TomoTherapy Incorporated Unveils CTrue(TM) Imaging Technology at ASTRO.

Company Demonstrates Unique Clinical Benefits Everyday Imaging Brings to Radiation Therapy

MADISON, Wis. -- In less than a decade since the company was founded, TomoTherapy Inc. has established itself as the leading innovator among radiation therapy solutions providers. To date, nearly 250,000 patient treatment fractions have been delivered worldwide on the company's advanced radiation therapy platform, the TomoTherapy([R]) Hi-Art System([R]). At ASTRO's 48th Annual Meeting in early November, TomoTherapy Inc. showcased its CTrue([TM]) imaging technology, which makes everyday image guidance a reality for the delivery of IMRT.

CTrue takes its name from the integrated true CT imaging that the TomoTherapy Hi-Art System was designed to facilitate. True CT imaging can be used with every patient, every day, for a range of purposes that combine to bring greater accuracy to the delivery of radiation therapy.

With every treatment fraction, clinicians can accurately calculate dose on any of the daily CTrue images, thereby evaluating the progress of treatment. If there is a need to adjust the treatment based on daily evaluation, it can easily be performed with the System's Planned Adaptive software. This is due to the fact that daily fan beam CTs have the same consistent CT numbers as any diagnostic CT scanner, and are just as suitable for highly accurate dose calculation.

In addition, with a multileaf collimator (MLC) designed specifically for IMRT, the dose delivered from imaging on a Hi-Art System (0.3 - 2.8 cGy) is less than the leakage/scatter dose from most IMRT systems during a normal IMRT treatment. Additionally, the images are free of high-Z and scatter artifacts.

"CTrue technology proves that image guidance is about more than just accuracy in daily set-up," says Dr. Thomas "Rock" Mackie, TomoTherapy Inc. co-founder. "The key is what a clinician is able to do with the images acquired during the course of treatment."

Mackie continues, "If you don't have CTrue technology, you cannot use images to quantitatively assess the progress of treatment and, when necessary, to provide adaptation during the course of radiotherapy. And adaptive radiotherapy is all about maintaining accuracy and precision through the whole course of treatment."

Beyond the accuracy afforded by CTrue imaging, the Hi-Art System leverages its ring gantry design for the highly-precise delivery of helical IMRT. Together, the System's distinctive attributes are literally reshaping radiation therapy.

About TomoTherapy Incorporated

Based in Madison, Wisconsin, TomoTherapy Incorporated has developed a revolutionary new medical system that integrates CTrue([TM]) imaging and the helical delivery of conformal radiation therapy to provide unprecedented accuracy and precision in the treatment of cancer patients. The TomoTherapy([R]) Hi-Art System([R]) is designed to target radiation treatment to the patient's tumor while helping to limit damage to the surrounding tissues. The technology was developed in collaboration with the University of Wisconsin. To find out more, please visit our website at www.tomotherapy.com.