Ct-Guided Liver Beacon Transponder Implantation

Objective: To investigate the method of CT-guided beacon transponder implantation and precautions after implantation for liver malignant tumor.Methods: CT-guided beacon transponder implantation in three patients with liver malignancies was the first time in China. The operations were performed using Siemens's 16-row large-aperture spiral CT and 17-G guide needles were using for percutaneous liver puncture.Results: All three operations were successfully completed. During the operations, the beacon transponders were successfully implanted at predetermined targets next to the lesion in the liver parenchyma, and there was no obvious bleeding, pain or discomfort. All patients underwent localized CT examination on the fifth day after operations. Only one beacon transponder moved slightly, the remaining eight beacon transponders did not move, and the CT images did not have obvious metal artifacts. After the completion of radiotherapy in three patients, the follow-up CT examination showed no movement of the beacon transponders, and the liver lesions shrank well. However, 3.0 T MRI of the liver showed that the magnetic sensitive artifacts at beacon transponders were more obvious, which affected the observation of local liver tissue.Conclusion: CT-guided liver beacon transponder implantation is safe and feasible. Beacon transponders may move in the liver parenchyma within a short period of time after implantation. Therefore, localized CT examination is recommended to be performed 4 days after the implantation. CT scans after beacon transponder implantation have no obvious metal artifacts. So CT is recommended for follow-up. However, magnetic resonance sensitive artifacts are more obvious when MRI is performed, which will affect the evaluation of local efficacy and detect new small lesions.