CT-guided transthoracic needle aspiration biopsy of small (≤ 20 mm) solitary pulmonary nodules

OBJECTIVE. The purpose of our study was to determine the diagnostic accuracy and to analyze the factors influencing the diagnostic accuracy and incidences of pneumothorax and chest tube insertion rates for percutaneous CT-guided needle biopsy of small (less than or equal to 20 mm) solitary pulmonary nodules. SUBJECTS AND METHODS. One hundred sixty-two patients with 162 small solitary pulmonary nodules underwent CT-guided transthoracic needle aspiration biopsy. The overall diagnostic accuracy, pneumothorax rate, and chest tube insertion rate were calculated. Factors influencing the diagnostic accuracy and pneumothorax rate were statistically evaluated. Influencing factors, diagnostic accuracies, pneumothorax rates, and chest tube insertion rates were statistically compared. RESULTS. Overall diagnostic accuracy, pneumothorax rate, and chest tube insertion rate were 77.2%, 28.4%, and 2.5%, respectively. Diagnostic accuracy was significantly affected by length of needle path and lesion size (p < 0.05). The pneumothorax rate was significantly affected by the percentage of predicted forced expiratory volume in 1 sec, the number of punctures, and the needle path length (p < 0.05). The chest tube insertion rate was significantly affected by the number of punctures (p < 0.05). For diagnostic accuracy, needle path lengths of 40 mm or less and lesion sizes greater than 10 mm were significantly more accurate than other factors (p < 0.05). For pneumothorax rates, a percentage of predicted forced expiratory volume in 1 sec of greater than 70%, a single puncture, and a needle path length of 40 mm or less were significantly lower than other factors (p < 0.05). CONCLUSION. CT-guided transthoracic needle aspiration biopsy is a useful diagnostic tool for small solitary pulmonary nodules smaller than 20 mm in diameter. The diagnostic accuracy is significantly improved for large (> 10 mm) lesion size and short (less than or equal to 40 mm) needle path length.