Transbronchial biopsy guided by low-dose MDCT: a new approach for assessment of solitary pulmonary nodules.

Abstract

The objective of our study was to determine whether transbronchial bronchoscopic biopsy of solitary pulmonary nodules under CT guidance using a low-dose protocol can increase diagnostic yield in patients who had undergone unsuccessful conventional bronchoscopic biopsy. We included 33 consecutive patients (25 men; mean age +/- SD, 64 +/- 9.6 years) with solitary pulmonary nodules at different sites and with a lesion-to-pleura distance of at least 2 cm who previously underwent conventional bronchoscopy that did not result in histologic diagnosis. All patients were prospectively investigated with transbronchial bronchoscopic biopsy under MDCT guidance. Examinations were performed with the patient in conscious sedation using a low-dose protocol (80 kV, 20 mAs, 5-mm collimation, 10-mm slices). The position of the tip of the biopsy device was confirmed and documented before biopsies were performed. All specimens were examined by standard histopathologic techniques. The effective radiation dose was calculated for every patient. The diagnostic yield was 24 in 33 selected patients (overall accuracy, 72.7%): 13 (54%) had primary lung cancer and 11 (46%) had benign diagnoses. The formal operative characteristics were sensitivity, 59%; specificity, 100%; positive predictive value, 100%; and negative predictive value, 55%. The final diagnoses of the remaining nine patients in whom transbronchial bronchoscopic biopsy was not diagnostic were non-small cell lung cancer (n = 3); small cell lung cancer (n = 3); and alveolar carcinoma, carcinoid tumor, and hemorrhaged bulla (n = 1 each). All nonmalignant diagnoses were confirmed by 6 months radiographic and clinical follow-up. The mean duration of the procedure was 39 +/- 15 minutes, and the average effective dose was 0.7 mSv (range, 0.5-1.1 mSv). One case of pulmonary hemorrhage (3%) occurred after the procedure. MDCT-guided transbronchial bronchoscopic biopsy is a promising and safe tool for the diagnostic pathway of solitary pulmonary nodules in previously undiagnosed patients. Image quality was sufficient with low-dose protocols, which resulted in low radiation exposure for patients and personnel.