Analysis of 99mTc-RBC labeling efficiency between modified in-vitro method and AMC method

The aim of this study was to increase the labeling efficiency of 99mTc-RBC. We compared the clinical utility of the conventional modified in-vitro method (MIM) with our new AMC method. Seventy-two patients (M:44 F:28) were examined. The MIM and AMC method were carried out at the same time. The mean labeling efficiency (%) of MIM vs. AMC were as follows: (1) 90.8 ± 11.4 vs. 95.9 ± 6.8 in total (p = 0.0001); (2) 89.7 ± 12.0 vs. 95.7 ± 6.8 in males (p = 0.0001), 92.9 ± 10.6 vs. 96.3 ± 3.9 in females (p = 0.0001); (3) 89.5 ± 12.9 vs. 95.5 ± 7.8 in the G-I bleeding scan (p = 0.0001), 94.6 ± 4.8 vs. 96.7 ± 3.5 in the liver hemangioma scan (p = 0.035), 96.2 ± 1.96 vs. 97.5 ± 1.11 in the MUGA scan (p = 0.08); and (4) 89.4 ± 12.5 vs. 95.5 ± 7.6 in the decreased RBC count group (p = 0.0001), and 95.9 ± 3.9 vs. 97.1 ± 3.1 the normal RBC count group (p = 0.062). There were significant differences in labeling efficiency between the MIM and AMC methods. In particular, the AMC labeling method was quite useful in decreased RBC count patients.