Adenocarcinoma originating in the anterior mediastinum diagnosed by endobronchial ultrasound-guided transbronchial cryobiopsy: a case report.

BACKGROUND: Endobronchial ultrasound-guided transbronchial cryobiopsy (EBUS-cryobiopsy) is advantageous for collecting larger specimens with minimal crushing; however, it has not been widely used for mediastinal tumors. CASE PRESENTATION: A 73-year-old woman with a history of left breast cancer underwent surgery followed by radiotherapy. Computed tomography showed a mass in the anterior mediastinum that was in extensive contact with the sternum on the ventral side and partly with the trachea on the dorsal side. Two computed tomography-guided needle biopsies (CTNBs) were performed on the mass; however, a definitive diagnosis was not made because of severe crush artifacts. Subsequently, we performed EBUS-cryobiopsy and safely obtained sufficient specimen volume with minimal crushing. The histopathological diagnosis was adenocarcinoma, with immunobiological features distinct from those of previous breast cancers. Her overall diagnosis was a rare tumor originating in the anterior mediastinum. CONCLUSIONS: EBUS-cryobiopsy can be safely performed in narrow areas surrounded by major blood vessels, and the obtained specimens may be superior to CTNBs for histopathological diagnosis.

Comparison of the specimen quality of endobronchial ultrasound-guided intranodal forceps biopsy using standard-sized forceps versus mini forceps for lung cancer: A prospective study.

BACKGROUND AND OBJECTIVE: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a diagnostic procedure with adequate performance; however, its ability to provide specimens of sufficient quality and quantity for treatment decision-making in advanced-stage lung cancer may be limited, primarily due to blood contamination. The use of a 0.96-mm miniforceps biopsy (MFB) permits true histological sampling, but the resulting small specimens are unsuitable for the intended applications. Therefore, we introduced a 1.9-mm standard-sized forceps biopsy (SFB) and compared its utility to that of MFB. METHODS: We prospectively enrolled patients from three institutions who presented with hilar/mediastinal lymphadenopathy and suspected advanced-stage lung cancer, or those who were already diagnosed but required additional tissue specimens for biomarker analysis. Each patient underwent MFB followed by SFB three or four times through the tract created by TBNA using a 22-gauge needle on the same lymph node (LN). Two pathologists assessed the quality and size of each specimen using a virtual slide system, and diagnostic performance was compared between the MFB and SFB groups. RESULTS: Among the 60 enrolled patients, 70.0% were diagnosed with adenocarcinoma. The most frequently targeted sites were the lower paratracheal LNs, followed by the interlobar LNs. The diagnostic yields of TBNA, MFB and SFB were 91.7%, 93.3% and 96.7%, respectively. The sampling rate of high-quality specimens was significantly higher in the SFB group. Moreover, the mean specimen size for SFB was three times larger than for MFB. CONCLUSION: SFB is useful for obtaining sufficient qualitative and quantitative specimens.

Aorta and main pulmonary artery segmentation using stacked U-Net and localization on non-contrast-enhanced computed tomography images.

BACKGROUND: The contact between the aorta, main pulmonary artery (MPA), main pulmonary vein, vena cava (VC), and esophagus affects segmentation of the aorta and MPA in non-contrast-enhanced computed tomography (NCE-CT) images. PURPOSE: A two-stage stacked U-Net and localization of the aorta and MPA were developed for the segmentation of the aorta and MPA in NCE-CT images. METHODS: Normal-dose NCE-CT images of 24 subjects with chronic thromboembolic pulmonary hypertension (CTEPH) and low-dose NCE-CT images of 100 subjects without CTEPH were used in this study. The aorta is in contact with the ascending aorta (AA) and MPA, the AA with the VC, the aortic arch (AR) with the VC and esophagus, and the descending aorta (DA) with the esophagus. These contact surfaces were manually annotated. The contact surfaces were quantified using the contact surface ratio (CSR). Segmentation of the aorta and MPA in NCE-CT images was performed by localization of the aorta and MPA and a two-stage stacked U-Net. Localization was performed by extracting and processing the trachea and main bronchus. The first stage of the stacked U-Net consisted of a 2D U-Net, 2D U-Net with a pre-trained VGG-16 encoder, and 2D attention U-Net. The second stage consisted of a 3D U-Net with four input channels: the CT volume and three segmentation results of the first stage. The model was trained and tested using 10-fold cross-validation. Segmentation of the entire volume was evaluated using the Dice similarity coefficient (DSC). Segmentation of the contact area was also assessed using the mean surface distance (MSD). The statistical analysis of the evaluation underwent a multi-comparison correction. CTEPH and non-CTEPH cases were classified based on the vessel diameters measured from the segmented MPA. RESULTS: For the noncontact surfaces of AA, the MSD of stacked U-Net was 0.31 ± 0.10 mm (p < 0.05) and 0.32 ± 0.13 mm (p < 0.05) for non-CTEPH and CTEPH cases, respectively. For contact surfaces with a CSR of 0.4 or greater in AA, the MSD was 0.52 ± 0.23 mm (p < 0.05), and 0.68 ± 0.29 mm (p > 0.05) for non-CTEPH and CTEPH cases, respectively. MSDs were lower than those of 2D and 3D U-Nets for contact and noncontact surfaces; moreover, MSDs increased slightly with larger CSRs. However, the stacked U-Net achieved MSDs of approximately 1 pixel for a wide contact surface. The area under the receiver operating characteristic curve for CTEPH and non-CTEPH classification using the right main pulmonary artery (RMPA) diameter was 0.97 (95% confidence interval [CI]: 0.94-1.00). CONCLUSIONS: Segmentation of the aorta and MPA on NCE-CT images were affected by vascular and esophageal contact. The application of stacked U-Net and localization techniques for non-CTEPH and CTEPH cases mitigated the impact of contact, suggesting its potential for diagnosing CTEPH.

Identifying factors causing failure of nodal staging by endobronchial ultrasound-guided transbronchial needle aspiration in non-small cell lung cancer.

Background: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is recommended for nodal staging in non-small cell lung cancer (NSCLC). Although this method may rarely fail, reports on the causes are few. We therefore retrospectively investigated the factors causing failure of nodal staging by EBUS-TBNA. Methods: Consecutive patients who underwent EBUS-TBNA at National Cancer Center Hospital between January 2017 and December 2020 for systematic nodal staging in NSCLC were extracted. The nodal stages at diagnosis including EBUS-TBNA and at treatment were investigated separately, and unmatched cases were defined as failures. Factors associated with them were explored while dividing the cases into punctured and not-punctured groups. Results: Of the 264 patients, 21 (8.0%) failed the nodal staging: 10 (3.8%) in the punctured group and 11 (4.2%) in the not-punctured group. The latter was subdivided into the following three categories: (I) difficult-to-reach; (II) omission due to false-positive rapid on-site cytologic evaluation (ROSE) results; and (III) non-significant EBUS findings. The nodal staging failure rate was significantly higher in cases with driver oncogenes positive than in those negative (16.1% vs. 3.3%, P=0.026) for adenocarcinomas. Note that all cases categorized as non-significant EBUS findings involved various driver oncogenes. Conclusions: The present study demonstrated the risk of false positives with ROSE and the involvement of driver oncogenes as factors associated with nodal staging failure in NSCLC by EBUS-TBNA, in addition to limitations of the procedure itself, including sampling performance and reachability. Especially in adenocarcinoma patients with driver oncogenes, their nodal staging results should be interpreted cautiously.

Tumor microenvironment-mediated immune profiles and efficacy of anti-PD-L1 antibody plus chemotherapy stratified by DLL3 expression in small-cell lung cancer.

BACKGROUND: Delta-like ligand 3 (DLL3) is a therapeutic target in small-cell lung cancer (SCLC). However, how DLL3 expression status affects the tumor microenvironment (TME) and clinical outcomes in SCLC remains unclear. METHODS: This retrospective study included patients with postoperative limited-stage (LS)-SCLC and extensive-stage (ES)-SCLC treated with platinum and etoposide (PE) plus anti-programmed cell death ligand 1 (PD-L1) antibody. We investigated the relationship of DLL3 expression with TME, mutation status, tumor neoantigens, and immunochemotherapy. RESULTS: In the LS-SCLC cohort (n = 59), whole-exome sequencing revealed that DLL3High cases had significantly more neoantigens (P = 0.004) and a significantly higher rate of the signature SBS4 associated with smoking (P = 0.02) than DLL3Low cases. Transcriptome analysis in the LS-SCLC cohort revealed that DLL3High cases had significantly suppressed immune-related pathways and dendritic cell (DC) function. SCLC with DLL3High had significantly lower proportions of T cells, macrophages, and DCs than those with DLL3Low. In the ES-SCLC cohort (n = 30), the progression-free survival associated with PE plus anti-PD-L1 antibody was significantly worse in DLL3High cases than in DLL3Low cases (4.7 vs. 7.4 months, P = 0.01). CONCLUSIONS: Although SCLC with DLL3High had a higher neoantigen load, these tumors were resistant to immunochemotherapy due to suppressed tumor immunity by inhibiting antigen-presenting functions.

Suitability of respiratory endoscopy for sampling malignant thoracic tumors for comprehensive genomic profiling.

Comprehensive genomic profiling (CGP) is implemented to detect actionable gene aberrations and design matched therapies. Although malignant thoracic tumors are commonly detected through respiratory endoscopy, it is questionable whether the small specimens obtained thereof are sufficient for CGP. Therefore, this study aimed to investigate the suitability of respiratory endoscopy for sampling primary and metastatic thoracic tumors for CGP. Patients whose specimens were collected through respiratory endoscopy and assessed by pathologists to determine their suitability for CGP at our institution between June 2019 and May 2022 were reviewed retrospectively. The suitability of each procedure as a sampling technique for CGP and, in the cases actually analyzed, the distribution of the detected gene aberration were assessed. In total, 122 patients were eligible for analysis; the median age was 61 (range, 29-86) years, and 71 (58.2%) patients were male. Primary intrathoracic tumors were found in 91 (74.6%) cases, including 84 (68.9%) primary lung cancers; the remaining thoracic metastases of extrathoracic origin included various types. The suitability rates of specimens obtained using conventional bronchoscopy with and without cryobiopsy, endobronchial ultrasound-guided transbronchial needle aspiration, and medical thoracoscopy were 82.8% (24/29), 70.4% (19/27), 72.9% (35/48), and 100% (18/18), respectively. Of the 96 cases judged suitable, 83 were subjected to CGP, and all but one were successfully analyzed. Finally, 47 (56.6%) patients had at least one actionable gene aberration and eight (9.6%) were treated with the corresponding targeted therapies. In conclusion, specimens obtained through respiratory endoscopy are suitable for CGP; medical thoracoscopy and cryobiopsy in conventional bronchoscopy are particularly useful.

Concordance between cryobiopsy and forceps biopsy specimens in assessment of immunohistochemistry staining for non-small cell lung carcinoma.

Background: Cryobiopsy is recently being promoted for biopsy of tumors in the lung periphery in precision medicine for lung cancer; the obtained tissue samples have been reported to be more useful compared to those obtained using forceps, because of the larger volume and higher quality. However, the influence of freezing and thawing of tissues when performing cryobiopsy on the results of immunohistochemistry (IHC) has not been completely understood. Methods: In this study, consecutive patients who underwent diagnostic bronchoscopy with cryobiopsy for peripheral pulmonary lesions (PPLs) at our institution between June 2017 and November 2021 were reviewed retrospectively. Specimens of diagnosed cases of unresectable or recurrent non-small cell lung carcinoma (NSCLC) were selected. We compared the results of IHC assessment for programmed death-ligand 1 (PD-L1), human epidermal growth factor receptor 2 (HER2), and human epidermal growth factor receptor 3 (HER3) in cryobiopsy specimens versus conventional forceps biopsy specimens from the same site in the same procedure. Results: Twenty-four of 40 patients were male (60%). The most frequent histologic type of cancer was adenocarcinoma (n=31, 77.5%), followed by NSCLC (n=4, 10%), squamous cell carcinoma (n=3, 7.5%), and others (n=2, 5%). The concordance rates of the tumor proportion scores (TPSs) for PD-L1, IHC score for HER2 and, IHC scores for HER3 were 85%, 72.5%, and 75%, respectively; the weighted kappa were 0.835, 0.637, and 0.697, respectively. Conclusions: Freezing and thawing associated with cryobiopsy had virtually no effect on the results of IHC. We suggest that cryobiopsy specimens would therefore be ideal for precision medicine and translational research.

Utility of the endobronchial Watanabe spigot for intractable cancer-related pneumothorax: a retrospective observational study.

BACKGROUND: The use of endobronchial Watanabe spigots for intractable secondary pneumothorax in patients with cancer has not been adequate. This study aimed to investigate the use of endobronchial Watanabe spigots for intractable pneumothorax in patients with malignant tumors. METHODS: Consecutive patients with malignant tumors who underwent occlusion with an endobronchial Watanabe spigot for intractable pneumothorax associated with perioperative treatment or drug therapy at our institution between January 2014 and February 2022 were reviewed. RESULTS: Of the 32 cases in which an endobronchial Watanabe spigot was used, six were excluded; we thus evaluated 26 cases in which the chest tube was removed. Chest tubes were removed in 19 cases (73.1%) and could not be removed and required surgical treatment under general anesthesia in seven patients (26.9%), of which four (14.8%) underwent open-window thoracostomy. Half of the patients were treated with both an endobronchial Watanabe spigot and pleurodesis. Although thin-slice chest computed tomography revealed a fistula in 15 patients, the chest tube was removed in 11 (57.9%) patients. A significant difference was only observed in patients with a history of heavy smoking. CONCLUSIONS: The chest tube removal rate was comparable to those reported in previous studies. An endobronchial Watanabe spigot may be a useful treatment option for intractable cancer-related pneumothorax.

Identification of inflamed-phenotype of small cell lung cancer leading to the efficacy of anti-PD-L1 antibody and chemotherapy.

BACKGROUND: Platinum etoposide plus anti-programmed cell death ligand-1 (PD-L1) antibody therapy is the standard of care for extensive-stage small cell lung cancer (ES-SCLC). However, patient characteristics associated with the efficacy of the combination therapy in SCLC are unclear. METHODS: We retrospectively reviewed post-surgical limited-stage (LS)-SCLC and ES-SCLC patients treated with atezolizumab plus carboplatin and etoposide (ACE). The association between SCLC subtypes based on transcriptomic data and pathological findings, including CD8-positive tumor-infiltrating lymphocyte (TIL) status, was investigated in the LS-SCLC cohort. The association between the efficacy of ACE therapy, pathological subtypes, and TIL status was evaluated in the ES-SCLC cohort. RESULTS: The LS-SCLC cohort (N = 48) was classified into four SCLC subtypes (ASCL1 + NEUROD1 [SCLC-A + N, N = 17], POU2F3 [SCLC-P, N = 15], YAP1 [SCLC-Y, N = 10], and inflamed [SCLC-I, N = 6]) based on transcriptomic data. SCLC-I showed enriched immune-related pathways, the highest immune score (CD8A expression and T-cell-inflamed gene expression profiles), and epithelial-mesenchymal transition (EMT), in transcriptional subtypes. Immunohistochemical staining (IHC) showed that SCLC-I had the highest density of CD8-positive TILs in transcriptional subtypes. In the ES-SCLC cohort, the efficacy of ACE therapy did not differ according to pathological subtypes. The progression-free survival (PFS) of TILHigh patients was significantly longer than that of TILLow patients (PFS: 7.3 months vs. 4.0 months, p < 0.001). CONCLUSION: Tumors with a high density of TILs, which represent the most immunogenic SCLC subtype (SCLC-I), based on transcriptomic data could benefit from ACE therapy.

Computed Tomography Bronchus Sign Subclassification during Radial Endobronchial Ultrasound-Guided Transbronchial Biopsy: A Retrospective Analysis.

The presence of computed tomography bronchus sign (CT-BS) substantially increases the diagnostic yield of peripheral pulmonary lesions. However, the clinical significance of subdividing CT-BS remains controversial. We classified bronchus types on CT into six subtypes (CT-BS group I: types Ia-Ic with the bronchus connected within the lesion, group II: types IIa-IIc without connection) to clarify the differences in their characteristics and investigate the factors associated with diagnosis during radial endobronchial ultrasound (rEBUS)-guided bronchoscopy. In total, 1021 cases were analyzed. Our findings in diagnostic yields were that in CT-BS group I, penetrating type Ic was inferior to obstructed type Ia and narrowing type Ib (59.0% vs. 80.0% and 76.3%, p < 0.001, p = 0.004); in CT-BS group II, compressed type IIa showed no difference when compared with invisible type IIb and uninvolved type IIc (IIa: 52.8% vs. IIb: 46.3% and IIc: 35.7%, p = 0.253). Multivariable analysis revealed that bronchus type (types Ia and Ib vs. Ic) was a significant independent predictor of successful diagnosis in CT-BS group I (odds ratio, 1.78; 95% confidence interval, 1.04-3.05; p = 0.035), along with known factors such as rEBUS visualization. CT-BS subclassification may provide useful information regarding the bronchoscopic technique to facilitate accurate diagnosis.

Mucoepidermoid carcinoma cured by a combination of high-frequency snare and photodynamic therapy: A case report.

Mucoepidermoid carcinoma (MEC) is a rare salivary gland tumor, accounting for 0.2% of all lung tumors. The standard treatment for MEC of the primary bronchus is surgery, although intraluminal bronchoscopic treatment has recently become an option. A 68-year-old man presented with an asymptomatic bronchial tumor in the right intermediate bronchus. The tumor was resected using a high-frequency snare (HFS) during bronchoscopy, and the specimen was pathologically diagnosed as low-grade MEC. A residual lesion was detected in the resected area by autofluorescence imaging. The tumor appeared to be localized within the subepithelial layer without metastases, and photodynamic therapy (PDT) was performed as a local treatment. The patient had no recurrence for 18 months. PDT is effective and safe for patients with centrally located early-stage lung cancer, but there are few reports of its use for rare tumors, such as MEC. In this case, PDT allowed for local control and avoided surgery, including bronchoplasty, for MEC. Combined treatment of tumor reduction by HFS and PDT of the residual lesion may be an optimal treatment for MEC of the bronchus.

Diagnostic efficacy of cryobiopsy for peripheral pulmonary lesions: A propensity score analysis.

OBJECTIVES: Recently introduced cryobiopsy can provide quantitatively and qualitatively excellent specimens. However, few studies have directly compared the diagnostic yield of cryobiopsy for peripheral pulmonary lesions (PPLs) with that of conventional sampling methods. MATERIAL AND METHODS: We retrospectively reviewed data from consecutive patients who underwent diagnostic bronchoscopy using radial endobronchial ultrasound and virtual bronchoscopic navigation for PPLs (October 2015 to September 2020). Patients who underwent cryobiopsy were assigned to the cryo group, whereas those who did not undergo cryobiopsy were assigned to the conventional group. The diagnostic outcomes of both groups were compared using propensity score analyses. RESULTS: A total of 2,724 cases were identified, including 492 and 2,232 cases in the cryo and conventional groups, respectively. Propensity scoring was performed to match baseline characteristics, and 481 pairs of cases were selected for each matched group (m-group). The diagnostic yield was significantly higher in the m-cryo group than in the m-conventional group (89.2% vs. 77.6%, odds ratio [OR] = 2.36 [95% confidence interval [CI] = 1.65-3.38], P < 0.001). Propensity score stratification (OR = 2.35 [95% CI = 1.71-3.23]) and regression adjustment (OR = 2.54 [95% CI = 1.83-3.52]) also demonstrated the diagnostic advantages of cryobiopsy. The subgroup analysis revealed that cryobiopsy was notably effective for lesions in the middle lobe/lingula, right/left lower lobe, lesions with ground-glass opacity, and lesions invisible on chest radiography. Although there were more cases of grade 2 and 3 bleeding in the m-cryo group than in the m-conventional group (38.0% vs. 10.2% and 1.5% vs. 0.8%, respectively; P < 0.001), no grade 4 bleeding was observed. CONCLUSION: The propensity score analyses revealed that cryobiopsy was associated with a higher diagnostic yield for PPLs than conventional sampling methods. However, increased bleeding risk should be noted as a potential complication.

A study of laser dose in photodynamic therapy with talaporfin sodium for malignant central airway stenosis.

Photodynamic therapy (PDT) has been shown to be effective and safe in the treatment of malignant central airway stenosis. However, the laser dose for talaporfin PDT is unclear. We herein review cases where talaporfin PDT was used to treat malignant central airway stenosis. A total of 17 lesions were treated with talaporfin PDT at laser doses of 50-150 J/cm2. Improvement of airway stenosis was observed in all cases except for 1 lesion treated with a dose of 50 J/cm2. The results show that talaporfin PDT with 100 J/cm2 of laser dose is a feasible treatment for malignant central airway stenosis. (This is a secondary publication from the Journal of Japan Society for Laser Surgery and Medicine 2022; 43(1): 9-12.).

Thoracic SMARCA4-deficient undifferentiated tumor diagnosed by transbronchial mediastinal cryobiopsy: A case report.

Thoracic SMARCA4-deficient undifferentiated tumors (SMARCA4-UT) have a poor prognosis and are often diagnosed at an inoperable advanced stage. Herein, we report a case of SMARCA4-UT diagnosed by endobronchial ultrasound-guided transbronchial cryobiopsy (EBUS-cryo). The patient was a 42-year-old man with a history of smoking. Chest computed tomography revealed a right upper lobe nodule and an enlarged #11s lymph node. Core tissues could not be obtained by EBUS-guided transbronchial needle aspiration (EBUS-TBNA) for diagnosis and mediastinal staging; hence, EBUS-guided intranodal forceps biopsy (EBUS-IFB) was performed. However, a detailed diagnosis beyond poorly differentiated carcinoma could not be obtained. Subsequent EBUS-cryo provided sufficient specimens for immunohistochemical and molecular evaluation and SMARCA4-UT was definitively diagnosed. Thus, EBUS-cryo could be of additional diagnostic value for uncommon tumors, such as SMARCA4-UT, conjointly with EBUS-IFB as well as EBUS-TBNA.

Feasibility of Modified Endobronchial Ultrasound-Guided Intranodal Forceps Biopsy: A Retrospective Analysis.

BACKGROUND: Endobronchial ultrasound (EBUS)-guided intranodal forceps biopsy (IFB), a diagnostic bronchoscopic technique for intrathoracic lymphadenopathy, is performed following EBUS-guided transbronchial needle aspiration (TBNA). The current EBUS-IFB technique is complex and provides small sample volumes. We modified this technique to allow the use of standard-sized forceps. OBJECTIVES: The aim of this study was to assess the feasibility of the modified EBUS-IFB technique, which combines standard-sized forceps with standard EBUS-TBNA equipment. METHOD: This retrospective analysis included consecutive patients scheduled for EBUS-TBNA with attempted additional IFB between July 2020 and March 2021. The feasibility indices of IFB, technical success rate, diagnostic accuracy, and major complications were retrospectively investigated. We performed semi-quantitative evaluation of the histological specimens and univariable analyses to identify factors associated with IFB failure. RESULTS: During the study period, 295 patients underwent 307 EBUS-TBNAs; 195 cases were included in the analyses. Target lesions were mainly mediastinal lymph nodes (134 cases, 68.7%); the most frequent sites were #7 (61 cases) and #4R (50 cases). The median lesion size was 16.1 mm, the technical IFB success rate was 90.8%, and the diagnostic accuracy of the TBNA and IFB combination was 99.5%. One patient was lost to follow-up. Univariable analyses did not identify any factors involved in technical IFB failure. Major complications of pneumonia and pneumothorax occurred in 2 cases (1.0%). The median histological score was significantly higher in the IFB group than in the TBNA group (1.67 vs. 1.50, p = 0.032). CONCLUSIONS: Modified EBUS-IFB, combining standard-sized forceps with common EBUS-TBNA equipment, is feasible with few major complications.

A Diagnostic Predictive Model of Bronchoscopy with Radial Endobronchial Ultrasound for Peripheral Pulmonary Lesions.

BACKGROUND: Several factors have been reported to affect the diagnostic yield of bronchoscopy with radial endobronchial ultrasound (R-EBUS) for peripheral pulmonary lesions (PPLs). However, it is difficult to accurately predict the diagnostic potential of bronchoscopy for each PPL in advance. OBJECTIVES: Our objective was to establish a predictive model to evaluate the diagnostic yield before the procedure. METHOD: We retrospectively analysed consecutive patients who underwent diagnostic bronchoscopy with R-EBUS between April 2012 and October 2015. We assessed the factors that were predictive of successful bronchoscopic diagnosis of PPLs with R-EBUS using a multivariable logistic regression model. The accuracy of the predictive model was evaluated using the receiver operator characteristic area under the curve (ROC AUC). Internal validation was analysed using 10-fold stratified cross-validation. RESULTS: We analysed a total of 1,634 lesions; the median lesion size was 25.0 mm. Of these, 1,138 lesions (69.6%) were successfully diagnosed. In the predictive logistic model, significant factors affecting the diagnostic yield were lesion size, lesion structure, bronchus sign, and visible on chest X-ray. The predictive model consisted of seven factors: lesion size, lesion lobe, lesion location from the hilum, lesion structure, bronchus sign, visibility on chest X-ray, and background lung. The ROC AUC of the predictive model was 0.742 (95% confidence interval: 0.715-0.769). Internal validation using 10-fold stratified cross-validation revealed a mean ROC AUC of 0.734. CONCLUSIONS: The predictive model using the seven factors revealed a good performance in estimating the diagnostic yield.

Predicting Malignant Lymph Nodes Using a Novel Scoring System Based on Multi-Endobronchial Ultrasound Features.

Endobronchial ultrasound (EBUS) features with B-, power/color Doppler, and elastography modes help differentiate between benign and malignant lymph nodes (MLNs) during transbronchial needle aspiration (TBNA); however, only few studies have assessed them simultaneously. We evaluated the diagnostic accuracy of each EBUS feature and aimed to establish a scoring system to predict MLNs. EBUS features of consecutive patients and final diagnosis per lymph node (LN) were examined retrospectively. In total, 594 LNs from 301 patients were analyzed. Univariable analyses revealed that EBUS features, except for round shape, could differentiate MLNs from benign LNs. Multivariable analysis revealed that short axis (>1 cm), heterogeneous echogenicity, absence of central hilar structure, presence of coagulation necrosis sign, and blue-dominant elastographic images were independent predictors of MLNs. At three or more EBUS features predicting MLNs, our scoring system had high sensitivity (77.9%) and specificity (91.8%). The area under the receiver operating curve (AUC) was 0.894 (95% confidence interval (CI): 0.868−0.920), which was higher than that of B-mode features alone (AUC: 0.840 (95% CI: 0.807−0.873)). The novel scoring system could predict MLNs more accurately than B-mode features alone. Multi-EBUS features may increase EBUS-TBNA efficiency for LN evaluation.