99mTc MIBI scintimammography is a sensitive and specific diagnostic technique for breast cancer detection when cancers more than 1 cm sized are considered. However the sensitivity falls in the case of submillimetric lesions. We developed a new Small Field of View, High Resolution Detector, able to image the breast in similar conditions of x-ray mammography: it allows the performance of Single Photon Emission Mammography (SPEM) studies. Seven patients with suspicion of malignant lesions were comparatively submitted to a Prone Scintimammography (PSM) by Anger camera and to a cranio-caudal view SPEM. The final diagnosis was reached by histopathology. Four malignant lesions were identified by SPEM but not by PSM, which that failed to image two submillimetric cancers. Both the cameras gave normal findings for benign lesions, confirming the high sensitivity of this technique. The results allow us to consider the SPEM camera as promising to improve scintimammographic sensitivity, even when small-sized tumors are examined.

Breast Diseases↗

PubMedDate not supplied

The role of Compton background and breast compression on cancer detection in scintimammography.

99mTc MIBI scintimammography is a promising diagnostic technique for cancer detection. Using a dedicated Small Field Of View Gamma Camera (SFOVGC) with the high spatial resolution recently developed, it is possible to improve the sensitivity and to achieve images in projections 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 thickness, tumor-collimator distance and body activity. A phantom study was performed 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 detector and by SFOVCG. Five patients with 7 to 18 mm sized cancer were studied. The intensity of Compton scattering resulted from 4 to 10 times greater than true events. The fundamental role played by breast compression to improve the scintimammographic sensitivity is discussed.

Breast↗

PubMedDate not supplied

Single tube gamma camera for scintimammography.

The development of large area Position Sensitive Photo Multiplier Tubes (PSPMT) by Hamamatsu is opening new imaging possibilities in Nuclear Medicine. In particular the realization of the 8" PSPMT prototype represents the first important technological advantage since the discovery of the Anger Camera. PSPMT virtually integrates in one hundreds PMT allowing the creation of dedicated detectors. A Single Tube Gamma Camera based on a 5" PSPMT dedicated to scintimammography is presented and discussed in this work. To optimize gamma camera response two different scintillating arrays were tested: YAP:Ce and CsI (Tl). Their overall size cover all photocathode active area, and crystal pixel size was 2 mm x 2 mm. The detection efficiency was comparable to that of Anger Camera. The best result was obtained by CsI (Tl) scintillating: an intrinsic spatial resolution of 1.6 mm FWHM and a relative energy resolution of 17% FWHM. New image possibilities in scintimammography are offered by Single Tube Gamma Camera operating in the same radiological projection of RX mammography.

Breast Neoplasms↗