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

AIMS: To evaluate the efficacy and the complication rate of CT-guided percu taneous lung biopsy of pulmonary nodules smaller than 20 mm in diameter usi ng a 20-gauge coaxial automated biopsy device. MATERIAL AND METHODS: A pros pective study was undertaken of 200 patients who underwent 202 consecutive biopsies of pulmonary nodules, performed with a single type of automated bi opsy device. Sixty-seven biopsies of nodules smaller than 20 mm in diameter were performed in 66 patients (group A). One hundred and thirty-five biops ies of lesions of 20 mm or greater in size were performed in 134 patients ( group B). Patient characteristics, lesion and procedure variables, the accu racy 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 malignanc y were 89.5 and 100%, respectively (positive predictive value 100%, negativ e 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 h aemorrhage were noted in 28 (43%) and haemoptysis occurred in five patients (5.9%). In group B, the sensitivity and specificity for a diagnosis of mal ignancy were 95.5% and 100%, respectively (positive predictive value 100%, negative predictive value 82.7%). A specific diagnosis of benignity was mad e in 14 cases (58.3%). Complications included pneumothoraces in 22 cases (1 6.2%) requiring drainage in one (0.7%). Presumed alveolar haemorrhage was r ecorded 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 al veolar haemorrhage (P < 0.001). CONCLUSION: The accuracy and complication rate of percutaneous CT-guided bi opsy of nodules smaller than 20 mm, performed using an automated 20-gauge c oaxial biopsy device, are comparable to those for larger lesions. (C) 2000 The Royal College of Radiologists.