Clinical use of IMRT—an advanced form of radiotherapy—has surged in the last year. With IMRT, doctors are now treating cancers of the head and neck, prostate, lung, breast, gastrointestinal organs, cervix, and uterus as well as pediatric tumors, sarcoma, spinal metastases, and lymphoma.

Arno Mundt, MD, radiation oncologist at the University of Chicago and medical director for radiation oncology at the University of Illinois at Chicago, and his colleague, medical physicist John C. Roeske, PhD, have compiled a comprehensive textbook on IMRT, collecting 30 chapters from 183 contributors at 43 treatment centers in nine countries. Chapters cover the use of IMRT to treat almost every type of solid tumor.

Their book illustrates how far IMRT has come since its introduction in the mid-1990s. “IMRT is coming into its own,” says Mundt. “People are using it in more sophisticated ways, radiation oncology residents are being trained, and there’s an explosion of literature showing the benefits of IMRT and how it can be applied.”

Mundt conducted his first IMRT usage study in 2002, surveying 450 radiation oncologists in the United States. Published in the journal Cancer, the study showed that 32 percent of respondents were using IMRT. Most had adopted IMRT during the prior two years and were using it only to treat head-and-neck tumors and prostate cancer.

In 2004, Mundt’s team did a follow-up study. This time, 73 percent of the respondents were using IMRT. Of those who were not, 90 percent planned to adopt it within three years. “There was a huge conversion of nonusers into users,” says Mundt. “We also surveyed the chief residents at 77 accredited training programs and found that about 85 percent of the nation’s residents are being trained to use IMRT. That really sets the stage for the future.”

Varian figures echo the survey results. At the end of fiscal year 2003, the number of radiation oncology centers treating patients with Varian’s SmartBeam™ IMRT had more than doubled to 472. By September 2004, that number had risen to 866. About half of the roughly 2,600 Varian-equipped sites around the world have the technology needed to deliver IMRT. And nearly 95 percent of the new linear accelerators ordered in 2004 included IMRT capabilities.

At the Princess Royal Hospital in Hull, England, IMRT has become one of the standard treatments for head-and-neck cancers. Chief physicist Andy Beavis, PhD, has also been running a dose escalation trial using IMRT for pancreatic cancers. “It has proven especially beneficial in palliative and other cases where there’s no other way to get the necessary dose level to control the tumor,” says Beavis. “IMRT is here to stay.”