CT-Guided Transthoracic Needle Biopsy of Pulmonary Nodules Smaller than 20 mm: Results with an Automated 20-Gauge Coaxial Cutting Needle

Abstract

AIMS: To evaluate the efficacy and the complication rate of CT-guided percutaneous lung biopsy of pulmonary nodules smaller than 20mm in diameter using a 20-gauge coaxial automated biopsy device.MATERIAL AND METHODS: A prospective study was undertaken of 200 patients who underwent 202 consecutive biopsies of pulmonary nodules, performed with a single type of automated biopsy device. Sixty-seven biopsies of nodules smaller than 20mm in diameter were performed in 66 patients (group A). One hundred and thirty-five biopsies of lesions of 20mm or greater in size were performed in 134 patients (group B). Patient characteristics, lesion and procedure variables, the accuracy and complication rates were compared.RESULTS: In group A, the final diagnosis of the nodules was malignant in 47 and benign in 19 cases (prevalence of malignancy 71.2%). In group B, there were 111 malignant and 21 benign diagnoses (prevalence of malignancy 82.2%). In group A, the sensitivity and specificity for a diagnosis of malignancy were 89.5 and 100%, respectively (positive predictive value 100%, negative predictive value 76%). A specific diagnosis of benignity was obtained in nine out of 19 (47%) biopsies. The pneumothorax rate was 15% (10 patients) of which two (3%) required drainage. CT signs thought to reflect alveolar haemorrhage were noted in 28 (43%) and haemoptysis occurred in five patients (5.9%). In group B, the sensitivity and specificity for a diagnosis of malignancy were 95.5% and 100%, respectively (positive predictive value 100%, negative predictive value 82.7%). A specific diagnosis of benignity was made in 14 cases (58.3%). Complications included pneumothoraces in 22 cases (16.2%) requiring drainage in one (0.7%). Presumed alveolar haemorrhage was recorded in 19 cases (14.1%) and haemoptysis occurred in seven (5.2%). There were no significant differences between group A and group B, except for alveolar haemorrhage (P<0.001).CONCLUSION: The accuracy and complication rate of percutaneous CT-guided biopsy of nodules smaller than 20mm, performed using an automated 20-gauge coaxial biopsy device, are comparable to those for larger lesions.Laurent, F. (2000). Clinical Radiology55, 281–287.