C-arm cone-beam CT-guided percutaneous transthoracic needle biopsy (PTNB) is a highly accurate and safe technique for pulmonary lesion diagnosis and may be a viable alternative to more traditional CT-guided or CT fluoroscopically-guided techniques, according to a study published online Nov. 27 in Radiology.

Though both CT-guided PTNB and CT fluoroscopy-guided PTNB are accurate and safe approaches to pulmonary lesion diagnosis, both methods have limitations. Recently, cone-beam CT systems comprised of a C-arm gantry, an x-ray tube, and a flat-panel detector have been developed for interventional radiology.

“This system offers great flexibility in orienting the detector around the patient and provides three-dimensional reconstructed CT images and real-time fluoroscopy capability,” wrote Sang Min Lee, MD, of Seoul National University College of Medicine in Seoul, Korea, and colleagues. “Furthermore, great accessibility by means of a flexible approach through an open gantry is feasible with cone-beam CT guided biopsy; this is not possible with conventional CT or CT fluoroscopy-guided biopsy.”

Lee and colleagues thus created a study to retrospectively evaluate the diagnostic performance and complications of cone-beam CT PTNB in a large population. The study’s population was made up of 1,108 patients who underwent cone-beam CT PTNBs with a coaxial needle system and 18-gauge cutting needles.

The study’s pathologic analysis revealed that 98.6 percent of the PTNBs were technically successful, with a mean procedure time of 14.9 minutes. Respectively, the sensitivity, specificity, and accuracy for diagnosis of malignancy were 95.7 percent, 100 percent, and 97 percent. Lesions one centimeter in diameter or smaller and lesions in the lower lobe were significant risk factors. Pneumothorax occurred in 17 percent of the procedures and hemoptysis occurred in 6.9 percent.

“We believe that the advantages of cone-beam CT guidance, such as real-time imaging guidance and great flexibility in entry site selection, can contribute to high diagnostic accuracy in small lesions,“ wrote Lee and colleagues. “In addition, the cone-beam CT system can provide operators with more spatial room, it can enable effective control of patient breathing with real-time fluoroscopy during the procedure compared with the CT fluoroscopy system, and it can enable operators to avoid dangerous organs or overlying ribs that block the needle pathway to target nodules.”