Proton Beam Therapy: The Most Precise Cancer Radiation Treatment

Conventional radiation therapy (radiotherapy 1) for more than 100 years: Primary objective to kill cancer (malignant 1) cells, utilizing high energy particles or x-ray particles. Also, the therapy referred to as ionizing radiation. 1 High - energy beams are directed to deposit a radiation dose, location of cancer cells in the body. Most often conventional radiation is applied in conjunction with surgery, hormone therapy and chemotherapy (drugs) or a combination. In a few applications, radiotherapy is utilized to treat non - malignant conditions, including thyroid eye disease. 1 Many patients have benefited from conventional radiation therapy however side effects or drawbacks have been known to be toxic, surrounding healthy tissues exposed to radiation; kills healthy cells.

Severity of damage as result of conventional radiation therapy does vary. During breast cancer therapy, patients may be affected by developing cardiovascular disease or secondary malignancies. 2 Consequences of conventional radiation therapy may cause skin damage (depending upon length of treatment), throat, esophagus, mouth and bowel may be damaged. Also, this type of radiation therapy, may affect ovaries and testicles, which are very sensitive to radiation, as result may cause infertility. Other common side effects include hair loss. 1

"Proton beam therapy is a very precise type of radiation therapy that delivers a more accurate dose of radiation to the specific target site." The benefits of proton beam radiation compared to conventional radiation treatment increasingly become more recognizable and increased usage. 2 About 5,000 United States cancer patients undergo proton therapy, compared to approximately 800,000 who undergo radiation every year. 3 Worldwide proton therapy has treated about 50,000 people. 9 Proton beam therapy utilizes protons (charged particles found in the nucleus of an atom) compared to radiotherapy uses x-ray beams. 2 Physicists separate positively charged protons from hydrogen atoms by stripping off the negatively charged electrons. 7 A machine called cyclotron or a synchrotron generate and accelerate protons."The protons leave the machine and are steered by magnets toward the tumor. Other pieces of equipment are used to modify the range of the protons, shape of the beam and to compensate for organ location." 5

"The proton beam enters the body at a low concentration and reaches its maximum concentration at the target site." Effectively the charged particles deliver an increase dosage of radiation at the tumor site and side effects are limited to a lower dose of radiation to the surface of the tissue. Also, proton beam therapy directs the radiation treatment to any conformed or size shaped tumor, and decrease toxicity to surrounding cells (half a millimeter away 10), compared to conventional radiation therapy. 2 "Exit dose" (doctors call) from X-rays after a tumor is targeted by radiation does not occur during proton beam therapy, reducing the risk of complications. Proton beam therapy often used for prostate - cancer patients, reduces the risk damaging nerves and bladder, leading to impotence and continence, common occurrence after conventional radiation therapy. 3 This type of therapy is used effectively on tumors that are localized and have not spread to other distant areas of the body. 4 Within areas of the body, most effective treatment utilizing proton beam therapy: Eye Tumors, prostate, brain, head, neck, and lung. 5 According to Dr. Wayne Jenkins, a radiation oncologist and medical director of M.D. Anderson Cancer Center Orlando, proton beam therapy better cancer treatment for children (pediatric tumors 9) than exposure to adverse affects of conventional radiation therapy. 3 "Depending on the case, proton therapy may be used in combination with traditional radiation, chemotherapy, and/or as a follow-up to surgery". 4 Research is underway evaluate if proton therapy might be effective to treat non-cancerous conditions, including macular degeneration. 8

Proton therapy treatment performed on an outpatient basis, from one day to seven weeks, depending on tumor size. 5 The intensity of radiation during proton treatment can be increased thus treat the malignancy more effectively, and because of the safety issue, patients are less exposed to side effects. 4 The total length of time in the treatment room 15 - 20 minutes, including about one minute for delivery of the proton beam to the target site. Most of the time is required to position and adjust for equipment settings. Patients do not feel any pain or discomfort during proton therapy treatment. Depending upon amount of dose, size of treatment area, and whether chemotherapy is additionally required, patients may experience loss of hair, skin reactions and fatigue. 5 Success is measured, if the cancer does not reoccur within five years after treatment. Medical insurance covers the cost of proton beam therapy, but costs more than conventional radiation, however less expensive than surgery. 4 Always best to contact your medical insurance company regarding coverage for proton beam therapy.

In 1990, the first Proton treatment center opened in Loma Linda University Medical Center. Many radiation oncologists are starting to become familiar and trained working with proton technology, as an advance method of radiation to treat cancer patients. 4 Encompassing team of trained individuals during a proton beam therapy treatment include radiation physicist, radiation oncologist (Uses a computer to trace the tumor and the surrounding normal tissues.), physicist, dosimetrist, immobilization specialist (Patients are fitted with an immobilization device, secures the positioning of the body in an exact position during treatment. Some cases, foam liners are required surrounded by rigid shells for patients with a tumor in the neck or custom made mask for patients with a tumor in the eye, brain or head), radiation therapist and nurse. The radiation physicist and the dosimetrist evaluate the most effective treatment calculations. 5 The cost to build a proton therapy facilities is very expensive (Costing $100 million or more. 3), limiting the capabilities of many universities, and academic medical centers to per sue this expensive endeavor. 4 Also, the facility requires a foot-ball sized location to house it. 3 The equipment weighing into the hundreds of tons. ("For instance, the Orsay proton therapy center in France uses a synchrocyclotron weighing 900 tons in total.") 6

Currently, five proton facilities are available nationwide. 3 Unfortunately, only about 6,000 treatment slots are available each year. "As a result, doctors face agonizing decisions about whom to treat - and some patients are lucky if they're in a waiting room rather than on a waiting list." Besides, many patients have to travel hundreds or thousands of miles to a nearest proton treatment center. 10 During the past two years, two proton beam therapy facilities opened in Anderson Proton Therapy Center in Houston, and University of Florida Proton Therapy Institute in Jacksonville. As of 2008, these facilities have treated

60 - 80 patients daily. 4 M.D. Anderson Cancer Center Orlando plans to start construction on a smaller size proton therapy facility on Orange Avenue costing $20 million and begin to treat patients by 2010. The manufacturer is in the process of evaluating, if smaller sized machinery would be effective. 3 A comparatively small accelerator system produces proton therapy for patients being developed by the Massachusetts Institute of Technology (MIT) in collaboration with an industrial team. 6 Other new proton beam facilities under construction in National Taiwan University Hospital in Taipei City, Taiwan (Received $400 million donation from Foxconnn - proton therapy center due for completion in 2010) and construction is in progress on a private Proton Center in Oklahoma City is planned to open in 2009. 8 ProCure Treatment Centers (company offers State - of - the Art Proton Beam Therapy Centers (11) - partners with hospitals to plan, install and run the complex proton facilities) estimates proton therapy treatment could help a quarter of a million patients.

"In January 2007, Varian acquired ACCEL Instrument GmbH, a private - held supplier of proton therapy systems for cancer treatment and scientific research instruments." 9

References:

1.) Radiation therapy - http://en.wikipedia.org/wiki/Radiation_oncology

2.) Questions and Answers - http://www.tigerlilyfoundation.org/doctor.htm

3.) Cancer patients pin hopes on pricey proton therapy in Florida - http://www.orlandosentinel.com/orl-proton2808apr28,0,674529.story?track=rss

4.) Proton Therapy -- A Mainstream Option for the Treatment of Cancerous and

Non-Cancerous Tumors - http://www.proton-therapy.org/questions.htm

5.) Proton Therapy - http://www.radiologyinfo.org/en/info.cfm?PG=protonthera&bhcp=1

6.) Proton therapy - http://en.wikipedia.org/wiki/Proton_therapy

7.) Learn About Proton Therapy - http://pennhealth.com/perelman/proton/therapy.html

8.) Proton therapy - http://www.nlm.nih.gov/medlineplus/ency/article/007281.htm

9.) Proton Therapy / Overview - http://www.varian.com/us/oncology/proton/

10.) The Promise of Proton-Beam Therapy - http://health.usnews.com/articles/health/cancer/2008/04/16/the-promise-of-proton-beam-therapy.html

11.) Welcome to ProCure - http://www.procurecenters.com/