Clinical evaluation of pixellated NaI : Tl and continuous LaBr3 : Ce, compact scintillation cameras for breast tumors imaging

摘要

The principal limiting factor in the clinical acceptance of scintimammography is certainly its low sensitivity for cancers sized < 1 cm, mainly due to the lack of equipment specifically designed for breast imaging. The National Institute of Nuclear Physics (INFN) has been developing a new scintillation camera based on Lanthanum tri-Bromide Cerium-doped crystal (LaBr3:Ce), that demonstrating superior imaging performances with respect to the dedicated scintillation gamma-camera that was previously developed. The proposed detector consists of continuous LaBr3:Ce scintillator crystal coupled to a Hamamatsu H8500 Flat Panel PMT. One centimeter thick crystal has been chosen to increase crystal detection efficiency. In this paper, we propose a comparison and evaluation between lanthanum gamma-camera and a Multi PSPMT camera, NaI(T1) discrete pixel based, previously developed under "IMI" Italian project for technological transfer of INFN. A phantom study has been developed to test both the cameras before introducing them in clinical trials. High resolution scans produced by LaBr3:Ce camera showed higher tumor contrast with a detailed imaging of uptake area than pixellated NaI(T1) dedicated camera. Furthermore, with the lanthanum camera, the Signal-to-Noise Ratio (SNR) value was increased for a lesion as small as 5 mm, with a consequent strong improvement in delectability. (c) 2006 Elsevier B.V. All rights reserved.