A novel Laser Navigation System reduces radiation exposure and improves accuracy and workflow of CT-guided spinal interventions: a prospective, randomized, controlled, clinical trial in comparison to conventional freehand puncture.

PURPOSE: Phantom model evaluation and prospective randomized clinical trial to assess the clinical feasibility and benefit of using a novel Laser Navigation System (LNS) in CT-guided epidural and perineural injections in comparison to the conventional freehand procedure. METHODS: The LNS guided puncture technique was compared to the standard CT-guided freehand treatment using a phantom model and a randomized clinical trial. Spinal injections were administered by an experienced interventional team to evaluate needle placement accuracy, treatment time and radiation exposure. RESULTS: In the LNS group of the phantom model study, the needle entrance point accuracy of 0.5mm (freehand 3.1mm), needle target point accuracy of 2.0mm (freehand 3.5mm), number of control CT slices of 1.4 (freehand 2.7) and needle placement time of 5min 4s (freehand: 9min 18s) showed significant improvements compared to freehand in 60 punctures. In the clinical trial the LNS group achieved needle entrance point accuracy of 1.3mm (freehand 4.6mm), needle angulation accuracy of 0.4° (freehand 2.3°), number of control CT slices of 1.1 (freehand 1.8) and needle placement time of 6min 54s (freehand 9min 00s), showing significant improvements compared to freehand in a total of 58 CT-guided interventions. CONCLUSION: The LNS group showed significantly improved results in both study designs. Both the phantom model evaluation and the clinical trial of spinal injections showed feasibility and efficacy of using the novel LNS. Even an experienced interventional team worked with it more precise, faster and with reduced radiation exposure.

Localization of acupuncture points BL25 and BL26 using computed tomography.

OBJECTIVES: The aim of this study was to provide a metric description of acupuncture points BL25 and BL26, to investigate their relation to individual anatomical landmarks and structures, and to identify anatomical structures that are involved in needle manipulation during de qi. DESIGN: Fifty-eight (58) white patients with low-back pain received 107 needlings that were documented using computed tomography (CT). OUTCOME MEASURES: For each patient, the body-mass index (BMI) and the interscapular distance were measured. Using the CT scan, the following parameters were assessed: thickness of the soft tissue layer, distance of the puncture site and the needle tip to the vertebral line, distance of the needle tip to the body surface and the intermuscular space, and the needle depth in muscle tissue. RESULTS: The mean distance from the puncture site to the vertebral line was 3.5 +/- 0.5 cm for BL25 and 3.4 +/- 0.4 cm for BL26. The distance of the needle tip to the vertebral line was similar (3.4 +/- 0.5 cm for BL25 and 3.2 +/- 0.4 cm for BL26). The mean distance of the needle tip to the body surface was 4.1 +/- 0.9 cm at BL25 and 3.9 +/- 0.8 cm at BL26. The majority of the needle tips were located in the intermuscular region between the erector spinae and the transversospinal muscles. There was a significant correlation between the interscapular distance and the thickness of the soft tissue layer with the BMI at both acupuncture points. Nearly all parameters correlated with the BMI. At BL26, correlations between the distance of needle to the vertebral line and the BMI were not statistically significant but the scatter plots indicate a positive dependency. CONCLUSIONS: The results of this study show an association between de qi and needle location within the intermuscular septa. BL25 and BL26 are located as clusters in and around the intermuscular region of the erector spinae and the transversospinal muscles, with a distance to the vertebral line of 3.49 +/- 0.58 cm and 3.32 +/- 0.53 cm, respectively. Using proportional methods is relevant for the success of acupuncture therapy.

Image-guided radiofrequency ablation (RFA) of spinal tumors.

PURPOSE: To evaluate retrospectively the efficacy and safety of radiofrequency ablation (RFA) in patients with spinal tumors. MATERIALS AND METHODS: Forty-one patients (25 men, 16 women; age range, 46-82 years) with nonresectable primary or secondary tumor involvement of the spine unresponsive to chemo- and radiotherapy received RFA treatment. Two radiofrequency ablation systems, one with a cool-tip electrode and one with an expandable electrode catheter, were used. Both systems work impedance controlled with a power output of 150- 200 W. Each coagulation cycle lasted 12-15 min depending on tumor impedance. Several single RFA cycles of 15 min each were used for overlapping RFAs in tumors with diameters of more than 3 cm. Temperature was kept between 50 degrees C and 120 degrees C and was chosen according to spinal cord distance and patient heat tolerance during the ablation. Multi-slice computed tomography (CT) combined with C-arm fluoroscopy guided the intervention. Efficacy outcomes were assessed after about 6 weeks, 6 months, and more than 6 months using standardized questionnaires and indices regarding tumor pain, pain disability, functional activities, quality of life, neurological status, and tumor progression. RESULTS: RFA significantly reduced tumor-induced pain within 6 weeks, improved daily activities, and maintained quality of life. Mean time to tumor progression was 730+/-54 days (Kaplan-Meier estimate). No RFA-associated complications were reported. CONCLUSION: RFA of primary and secondary spinal tumors, which were unresponsive to chemo- and radiotherapy and prone to progression, is a safe, resource-saving, and highly effective percutaneous technique in patients with nonresectable spinal tumors.