Cryobiopsy enables specialists to perform high-quality, large, entirely circumferential biopsies; therefore, it may improve the diagnostic yield of peripheral pulmonary lesions (PPLs), as has been previously observed with regard to endobronchial tumors and interstitial lung diseases. How do the diagnostic accuracy and safety change by cryobiopsy when performed alongside conventional biopsy for PPLs? Consecutive patients who underwent cryobiopsy in addition to conventional biopsies for PPL diagnosis at our institution between June 2017 and May 2018 were reviewed retrospectively. The target location was estimated and sampling was performed using conventional devices (i.e., forceps, brush, and/or aspiration needle), and cryobiopsy was performed at the same location. Diagnostic outcomes and cryobiopsy safety when performed in addition to conventional sampling methods were analyzed in this observational study. In total, 257 patients were analyzed, and the overall diagnostic yield was 89.9%. Among them, 22 lesions were diagnosable by cryobiopsy exclusively, which improved the rate of diagnosis by 8.6%. Advantages of the use of cryobiopsy were the most apparent when lesions were adjacent to areas assessed via radial endobronchial ultrasound (69.4% vs. 84.3%). Multivariable analysis identified bronchus sign (positive/negative, P=0.001), lobe (other lobes/right upper lobe + left upper segment, P=0.028), and visibility on X-ray (visible/invisible, P=0.047) as factors that significantly affected diagnostic yield. On the other hand, three instances of severe hemorrhage (1.2%), and two of pneumothorax (0.8%) occurred. Although most complications were minor, two patients required hospitalization due to cerebral infarction and lung abscess. Cryobiopsy improves the diagnostic yield of PPLs when combined with other conventional sampling methods; however, caution is required due to the possibility of complications.

Background: Cryobiopsy is an established technique that yields larger and higher-quality samples than does a forceps biopsy. However, it remains underutilised in the diagnosis of peripheral pulmonary lesions (PPLs), mainly because of difficulties in handling conventional cryoprobes. A recently introduced single-use cryoprobe with a smaller diameter and more flexibility than conventional ones may improve its diagnostic ability for PPLs. We conducted this prospective study to evaluate the feasibility of transbronchial cryobiopsy in the diagnoses of PPLs, using a new 1.7-mm cryoprobe. Methods: The study included patients with PPLs less than 30 mm in diameter scheduled to undergo bronchoscopy. All the procedures were performed using a combination of virtual bronchoscopic navigation, radial endobronchial ultrasound (R-EBUS) and X-ray fluoroscopy, and all the samples were collected using the cryoprobe alone. Thereafter, we assessed the diagnostic outcomes and safety profiles. Results: A total of 50 patients were enrolled and underwent cryobiopsy. The median lesion size was 20.8 mm (range, 8.2–29.6 mm), and the negative bronchus sign was seen in 34% of lesions. The diagnostic yield was 94% (95% confidence interval, 83.5–98.8%). A positive bronchus sign had a significantly higher diagnostic yield than did a negative bronchus sign (100% vs. 82.4%; P = 0.035). The yield was achieved regardless of other variables, including lesion size, location, and R-EBUS findings. The major complications were mild and moderate bleeding in 28% and 62% of patients, respectively. Pneumothorax was identified in one patient. Conclusion: Transbronchial cryobiopsy using the new 1.7-mm cryoprobe is a feasible procedure that has the potential to increase the diagnostic accuracy for PPLs. Trial registration: Japan Registry of Clinical Trials, jRCT1032200065. Registered July 8 2020, https://jrct.niph.go.jp/en-latest-detail/jRCT1032200065

Re-biopsy for resistant non-small cell lung cancer (NSCLC) after treatment with epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) is important for selection of better therapy, but there have been no reports about the utility of endobronchial ultrasound (EBUS)-guided procedures for such purpose. The aim of this study was to evaluate the utility of EBUS-guided re-biopsy for resistant NSCLC after treatment with EGFR-TKIs. From January 2013 to December 2015, 53 consecutive patients who underwent EBUS-guided re-biopsy for mutation analysis of NSCLC after EGFR-TKI treatment were assessed. Nine patients underwent EBUS-guided transbronchial needle aspiration (EBUS-TBNA) and 44 patients underwent EBUS with a guide sheath (EBUS-GS) transbronchial biopsy. The technical success rates were 100 %. As for mutation analysis, all 9 specimens (100 %) from EBUS-TBNA and 33 specimens (75.0 %) from EBUS-GS were adequate for gene profiling. The remaining 11 specimens from EBUS-GS procedures were inadequate for mutation analysis owing to the absence of tumor component in the sample (n = 6) or insufficient specimen (n = 5). There were no related severe complications. Re-biopsy by both EBUS-TBNA and EBUS-GS were useful and safe sampling procedures for mutation analysis of EGFR-TKI resistant NSCLC.

The success rate of next-generation sequencing (NGS) with specimens obtained through endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) among patients with lung cancer as well as the related clinical factors remain unclear. We aimed to determine the optimal number of punctures and core tissues during EBUS-TBNA for NGS in patients with non-small-cell lung cancer (NSCLC) as well as the association of chest computed tomography (CT) and EBUS findings with successful NGS. We retrospectively reviewed 156 consecutive patients with NSCLC who underwent EBUS-TBNA for NGS (Oncomine^TM Dx Target Test). Using the receiver operating characteristic curve, we calculated the optimal numbers of punctures and core tissues for NGS and evaluated CT and EBUS findings suggestive of necrosis and vascular pattern within the lesion. The success rate of NGS was 83.3%. The cut-off value for the number of core tissues was 4, and the sensitivity and specificity of successful NGS were 73.8% and 61.5%, respectively. Logistic regression analysis revealed that the number of core tissues (≥4) was the sole predictor of successful NGS. CT and EBUS findings were not associated with successful NGS. Bronchoscopists should obtain sufficient core tissues for successful NGS using EBUS-TBNA specimens.