Hematogenous pulmonary metastasis: an experimental study by using VX-2 carcinoma in rabbit

To evaluate sequential radiological changes and detectability of various radiological modalities in hematogenous pulmonary metastasis we performed an experimental study by using VX-2 carcinoma in rabbits. Hematogenous pulmonary metastasis was induced by injecting suspension of VX-2 carcinoma through the vein of the ear. Five rabbits in each group were sacrificed after 3, 7, 14, 21 and 30 days of injection. Sequential follow-up chest radiography in vivo state and soft tissue radiography, high resolution CT, microradiography of the inflated and fixed lungs were done. Gross pathological and radiological evidence of pulmonary metastasis were seen in all rabbits sacrificed after 21 days. Chest radiographic evidence of pulmonary metastasis began to appear after 14 days of injection and showed well defined nodules about 4 mm in diameter. High resolution CT of the inflated and fixed lung showed metastatic nodules at 7th day of injection as tiny nodules about 1 mm in diameter. Besides the nodules, HRCT and microradiography showed clearly peribronchovascular and perinodular lymphangitic tumor spread in all five rabbits sacrificed after 30 days. In conclusion, even with a genuine hematogenous pulmonary metastasis, lymphangitic metastasis is associated in late stage of the disease and HRCT provides early detection of the nodules