Application of ⁹⁹Tc^m-HL91 hypoxia tissue imaging and ⁹⁹Tc^m-MIBI imaging in diagnosis of breast tumors

Objective: To evaluate the application of ⁹⁹Tc^m-4, 9-diaza-3, 3, 10, 10-tetramethyldodecan 2, 11-dione dioxime (⁹⁹Tc^m-HL91) hypoxia tissue imaging and ⁹⁹Tc^m-methoxyisobutylisontrile (⁹⁹Tc^m-MIBI) imaging in diagnosis of breast tumors. Methods: Fifty-two patients (55 lesions) with clinically diagnosed breast tumors underwent surgical treatment; all lesions were confirmed by histopathological examination. ⁹⁹Tc^m -HL91 imaging was performed before surgery in all patients, and ⁹⁹Tc^m-MIBI imaging was performed in 34 patients with 37 lesions. Visual and semiquantitative analysis was applied for breast imaging. Results: With pathological results as gold standard, the sensitivity, specificity and accuracy of ⁹⁹Tc^m-HL91 imaging by visual analysis were 94.4%, 78.9% and 89.1%, respectively, and those of ⁹⁹Tc^m-MIBI were 88.0%, 75.0% and 83.8% respectively. There were no statistical differences in sensitivity and specificity between two methods. Semiquantitative analysis showed that the T/N ratios of ⁹⁹Tc^m -HL91 at 1, 3 and 6 h planar for malignant group (36 lesions) were 1.36±0.34, 1.49±0.38 and 1.57±0.38, respectively, which were significantly higher than those for benign group (19 lesions). The T/N ratios of ⁹⁹Tc^m-MIBI at 5 min, 1 h and 3 h planar were 1.33±0.35, 1.29±0.22 and 1.18±0.15 respectively in malignant group, which were significantly higher than those in benign group. Conclusion: ⁹⁹Tc^m-HL91 imaging shows high sensitivity, specificity and accuracy in differential diagnosis of breast cancer from benign breast tumors.