Radiations' evolving choices in Cancer Treatment

"Most radiation is done with 'external radiation,' which is delivered from outside the body, with X-rays or electrons with a machine called a linear accelerator," says Dr. Matthew Katz, medical director of radiation oncology at Lowell General Hospital in Massachusetts.
The technology keeps improving, Katz say, from the early 1990s when CT scans first allowed oncologists to treat tumors in 3-D to current techniques. One is intensity modulated radiation therapy or IMRT, which shapes the beams more precisely and sends stronger radiation doses to some parts of the body and weaker doses to others. Continued improvements allow practitioners "to more accurately target common cancers better than before," he says. "That accuracy ensures we're more comfortable that the cancer is receiving treatment rather than the normal tissue, and in many cases can also lessen side effects." Then there are the high-dose, ultraprecise types of radiation (including the brands Gamma Knife and CyberKnife). "Stereotactic radiation was used originally for brain metastasis, cancer spread to the brain, where the accuracy needed to be within a millimeter," Katz says. Now, he continues, it's improving cure rates for inoperable early-stage lung cancer, and other uses are increasing. "All need more research," he adds.
Proton beam therapy is coming to the University of Maryland Medical Center within the year, Tyer says. It uses protons instead of X-rays and is meant to deliver more radiation to tumors while decreasing radiation to healthy tissue.
Because the cyclotron machine costs tens of millions of dollars and requires specialized staff, only a handful of U.S. centers offer it, and availability is limited.
Dr. Bruce Haffty, ​chair of the board of directors for American Society for Radiation Oncology, or ASTRO, says while proton radiation has been around for decades, it was largely experimental. Now, with nearly 20 facilities nationwide, he expects every state to have one within a few years. More types of patients will benefit as availability increases, he says, and as data from clinical trials unfold.