Pencil Beam Continued

Rapid Fire with Exquisite Precision
The Proton Therapy Center, which began treating patients with pencil beam in May 2008, was the first in North America and one of only three clinical centers in the world to employ this technology. Because pencil beam does not require any shaping devices the treatment is less time consuming than passively scattered beams, with most treatments only taking a few minutes. •
Using rapidly fired pulses, the pencil beam hits each planned spot within the tumor with a set dose of radiation, starting at the deepest layer and working in succession, layer by layer, until the whole tumor is covered. Lee estimates that a typical tumor will have between 1,000 to 2,000 separate spots arranged in up to 24 layers in a single pencil beam treatment. “We are able to maximize the protons generated and deposit more energy directly into the tumor,” Lee said.
THOUSANDS OF TARGETED PROTON BEAMS
Powerful scanning magnets direct thousands of ultra fine proton beams, one by one, toward a patient’s tumor. Intricate treatment planning allows for the protons to deposit their potent dose of radiation to the exact dimensions of the tumor, leaving nearby healthy tissue and critical structures untouched.

He notes that pencil beam could ultimately be applied to any tumor site where proton therapy is used, including cancers of the prostate, eye and head and neck. It is an especially attractive future option for solid tumors in children, who are generally more sensitive to the adverse effects of radiation. “Without the apertures, pencil beam deflects fewer neutrons into healthy tissue, which have been shown to increase the risk of second malignancies in young, still growing patients.” M. D. Anderson has treated over 40 patients with pencil beam to date.

Have a good Wednesday.

Today is Tea Party Day. Enough is enough already.

Blessings,
Rick

Pencil Beam Continued

A New Frontier for Proton Therapy
Proton therapy derives its advantage over conventional forms of radiation from its ability to deliver radiation doses to a targeted tumor with remarkable precision that avoids the surrounding tissue, generates fewer side effects and improves tumor control. Most proton patients are treated with a form of therapy known as passive scattering which uses apertures to shape the proton beam and deliver a uniform dose to the tumor. Since opening in the spring of 2006, M. D. Anderson’s Proton Therapy Center has treated more than 1,000 patients with this passive scattering technique.
Pencil beam for proton therapy delivers a single, narrow proton beam (about a centimeter in diameter) that is magnetically swept across the tumor, depositing the radiation dose like a painter’s brush strokes, without the need to construct beam shaping devices. The technology continues to build on the patient benefits already offered with proton therapy – more targeted, higher tumor dose, shorter treatment times, reduced side effects and increased treatment options – to treat complicated tumors perilously close to critical structures, such as the eye, brain and esophagus.
“The difference between passive scattering and pencil beam is like painting something with a can of spray paint versus using an airbrush,” said Andrew Lee, M.D., M.P.H., associate professor in the Department of Radiation Oncology at M. D. Anderson, and the director of the Proton Therapy Center. “Pencil beam is more like an airbrush. Instead of needing a stencil to master the shape, the proton beam is made ultra fine to define the contours and landscape of a tumor.”

One more article tomorrow about this amazing technology.
Have a good Tuesday.
Blessings,
Rick

New Pencil Beam for Proton Therapy Delivery

It is the radiation oncologist’s mantra. Deliver the maximum dose of radiation to the malignant tumor, while limiting damage to healthy surrounding tissue. In proton therapy, achieving this balance is equally one part particles and another part contriving the particles, once accelerated to nearly the speed of light, to mimic the shape of a tumor with sub-millimeter precision.
Today more than ever, new tools are enabling physicians at the Proton Therapy Center at The University of Texas M. D. Anderson Cancer to harness supercharged proton particles and conform them more closely to the rugged landscape and uneven contours of a cancer tumor. Using a technology known as pencil beam scanning, also known as spot scanning, protons are given the mission: home in on cancer cells and destroy. As much an art form as a war tactic, pencil beam has the ability to treat the most complex of tumors, like those of the prostate, brain, base of the skull and eye, while leaving healthy tissue and critical structures untouched. The powerful coupling of strength and accuracy offers unmatched capacity to treat a patient’s tumor without compromising quality of life.
In nearly a decade since pencil beam’s birth in a Swiss physics institute, the world’s leading practitioners in radiation science at M. D. Anderson’s Proton Therapy Center will integrate the tested technology into the institution’s multidisciplinary approach to cancer care and translational research.

Tomorrow, a bit more about this new and exciting technology.

Have a good Monday.
Blessings,
Rick