Carbon, the next wave?

Lessons from Proton Therapy Center Design will come in handy when this promising particle beam technology becomes more widely available.

One’s vision of future of the proton beam therapy industry may depend on perspective and how far ahead one looks. One portion of the industry is looking towards smaller proton centers, even single room solutions and highly cost effective projects. Others are looking beyond protons (hydrogen ions) to see what’s next in non-invasive radiotherapy, several years down the road. And that’s carbon.

Carbon ion beam therapy uses a heavier particle than proton, which has many benefits for the clinician and patient. Carbon ion can reach deeper tissue. Carbon beams release 100% of their radiation energy to the treatment site, rather than proton’s 99%, so there’s very little damage to healthy tissue. Carbon can carry more radiation to tumor sites and produce 2-3 times higher biological effect compared to X/gamma-rays, which means less patient visits for treatment. A patient’s treatment cycle can be shortened by weeks with carbon.

Japan, where the profusion of bone cancer cases and demographics make it an attractive treatment option, has pioneered the use of carbon ion therapy. HIMAC, the Heavy Ion Medical Accelerator in Chiba, Japan, began the first full clinical trials with carbon-ion therapy in 1994. Germany is a distant second with the Heidelberg Ion-Beam Therapy (HIT) Center.

The conventional view up until recently has been that a carbon ion requires even bulkier, more expensive facilities than proton therapy; more energy and a robust electrical supply, more cooling from larger chiller pants and bigger magnets in the accelerator to drive the heavier particle. This results in a larger footprint and intimidating expense.
But we can take the lessons we’ve learned in shrinking the footprint for proton therapy centers from a building efficiency standpoint and apply them to a new developing market for carbon. Incorporating these lessons will make it more likely for carbon to come to market competitively.

Working in carbon’s favor is the technological evolution of superconducting magnets and power supply devices. Larger magnets are required to push carbon ions, but with superconducting magnets, these are getting smaller all the time. Advances in power supply device technology have helped reduce carbon facility energy demands from 5MW down to just over 2MW. And enthusiasts for carbon say its physical footprint is now only slightly larger (10%) than proton.

The smaller footprint Japanese Gunma facility, which opened in 2012, is the prototype for additional, more compact carbon-ion accelerators planned for that country.

Carbon still has challenges to overcome beyond equipment and building size and expense. There’s no FDA approved system in the United States. And while proton therapy is now covered by Medicare and most health insurance companies in the U.S., carbon ion therapy is considered experimental at present. In Germany and Japan health care providers cover carbon ion therapy. But considering the treatment’s great potential and growing interest in the States, these hurdles are unlikely to be permanent.

While carbon therapy centers have been talked about in the U.S., they have yet to be built here. But now feasibility studies abound and it’s not a question of if we will see a carbon center in the States, but rather when.

Photo: Radiation treatment in the Heidelberg Ion-Beam Therapy Center (HIT), Photo: Heidelberg University Hospital

Download the complete Design Quarterly Winter 2015 – Trends in Proton Therapy Center Design now.

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