ARLINGTON, Va., Dec. 1, 2004 – A new imaging and modeling system for more personalized radiation therapy could mean safer and more effective cancer treatments for patients.

The new system is up to 95 percent effective in controlling tumor growth, regardless of the type of radiation treatment, aiding doctors in translating medical images into patient therapies. It can compensate for how tumors change and shift between the time of diagnosis and subsequent treatment, between successive treatments, and during treatment, even as patients breathe.

The advanced computer modeling system created and tested by researchers at the Georgia Institute of Technology and Memorial Sloan-Kettering Cancer Center uses information about the location and density of cancer cells to deliver precise escalated doses of radiation to the tumor.

"The benefit to the patient would be in improved local tumor control," said biomedical engineer Eva K. Lee, Ph.D., the project leader and an associate professor in the School of Industrial and Systems Engineering at the Georgia Institute of Technology and the Winship Cancer Institute at Emory University School of Medicine. "That means the rate of recurrence should be lower and there will be fewer complications affecting the normal tissue. Patients should also experience fewer side effects from the treatment."

Although the research originally focused on treating prostate cancer, the system could be refined to include treatments for other types of cancer, especially those involving delicate tissues, said Lee, who is collaborating with clinical researchers for possible lung cancer treatments.

An automated treatment planning system for prostate brachytherapy that Lee developed with collaborator Marco Zaider, a professor at Cornell University Medical College and the head of Brachytherapy Physics at Memorial Sloan-Kettering Cancer Center, improved local tumor control from 65 percent to 95 percent in human trials. She presented findings on this work last month at the annual meeting of the American Society for Therapeutic Radiology and Oncology (ASTRO) in Atlanta.

Increasingly sophisticated imaging technologies and radiation treatment options have put physicians in a difficult spot: translating the diagnostic information into the optimum treatment for the patient. Functional imaging, for example, can show how the cancer cells actually proliferate within an organ.

“For that technology to really be useful,” said Lee, “we have to be able to translate it into the clinical setting. But until now, these biological factors couldn't usually be used in treatment because the imaging modalities are so different. This new system allows us to use the diagnostic imaging information in a practical sense. It allows us to put everything together."

The new system translates the spatial information about tumor concentrations from the magnetic resonance imaging system to the treatment planning system, morphing that information onto the ultrasound/CT images typically used by planning and delivery systems. The spatial information can be translated even when the organ has changed shape due to treatment preparation.

The ability to adapt radiation treatment to changes in organs is particularly important in lung cancer. Though patients can be asked to briefly hold their breath, the effectiveness of treatment can be adversely affected by the motion of tumors as patients breathe during treatment.

The system Lee is developing can account for those spatial changes over time, tailoring radiation to provide effective dosages to cancer cells even when the tumors are moving.

This work was supported by The Whitaker Foundation through a research grant to Lee in 2000.

Contact:
Eva Lee, Georgia Tech
Mark Bowman, The Whitaker Foundation