Purpose: This study was performed to analyse the variables affecting the diagnostic accuracy of computed tomography (CT)-guided transthoracic needle biopsy of pulmonary lesions.
Materials and methods: A retrospective study of 612 consecutive procedures with confirmed final diagnoses was undertaken. Benign and malignant needle biopsy results were compared with final outcomes to determine diagnostic accuracy. A statistical analysis of factors related to patient characteristics, lung lesions and biopsy technique was performed to determine possible influences on diagnostic yield. A p value less than 0.05 was interpreted as statistically significant.
Results: There were 508 (83%) malignant and 104 (17%) benign lesions. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy for a diagnosis of malignancy were 90.2%, 99.0%, 99.8%, 67.3% and 91.7%, respectively. Overall diagnostic accuracy was 83.3%. Variables affecting diagnostic accuracy were the final diagnosis (benign 67%, malignant 92%; p<0.001) and lesion size (lesions<1.5 cm 68%, lesions 1.5-5.0 cm 87%, lesions>5 cm 78%; p<0.05).
Conclusions: In CT-guided transthoracic needle biopsy, the final diagnosis and lesion size affect diagnostic accuracy: benign lung lesions and lesions smaller than 1.5 cm or larger than 5.0 cm in diameter provide lower diagnostic yield.