1. Department of Radiation Oncology, Puget Sound Health Care System, Seattle, Washington
2. Department of Veterans Affairs, Department of Radiation Oncology, University of Washington, Seattle, Washington
3. Group Health Cooperative, Seattle, Washington
4. Schiffler Cancer Center and Wheeling Jesuit University, Wheeling, West Virginia
5. Department of Pathology, Puget Sound Health Care System, Seattle, Washington
6. Department of Veterans Affairs, Department of Pathology, University of Washington, Seattle, Washington