Advocates urge uniformity for change analysis tools

Forty researchers, executives, and government officials met during the 2005 RSNA meeting to address a key barrier to using medical imaging as a surrogate measure of therapeutic response: variability.

Ideally, in drug testing, all components are constant except for changes associated with disease therapy response. The Reference Image Database to Evaluate Response (RIDER) project aims to eliminate variability in proprietary commercial and academic software used in change analysis. Those attending the meeting were briefed about the need for community-wide adoption of the RIDER's Web-based system to assure uniformity in evaluating the performance of change analysis software.

The RIDER project will initially focus on CT-based lung cancer screening and diagnosis, according to Laurence P. Clarke, Ph.D., a branch chief in the National Cancer Institute's imaging program. To aid calibration of their software, researchers will have online access to serial images, annotated by expert physicians, demonstrating tumor volume and other changes in response to treatments over time. The objective is uniform measurement among modalities and sites, making comparisons between facilities possible.

"When measuring drug response, you don't want your tools to be the source of uncertainty," Clarke said.

The NCI, the Institute for Biomedical Imaging and Biomedical Engineering, and the Cancer Research and Prevention Foundation are funding the RIDER project. Collaborators include the RSNA, the American College of Radiology, and the National Institute of Standards and Technology.

One of the aims of the RIDER project is to enable industry and academia to develop, test, and compare semiautomated and automated software tools for change analysis. The NCI eventually wants to combine the RIDER with larger image database initiatives such as the Lung Image Database Consortium (LIDC).

Future public meetings, coordinated by the foundation for the National Institutes of Health, will solicit industry interest and include development of a public-private partnership to fund the RIDER Web site. A final version of the calibration tool will be completed in about two years, Clarke said.