Transbronchial evaluation of peripheral pulmonary lesions using ultrasonic spectrum analysis in lung cancer patients

Abstract

Background and objective Analysis of the endobronchial ultrasound (EBUS) radiofrequency spectrum has been used for convex‐probe EBUS technology. Quantitative imaging analysis is also warranted for guided bronchoscopy using radial‐probe EBUS (RP‐EBUS) targeting peripheral pulmonary lesions (PPL). This study aimed to determine the feasibility of radiofrequency spectrum analysis for distinguishing malignant and benign PPL during diagnostic bronchoscopy. Methods Raw RP‐EBUS images with radiofrequency data, including backscatter signals, were prospectively recorded. The ultrasonic spectral parameters, such as intercept, midband‐fit and slope within the region of interest, were retrospectively computed by linear regression analysis and compared with the final diagnosis. Results A total of 71 PPL, including 45 malignant and 26 benign lesions, were analysed. Malignant PPL showed a significantly lower intercept (P < 0.0001), lower midband‐fit (P < 0.0001) and higher slope (P = 0.014) than benign PPL. Analyses of the area under the curve of receiver operating characteristic plots demonstrated that the intercept showed the best diagnostic performance among three parameters (0.87, 0.77 and 0.69 for intercept, midband‐fit and slope, respectively). The sensitivity, specificity, accuracy, positive likelihood and negative likelihood were 75.6%, 96.2%, 83.1%, 19.6 and 0.25 for the intercept; 88.9%, 57.7%, 77.5%, 2.1 and 0.19 for the midband‐fit; and 68.9%, 73.1%, 70.4%, 2.6 and 0.43 for the slope. Conclusion Spectrum analysis of EBUS radiofrequency can be used as a novel non‐invasive predictor of malignant or benign PPL. Analysis of the ‘intercept’ of the targeted lesion may provide useful supporting data for real‐time sampling from PPL during diagnostic bronchoscopy.

Inheritance and innovation of the diagnosis of peripheral pulmonary lesions

“…As a non-invasive quantitative imaging analysis method, radiofrequency spectrum is of great significance in differentiating malignant or benign PPLs in EBUS-guided bronchoscopy. Ishiwata et al 81 discovered that malignant PPLs had a lower intercept, lower midband-fit and higher slope than benign PPLs, with intercept showing the best diagnostic performance. In addition, confocal laser microendoscopy (CLE), known as 'optical biopsy', enables real-time observation of the cytological morphology of target lesions.…”

Sonic biopsy: A new tool for the assessment of peripheral pulmonary lesions

“…In a recent publication in Respirology, Ishiwata et al have moved closer towards achieving a 'sonic biopsy'. 9 During the evaluation of peripheral pulmonary lesions with radial endobronchial ultrasound (rEBUS), they captured raw ultrasound images with radiofrequency spectral data. The raw image data first underwent a Fourier transform followed by a frequency amplitude distribution plot.…”