Using Tc-99m MIBI scintimammography to differentiate nodular lesions in breast and detect axillary lymph node metastases from breast cancer

To test the clinical value of using Tc-99m MIBI scintimammography (Tc-99m MIBI SMM) to differentiate nodular lesions in breasts and detect axillary lymph node metastases of breast cancer Methods The subjects consisted of sixty female patients exhibiting unilateral palpable breast mass The early and delay static acquisitions were undertaken in all subjects at 10 and 90 min after injection with Tc-99m MIBI The acquisition included three positions: anterior supine, left lateral prone and right lateral prone A special device for SMM which was developed by our laboratory was used The ratio of [(T-B)/(NT-B)] was calculated as radioactivity of mass to that of opposite corresponding tissue, and [(T-B)/(NT-B)]≥1 21 was used as the cut-off for semi-quantitative discrimination of malignancy from benignity in semi-quantitative analysis The final diagnosis was obtained from histology examination in all subjects Results Using Tc-99m MIBI SMM to differentiate between nodular lesions in breasts, the diagnostic sensitivity and specificity were 92 9% and 90 6% respectively, the positive predictive value 89 7%, the negative predictive value 93 5%, and the accuracy 91 7% The sensitivity, specificity, positive predictive value, negative predictive value and accuracy obtained with Tc-99m MIBI SMM for detecting axillary lymph node metastases were 83 3%, 86 1%, 80%, 88 6% and 85% respectively Conclusions It is suggested that Tc-99m MIBI SMM may be not only valuable in differentiating malignant lesions from benign nodular masses of breast, but also helpful in detecting axillary lymph node metastases of breast cancer

^(99m)Tc-MIBI and ^(99m)Tc-MDP scintimammography for detecting breast carcinoma

To assess the value of scintimammography with both 99m TC-MIBI and 99m Tc-MDP in detecting breast cancer. Methods A total of 35 women with clinical findings of suspicious breast lesions were studied with both 99m Tc MIBI and 99m Tc-MDP scintimammography. All patients underwent surgery within one week and the finaldiagnostic results (histopathological) were obtained. Results Eighteen of 35 abnormalities of breast were pathologically confirmed as breast cancer and 17 as benign lesions. In this group of patients studied, the sensitivity, specificity and accuracy of 99m Tc-MIBI scintimammography were 77. 8%, 88.2% and 82.9%, respectively and those of 99m TC-MDP scintimammography were 72.2%, 88.2% and 80.0%, respectively. There was no significant difference between 99m TC-MIBI and 99m Tc-MDP scintimammography.Conclusion This study showed the high diagnostic accuracy of both 99m TC-MIBI and 99m TC-MDP scintimammography in detecting breast cancer. Both can be used as non-invasively assess breast cancer invasiveness before surgery.

Monte Carlo assessment of coded aperture tool for breast imaging: a Mura-mask case study

The main purpose of this work was to perform a rigorous computational study on scintimammography with a Mura-mask based on Monte Carlo simulation of voxelized breast phantoms. Three main objectives were addressed:(1) verification of Geant4 version 10.4,(2)optimization of the imaging setup, and(3) small tumor detection and localization. We successfully verified the Geant4-based imaging of a commonly used phantom in the field. We used a Mura-mask with a 41× 41 array pattern with adjustable thickness, material, and hole shape(box and cylinder);a low-energy high-resolution collimator with different hole shapes(cylinder and hexagon);and a voxelized breast phantom with different sizes(small, medium,and large) and glandularity percentages(low, medium, and high). We also compared the detector crystal outputs of CdZnTe and NaI(Tl). The simulation was followed by a deconvolution procedure, and the data(images) were statistically emphasized. Statistical metrics indicate that the Mura-mask(W material with 1.5 mm thickness and box holes) combined with a CdZnTe detector leads to the optimum point spread function. Finally, a preliminary study on small-sized tumor detection and localization was conducted with different tumor-to-background ratios(from2 to 12). Tumors with diameters of 5 and 8 mm could be detected, while those of 2 mm were undetectable. Nevertheless, this study enhances our understanding of the early detection of tumors in the field of scintimammography.