Accuracy, Safety and Diagnostic Outcome of Percutaneous Fluoroscopic vs. CT Guided Transpedicular Core Needle Biopsy for Spinal Infections and Tumors. A Prospective Randomized Trial

This prospective randomized study was carried out in a single institution from November 2016 to June 2018.

Patients were recruited by three spine surgeons from the same institution after eligibility assessment. Sixty consecutive patients were randomized equally into fluoroscopic and CT guided spinal biopsy groups. Randomization procedure was performed using a computer generated random number sequence on www.random.org. Separate individuals completed the random allocation sequence, patient enrollment and outcome assessment. Outcome assessors were blinded to group assignment.

Data collection Clinical data collected were: patient demographics, comorbidities, infective parameters, tumor markers, Magnetic Resonance Imaging (MRI) findings and pre-biopsy pain score at rest using visual analogue scale (VAS). Intraoperative data included radiation exposure dosage, biopsy duration and complications encountered. Following biopsy, we recorded the biopsy result, 6-hourly pain score (VAS) at for 48 hours, additional analgesia requirement and complications.

Radiation measurement Commercial optically stimulated luminescence dosimeters, OSLDs (NanoDotTM Dosimeter, Landauer Inc, Glenwood, IL) were used to measure radiation dose. Ten OSLDs were placed on patients and doctors prior to all biopsies over selective areas representing radiosensitive organs. Placements of the OSLDs were done by a single observer. OSLDs were processed using MicroStar OSLD reader system (Landauer, Inc. Glenwood, IL). Each OSLD was processed 3 times during each reading to obtain a mean value to minimize error. The absorbed doses were measured in centigrays (cGy). Bleaching/zeroing of the OSLDs were done using optical annealing system containing fluorescent lamps (Osram lumilux, 24 W, 280 ~780 nm) in between each use of OSLDs.

Biopsy technique Transpedicular approach with an 8-gauge T-Lok™ bone marrow biopsy needle (Argon Medical Devices, Athens, TX, USA) was used in both arms. 10cc 2% lignocaine was infiltrated prior to biopsy. Biopsy needle was tapped gently with mallet through the pedicle and into the lesion under imaging guidance. Trocar was then withdrawn once it reached the affected area. The cannula was rotated several times to disengage sample from surrounding tissue. Then, aspiration of samples was done using 10-ml syringe prior to retraction of the cannula. Tissue samples were retrieved from the cannula with the use of stylet.