CT-guided percutaneous lung biopsies more effective for larger pulmonary nodules [Classics Series]

This study summary is an excerpt from the book 2 Minute Medicine’s The Classics in Medicine: Summaries of the Landmark Trials

1. Computed tomography (CT)-guided percutaneous lung biopsies demonstrated significantly higher accuracy for pulmonary nodules greater than 1.5 cm in diameter compared to small pulmonary nodules (< 1.5 cm)

2. There were no significant differences in the rates of complications for either large or small pulmonary nodules

Original Date of Publication: July 1996

Study Rundown: CT-guided percutaneous needle aspiration lung biopsy provides a minimally-invasive method of distinguishing benign and malignant lung lesions. However, this procedure may be associated with an increased risk of complications, including pneumothorax, air embolism, and inadequate sampling leading to false-negative results. The purpose of this landmark retrospective review was to explore the differences in diagnostic accuracy as well as the complication rates for CT-guided percutaneous needle aspiration biopsies between small (< 1.5 cm) versus large (> 1.5 cm) lung nodules. This trial retrospectively reviewed the outcomes of 97 consecutive patients that underwent CT-guided percutaneous needle aspiration of a lung mass. At the conclusion of the trial, the diagnostic accuracy of needle aspiration was high for both small and large pulmonary nodules; however, percutaneous biopsies of larger nodules demonstrated significantly higher diagnostic accuracy and overall sensitivity compared to small nodules. Furthermore, small pulmonary nodules had a higher false-negative rate compared to large nodules. With respect to procedural complications, there were no significant differences in the rates of pneumothorax between patients with small and large lung nodules, with an overall low number requiring chest tube placement. This trial demonstrated that CT-guided percutaneous needle aspiration was safe and had an acceptable accuracy for both large and small pulmonary nodules; however, biopsy of small nodules resulted in a significantly lower accuracy. Additionally, the high false-negative rate for small nodules indicates that a negative result may be of limited clinical value. The results of this trial support the use of additional biopsy procedures for negative percutaneous results. Furthermore, although the size cut-off in this trial was 1.5 cm, most large pulmonary nodules in the study were larger than 3 cm. The majority of subsequent studies on percutaneous lung biopsies have used 3 cm as the cut-off for small pulmonary nodules.

Click to read the study in AJR

In-Depth [retrospective cohort]: This study included 97 consecutive patients that underwent CT-guided percutaneous needle aspiration lung biopsy in a single center. The primary outcome was the diagnostic accuracy and safety of CT-guided lung biopsies. All biopsies were performed by chest radiologists, chest radiology fellows, or radiology residents under the supervision of attending radiologists. Overall, 27 small nodules (mean size: 1.15 cm; range: 0.4 to 1.5 cm) and 70 large nodules (mean size: 3.17 cm; range: 1.6 to 8.2 cm) were biopsied. All biopsy specimens were correlated with pathologic findings from surgery. At the conclusion of the trial, 23 of 27 (85%) small nodules and 62 of 70 (89%) large nodules were found to be malignant. Biopsy of large pulmonary nodules demonstrated a significantly higher sensitivity (94% versus 72%; p < 0.05) and accuracy (96% versus 74%; p < 0.05) compared to small nodules. There were no differences between specificity between large and small nodule biopsy. There were similar rates of pneumothorax for patients with both small and large pulmonary nodules. There were no post-procedural fatalities in either group.

Li H, Boiselle PM, Shepard JO, Trotman-Dickenson B, McLoud TC. Diagnostic accuracy and safety of CT-guided percutaneous needle aspiration biopsy of the lung: comparison of small and large pulmonary nodules. Am J Roentgenol. 1996 Jul 1;167(1):105–9.

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