The pinhole SPECT for animal model of bone metastasis with SPC-A-1BM human pulmonary adenocarcinoma bone metastasis cell line

The study was to investigate the role of pinhole single photon emission computed tomography (SPECT), the human pulmonary adenocarcinoma bone-seeking metastasis cell line SPC-A-1BM was used. These cells form typical osteolytic bone metastases when inoculated into the arterial circulation of NIH-Beige-Nude-XD (BNX) mice via the left ventricle. In order to evaluate the irradiation impact of 99mTc-MDP versus X-ray on cells growth, we used six groups of SPC-A-1BM cells in our imaging scheme and irradiated by various doses of 99mTc-MDP (37, 74, 111, 370, 740 MBq) and X-ray(40 kV, 2 mA, 6 s) respectively. The cell's number of each group was well recorded in different exposure time( 4, 8, 12, 24, 48, 72, 96 hours). After that, SPC-A-1BM cells (1×106) were inoculated into the mice via left ventricle. We compared the results obtained with those different doses of 99mTc-MDP using pinhole SPECT and conventional X-ray skeletal surveys. The data show that the cell-survival number of 111 MBq group has insignificant difference with that of X-ray and the dose is adequate to have an ideal image. Besides, it is important that the chromosome of the cells in the group of 111 MBq showed no irradiation-related damages in our test. These results implied that 99mTc-MDP pinhole SPECT may provide another way other than conventional X-ray skeletal surveys in detecting bone metastasis of pulmonary adenocarcinoma in BNX mice.