Percutaneous ultrasound-guided fiducial marker placement for liver cancer robotic stereotactic radio-surgery treatment: A comparative analysis of three types of markers and needles.

BACKGROUND AND STUDY AIMS: Percutaneous placement of fiducial markers is required to perform stereotactic body radiation therapy (SBRT) for liver neoplastic lesions. This prospective trial was designed to evaluate the feasibility and safety of percutaneous ultrasound-guided placement of three different types of markers in patients with liver cancer referred for SBRT.

PATIENTS AND METHODS: Fifty patients underwent percutaneous ultrasound-guided implantation of a fiducial marker in the liver. Three sizes of needles were used: 25 gauge (G), 22G, and 17G. The 25G and 22G needles contained gold anchor markers of 0.28×10mm and 0.4 ×10mm size, respectively. In contrast, the 17G needle contained a gold grain marker of 1×4mm. Each patient received 1-6 markers, depending on lesion size and numbers. Technical feasibility and the occurrence of adverse events were registered. Computed tomography scans were acquired prior to SBRT to evaluate the location, visibility, or complications related to the markers.

RESULTS: A total of 163 needles were used to deliver 163 markers in 50 patients. No major complications occurred. Minor complication occurrence rate was 12%. The total complication occurrence for all type of markers was 8.5%. No complications were observed with the use of the gold anchor marker of 0.4 ×10mm size. Variance analysis of the three markers showed a significant difference in the frequency of complications amongst the three markers (p<0.01).

CONCLUSION: Percutaneous ultrasound-guided placement of fiducial markers for SBRT of liver neoplastic lesions is safe and feasible. In our series, the 22G needle showed some advantage in terms of handling and safety when compared with the 25G and 17G needles. In addition, the gold anchor marker of 0.4 ×10mm size displayed a lower percentage of displacement.