U.K. HOSPITAL TREATS CANCER PATIENTS WITH SMARTBEAM IMRT.

Ipswich Hospital NHS Trust, Ipswich, U.K., has commenced treating cancer patients with a new radiotherapy technique called SmartBeam(TM) IMRT (Intensity Modulated Radiotherapy), a technique that allows more precise targeting of tumors with much less damage to nearby healthy tissues. Clinicians at Ipswich used SmartBeam IMRT for the first time to treat a patient with a lung tumor that was very close to her spinal cord.

"This is a technically challenging site to treat with any technique, because of the close proximity of the spinal cord," said Andrew Poynter, head of the Radiotherapy Physics Department at Ipswich Hospital. "The clinical advantages of IMRT for this particular patient were significant."

"IMRT allows us to more effectively avoid critical structures, and, hopefully in the near future, to safely escalate the dose to improve local tumor control," said Dr. Jamey Morgan, clinical oncologist at Ipswich Hospital. Enhancing the dose concentrations to the tumor gives clinicians a much greater chance of completely eradicating a tumor. In addition, increased precision enables clinicians to use radiation to treat areas that would have been considered too risky to treat.

IMRT treatments are delivered using a sophisticated computer-controlled medical linear accelerator that is outfitted with a beam-shaping accessory called a multi-leaf collimator. The linear accelerator generates the high-energy X-rays used to treat cancer. Ipswich Hospital's multi-leaf collimator has 120 computer-controlled mechanical "leaves" or "fingers" that control the shape, size, and timing of the beam to deliver an exact dose directly to the tumor.

Doctors at Ipswich have now also treated a patient with a thyroid tumor in her neck. They compared a conventional radiation treatment plan with a plan for IMRT and found that the conventional treatment plan would have delivered too much radiation to a large length of the patient's spinal cord. This could have injured the cord and even caused paralysis from the neck downward.

"That is not a side effect you'd want to have, and it would be irreversible," said Poynter. "With IMRT we were able to give ourselves a big margin of safety, and keep the cord dose below known tolerances. From our point of view, this was a safer treatment than conventional."

The new IMRT technique has contributed to substantially improved clinical outcomes, according to studies in the Journal of Radiotherapy and Oncology and the International Journal of Radiotherapy and Oncology. Published prostate cancer studies conducted at Memorial Sloan-Kettering Cancer Center in New York showed that, when compared with other forms of radiation therapy, IMRT more than doubled the rate of tumor control, from 43% to 96%. At the same time, the rate of normal tissue complications decreased from 10 percent to 2 percent.

"There are clearly going to be certain cases where you can only offer a radical treatment if you have IMRT," said Dr. Morgan. "We plan to use IMRT in selected paraspinal, head and neck, breast and prostate cancer cases. We're also thinking about retroperitoneal and pancreatic tumors," he added.

Ipswich Hospital is one of the first hospitals in the UK to offer IMRT on a clinical basis. According to Mr. Poynter, it took about five and a half months, from the time IMRT equipment arrived at Ipswich to the first IMRT treatment on June 18, 2001. "Institutions like Memorial Sloan-Kettering and Emory University in the U.S. and the Royal Marsden Hospital here in the UK have done the founding work in this field, and we are lucky to be able to stand on their shoulders. In my opinion, IMRT is now a mature product, at the point where a department like ours, in a non-academic, non-teaching hospital, can pick it up and use it."

The Ipswich Hospital is one of the largest general hospitals in East Anglia and provides acute healthcare services to a population of over 310,000 people. The hospital occupies a 46 acre site on the outskirts of the town and has approximately 800 beds in wards built on the nucleus design. The Radiotherapy facility is accredited to ISO 9002 Quality standards and the centre has been recently been picked as one of only two UK Varian reference sites for the use of IMRT (Intensity Modulated Radiotherapy). For more information, visit http://www.ipswichhospital.org.uk/.

Varian Medical Systems, Inc., (NYSE:VAR) of Palo Alto, Calif., is the world's leading manufacturer of integrated cancer therapy systems as well as X-ray tubes and flat-panel sensors for imaging in medical, scientific, and industrial applications. Varian Medical Systems employs approximately 2,400 people and reported sales of $690 million in its most recent fiscal year ended September 29, 2000.

For more information, visit http://www.varian.com or call 650/424-5782.