Published by the MIT News Office at the Massachusetts Institute of Technology, Cambridge, Mass.
Published by the MIT News Office at the Massachusetts Institute of
Technology, Cambridge, Mass.
Clinical Trials to Begin On Brain Cancer Therapy By Robert C. Di Iorio News Office A treatment for a brain cancer using neutrons generated by the MIT nuclear research reactor is in the final stages of development and clinical trials are expected to start early in 1992. The treatment is being developed by MIT and the New England Medical Center under a $3-million grant from the US Department of Energy. An October 31-November 1 international workshop on the treatment-known as neutron capture therapy-is being sponsored by MIT, the New England Medical Center and the DOE. At the workshop, to be held at the Student Center, scientists who have been working since 1987 to develop the therapy will present papers on the amount of radiation and the treatment regimen planned for the clinical trials. The co-chairmen of the workshop are Professor Otto K. Harling of MIT, director of the MIT Research Reactor and a member of the Department of Nuclear Engineering, and Professor Robert G.A. Zamenhof of the New England Medical Center, principal investigator of the Neutron Beam Capture Therapy Group there. Neutron capture therapy was conceived as a potential treatment three decades ago, but early clinical trials at MIT and at Brookhaven National Laboratory were unsuccessful because the technique used to confine radiation to the cancerous brain cells was not effective. A participant in those trials in the early 1960s was Dr. Hiroshi Hatanaka, now a professor of neurosurgery at Teikyo University in Tokyo. He returned to his native country and continued to work on the therapy. His improvements eventually led to reported successes and attracted attention of researchers in the United States. Professor Harling, the principal investigator for MIT's portion of the research, said the type of cancer being targeted-high-grade astrocytoma-kills 6,000 people a year in the United States alone. "These are highly refractory brain tumors for which there is no successful therapy," Professor Harling said. Conventional treatment begins with surgeons removing from the brain as much of the tumor as possible. However, this type of cancer also develops hair-thin fingerlets that cannot be removed surgically without destroying healthy brain cells. It is at these fingerlets that neutron capture therapy is directed. Patients in the coming clinical trials will have undergone surgery for the removal of as much of the tumor as possible. They then will be administered a compound containing boron-10, a nonradioactive isotope which will find its way primarily into cancer cells. The patients then will enter a special room directly under the MIT research reactor and a filtered stream of epithermal neutrons, generated in the reactor, will be directed to their heads. Exposure periods of one hour a day for four days are being planned. The boron-10, concentrated in the cancer cells, will absorb the neutrons. The absorption causes a reaction that releases additional radiation powerful enough to kill the cancer cells but not of sufficiently long range to damage adjacent healthy cells. Professor Harling said neutron capture therapy may be applicable to other forms of cancer. The clinical trials will begin with patients suffering from malignant brain tumors because increases in survival rate would in the future be more easily noted in those cases, he said.