High resolution scintimammography helps in differentiating benign from malignant findings in scintigraphic hot spots

Several efforts have been focusing on the development of detectors devoted to high resolution 99mTc sestamibi scintimammography to improve sensitivity for non palpable lesions. To this aim new high resolution scintillation gamma camera was developed under the "Integrated Mammographic Imaging" project. The gamma camera, made by CAEN and Pol.Hi.Tech, has an overall dimension of 112x120x75mm3. It consists of an array of 1 in. PSPMTs Hamamatsu H8520-C12 closely packed, a Nal(Tl) scintillation array (1.8x1.8x6mm3 pixel) and a general purpose collimator. By this gamma camera a clinical experience on a few patients with breast cancer suspicion was performed. In this paper we show how high resolution approach allows to better categorize the lesions on the basis of the morphology of the spatial distribution of the radiotracer in the breast tissue. By comparing conventional and high resolution images of a young patient (29 y.o.) with breast cancer suspicion, it appears clear how the Anger camera images showed a defined hot spot, highly suggestive of malignant lesion; on the contrary, the high resolution scan shown a large and inhomogeneous uptake area with the absence of clear and focal character of the uptake, to be considered as a probably non malignant lesion. This result was confirmed by byoptical findings that diagnosed the echographic findings as a benign inflammatory lesion.