Steve Mellon, Post-Gazette Radiation therapist Victor Pregel examines the images of a cancer patient undergoing a new form of radiation treatment at West Penn Hospital. It more accurately focuses radiation on tumors, away from healthy tissue. Click photo for larger image.

Just before Julie Sadecky had a recent radiation treatment, a follow-up therapy for uterine cancer, her medical team at West Penn Hospital used cutting-edge technology to take a CT scan.

Guided by a computer analysis of the image and earlier scans, the team changed her body position to better direct radiation to the targeted area.

The new technology, known as Image-Guided Radiation Therapy, or IGRT, is helping doctors to deliver an optimal dose of radiation to cancerous areas while reducing the risk to healthy tissues, said Dr. David Parda, director of the West Penn Allegheny Health System's radiation oncology network.

Dr. Parda, chairman of radiation oncology at Allegheny General Hospital, and other experts said IGRT complements another advanced treatment, intensity-modulated radiation therapy, or IMRT. That therapy, which has been available longer, is being used at UPMC Shadyside to treat Mayor Bob O'Connor, who is battling a rare form of brain cancer.

IMRT helps doctors contour radiation around tumors and away from healthy tissues. It can be off target, however, as tumors or organs shift.

IGRT addresses the problem by allowing doctors to take scans and make adjustments just before the radiation beam is turned on.

"The IGRT concept really is going to be the next great leap forward," said Dr. Dwight Heron, director of radiation services for UPMC Cancer Centers.

Steve Mellon, Post-Gazette Julie Sadecky, 63, of Natrona Heights, receives a new type of radiation treatment at West Penn Hospital that promises to reduce radiation exposure to healthy tissue. Behind Ms. Sadecky is radiation therapist Victor Pregel. Click photo for larger image.

In some ways, the idea is not new, Dr. Heron noted. CT scans or other imaging techniques have been used for years to guide radiation therapy, which is often used to treat cancers of the head, neck, breast, prostate, brain and lung.

But only with the latest technology, he said, has IGRT involved "near real-time images of patients before you treat them."

In recent months, the West Penn Allegheny Health System and UPMC have started to use systems that incorporate IGRT.

UPMC's was developed by Varian Medical Systems; Allegheny General is one of five medical centers testing a system developed by Siemens. Both make use of linear accelerators -- machines that create high-energy radiation to treat cancer.

Last month, West Penn Hospital began using still another system produced by TomoTherapy Inc. Nationwide, about 60 TomoTherapy systems are installed or soon to be operating.

Dr. Judith Figura, West Penn's chief of radiation oncology, said TomoTherapy offers advantages for treating certain cancers, including those like multiple myeloma that are treated with total body irradiation.

But doctors noted that available IGRT technologies also have limitations and that the approach is still being investigated.

Dr. Moyed Miften, director of medical physics for Allegheny General's radiation oncology department, said preliminary findings using the technology are encouraging. He noted that radiation therapy, "like real estate, is all about location, location, location."

Through improved targeting, IGRT may permit more powerful doses of radiation, and that could shorten the length of treatment and perhaps enhance cure rates, Dr. Heron said.

IGRT, like IMRT, also appears to limit side effects by reducing the amount of healthy tissue exposed to radiation.

The techniques allow doctors to limit healthy margins around tumors to about two-tenths of an inch, down from half an inch or more, Dr. Figura said.

Without the improved targeting, healthy structures near tumors are at greater risk of injury. Radiation to a cancerous prostate that spills over to the rectum, for example, can cause rectal bleeding.

West Penn was one of the nation's first hospitals to offer IMRT in the early 1990s, though the technology has been more generally available for the past six or seven years, Dr. Figura said.

Dr. Heron compared delivery of radiation before IMRT to the uniform streams of water that pour from the holes in a shower head.

IMRT, he said, allows doctors to lessen or stop some streams of radiation that could affect healthy tissue, while intensifying others directed toward tumors.

Planning for IMRT often begins days before the radiation is delivered. Computer specialists develop sophisticated plans to optimize dose distribution.

But the actual treatment may be less effective than envisioned if the target moves. And that can happen for a variety of reasons.

The patient's alignment on the table may be slightly different than during the planning session. Contents of the bowel or bladder can cause prostate cancers to shift. Breathing can cause movement of lung cancers.

IGRT makes last-minute fine-tuning possible.

"I'd say IMRT has improved dosing of the target, and IGRT has improved targeting," Dr. Parda said.

Before long, doctors also hope to modify treatment as tumors shrink in response to therapy, noted Dan Pavord, West Penn's director of radiation oncology. The concept is known as adaptive radiotherapy.

But Dr. Parda noted that improvements are needed to better integrate and update all the computer data and quickly provide the information to the treatment team.

Researchers also are working to determine just how much IGRT improves clinical outcomes.

With multiple companies offering different versions of the technology, "demonstrating conclusively that there is a benefit" poses a challenge, said Dr. Jeff Michalski, professor of radiation oncology at Washington University in St. Louis. He chairs the IGRT committee for a group of oncology institutions funded by the National Cancer Institute.

Dr. Michalski noted that studies are underway to determine the effectiveness of high-dose, targeted radiation and shorter periods of treatment for patients with certain cancers.

The promise offered by the therapy "spurs on the adoption of this kind of advanced technology," Dr. Parda said.

For Ms. Sadecky, 63, of Natrona Heights, it is also reassuring.

She was diagnosed with cancer in February and had surgery the following month. Tests indicated cancer in a lymph node, so doctors recommended chemotherapy followed by radiation.

While chemotherapy left her tired and weak, Ms. Sadecky said she has had minimal side effects from TomoTherapy.

She said she feels good that "better technology is coming along, and that it's able to help me."