Al's Comment:
Boron neutron capture therapy is an old treatment consisting of giving the patient a boron containing drug which concentrates in the tumor, and then shooting neutron beams at it. The neutron beams do not hurt the cells that do not have boron - but in the cells that did take up boron, the neutrons split the boron releasing radioactive particles that kill the cell.
This has been tried before but the problem was fiding a way to get the boron into all of the tumor cells. Years ago we did not have that technology, but now we are much closer! Worth trying again.
Posted on: 08/26/2013
Researchers start clinical trials on neutron beams to treat cancer
August 20, 2013
By YURI OIWA/ Staff Writer
Japanese researchers are developing a new radiation therapy for cancer that uses neutron beams, and the government is eager to sell this new technology overseas as part of its economic growth strategy.
But scientists are only beginning to investigate the effects and safety of the therapy. And they are still fine-tuning the equipment.
The potential applications for the Boron Neutron Capture Therapy (BNCT) are impressive. Researchers expect the neutron beams to treat tumors of complex shapes, cancer in multiple areas and recurrent cancer while avoiding most damage to normal cells.
The basic principles of the treatment were proposed 80 years ago. The patient receives an intravenous dosage of a tumor-localizing drug containing boron-10, which has a high propensity to capture neutrons, and is then exposed to neutron beams.
When the boron atoms capture the neutrons, they split and release radioactive alpha particles. The alpha particles only damage nearby cancer cells because they travel just 5 to 10 micrometers (millionths of a meter), a relatively short distance compared with X-rays and gamma rays.
“I expect it will yield results in therapy for cancer that is difficult to treat with surgery or conventional radiation therapy, such as multiple tumors in one organ or tumors located near healthy nerves,” said Koji Ono, a professor emeritus of radiology at Kyoto University who is working on the technique.
The Kyoto University Research Reactor Institute in Osaka Prefecture and Osaka Medical College conducted a clinical trial from 2002 through 2007 on 19 patients with recurrent glioblastoma, a type of brain tumor. Half the patients died about 19 months after recurrence, more than six months longer than patients undergoing other treatments.
Clinical trials to receive approval of the equipment as medical devices began in October last year at the Kyoto University Research Reactor Institute. The subjects are patients with malignant glioma, a type of brain tumor.
Prime Minister Shinzo Abe, who has cited health care as a core component of Japan’s growth strategy, visited Russia in April, accompanied by business leaders who promoted the equipment used in the therapy.
The National Cancer Center in Tokyo will begin operating its equipment on an experimental basis in February 2014.
“We will begin clinical trials with skin cancer patients sometime next year, and we want to commercialize this Japanese technology so we can offer it overseas,” said Jun Itami, head of the center’s radiation therapy department.
The Southern Tohoku Research Institute for Neuroscience in Fukushima Prefecture also plans to begin clinical trials in 2015, primarily on patients with cancer of the head and neck.
“We want to make a center for the effective use of radiation in Fukushima,” said Kazuo Watanabe, the institute’s director and a neurosurgery specialist.
One major hurdle to practical applications was the need for nuclear reactors. Since the beginning of the 2000s, progress has been made in Japan on developing machines that produce neutrons through a compact accelerator. Treatments are nearly ready for practical application.
Two types of equipment are currently under development.
A device that Kyoto University and Sumitomo Heavy Industries Ltd. are jointly developing shoots protons produced by a compact accelerator at a beryllium target to create neutrons.
The device that the National Cancer Center is developing with Tokyo-based Cancer Intelligence Cares Systems Inc. produces neutrons by shooting accelerator-generated proton beams at a lithium target.
Operating the equipment requires fine skills to adjust the settings, such as proton and neutron speed and the strength of the target.
Another issue is how to produce a steady stream of therapeutic neutrons safely and efficiently.
There are also variations between individual patients on how well the cancerous cells absorb drugs made with boron-based compounds. The effectiveness drops when they do not accumulate enough in the cancer cells.
And because neutron beams only penetrate 6 centimeters beneath the skin, a patient with a deep tumor will require BNCT combined with other treatments.
“If we can develop better tumor-localizing drugs and devices that expose patients to even more neutrons during the same time period, then we could make the therapy more effective,” Ono said. “We really need physicists knowledgeable about neutrons and accelerators to participate in the research, not just health-care professionals.”
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