[ RadSafe ] Article: Is the Future Bright for Proton Therapy?

Thu Oct 4 09:55:11 CDT 2007

MIT I believe has one and the Massachusetts General Hospital is considering 
one.  I was at one time going to be a patient who would be undergoing this 
treatment.  It was called off after careful consideration.  It is actively 
being used here in Boston.

Ed Baratta

edmond0033 at comcast.net

----- Original Message ----- 
From: "John Jacobus" <crispy_bird at yahoo.com>
To: "radsafe" <radsafe at radlab.nl>; <know_nukes at yahoogroups.com>
Sent: Monday, October 01, 2007 10:54 PM
Subject: [ RadSafe ] Article: Is the Future Bright for Proton Therapy?

> >From another list server.
> -------------
> Is the Future Bright for Proton Therapy?
>
> Despite the promise it's shown, proton beam therapy is
> only available at a handful of U.S. facilities. Will
> it become a key component of cancer treatment?
>
> By Mark McGraw
>
> This past January, the University of Florida Proton
> Therapy Institute (UFPTI) performed its 1,000th proton
> therapy treatmentâ?"less than six months after opening
> its doors to patients. The milestone came just days
> after the Jacksonville, Fla.-based facility opened a
> second treatment room, which effectively doubled
> patient volume. The Loma Linda ( Calif. ) University
> Medical Center 's James Slater Proton Treatment Center
> has successfully treated more than 12,000 patients
> since opening its doors in 1990.
>
> Proton beam radiation therapy essentially operates on
> the same principle as conventional radiotherapy
> --ostensibly killing cancerous cells and preventing
> them from replicating. Proton therapy works by aiming
> energetic ionizing particles at a targeted tumor. As
> protons scatter less easily in the tissue, there is
> very little dispersion, and the beam remains focused
> on the tumor shape without causing much damage to
> surrounding tissue.
>
> The treatment has shown positive results in treating
> various types of cancer -- pediatric cancers, brain
> and spinal tumors, prostate, lung, head and neck
> cancer, malignant melanomas -- while reducing some of
> the side effects commonly associated with
> radiotherapy. While conventional radiation therapy
> remains a proven and often preferred form of
> treatment, proton therapy holds great potential, says
> James D. Cox, MD, head of the division of radiation
> oncology at M. D. Anderson Proton Therapy Center .
>
> But the M. D. Anderson proton center, UFPTI and the
> Loma Linda center are three of just five facilities
> currently providing proton therapy cancer treatment in
> the United States .
>
> Despite its promise, the cost and logistics required
> to start and maintain a proton therapy facility have
> prevented the treatment from becoming commonplace. But
> proton therapy's development steadily continues, as
> existing centers are successfully treating patients by
> the thousands, and plans for additional, world-class
> facilities are being put in motion.
>
> The University of Pennsylvania, for example, is slated
> to open a proton therapy institute in 2009. Hampton
> (Va.) University has received approval to begin
> construction on the Hampton University Proton Beam
> Therapy Center , and a facility at Northern Illinois
> University that has gained the support of some of the
> state's political heavy hitters will start seeing
> patients in 2011.
>
> Stopping on a dime
>
> The idea that proton treatment could be effective in
> fighting cancer isn't exactly a new one. Robert R.
> Wilson, the physicist generally considered "the father
> of proton therapy," first suggested as much in a paper
> published in 1946, when he was involved in the design
> of the Harvard Cyclotron Laboratory (HCL).
>
> The first treatments were performed at particle
> accelerators built for physics research, such as
> Berkeley Radiation Laboratory in 1954. A collaboration
> between HCL and Massachusetts General Hospital in
> Boston to pursue proton therapy began in 1961. That
> program treated more than 9,000 patients before the
> Cyclotron was shut down in 2002. Overall, more than
> 55,000 patients around the world have been treated
> with proton therapy, and between 15,000 and 17,000
> have been treated exclusively in the United States for
> some 50 different types of tumors, according to the
> National Association for Proton Therapy.
>
> Still, proton therapy has largely been used for
> research purposes, says Dr. Cox. The Loma Linda
> center, which was recently renamed to honor its
> founder, became the world's first clinically-based
> proton facility a mere 17 years ago. The M. D.
> Anderson proton center is just the fourth of its kind;
> the only proton therapy facility in the Southwest.
>
> M. D. Anderson, one of the world's most renowned
> comprehensive cancer centers, opened its
> 94,000-square-foot proton therapy center in May 2006.
> The center now treats an average of 55 to 60 patients
> on a daily basis, Dr. Cox says. The most precise form
> of radiation treatment for some tumors, proton therapy
> has the same biological effect as an X-ray, he adds.
> The difference is the radiation dose distribution.
>
> Protons are heavily charged particles that "deposit
> energy [in the body] very differently" compared to an
> X-ray, Dr. Cox says. In proton treatment, the dose is
> much lower upon entering the body, he adds, and the
> major dose distribution occurs when the proton comes
> to a stop. Protons have a very low dose of energy when
> entering the body, and no dose as they exit.
>
> The way protons distribute energy is comparable to
> that of a firecracker going off at the site of the
> tumor, says Stuart Klein, executive director of UFPTI.
> The effect is different in standard radiation therapy,
> which he likened to a bullet going through one side of
> the body and coming out the other. The ability to stop
> protons "on a dime" without disturbing surrounding
> tissue is the key advantage of proton therapy, he
> says.
>
> The point where the proton comes to a halt is
> determined by how much energy it is given, Dr. Cox
> says. At M. D. Anderson and Loma Linda, for example, a
> compact particle accelerator known as a synchrotron
> accelerates protons to variable energies into the beam
> transport line. The synchrotron contains magnets that
> confine the protons so they travel in a set path
> through a vacuum chamber. During each revolution
> through the chamber, protons gain an increment in
> energy from radiofrequency power. After many cycles,
> the protons reach the energy required by a treatment
> plan and are extracted into the beam transport line,
> which then directs the proton beam to the patient in a
> treatment room.
>
> In the process, "we can focus [proton treatment] and
> shape it, so we can make the high-dose area in the
> body correspond to the shape and size of the tumor,"
> Dr. Cox says. "That's something we can't do with
> X-ray."
>
> A weighty issue
>
> As noted, the costly technology and large space
> necessary to house it has contributed to keeping
> proton treatment from becoming more common in the
> clinical setting.
>
> At the two-story M. D. Anderson proton center, for
> example, there is one fixed-beam treatment room, an
> experimental treatment area, a range of patient and
> research support areas, a synchrotron, beam transport
> system and three gantry treatment rooms. Gantry
> patient treatment rooms have a patient treatment bed
> framed by a large wheel known as a gantry. The
> gantries here, which rotate around the patient to
> direct the proton beam at its target, are 35 feet in
> diameter and weigh about 200 tons, about the same as a
> Boeing 757 aircraft.
>
> At UFPTI, each gantry room is three stories high, and
> each gantry weighs about 200,000 pounds, says Klein.
> The facility is equipped with a cyclotron, a 440,000
> pound accelerator that speeds the protons to the
> desired energy, ranging from 230 MeV to 250 MeV. Once
> protons reach the optimal speed, magnets are used to
> direct the protons into a beam line that carries the
> protons into treatment rooms.
>
> The equipment in use at UFPTI is comparable to that
> found at the Francis H. Burr Proton Therapy Center in
> Boston , Klein says. Two of the treatment rooms at the
> Burr center, located on the main hospital campus of
> Massachusetts General, incorporate 110-ton gantries
> that can be rotated to aim the proton beam from
> various directions. Patients in gantry rooms lie on
> robotic beds which can be adjusted for exact alignment
> of targets contained throughout the body.
>
> The sheer size of proton therapy equipment, however,
> and the considerable expense attached to a proton
> facility doesn't figure to decrease anytime soon,
> which will likely limit the treatment to select
> centers for the foreseeable future, he predicted.
>
> "[Proton therapy] will continue to be more of a
> regional resource," Klein says, "as opposed to being
> located at every community cancer center. You'll never
> see a proton therapy facility on every street corner."
>
>
> Demonstrating value
>
> Nevertheless, Dr. Cox is optimistic that proton
> treatment will be proven as a viable alternative -- or
> complement -- to conventional radiotherapy in treating
> cancers.
>
> The precision with which proton therapy allows
> physicians to focus treatment and administer higher
> doses while still seeing reduced side effects bodes
> well for proton therapy's continuing development, he
> says.
>
> "I really do think proton therapy is the wave of the
> future," Dr. Cox continues, adding that he believes it
> will become much more widely used as technology is
> further developed and refined, which will help in
> driving cost down.
>
> Recent improvements in diagnostic technology, such as
> high-resolution MRI and CT scanners, allow physicians
> to more accurately visualize the exact shape, size and
> depth of tumors, Klein notes. The exact knowledge of
> the three-dimensional aspects of the tumor has
> advanced the applicability of proton therapy.
>
> A wide range of patients stand to gain from the
> treatment; patients that should be carefully selected
> based on the criteria that their tumor needs a high
> dose and is close to sensitive organs, Dr. Cox says.
> Such decisions are made by an accomplished team of
> radiation oncologists at the relatively new M. D.
> Anderson proton facility, which is treating patients
> 10 hours a day despite not being at full capacity just
> yet, he adds.
>
> Proton therapy facilities such as M. D. Anderson,
> UFPTI and Francis Burr are also home to research
> programs that are investigating new disease sites that
> may benefit from the therapy, and searching for ways
> to improve current treatment techniques and equipment.
>
>
> The ultimate aim of such efforts is to prove proton
> therapy's efficacy, "to be able to demonstrate the
> much more widespread applicability and advantage of
> this kind of treatment," Dr. Cox says, "and combine it
> with the other disciplines that are involved in cancer
> treatment."
>
> Mark McGraw is an associate editor at ADVANCE. He can
> be reached at mmcgraw at merion.com.
>
> +++++++++++++++++++
> "If you guard your toothbrushes and diamonds with equal zeal, you'll 
> probably lose fewer toothbrushes and more diamonds."
> - Former national security advised McGeorge Bundy
> -- John
> John Jacobus, MS
> Certified Health Physicist
> e-mail:  crispy_bird at yahoo.com
>
>
>
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