Phantom tests with a stereotactic gamma-localization system

Results of the validation of the performance of a gamma-guided localization system using realistic breast phantoms is presented. The system is intended for use in localizing suspected breast cancer lesions not visible with other imaging modalities. The system consists of a pair of slant-hole collimators, a grid localization system and a set of sources that can be seen with the gamma camera. These components are used in three steps: 1) localization of the lesion, 2) correlation of the location with the breast, and 3) verification of the location. Tests with realistic breast phantoms have been conducted to validate the operation of the system in a clinical setting. Phantoms with various lesion sizes and specific activities were used in the validation. A vacuum-assisted core needle biopsy system was used to collect samples from the indicated location, and the fraction of the lesion that was collected by the biopsy system was estimated, in an effort to quantify the operation of the system. The results of these phantom tests will be presented.