Machine learning approaches in the interpretation of endobronchial ultrasound images: a comparative analysis.

BACKGROUND: This study explores the application of machine learning (ML) in analyzing endobronchial ultrasound (EBUS) images for the detection of lymph node (LN) malignancy, aiming to augment diagnostic accuracy and efficiency. We investigated whether ML could outperform conventional classification systems in identifying malignant involvement of LNs, based on eight established sonographic features. METHODS: Retrospective data from two tertiary care hospital bronchoscopy units were utilized, encompassing healthcare reports of patients who had undergone EBUS between January 2017 and March 2023. The ML model was trained and tested using MATLAB, with 80% of the data allocated for training/validation, and 20% for testing. Performance was evaluated based on validation and testing accuracy, and receiver operating characteristic curves with comparing trained models and existing classification rules. RESULTS: The study analyzed 992 LNs, with 42.3% malignancy prevalence. Malignant LNs showed characteristic features such as larger size and distinct margins. The fine tuned models achieved testing accuracies of 95.9% and 96.4% for fine Gaussian SVM and KNN, respectively. Corresponding AUROC's were 0.955 and 0.963, outperforming other similar studies and conventional analyses. CONCLUSION: Fine tuned ML applications like SVM and KNN, can significantly enhance the analysis of EBUS images, improving diagnostic accuracy.

Prediction of malignancy in mediastinal lymph nodes during endobronchial ultrasound: A comparative validation study.

Background: In this study, we aimed to compare the diagnostic performances of three existing prediction tools in visually identifying a malignant lymph node. Methods: Between April 2016 and January 2021, a total of 827 lymph nodes of 259 patients (211 males, 48 females; mean age: 61.1±7.2 years; range, 41 to 79 years) who underwent endobronchial ultrasound procedure for diagnosis and/or staging of lung cancer and diagnosis of mediastinal lymphadenopathy of unknown origin were retrospectively analyzed. This external validation study was designed to compare the diagnostic yields of the prediction tools developed by Shafiek et al., Alici et al., and Canada Lymph Node Score (CLNS). Endobronchial ultrasoundguided transbronchial needle aspiration results and predictions were compared to gold-standard tool. Results: Overall, endobronchial ultrasound-guided transbronchial needle aspiration had a sensitivity, specificity, positive and negative predictive value, and accuracy of 95.6%, 100%, 100%, 97.6%, and 98.4%, respectively. Diagnostic performances of proposed tools were quite remarkable. Among them, Alici algorithm had a higher sensitivity and negative predictive value, which were matched by excellent specificity and positive predictive value offered by CLNS ≥3 and Shafiek tool. The area under the curve value of CLNS ≥3 was higher than Shafiek tool and CLNS ≥2. Conclusion: Conventional prediction tools relying on simple real-time sonographic features were found to be consistent by the means of diagnostic performance in this external validation dataset. Despite being inferior to cytology, their superior performance was proven with defined individual strengths and weaknesses.

Risk Factors for Mortality in Denim Sandblasters Silicosis: Selecting Candidate for Lung Transplantation.

OBJECTIVE: This study aimed to review the risk factors for silicosis together with survival analysis and a perspective for lung transplantation with data from a single center. MATERIAL AND METHODS: We reviewed the medical records of denim sandblasters who were referred to our center between January 2006 and December 2011 and evaluated 219 patients with a history of denim sandblasting with a minimum follow-up period of 5 years until 2016. We analyzed several personal and occupational features, together with functional and radiologic data. RESULTS: Of the 219 denim sandblasters, 107 (49%) had been diagnosed with silicosis. In the logistic regression analysis, the duration of exposure was the only independent risk factor for the development of silicosis, indicating a 9% increased risk of silicosis for every month of exposure (p<0.001; odds ratio 1.09; 95% confidence interval 1.050-1.132). Of the patients, 7 (3%) died. A forced expiratory volume in the first second of <44% and a forced vital capacity of <47% were associated with an increased risk of mortality. Mortality was significantly higher in the international labor office category 3 patients, and 5-year survival rates of patients with A, B, and C lung opacities were 88%, 67%, and 25%, respectively. CONCLUSION: Silicosis still kills young workers. Severe radiologic involvement and decreased lung volumes are related to mortality, and lung transplantation is the only therapeutic option.

EUS-B-FNA for Left Adrenal Lesions in Non-Small Cell Lung Cancer Patients: Report of Cases and Literature Review.

The left adrenal gland (LAG) is a common metastatic site in patients with non-small-cell lung cancer. In practice, staging mainly relies on radiologic studies and endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). Recently, a new technique using convex probe-endobronchial ultrasound (CP-EBUS) scope through the esophagus (EUS-B) has been introduced. A complete mediastinal staging and a reach for upper-abdominal structures in a single session naturally attract attention. However, scientific data are not sufficient to clearly judge the role of this technique in the cytological diagnosis of left adrenal lesions. Therefore, we present cases in which our patients have undergone EUS-B for LAG lesions to increase the data in the literature with regard to accessibility, diagnostic performance, and rate of complications.

Contribution of Cell Block Obtained by Thoracentesis in the Diagnosis of Malignant Pleural Effusion.

AIM: The aim of this study wass to compare the cytological features of pleural exudative fluids by conventional smear (CS) method and cell block (CB) method and also to assess the utility of the combined approach for cytodiagnosis of these effusions. MATERIALS AND METHODS: In all, 113 pleural exudative fluid samples were subjected to evaluation by both CS and CB methods over a period of 2 years. Cellularity, architecture patterns, morphological features, and yield for malignancy were compared, using the two methods. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for diagnosis of malignancy were calculated for both the methods, using histology as a gold standard. RESULTS: CB method provided higher cellularity, better architectural patterns, and additional yield for malignancy when compared with CS method. For 22 (40%) patients, histologic subtype was determined with CB especially for adenocarcinoma. The sensitivity, specificity, positive, and negative predictive values of cytology and CB were 48%, 100%, 100%, 67.8% and 59.2%, 100%, 100%, 72.8%, respectively. CONCLUSION: CB technique definitively increased detection of malignancy in pleural fluid effusion when used as an adjunct to CSs. Also, CB provides material suitable for molecular genetic analysis for targeted therapies especially in the treatment of adenocarcinoma.

A promising tool for T-staging of lung cancer: Is convex probe endobronchial ultrasound superior to computed tomography in detecting invasion of mediastinal and hilar vessels?

BACKGROUND: In the present study, we aimed to compare performance of convex probe endobronchial ultrasound and computed tomography in detecting vascular invasion of mediastinal and hilar lesions. METHODS: Medical data of a total of 55 patients (47 males, 8 females; mean age 59.6±7.7 years; range, 29 to 76 years) who underwent convex probe endobronchial ultrasound for diagnosis and staging of lung cancer in a tertiary care hospital between May 2016 and December 2017 were retrospectively analyzed. The presence of vascular invasion was determined according to two main criteria: visualization of the tumor tissue within the vessel lumen and loss of vessel-tumor hyperechoic interface. All available contrast enhanced computed tomography images were retrospectively re-evaluated by a blinded radiologist. The intra-rater agreement between convex probe endobronchial ultrasound and computed tomography was analyzed. The sensitivity, specificity, positive and negative predictive values, and accuracy of both modalities were calculated. RESULTS: A total of 65 vessel-tumor interface areas of 55 patients were analyzed. Almost all mediastinal and hilar vascular structures including pulmonary arteries and veins, aorta, superior vena cava and its branches, and left atrium with pulmonary veno-atrial junctions could be easily assessed by convex probe endobronchial ultrasound. The intra-agreement of both modalities in detecting vascular invasion was k=0.268 (p=0.028). In nine patients with a surgical confirmation, the sensitivity, specificity, positive and negative predictive values, and accuracy values were 100%, 33.3%, 75.0%, 100%, and 77.7%, respectively for convex probe endobronchial ultrasound and 66.6%, 33.3%, 66.6%, 33.3%, and 55.5%, respectively for computed tomography. CONCLUSION: Convex probe endobronchial ultrasound can be used to detect vascular invasion alone or in conjunction with contrast-enhanced computed tomography. Hence, a T4 lesion would be better differentiated from T3 in clinical staging of lung cancer.

Pitfalls and Challenges of Lung Transplant in a Patient With Kartagener Syndrome and Scoliosis.

We present a 22-year-old woman with Kartagener syndrome and scoliosis who died 112 days after single lung transplant. The classic thoracic involvement of situs inversus totalis and the asymmetric arrangement of the thoracic vascular structures might be a pitfall for surgeon. Anatomic obstacles have forced the surgeon to perform a single transplant. The period of primary graft dysfunction in a single transplanted lung patient was a challenge; supporting the patient with a high flow and long period of extracorporeal membrane oxygenation might lead to a vanishing bronchus. Immotile cilia, a feature of Kartagener syndrome, were another challenge and patient needed several daily aspiration bronchoscopies. Vanishing bronchus is a gradual process with high mortality rates; commonly, stenosis is at the non anastomotic bronchial tree because of insufficient nourishment of the bronchial cartilages. Several repeat bronchoscopic balloon dilatations accompanied with medical treatment were unsuccessful.

EBUS may arise as an initial time saving procedure in patients who are suspected to have small cell lung cancer.

BACKGROUND: Small cell lung cancer (SCLC) commonly presents as hilar/mediastinal masses. In some occasions, conventional flexible bronchoscopy fails and a substantial amount of time is lost until establishing the diagnosis. OBJECTIVE: The aim of the study was to demonstrate the superiority of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) compared to conventional methods in establishing the diagnosis as an initial modality as well as to point out the saved time until the diagnosis. METHODS: We retrospectively reviewed the patients who were diagnosed as SCLC by EBUS-TBNA between April 2010 and January 2016. The demographics of the patients, smoking history were all recorded. We also compared the time between the first computed tomography (1stCT) and first diagnostic procedure (1stDP), 1stDP and final diagnosis (FDx), 1stCT and FDx, and 1stDP and EBUS procedure were also compared. RESULTS: One hundred and thirty-three patients were included in the study. The diagnostic yield of EBUS-TBNA was 98.5%. The mean time between the 1stCT and 1stDP; 1stDP and FDx; 1stCT and FDx; 1stDP and EBUS procedure were 7.0 ± 9.0; 11.8 ± 16.1; 18.8 ± 17.9; and 10.8 ± 16.0 days, respectively. The time between 1stCT to 1stDP was not significantly different in patients with or without previous diagnostic procedures. However, the time between 1stDP to FDx and 1stCT to FDx were significantly higher in the patients with previous procedures (P < .001). The difference in time between 1stDP to FDx and 1stCT to FDx was also similar in patients with only hilar and/or mediastinal lesions (P = .001, P = .006, respectively). CONCLUSION: EBUS-TBNA may be an initial diagnostic procedure in SCLC. Patients with only hilar/mediastinal masses without any endobronchial lesion could be directed to centers with the capability for performing EBUS-TBNA to have a rapid diagnosis without any time loss.

Can Sericin Prove Useful as a Pleurodesis Agent or Tissue Glue?

Background Sericin is a natural, gum-like, macromolecule protein, synthesized from silkworms for the formation of cocoon shells. The aim of the present study is to describe the effects of sericin when used for pleurodesis and/or as tissue glue. Methods Adult, male, 12-week-old Wistar albino rats, weighing 257 to 395 g were used in the present study (n = 12). The animals were randomly divided into two equal groups as the sericin and the control group. After intramuscular administration of the anesthetic agent, the rats were intubated and mechanically ventilated. A left thoracotomy was performed and 30 mg sericin powder was instilled into the thoraxes of the sericin group. The remaining rats were allocated to a sham thoracotomy group. The animals were housed in individual cages, fed ad-libitum, and sacrificed 8 days after. After sacrifice, the left hemithoraxes were removed en bloc and underwent histopathologic examination. Results Masson trichrome staining was applied on the visceral pleura sections of all the animals. Each animal specimen (n = 6, 100%) in the control group showed minimal collagen deposition, while only one rat (16.67%) in the sericin group had minimal collagen deposition. However, in the sericin group, five animals (83.33%) showed dense collagen deposition, fibroblastic activity, and fibrosis. According to the test method, independent t-test, developing fibroblastic activity and fibrosis are statistically significant between the two groups (p < 0.01). There were no foreign-body reactions and no evidence of biological glue on the specimens in the sericin group. The rats in the sericin group had lower inflammatory reactions compared with those in the control group. Emphysema was observed in two rats (33.33%) in the sericin group and in four rats (66.67%) in the control group. Therefore, sericin was found to be associated with an increase in fibroblastic activity and fibrosis in visceral pleura without exerting any adverse effect on the lung parenchyma. Conclusion Sericin is a new and researchable protein for chest diseases and thoracic surgery. To develop an effect of dense collagen deposition, fibroblastic activity, and fibrosis in the visceral pleura, without significant adverse effects, is remarkable. Therefore, sericin may be useful as a pleurodesis agent or natural biological glue in the future. Sericin treatment can add value to the disciplines of pulmonology and thoracic surgery.

How many samples would be optimal for endobronchial cryobiopsy?

BACKGROUND: Cryobiopsy, which provides larger specimens without crush artifact, is a good option for the diagnosis of visible endobronchial tumors. While there are several papers on diagnostic performance, application protocols vary between centers. In this study, we aimed to find the optimal number of cryobiopsies in endobronchial tumors. METHODS: We prospectively involved cases with a visible endobronchial tumor in which conventional diagnostic measures failed and/or a therapeutic interventional bronchoscopy was planned. Endobronchial tumor was visualized, and four cryobiopsies were taken with a dedicated flexible probe. The samples were evaluated by a pathologist who was blinded to the order of the biopsies. The cumulative performances of one to four cryobiopsies were compared, and a complication analysis was conducted. RESULTS: A total of 50 patients were involved. Four cryobiopsies were taken from 49 patients, and a single biopsy was taken from one case. The sensitivities of one, two, three and four biopsies were 82, 93.9, 93.9 and 95.9 %, respectively. The difference in performance of one and two biopsies was significant (p = 0.031), but the third and fourth biopsies were found to be unnecessary (p = 1.0 for second versus third and p = 1.0 for second versus fourth). Bleeding risk increased when ≥3 cryobiopsies were taken (Odds Ratio 2.758). CONCLUSIONS: When the diagnostic benefits and complication rates were considered, two cryobiopsies were found to be optimal for endobronchial tumors. In patients with non-diagnostic conventional bronchoscopy, endobronchial tumors may be diagnosed by cryobiopsy.

The sonographic features of malignant mediastinal lymph nodes and a proposal for an algorithmic approach for sampling during endobronchial ultrasound.

INTRODUCTION: There are several papers on the sonographic features of mediastinal lymph nodes affected by several diseases, but none gives the importance and clinical utility of the features. OBJECTIVE: In order to find out which lymph node should be sampled in a particular nodal station during endobronchial ultrasound, we investigated the diagnostic performances of certain sonographic features and proposed an algorithmic approach. METHODS: We retrospectively analyzed 1051 lymph nodes and randomly assigned them into a preliminary experimental and a secondary study group. The diagnostic performances of the sonographic features (gray scale, echogeneity, shape, size, margin, presence of necrosis, presence of calcification and absence of central hilar structure) were calculated, and an algorithm for lymph node sampling was obtained with decision tree analysis in the experimental group. Later, a modified algorithm was applied to the patients in the study group to give the accuracy. RESULTS: The demographic characteristics of the patients were not statistically significant between the primary and the secondary groups. All of the features were discriminative between malignant and benign diseases. The modified algorithm sensitivity, specificity, and positive and negative predictive values and diagnostic accuracy for detecting metastatic lymph nodes were 100%, 51.2%, 50.6%, 100% and 67.5%, respectively. CONCLUSIONS: In this retrospective analysis, the standardized sonographic classification system and the proposed algorithm performed well in choosing the node that should be sampled in a particular station during endobronchial ultrasound.

Risk factors and maximum standardized uptake values within lymph nodes of anthracosis diagnosed by endobronchial ultrasound-guided transbronchial needle aspiration.

BACKGROUND/AIM: Enlarged mediastinal lymph nodes can result from serious etiologies including granulomatous disease, neoplasia, etc., and a rare condition called anthracosis . The aim of this study was to determine the incidence of risk factors and the uptake values within the anthracotic lymph nodes. MATERIALS AND METHODS: 106 patients who underwent endobronchial ultrasound transbronchial needle aspiration and were diagnosed as having anthracosis were analyzed retrospectively. Patients with positive confirmation by surgical biopsies or a 1-year follow-up period were enrolled. RESULTS: 201 lymph nodes were sampled from 106 patients. Subcarinal and interlobar lymph nodes were the most commonly affected stations (36.8% and 34.3%, respectively). The mean durations of exposure to biomass and cigarette smoke were 35.5 and 33 years, respectively. The mean maximum standardized uptake value (SUVmax) within the lymph nodes was 4.76. The SUVmax of the patients with associated malignancy was 4.19 and the SUVmax of nonmalignant patients was 5.28. This difference was statistically significant (P = 0.009). CONCLUSION: These findings suggest that anthracosis also affects the mediastinal and hilar stations; it should be considered in differential diagnosis in patients with mediastinal and hilar lymphadenopathies with intense uptake on positron emission tomography scans, especially when there is a history of exposure to known risk factors.

Starry sky sign: A prevalent sonographic finding in mediastinal tuberculous lymph nodes.

BACKGROUND AND OBJECTIVES: We report a prevalent finding in tuberculous lymphadenitis (TL): Starry sky sign, hyperechoic foci without acoustic shadows over a hypoechoic background. MATERIALS AND METHODS: We retrospectively searched the database for a possible relationship of starry sky sign with a specific diagnosis and also the prevalence and accuracy of the finding. RESULTS: Starry sky sign was found in 16 of 31 tuberculous lymph nodes, while none of other lymph nodes (1,015 lymph nodes) exhibited this finding; giving a sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of 51.6%, 100%, 100%, 98.5%, and 98.5%, respectively. CONCLUSION: Bacteriologic and histologic findings are gold standard in the diagnosis of tuberculosis, but this finding may guide the bronchoscopist in choosing the more pathologic node within a station and increase the diagnostic yield as it may relate to actively dividing mycobacteria.

Tamoxifen citrate: a glimmer of hope for silicosis.

BACKGROUND: Inhalation of crystalline silica nanoparticles causes pulmonary damage resulting in progressive lung fibrosis. Currently, there is no effective treatment for silicosis. Tamoxifen citrate is a selective estrogen receptor modulator, which is one of the adjuvant treatment choices for breast cancer. It is also known with its inhibitory effect on the production of transforming growth factor-beta (TGF-ß) and studied for the anti-fibrotic effect in some fibrotic diseases. The aim of the study was to determine the effect of tamoxifen citrate on the prevention of pulmonary fibrosis and the treatment of silicosis. METHODS: A total of 100 adult female Wistar Albino rats (200-250 g) were used in this study. The rats were divided into five groups including 20 rats in each. Rats were exposed to silica for 84 d in all groups. In group 1, rats were sacrificed on the day 84 without receiving treatment. In group 2, rats received 1 mg/kg tamoxifen (tmx1 + 1), from the first day of the study for the whole 114 d of the study. In group 3, (tmx10 + 10) rats were given 10 mg/kg tamoxifen from the first day of the study for the whole 114 d of the study. In group 4 (tmx1), rats were started 1 mg/kg of tamoxifen on day 84 and were given until day 114. In group 5 (tmx10), rats were fed with 10 mg/kg tamoxifen starting from day 84 to day 114. All rats except group 1 were sacrificed on 114 day of the study. Lung inflammation and fibrosis scores, serum TGF ß levels, lung smooth muscle antigen and tissue transforming growth factor ß (t-TGF-ß) antibody staining levels, and number of silicotic rats were compared between groups. RESULTS: Silicosis was caused successfully in all rats in group 1. There were six silicotic rats in group 3 and it was the lowest number of all groups. Plasma TGF-ß levels and fibrosis score were significantly lower in all groups when compared with the control group. Tamoxifen could have preventive or treating effects in silicosis and found that lung fibrosis score was significantly lower in rats treated with tamoxifen. CONCLUSIONS: Tamoxifen treatment after and/or before induction of silicosis decreased lung fibrosis score with blood TGF-ß levels. We hope that this study may introduce a new indication as prophylactic use of tamoxifen in high-risk groups for silicosis and for treatment of silicosis.

Two cases of tracheal disease misdiagnosed as difficult-to-treat asthma.

Initial management of patients with difficult-to-treat asthma must begin with confirmation of the diagnosis. We present 2 cases of tracheal disease misdiagnosed as difficult-to-treat asthma. After systemic evaluation, tracheomalacia and tracheobronchial narrowing due to diffuse calcification of the cartilaginous rings were found as mimicking asthma.

The combination of cytological smears and cell blocks on endobronchial ultrasound-guided transbronchial needle aspirates allows a higher diagnostic yield.

We compared the diagnostic performances of conventional smears and cell block preparations of tissue samples obtained with endobronchial ultrasound-guided transbronchial needle aspiration. We retrospectively analysed 451 patients (926 lymph nodes) who had undergone endobronchial ultrasound and for whom both smears and cell blocks were available and compared the diagnostic performances of these techniques when used alone and combined. Cell block preparations showed higher diagnostic performance over smears, but the combination was superior to either alone. The combination of smear and cell block techniques achieved a sensitivity, specificity and positive and negative predictive values of 92.5, 100, 100, 97.7 and 99.4, 95.0, 98.6, and 97.9 % for malignant and benign diseases, respectively. We recommend cell block preparations during endobronchial ultrasound-guided transbronchial needle aspiration.

Cryorecanalization: keys to success.

BACKGROUND: Symptomatic airway obstructions are common with endobronchial exophytic tumors and may result in lethal complications. Recently, a cryorecanalization procedure has emerged that plays a role in the immediate management of airway obstruction. This study was conducted to investigate the value of cryorecanalization for the immediate management of endobronchial obstructive pathology and to determine the factors that affect the success of the procedure. METHODS: We analyzed 40 patients with symptoms of airway obstruction who were admitted to our hospital from 2006 to 2010. Patients with exophytic stenosis due to primary bronchial or metastatic neoplasms who underwent cryorecanalization procedures were included. Patients were excluded if they had involvement of a major artery near the site of the intervention. The procedure was not performed on patients with coagulation abnormalities or thrombocyte count and aggregation problems. The data were collected retrospectively. RESULTS: Successful cryorecanalization was achieved in 72.5 % of patients. We found that the success rate was mainly related to the presence of the distal involvement and the older age of obstruction. Restenosis rate was 17.2 %. [corrected] The mean survival time after the cryorecanalization procedure was 11 ± 12.7 months. No complications occurred in 14 patients. No severe bleeding was observed for any patients, and moderate hemorrhaging occurred in ten patients, which was stopped with an argon plasma coagulator. We experienced no intraoperative mortality. CONCLUSIONS: Cryorecanalization is a successful and safe intervention for the immediate management of endobronchial stenosis. Appropriate patient selection and high success rates should be achieved after careful radiological assessments and with early management.