CT-guided transthoracic needle biopsy of pulmonary nodules smaller than 20 mm: Results with an automated 20-gauge coaxial cutting needle

AIMS: To evaluate the efficacy and the complication rate of CT-guided percutaneous lung biopsy of pulmonary nodules smaller than 20 mm 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 20 mm in diameter were performed in 66 patients (group A). One hundred and thirty-five biopsies of lesions of 20 mm 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 20 mm, performed using an automated 20-gauge coaxial biopsy device, are comparable to those for larger lesions. (C) 2000 The Royal College of Radiologists.