Diagnostic performance of CT-guided percutaneous transthoracic core needle biopsy using low tube voltage (100 kVp): comparison with conventional tube voltage (120 kVp).

Background Computed tomography (CT)-guided percutaneous transthoracic core needle biopsy (PTNB) is typically performed at 120 kVp tube voltage. However, there is no study that has demonstrated diagnostic performance including ground-glass nodules and radiation dose reduction at lower tube voltage in large population. Purpose To retrospectively compare the diagnostic performance and radiation dose between 100 kVp and 120 kVp during CT-guided PTNB. Material and Methods This study included 393 PTNBs performed in 385 patients (Group I; 120 kVp) from March 2011 to September 2011 and 1368 PTNBs performed in 1318 patients (Group II; 100 kVp) from October 2011 to December 2013. The patients underwent CT-guided PTNB with the coaxial technique. Diagnostic performance, complication rate, and radiation dose were compared between two groups. Results Technical success was achieved in 391 of 393 PTNBs (99.5%) in Group I and in 1344 of 1368 PTNBs (98.2%) in Group II ( P = 0.09). The diagnostic accuracies for pulmonary lesions were not significantly different between two groups (97.1% [362/373] versus 96.2% [1202/1249], P = 0.458). Complication rate showed no significant differences between two groups in terms of pneumothorax (19.7% [77/391] versus 19.4% [261/1344], P = 0.904) and hemoptysis (2.3% [9/391] versus 3.2% [43/1344], P = 0.360). Among patients who developed pneumothorax, three patients (3.9%, 3/77) in Group I and eight patients (3.1%, 8/261) in Group II required treatment with drainage catheter. Nobody needed further treatment for hemoptysis in the two groups. The mean radiation dose was 1.5 ± 1.9 mSv in Group I and 0.7 ± 0.3 mSv in Group II ( P < 0.001). Conclusion The 100-kVp protocol for CT-guided PTNB showed significant benefit of radiation dose reduction while maintaining high diagnostic accuracy and safety.