Factors affecting diagnostic accuracy of CT-guided coaxial cutting needle lung biopsy: Retrospective analysis of 631 procedures

PURPOSE: To analyze variables affecting diagnostic accuracy of computed tomography (CT)-guided percutaneous coaxial cutting needle biopsy of lung lesions. MATERIALS AND METHODS: A retrospective analysis of factors affecting diagnostic accuracy of CT-guided percutaneous coaxial cutting needle lung biopsy was performed in 631 consecutive procedures with confirmed final diagnoses. Benign and malignant needle biopsy results were cross-examined with correct and incorrect final outcomes to determine diagnostic accuracy. Factors affecting diagnostic accuracy were determined by multivariate logistic regression analysis of variables thought to affect diagnostic accuracy. A P value less than 0.05 was interpreted as statistically significant. RESULTS: The overall diagnostic accuracy of CT-guided percutaneous coaxial cutting needle biopsy of lung lesions was 95% (95% CI: 92.7%-96.2%). Sensitivity was 93%, specificity 98%, negative predictive value 6%, positive predictive value 99%, false-positive rate 0.7%, and false-negative rate 15%. The factors affecting diagnostic accuracy were final diagnoses (benign, 86%; malignant, 99%; chi(2) test, P < 0.001) and lesion size (lesions <1.5 cm, 84%; lesions 1.5-5.0 cm, 96%; lesions >5 cm, 93%; chi(2) test, P = 0.06). CONCLUSION: Benign lung lesions, lung lesions smaller than 1.5 cm (which pose technical difficulty), and lung lesions larger than 5 cm (which are associated with a higher necrosis rate) affect diagnostic accuracy of CT-guided percutaneous coaxial cutting needle biopsy of lung lesions.