Diagnostic Usefulness of Tc-99m Tetrofosmin Scintimammography in Patients with Primary Breast Cancer / 대한핵의학회잡지

PURPOSE: The purpose of this study was to evaluate the diagnostic usefulness of scintimammography performed with Tc-99m tetrofosmin in the detection of primary breast cancer. MATERIALS AND METHODS: Sixty-one patients underwent Tc-99m tetrofosmin scintimammography, plain-filrn mammography and ultrasonography. After intravenous injection of Tc-99m tetrofosmin (740 MBq), prone lateral and anterior scintimammograms were obtained. Scintimammogram was visually interpreted as positive, probably positive, probably negative and negative for malignancy. The tumor to background count ratio (T/B) was measured at 5 minutes and 1 hour. Plain-film mammogram was interprcted as one of 5 categories. Final diagnosis was achieved by surgical histology (58/61) or fine needle aspiration (3/61). Of 61 patients, 44 had cancer and 17 had benign lesion. Tumor size of malignant and benign lesions on ultrasonogram were 2.51+/-1.30 cm (range 1-8 cm), 2.50+/-1.35 cm (range 0.96-6 cm), respectively. RESULTS: The sensitivity of plain-film mammography was 88.6%, specificity 58.8%, positive predictive value 84.7%, and negative predictive value 66.7%. The sensitivity of Tc-99m tetrofosmin scintimammography was 90.9%; specificity, 88.2%; positive predictive value, 94.9%; negative predictive value, 78.9%. Of 25 patients with indeterminate degree of suspicion for malignancy on plain-film mammogram, 23 were correctly diagnosed by scintimamography. The T/B at 5 minutes and 1 hour were 3.78+/-2.21, 3.25+/-1.80 respectively. The T/B was decreased significantly at 1 hour (p<0.001). CONCLUSION: Tc-99rn tetrofosrnin scintimammography was useful diagnostic procedure in the detection of primary breast cancer, especially in patients with indeterminate degree of suspicion for malignancy on plain-film mammogram.

Biodistribution and Scintigraphy of Iodine-131-Iododeoxyadenosine in Rats Bearing Breast Cancer / 대한핵의학회잡지

PURPOSE: I-131 labeled (2'-deoxy-2-iodo-p-D-arabinofuranosyl) adenine (IAD) may be involved in DNA synthesis during active proliferation of tumor cells. We conducted this study to find out the biodistribution of IAD and its feasibility for scintigraphic tumor imaging. MATERIALS AND METHODS: Tosyl acetyl-adenosine was dissolved in acetonitrile, and I-131-NaI was added and heated to synthesize IAD. Female Fisher 344 rats innoculated with breast tumor cells were injected witb 0.27 MBq of IAD. Rats were sacrificed at 0.5, 1, 2, 4, 24h and the % of injected dose per gram of tissue (%ID/g) was determined. For scintigraphy, rats bearing breast cancer were administered with 1.11 MBq of IAD and imaging was perforrned after 2 and 24h. Then, rat body was fixed and rnicrotomized slice was placed on radiographic film for autoradiography, RESULTS: %ID/g of tumor wa.' 0.74 (0.5h), 0.73 (1h), 0.55 (2h), 0.38 (4h), and 0.05 (24h), respectively. At 1h after injection, %ID/g of tumor was higher than that of heart (0.34), liver (0.42), spleen (0.47), kidney (0,69), muscle (0.14), bone (0.33) and intestine (0.51). However, %1D/g of tumor was lower than blood (1.06), lung (0.77), and thyroid (177.71). At 4h, %ID/g of tumor in comparison with other tissue did not change. Tumor contrast expressed by tumor to blood ratio was 0.69 and tumor to muscle ratio was 5.11 at 1h. However, these ratios did not improve through 24h. On autoradiogram and scintigraphy at 2 and 24 hour, the tumor was well visualized. CONCLUSION: This results suggest that Ial) may have a potential for tumor scintigraphy. However, further work is needed to improve localization in tumor tissue.