Preliminary clinical study of 99Tcm-HL91 imaging in bone metastasis

Objective: 99Tcm-4, 9-diaza-3, 3, 10, 10-tetramethyldodecan-2, 11-dione dioxime (HL91), a new type of hypoxic agents, accumulates in tumor hypoxic tissue specifically. The aim of this study was to evaluate the value of 99Tcm-HL91 imaging in the diagnosis of bone metastasis. Methods: Nine- teen cases with bone metastasis (without any treatment) and 8 cases with benign lesions underwent SPECT imaging at 4 h after injection of 740 MBq of 99Tcm-HL91 along with 99Tcm-methylene diphosphonic acid (MDP) imaging. Regions of interest (ROIs) were drawn in tumor tissue and contralateral normal tissue respectively, and the radioactivity ratios of tumor-to-normal (T/N) were calculated. The t-test was used for data analysis with SPSS 11.0. Results: There were visible uptake of 99Tcm-HL91 in 79 out of 85 focuses in 19 patients of bone metastasis; however, there was no obvious uptake of 99Tcm-HL91 in 12 focuses of 8 patients of benign lesions. Significant difference existed between the T/N values of malignant (1.877 ± 0.288) and benign lesions [(0.735 ± 0.236); t=13.065, P<0.05]. However, the T/N value of bone metastasis from lung cancer did not differ with that from prostate cancer (1.915 ± 0.344 and 1.825 ± 0.175, respectively; t=1.378, P>0.05). Conclusion: The results indicated that 99Tcm-HL91 was useful in diagnosing the malignant and benign bone lesions. (authors)