The comparison of dual phase Tc-99m MIBI and tc-99m MDP scintimammography in the evaluation of breast masses: preliminary report

99mTC-sestamibi breast imaging: Current status, new ideas and future perspectives

Here we proposed the most recent innovations in the use of Breast Specific Gamma Imaging with ⁹⁹mTc-sestamibi for the management of breast cancer patients. To this end, we reported the recent discoveries concerning: a) the implementation of both instrumental devices and software, b) the biological mechanisms involved in the ⁹⁹mTc-sestamibi uptake in breast cancer cells, c) the evaluation of Breast Specific Gamma Imaging with ⁹⁹mTc-sestamibi as predictive markers of metastatic diseases. In this last case, we also reported preliminary data about the capability of Breast Specific Gamma Imaging with ⁹⁹mTc-sestamibi to identify breast cancer lesions with high propensity to form bone metastatic lesions due to the presence of Breast Osteoblast-Like Cells.

Comparison of Tc-99m maraciclatide and Tc-99m sestamibi molecular breast imaging in patients with suspected breast cancer

Background

Molecular breast imaging (MBI) performed with ^99mTc sestamibi has been shown to be a valuable technique for the detection of breast cancer. Alternative radiotracers such as ^99mTc maraciclatide may offer improved uptake in breast lesions. The purpose of this study was to compare relative performance of ^99mTc sestamibi and ^99mTc maraciclatide in patients with suspected breast cancer, using a high-resolution dedicated gamma camera for MBI. Women with breast lesions suspicious for malignancy were recruited to undergo two MBI examinations—one with ^99mTc sestamibi and one with ^99mTc maraciclatide. A radiologist interpreted MBI studies in a randomized, blinded fashion to assign an assessment score (1–5) and measured lesion size. Lesion-to-background (L/B) ratio was measured with region-of-interest analysis.

Results

Among 39 analyzable patients, 21 malignant tumors were identified in 21 patients. Eighteen of 21 tumors (86%) were seen on ^99mTc sestamibi MBI and 19 of 21 (90%) were seen on ^99mTc maraciclatide MBI (p = 1). Tumor extent measured with both radiopharmaceuticals correlated strongly with pathologic size (^99mTc sestamibi, r = 0.84; ^99mTc maraciclatide, r = 0.81). The L/B ratio in detected breast cancers was similar for the two radiopharmaceuticals: 1.55 ± 0.36 (mean ± S.D.) for ^99mTc sestamibi and 1.62 ± 0.37 (mean ± S.D.) for ^99mTc maraciclatide (p = 0.53). No correlation was found between the L/B ratio and molecular subtype for ^99mTc sestamibi (r_s = 0.12, p = 0.63) or ^99mTc maraciclatide (r_s = −0.12, p = 0.64). Of 20 benign lesions, 10 (50%) were seen on ^99mTc sestamibi and 9 of 20 (45%) were seen on ^99mTc maraciclatide images (p = 0.1). The average L/B ratio for benign lesions was 1.34 ±0.40 (mean ±S.D.) for ^99mTc sestamibi and 1.41 ±0.52 (mean ±S.D.) for ^99mTc maraciclatide (p = 0.75). Overall diagnostic performance was similar for both radiopharmaceuticals. AUC from ROC analysis was 0.83 for ^99mTc sestamibi and 0.87 for ^99mTc maraciclatide (p = 0.64).

Conclusions

^99mTc maraciclatide offered comparable lesion uptake to ^99mTc sestamibi, in both malignant and benign lesions. There was good correlation between lesion extent and uptake measured from both radiopharmaceuticals. ^99mTc maraciclatide offered a marginal (but not significant) improvement in sensitivity over ^99mTc sestamibi. Our findings did not support an association between the uptake of either radiopharmaceutical and tumor molecular subtype.

Trial registration

ClinicalTrials.gov, NCT00888589

Visual and semi-quantitative analyses of dual-phase breast-specific gamma imaging with Tc-99m-sestamibi in detecting primary breast cancer

OBJECTIVES

Breast cancer is the most common malignancy for females worldwide. This study was to evaluate the application of dual-phase breast-specific gamma imaging (BSGI) in detecting primary breast cancer.

METHODS

Seventy-six patients with indeterminate breast lesions that underwent dual-phase BSGI enrolled in this study. All included lesions were confirmed by pathology. BSGI was evaluated based on the visual interpretation and dual-phase semi-quantitative indices of lesion to non-lesion ratio (L/N), which were compared with pathological results. The optimal visual analysis and L/N for double-phase were calculated through receiver operating characteristic curve analysis.

RESULTS

Among 76 patients, 92 lesions were finally confirmed by the surgery and pathology, with 54 malignant and 38 benign lesions. Both early and delayed L/N of malignant breast diseases were significantly higher than those of benign (3.18±1.57 vs 1.53±0.59, and 2.91±1.91 vs 1.46±0.54, P<0.05). The optimal visual interpretation is over grade 3, and cut-off L/N was 2.06 and 1.77 for early and delayed imaging, respectively. Compared with visual analysis over grade 3 (77.8 and 81.6%), optimal early L/N (81.5 and 92.1%) or delayed L/N (79.5 and 89.5%) alone, the sensitivity and specificity of visual combined with early-phase L/N in diagnosing primary breast cancer are higher, which were 85.2 and 92.2%, respectively.

CONCLUSIONS

The combination of visual and semi-quantitative analysis could improve the sensitivity and specificity of BSGI in detecting primary breast cancer. In addition, the potential value of delayed BSGI in diagnosing primary breast cancer should be further investigated in large samples.

Tc-99m sestamibi scintimammography for the diagnosis of breast cancer: meta-analysis and meta-regression

Tc-99m sestamibi (MIBI) is a relatively noninvasive diagnostic modality in the evaluation of breast cancer. The purpose of this study was to review the existing literature on the accuracy of Tc-99m MIBI in the diagnosis of breast cancer. After a systematic review of English-language studies, the sensitivity, specificity, and other measures of accuracy of Tc-99m MIBI in the diagnosis of breast cancer were pooled using random-effects models. Summary receiver operating characteristic curves were used to summarize the overall test performance. Forty-five studies met our inclusion criteria. The summary estimates for Tc-99m MIBI in the diagnosis of breast cancer in the studies included were as follows: sensitivity, 0.83 [95% confidence interval (CI), 0.82-0.84]; specificity, 0.85 (95% CI, 0.83-0.86); positive likelihood ratio, 5.06 (95% CI, 4.26-6.01); negative likelihood ratio, 0.20 (95% CI, 0.17-0.24); and diagnostic odds ratio, 27.63 (95% CI, 21.63-36.10). For patients with a palpable mass, the sensitivity and specificity were 87 and 86%, respectively. For patients without a palpable mass, the sensitivity and specificity were 59 and 89%, respectively. Tc-99m MIBI has a high level of overall accuracy for the diagnosis of breast cancer.

Diagnostic performances of double-phase Tc-99m MIBI scintimammography in patients with indeterminate ultrasound findings: visual and quantitative analyses

The aim of the study was to compare the diagnostic performances of visual and quantitative analyses of double-phase Tc-99m methoxyisobutylisonitrile (MIBI) scintimammography (SMM) in patients with ultrasonographically indeterminate findings. SMM (early: 10min; delayed: 3h) was performed on 78 patients (malignant 66, benign 12). For visual analysis, the five-scoring method was used. For quantitative analysis, ratios of early and delayed lesions to non-lesion (L/Ns) were calculated. When a visual grade of over 3 was used as the cut-off value for the detection of primary breast cancer, the sensitivity and specificity were 86.4%/ and 100%, respectively. The area under the curve (AUC) was 0.972. The optimal L/N ratios were 1.22 for early and 1.1 for delayed images. When early L/N 1.22 was used as the cut-off point, the sensitivity and specificity of SMM were 92.4% and 91.7'%, respectively. The AUC was 0.952. When delayed L/N 1.1 was used as the cut-off value, the sensitivity and specificity were 78.8% and 91.7%, respectively. The AUC was 0.863. Visual interpretation and early L/N were superior to delayed L/N for the detection of breast cancer. This study suggests the possible diagnostic role of visual and quantitative analyses of double-phase SMM for differentiating malignant breast lesions in patients with ultrasonographi-cally indeterminate findings.

Usefulness of scintimammography as an adjunct to mammography and ultrasound in the diagnosis of breast diseases

This study was undertaken to evaluate the diagnostic efficacy of 99mtechnetium methoxyisobutylisonitrile scintimammography (SM) and combined use of mammography and ultrasound in the detection of the breast lesions in the symptomatic breast. Histopathological findings were the gold standard. Eighty patients with symptomatic breasts underwent mammography and/or ultrasound breast followed by SM. In 25 patients there were 27 lesions that were malignant and 55 patients had 65 lesions that were benign. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of SM were found to be 92, 72, 58, 96 and 78%, respectively, as compared with the combined use of mammography and ultrasound, which showed these parameters to be 89, 94, 86, 95 and 92%, respectively. In this study, SM showed slightly better sensitivity than combined mammography and ultrasound, whereas the specificity was clearly shown as higher in the latter.

Characterization of breast lesion using double phase Tc-99m Tetrofosmin scintimammography: Comparison of visual and quantitative analyses

To compare the diagnostic performances of visual and quantitative indices of double phase Tc-99m Tetrofosmin scintimammography (TF-SMM) for the detection of breast cancer.

METHODS

Double phase TF-SMM (early, 10 min; delayed, 3h) were performed after injection of 925 MBq of Tc-99m Tetrofosmin in 75 highly suspected breast cancer patients (malignant: 49, benign: 26). For visual analysis, five scoring method was used. For quantitative analysis, early, delayed lesions to non-lesion ratios (L/Ns) and washout rate (%, WR) were calculated. Receiver operating characteristic curve (ROC) analyses were performed to determine the optimal visual grade, to calculate cut-off values of quantitative indices, and to compare visual and quantitative diagnostic performances.

RESULTS

When over grade 3 of visual grade was used as cut-off value in the defection of primary breast cancer, the sensitivity and specificity were 75.5 and 80.8%, respectively. The positive and negative predictive values were 88.1 and 63.6%, respectively. The area under curve was 0.824 (95% CI, 0.719-0.902) and standard error (S.E.) was 0.047. The optimal L/N ratios were 3.13 for early and 2.56 for delayed image. When early L/N 3.13 was used as cut-off point, the sensitivity and specificity of TF-SMM were 61.2 and 96.2%, respectively. The positive and negative predictive values were 96.8 and 56.8%, respectively. The AUC was 0.809 (95% CI, 0.702-0.890) and S.E. was 0.049. When delayed L/N 2.56 was used as cut-off value, the sensitivity and specificity were 46.9 and 96.2%, respectively. The positive and negative predictive values were 95.8 and 49%, respectively. The AUC was 0.741 (95% CI, 0.627-0.835) and S.E. was 0.057. No statistical differences between visual assessment and quantitative analysis of early image (difference between area, 0.015; S.E., 0.044; 95% CI, -0.072 to 0.102; p = 0.736) and delayed image (difference between area, 0.083; S.E., 0.054; 95% CI, -0.023 to 0.060; p = 0.189) was noted. However, early L/N was superior to delayed L/N ratio for the detection of breast cancer (difference between area, 0.068; S.E., 0.033; 95% CI, 0.004-0.132; p = 0.038).

CONCLUSION

In conclusion, TF-SMM showed a favorable diagnostic accuracy in differentiating benign from malignant breast lesions. The optimal visual interpretation grades for the detection of primary breast cancer of double phase TF-SMM were grade 4 and 5. The optimal quantitative indices for the detection of breast cancer were 3.12 for early L/N and 2.56 for delayed L/N. Visual and quantitative analyses showed similar results. However, early L/N was superior to delayed one for the detection of breast cancer. Therefore, the delayed image should not be routinely performed for the purpose of primary breast cancer detection. These findings deserve further investigation on a larger number of patients to be performed to allow a better validation of the differentiation malignant from benign breast lesions using double phase TF-SMM.

Incremental Diagnostic Value of Quantitative Analysis of Double Phase Tc-99m MIBI Scintimammography for the Detection of Primary Breast Cancer Additive to Visual Analysis

Tc-99m MIBI scintimammography (SMM) is known to be a useful diagnostic tool for primary breast cancer. We conducted this study to establish optimal visual grades for the detection of primary breast cancer and to investigate whether the quantitative indices of double phase SMM could provide incremental diagnostic value additive to visual analysis.

METHODS

Five hundred and twenty highly suspected breast cancer patients (malignant: 370; benign: 150) were included in this study. Double phase Tc-99m MIBI SMM (early: 10 min; delayed: 3 h) was performed after injection of 750 MBq of Tc-99m MIBI. For visual analysis, five scoring method was used. The early and delayed lesion to non-lesion ratios (L/N) and retention index (RI) were calculated. Receiver operating characteristic curve (ROC) analyses was performed to determine the optimal visual grade, to calculate cut-off value of quantitative indices for differentiation malignant and benign diseases and to investigate whether the quantitative indices could provide incremental diagnostic value additive to visual analysis. To investigate the incremental diagnostic value of quantitative index in variable tumor size groups, the patients were subdivided into four groups (group A: size <or= 1 cm, group B: 1 cm < size <or= 3 cm, group C: 3 cm < size <or= 5 cm, group D: size > 5 cm).

RESULTS

When over visual grade 3 was used as the cut-off grade for the diagnosis of breast cancer, the sensitivity and specificity were 75.5, 86.4%, respectively. Early L/N of malignant breast disease was significantly higher than that of benign (2.00 +/- 1.88 vs. 0.60 +/- 0.7; p < 0.01). However, delayed L/N and RI had no significant difference between malignant and benign breast diseases. When early L/N of 1.27 was used as the cut-off value, the sensitivity and specificity of SMM were 77.6, 83.3%, respectively. When the early L/N was added to visual grade, the area under curve (AUC) of visual + quantitative analysis (V + Q) was higher than that of visual analysis (V) alone (AUC 0.893 vs. 0.803; p < 0.01). In group A, the AUC of V + Q was higher than that of V alone (0.843 vs. 0.808; p = 0.029). In group B, the AUC of V + Q was also higher (0.913 vs. 0.781; p < 0.01). However, in groups C and D, the AUCs of V + Q and V were not different (0.926 vs. 0.915; p = 0.144: 0.663 vs. 0.570; p = 0.093). For axillary lymph node involvement, the sensitivity, specificity, and of SMM were 66.9, 70.1, and 68%, respectively.

CONCLUSION

From this study, the optimal visual interpretation grades for diagnosis of breast cancer were grades 4 and 5 and cut-off value of early L/N was 1.27. Also, we found that delayed image was not required for breast cancer detection and quantitative index of early L/N provide incremental diagnostic value additive to visual analysis. Especially, when the tumor is small (size <or= 3 cm), the early L/N should be obtained for the diagnosis of breast cancer.

Nuclear medicine in primary breast cancer imaging

The application of nuclear medicine techniques to study patients with breast cancer has recently raised its profile, particularly in the investigation 'indeterminate mammographic lesions'. This review briefly points out some of the difficulties encountered with other more conventional imaging modalities and describes the radionuclide techniques most frequently employed in the investigation of those patients with breast cancer. Both planar and single photon emission tomography methods are discussed including the use of monoclonal antibodies, perfusion ligands, receptor binding hormones and other specific radiotracers, non-specific tumour markers, as well as deoxyglucose and other amino acids labelled with positron emitting radionuclides.