The University of Iowa
The University of Iowa News Services Home News Releases UI in the News Subscribe to UI News Contact Us


2130 Medical Laboratories
Iowa City IA 52242
(319) 335-9917; fax (319) 335-8034

Release: Oct. 6, 1999

UI acquires state-of-the-art radiation therapy system

IOWA CITY, Iowa — A new University of Iowa Health Care radiation therapy system means that UI radiation oncologists can now better treat patients with cancer in the head and neck region and the central nervous system.

The UI Hospitals and Clinics' Radiation Oncology Division is the first facility in the state and one of only a few in the Midwest to acquire the PEACOCK System, a state-of-the-art treatment planning and delivery system for Intensity Modulated Radiation Therapy (IMRT).

The PEACOCK System allows physicians to improve radiation targeting of tumors. It can be used for large tumors and those with complex shapes. The PEACOCK System's improved targeting makes it possible for the radiation to attack the cancer without damaging nearby healthy tissue and organs.

"This is truly a technological breakthrough in radiation therapy," said Ken Zhen, M.D., UI assistant professor of radiology. "It's a totally different concept of treatment planning and delivery of radiotherapy. With this new technology using 3-dimensional computerized imaging to tailor the beam to specific tumors, we can treat patients who previously couldn't receive optimal therapy."

Conventional radiation therapy uses radiation beams of uniform intensity, which makes it difficult, if not impossible, for physicians to direct the ideal amount of radiation to the tumor site. As a result, physicians must either stop short of optimally treating the tumor or run the risk of damaging nearby structures, which in some cases in the head and neck region can lead to blindness or even paralysis.

Rather than treating the tumor with a single, large uniform beam, IMRT uses many pencil-thin beams of varied intensity. This feature allows the PEACOCK System to deliver more radiation to the tumor than conventional radiation therapy systems. By cross firing at the tumor with these beams, a relatively uniform, lethal radiation dose is conformed and delivered to the tumor while protecting surrounding sensitive normal tissue.

The other significant difference between conventional therapy and IMRT is the new technique's powerful and advanced computer program that plans a precise dose of radiation based on the tumor size, shape and location. With the PEACOCK System, physicians determine the desired result such as an optimal dose to the tumor with minimum exposure to the normal structures, then PEACOCK's sophisticated computerized modeling system selects the best way to achieve that result. Once the computerized information is generated and transferred into the PEACOCK's treatment control computer, the radiation is delivered automatically through a sophisticated micro-multileaf collimator system.

In addition, the PEACOCK System can concurrently treat multiple tumor targets of all sizes, each with a different dose prescription.

Each patient treatment takes approximately 30 to 45 minutes and an entire course of treatment ranges up to 40 days, depending upon the tumor and the amount of radiation required. The treatment is comparable in price to the conventional strategy.

The UI Hospitals and Clinics bought the PEACOCK System a couple of months ago. So far, four patients have been or are being treated with this new technology.

"All patients are tolerating the treatment very well with good initial response," Zhen said.

Right now, the UI Hospitals and Clinics radiation oncologists are using the PEACOCK System to treat cancer in the head and neck areas. Eventually, UI radiation oncologists will use the system to treat cancer in other areas as well. The PEACOCK System can be used for tumors in the brain, prostate, lung, esophagus, kidney and liver.

University of Iowa Health Care describes the partnership between the UI College of Medicine and the UI Hospitals and Clinics and the patient care, medical education and research programs and services they provide.