Currently, screen-film mammography is the only technique for detecting breast cancer that has been proven to reduce the mortality of the disease. However, this screening method has its limitations, which include low sensitivity and positive predictive value. The development of a new method for detecting breast cancer would significantly reduce the number of false positives, and could be used in tandem with screen-film mammography to detect tumors.
In a joint effort with Hologic, Inc—the commercial leader in the development of breast tomosynthesis (BTS) technology—and the University of Massachusetts Medical School, Dartmouth’s Optics in Medicine Laboratory is combining the structural parameters of Near Infrared spectral tomography (NIRST) with the high-resolution 3D structural information of BTS into a singular breast-cancer detection method. Approved by the U.S. Food and Drug Administration (FDA) in 2011, tomosythesis works much like 2D mammography imaging except the data gathered during the examination is assembled into a detailed, 3D model after the X-ray generator finishes rotating around the patient. Once this imaging system is approved for clinical use, the Optics in Medicine Laboratory hopes that its superior receiver operating characteristics (ROC) and improved positive predictive values (PPVs) will significantly improve breast-cancer diagnostics.
The first prototype of this machine was modeled and built by MD/PhD student Kelly Michaelsen and Professor Venkataramanan Krishnaswamy, and was tested in the Dartmouth Hitchcock Medical Center (DHMC). After all of the machine’s components were designed, the system was calibrated on a series of tissue phantoms before the start of pre-clinical trials. Currently, a second-generation prototype featuring improved detector geometry and an increased dynamic range is being constructed by Professor Krishnaswamy. Once finished, this machine will be tested at DHMC and the first-generation prototype will be relocated to the University of Massachusetts (UMass) Memorial Medical Center to allow the institution’s researchers to conduct additional pre-clinical trials.
The research being conducted at all of the institutions involved in this project has been made possible by a funding opportunity provided by NIH and NCI that seeks to develop new in vivo imaging systems. The partnership between Dartmouth, the University of Massachusetts, and Hologic, Inc aims to integrate the two systems into a singular detection method, and also to establish the clinical potential of this combined imaging approach.