A full Monte Carlo simulation of the YAP-PEM prototype for breast tumor detection

A prototype for Positron Emission Mammography, the YAP-PEM, is under development within a collaboration of the Italian Universities of Pisa, Ferrara, and Bologna. The aim is to detect breast lesions, with dimensions of 5mm in diameter, and with a specific activity ratio of 10:1 between the cancer and breast tissue. The YAP-PEM is composed of two stationary detection heads of 6 6 cm, composed of a matrix of 30 30 YAP:Ce finger crystals of 2 2 30mm each. The EGSnrc Monte Carlo code has been used to simulate several characteristics of the prototype. A fast EM algorithm has been adapted to reconstruct all of the collected lines of flight, also at large incidence angles, by achieving 3D positioning capability of the lesion in the FOV. The role of the breast compression has been studied. The performed study shows that a 5mm diameter tumor of 37 kBq/cm (1 mCi/cm), embedded in active breast tissue with 10:1 tumor/ background specific activity ratio, is detected in 10min with a Signal-to-Noise Ratio of 8.771.0. Two hot lesions in the active breast phantom are clearly visible in the reconstructed image. r 2004 Elsevier B.V. All rights reserved. PACS: 87.53.Wz; 87.57.Ce; 87.57.Gg; 87.58.Fg; 87.59.Ek