy and precision of proton therapy for treatment delivery is approximately one millimeter.

Proton therapy procedure and side effects

Proton therapy is safe because the proton is directed precisely to the tumor, and undesirable side effects, such as loss of appetite, diarrhea and headache, can be avoided and enables a patient to maintain a relatively active lifestyle throughout treatment.

Is the treatment painless? How long does it take?
Each treatment is quick and painless. While the actual delivery of the proton beam to the patient lasts (on average) only about a minute, the time spent in the treatment room will be about 15-20 minutes; in some cases more time may be needed for precise patient positioning and equipment adjustments. Like conventional radiation therapy, proton therapy treatments will take anywhere from a few days and up to an average of five to seven weeks depending on the tumor.

Proton beam therapy treatment benefits

Proton therapy benefits patients most when tumors to be treated are solid, have defined borders and are localized, or before the tumor has spread anywhere else in the body. Proton therapy’s overall benefit is reduced if a cancer has metastasized and spread to other parts of the body. When a large area must be radiated or a tumor is close to the surface of the body, such as in treating breast cancer, or when the whole body is radiated, as in leukemia and most cases of lymphoma, X-rays and other therapies should be considered.

Effectiveness of proton beam therapy for children

Because children are growing, their bodies are extremely sensitive to the harmful effects of radiation. Further, children’s long-term survival makes them more vulnerable to secondary tumors caused by exposure of normal tissue to radiation. For these reasons, proton therapy is the preferred form of radiation therapy in the care of children.

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