Dr. John Thomson knows the joy of attending a high school graduation service of a young patient cured of cancer.
When he was 5 years old, the boy was diagnosed with a brain tumor. Radiation treatment cured him, allowing him to live to graduate with his friends and make plans for his future.It's the increasing hope of offering a cure that motivates Thomson in his work with cancer patients.
To those whose cancer is too advanced for a cure, radiation can ease the pain or offer precious days of survival.
"Cancer is the most feared word in the English language," says Thomson, radiation therapist at LDS Hospital. "When a patient hears the word, they begin to plan for what they think is an inevitable, painful death.
"But that's no longer true. Fifty percent of all patients diagnosed in 1992 will be cured."
To answer questions about cancer, Thomson will be answering calls on the Deseret News/-Inter-mountain Health Care Hotline Saturday, Dec. 12, from 11 a.m. to 1 p.m. He will be joined by Dr. Vince Hansen, oncologist with McKay-Dee Hospital in Ogden.
The physicians can be reached by calling a toll-free number from anywhere within Utah (including Salt Lake City) or in the continental United States. That number is 1-800-925-8177. Identity of callers remains confidential.
There are 210 different types of cancer, all characterized by uncontrolled cellular growth. To kill cancer cells or keep them from growing and dividing, radiation therapy destroys the DNA code in cells that determines growth. "When the DNA instructions are scrambled, the cells can't make new copies of themselves," Thomson said.
Standing next to a huge, multi-million-dollar machine called a linear accelerator, Thomson explains how he designs treatments specifically for patients to focus the radiation rays on the cancer cells without damaging healthy tissue.
To give an idea of the power of the machine's radiation, Thomson said an average X-ray machine uses 70,000 electron volts for a chest X-ray. The linear accelerator uses 4 million to 21 million electron volts to treat cancer.
Thomson takes X-rays of a patient to determine exact location of the cancer. A lead block is then designed "with razor-edge precision" to fit the patient; the lead protects healthy tissue with a tailor-made hole exposing only the area to be treated. For example, if a person has a cancerous tumor in the brain, the lead would protect the surrounding eyes, nasal cavities, throat and mouth. Only the brain would be exposed to radiation.
Radiation therapy is an effective way to treat many kinds of cancer in almost any part of the body, Thomson said. Half of all people with cancer are treated with radiation.
The cure rates are impressive: 93 percent of women diagnosed with breast cancer in the early stages who receive radiation are cured. "Radiation is less disfiguring and emotionally distressful for women," he said.
Larynx cancer treated in early stages results in a 90 percent cure rate.
And radiation now saves 75 percent of children with certain types of brain tumors who used to die, Thomson said.
Thousands of patients are free of cancer after having radiation treatments alone or in combination with surgery, chemotherapy and biological therapy.
Radiation can be used to shrink a tumor before surgery. And Thomson frequently treats a patient with the linear accelerator during surgery while a patient is still under anesthetic.
"If cancer is diagnosed early, it does not automatically mean a death sentence. Early detection can't be emphasized enough. It's extremely rewarding to see the lives that are saved and extended because of advances in radiation therapy."