THE ROLE OF COMPTON BACKGROUND AND BREAST COMPRESSION ON CANCER-DETECTION IN SCINTIMAMMOGRAPHY

(TC)-T-99m MIBI scintimammography is a promising diagnostic technique for cancer detection. Using a dedicated Small Field Of View Gamma Came ra (SFOVGC) with the high spatial resolution recently developed it is possible to improve the sensitivity and to achieve images in projectio ns similar to mammography with the breast under moderate compression. This new technique is called Single Photon Emission Mammography (SPEM) . Several factors affect the imaging of small cancers: breast thicknes s, tumor-collimator distance, and body activity. A phantom study was p erformed to assess the role of breast compression in scintimammography . In this work we analyze the intensity and the energy distribution of Compton scattering affecting the breast scintigraphy, by a Germanium defector and by SFOVCG. Five patients with 7 to 18 mm sized cancer wer e studied The intensity of Compton scattering resulted from 4 to 10 ti mes greater than true events. The fundamental role played by breast co mpression to improve the scintimammographic sensitivity is discussed.