Vanderbilt University Medical Center has partnered with three other not-for-profit hospitals across Middle Tennessee in a still-evolving project the hospitals say will boost medical services in suburban markets. Affiliation agreements with Williamson Medical Center in Franklin, Maury Regional Medical Center in Columbia, TN, and NorthCrest Medical Center in Springfield could lead to a joint approach in areas such as cancer treatment, cardiovascular services, high-risk pregnancies, diagnostic imaging and perhaps medical office development. Specific services could vary by location and are still being discussed, officials said. "It will let us be partners instead of competitors," said Dennis E. Miller, CEO of the 185-bed Williamson Medical Center.