The 2nd Annual Ladies' Home Journal Health Breakthrough Awards
Minesh P. Mehta, MD, and T. Rock Mackie, PhD: Revolutionizing Radiation Treatment
It's 1988, and two Wisconsin scientists spend night after night giving radiation therapy to cancer patients. One is an oncologist born in Uganda to Indian parents; he was 12 when his family relocated to Zambia after Idi Amin assumed power. The other is a young physicist from Canada who grew up in the town where cobalt therapy, a form of radiation treatment, was developed.
Eating pizza between seeing patients, the duo begins to brainstorm about a new approach to radiation therapy, one that would target tumors more precisely and not damage so much healthy tissue at the same time. "We thought there had to be a better way to make the whole process easier and more efficient," recalls Minesh P. Mehta, MD, program leader of radiation and imaging services at the University of Wisconsin Paul P. Carbone Comprehensive Cancer Center and a professor of human oncology at the University of Wisconsin School of Medicine and Public Health, both in Madison.
"We just started dreaming of a new machine," adds T. Rock Mackie, PhD, a researcher at the cancer center and a professor of medical physics and human oncology at the medical school. In their minds it was a CT scan-like device that would also let doctors pinpoint the tumor before each treatment. "Even I thought it was a crazy idea," says Dr. Mackie, 52.
Fast-forward nearly two decades. The crazy idea -- now called TomoTherapy HI-ART System -- has become a first-of-its-kind technology that is poised to transform cancer treatment.
Standard radiation therapy begins with just one CT scan to pinpoint the tumor. Tiny tattoo dots mark where the radiation machine will aim a rectangular beam at the tumor from several angles for a few minutes per dose. The problem is that over time, tumors change in size, shape, and location, making the tattoo a less-accurate guide. Patients may get less radiation than needed and more healthy tissue may be affected, with side effects such as dry mouth, vaginal burning, or intestinal problems.
With TomoTherapy, each treatment begins with a CT scan that outlines the tumor's current position and shape. Instead of a few angles, the machine slowly carries the patient past tens of thousands of tiny fan-shaped radiation beamlets that bombard the tumor in a 360-degree pattern.
"We can deposit a dose of radiation that reproduces the exact shape of the tumor, so the surrounding normal tissue gets far less exposure to radiation," says Dr. Mehta, 52. In people with head and neck cancer, for example, this minimizes how much radiation passes through the brain, salivary glands, and spinal cord.
Targeting also means doctors can safely deliver more radiation per dose and potentially slash treatment duration. Dr. Mehta has been able to reduce the standard eight- to nine-week treatment for prostate cancer to four to five weeks for some patients and lung cancer from eight to 10 weeks to five.
About 125 radiation centers around the world already use TomoTherapy. "It's the next generation of radiation therapy treatment machines," says Christopher J. Schultz, MD, professor of radiation oncology at the Medical College of Wisconsin, who uses the technology for his patients.