Role of 99mTc-Sestamibi scintimammography by SPEM camera in the management of breast cancer in the elderly

The incidence of breast cancer in the elderly is 10 fold higher than in the population younger than 65 years. Moreover, in this segment of the population there are not defined clear practice guidelines regarding patient management. X-ray mammography, the most widely used diagnostic technique, is often inadequate to differentiate benign from malignant lesions. 99mTc Sestamibi scintimammography plays an important role as complement to mammography; in fact it is a very sensitive and specific method for breast cancer detection, when cancers > 1 cm diameter are considered. However, sensitivity values fall to 50-60% in the case of small tumors (T(1a) and T(1b)). In this study we present the results of a new Small Field Of View (SFOV) Gamma Camera with very high spatial resolution that allows the first Single Photon Emission Mammography (SPEM). Eighteen patients aged 71 ± 6 years with mammographically detected breast lesions were submitted to a Prone Scinti Mammography (PSM) by conventional Gamma Camera and to a SPEM on craniocaudal view. A final diagnosis was reached by histopathology. SPEM correctly diagnosed 15 of 16 cancers, while PSM was not able to recognize 5 malignant lesions with subcentimeter size. Both the techniques provided normal findings in the case of benign lesions. The 99mTc Sestamibi scintimammography, particularly when performed by SPEM camera, is a sensitive, specific, and non invasive method to define the nature of radiologically described breast masses and would be very useful as a complement to X-ray mammography in screening programs for breast cancer.