Pleural Surface Research Articles

Single-step localization and excision of small pulmonary nodules using a mobile 3D C-arm.

The use of a hybrid operating room equipped with robotic C-arm cone-beam computed tomography for single-step localization and excision of small pulmonary nodules finds high cost barriers. The new generation of 3D C-arm system not only depicts soft tissues with high contrast but also offers a more affordable and sustainable solution. This approach has been chiefly applied in the field of orthopedic surgery. In this case series, we describe the use of a mobile 3D C-arm system for localizing and removing small pulmonary nodules. Between July and September 2020, we identified 14 patients who underwent localization and removal of small pulmonary nodules with a 3D C-arm system. We retrospectively reviewed clinical records to document the feasibility and safety of the procedure. The median tumour size was 7.5 mm [interquartile range (IQR): 5 - 9.75 mm], with a median distance from the pleural surface of 4.2 mm (IQR: 0.5 - 6.45 mm). We successfully visualized all of the pulmonary lesions by intraoperative CT imaging. Localization was achieved in 13 patients, who subsequently underwent complete thoracoscopic resection. The median time required to localize lesions was 41.5 min (IQR: 33.75 - 53.25 min), with a median radiation exposure (expressed through the skin absorbed dose) of 143.45 mGy (IQR: 86.1 - 194.6 mGy). Failure to localize occurred in 1 patient because of pneumothorax caused by repeated needle puncture. All patients were successfully discharged and the median length of stay was 2.5 days (IQR: 2 - 3 days). This case series demonstrates the feasibility of single-step localization and excision of small pulmonary nodules using a mobile 3D C-arm.

Pleuroparenchymal fibroelastosis in idiopathic pulmonary fibrosis: Survival analysis using visual and computer-based computed tomography assessment.

BackgroundIdiopathic pulmonary fibrosis (IPF) and pleuroparenchymal fibroelastosis (PPFE) are known to have poor outcomes but detailed examinations of prognostic significance of an association between these morphologic processes are lacking.MethodsRetrospective observational study of independent derivation and validation cohorts of IPF populations. Upper-lobe PPFE extent was scored visually (vPPFE) as categories of absent, moderate, marked. Computerised upper-zone PPFE extent (cPPFE) was examined continuously and using a threshold of 2·5% pleural surface area. vPPFE and cPPFE were evaluated against 1-year FVC decline (estimated using mixed-effects models) and mortality. Multivariable models were adjusted for age, gender, smoking history, antifibrotic treatment and diffusion capacity for carbon monoxide.FindingsPPFE prevalence was 49% (derivation cohort, n = 142) and 72% (validation cohort, n = 145). vPPFE marginally contributed 3–14% to variance in interstitial lung disease (ILD) severity across both cohorts.In multivariable models, marked vPPFE was independently associated with 1-year FVC decline (derivation: regression coefficient 18·3, 95 CI 8·47–28·2%; validation: 7·51, 1·85–13·2%) and mortality (derivation: hazard ratio [HR] 7·70, 95% CI 3·50–16·9; validation: HR 3·01, 1·33–6·81). Similarly, continuous and dichotomised cPPFE were associated with 1-year FVC decline and mortality (cPPFE ≥ 2·5% derivation: HR 5·26, 3·00–9·22; validation: HR 2·06, 1·28–3·31). Individuals with cPPFE ≥ 2·5% or marked vPPFE had the lowest median survival, the cPPFE threshold demonstrated greater discrimination of poor outcomes at two and three years than marked vPPFE.InterpretationPPFE quantification supports distinction of IPF patients with a worse outcome independent of established ILD severity measures. This has the potential to improve prognostic management and elucidate separate pathways of disease progression.FundingThis research was funded in whole or in part by the Wellcome Trust [209,553/Z/17/Z] and the NIHR UCLH Biomedical Research Centre, UK.

Electromagnetic navigation bronchoscopy localization of lung nodules for thoracoscopic resection.

BackgroundThoracoscopic localization of small peripheral pulmonary nodules is a concern. Failure can lead to larger parenchymal resection or conversion to thoracotomy. This study evaluates our experience in preoperative electromagnetic navigation bronchoscopy-guided localization of small peripheral lung lesions.MethodsFrom January 2017 to March 2020 clinical, radiographic, surgical, and pathological data of patients who underwent electromagnetic navigation bronchoscopy (ENB)-guided methylene blue pleural marking of highly suspected pulmonary lesions before a full thoracoscopic resection were evaluated. Localization was performed for solid or mixed subpleural nodules measuring <10 mm, solid nodules measuring <20 mm located at more than 1 cm from the pleura and any pure ground glass opacity. Successful localization was defined as successful identification and thoracoscopic resection of target lesions.ResultsForty-eight patients were included: 30 solid nodules (63%), 12 pure GGO (25%) and 6 mixed (13%). The median largest diameter at CT-scan was 11 mm (IQR, 9–14 mm) while the median distance from the pleural surface was 12 mm (IQR, 6–16 mm). The median ENB length was 25 min (19–33 min). Localization procedure was successful in 45 cases (94%). No procedural-related complications were reported.ConclusionsENB is a safe and accurate preoperative procedure to localize small lung peripheral lesions. The high successful rate, the absence of related complications, the possibility of performing the procedure in the same operating room with a single general anesthesia, make ENB-guided dye marking an advantageous tool for thoracoscopic pulmonary resection.

Role of a portable gamma-camera with optical view for margins assessment of pulmonary nodules resected by radioguided surgery.

Radioguided occult lesion localization (ROLL) of pulmonary nodules is an alternative to hook-wire. Both required of a histological margin assessment. The activity emerging from the radiotracer allows to obtain an intraoperative scintigraphic image of the surgical specimen by a portable gamma-camera (PGC) fitted with an optical view, which provides information about the localization of the nodule in relation to the margins. The aim of this study was to evaluate the intraoperative use of a PGC for margin assessment of pulmonary nodules. ROLL technique was used in 38 nodules (36 pulmonary, 1 chest wall, and 1 pleural nodules). A PGC intraoperative image of the surgical specimen was obtained in 32. Scintigraphic results were compared to the histological assessment. Other factors, such as nodule size, distance from the pleural surface, or distance covered by the needle, were considered as possible factors for non-centered lesions. PGC images showed that the lesion was in contact with the margins in 8/32 cases and centered in 24. In all cases in which the lesion was considered as centered by the PGC, the margins were free of involvement (NPV 100%), although the PPV is low. The use of a PGC for margin assessment after pulmonary nodule resection is feasible and provides a high NPV in our series. In addition, the short intraoperative time required for its use makes the PGC a useful tool for providing supplementary information to histopathologic results. Further studies from different surgical teams are required for an external validation.

Identification of factors affecting the surgical margin in wedge resection using preoperative lipiodol marking.

BackgroundThe factors affecting the surgical margin distance in resection of small lung lesions after preoperative marking are still unclear. The purpose of this study was to identify these factors in wedge lung resection using a localization technique.MethodsThe subjects were 45 patients with small pulmonary nodules who underwent preoperative computed tomography-guided lipiodol marking followed by video-assisted thoracoscopic surgery between April 2017 and December 2019. Data were obtained for nodule size, depth from the pleural surface, imaging features, and procedure-related factors that could affect the surgical margin. Subjects were divided into groups with margin distances <10 and ≥10 mm. Logistic regression analysis was used to identify factors associated with the margin distance.ResultsPreoperative marking was performed using lipiodol prior to resection of 52 nodules (median size, 10.1 mm; range, 6.75–12.3 mm) in 45 patients (23 men, 22 women; median age, 65.4 years). The mean distance from the pleural surface to the pulmonary lesion was 13.8 mm (range, 5.44–22.2 mm). The 3D deviation of the radio-opaque nodule (lipiodol spot) from the lesion was the only significant difference in nodule- and procedure-related factors between the two groups. Multivariate analysis also showed that this 3D deviation was the most significant factor affecting the margin distance (odds ratio, 0.26; 95% CI, 0.08–0.81; P=0.02).ConclusionsThe findings in this study may help to ensure a sufficient surgical margin after preoperative lipiodol marking, through recognition that the 3D deviation of the radio-opaque nodule from the target lesion has a particularly important influence on the margin distance.

Narrative review of theoretical considerations regarding HITHOC between past and future.

Hyppocrates constructed the medicines-surgery-energy triangle which includes all therapeutical modalities. Hyperthermic intraoperative chemotherapy (HITHOC) is a synergy-based single stage multimodality treatment encompassing the locoregional manifestation of the systemic malignant process. Pleural space, thermal effect, lavage/irrigation and chemotherapy represent the basic science ports of the network hub: HITHOC. The malignant transformation and process of the pleural surface (and underlying lung) challenges space management and tissue control. Thermotherapy without local chemotherapy is insufficient, similar to the normothermic local irrigation aligned with anticancer agents. The local administration of combined heat-transfer fluid and chemotherapy with or without subsequent surgical removal offers reasonable outcome in extensive primary pleural neoplasms (malignant mesothelioma), advanced (> Stage IIIA) NSCLC, functionally inoperable lung cancer and pleural carcinosis from extrathoracic malignancies. Measured by symptom-free survival and the quality of life, HITHOC in its present form, offers a modest yet fully substantiated solution. HITHOC in combination with the local application of targeted therapy and/or immunotherapy administered in the pleural space are currently under investigation. Additional development including new acting substances, their solvents and the means regarding surgical delivery and anesthesiology techniques are sign posts up ahead. Level 2 evidence are required in order to stepping up the recommendation levels, rewriting protocols and guidelines, in which HITHOC earns its revered position in the decision making process it deserves.

Surgical Morbidity and Lung Function Changes After Laser-Assisted Pulmonary Metastasectomy: A Prospective Bicentric Study.

Objective: The surgical resection of pulmonary metastases is associated with a survival benefit in selected patients. The use of laser devices for pulmonary metastasectomy (PM) is believed to facilitate the complete resection of metastases while preserving a maximum of healthy parenchyma. This is a prospective study to evaluate surgical outcome including the changes of lung function after laser–assisted surgery (LAS).Methods: A total of 77 operations in 61 patients in which PM was carried out in a curative intent were analyzed. A 1.320 nm diode-pumped Nd: YAG-Laser was used for resection of the metastases. Surgical and clinical data were collected using a standardized form and postoperative lung function changes 3 and 6 months after surgery were assessed using whole body plethysmography and diffusion capacity for carbon monoxide (DLCO). Size and distance of metastases to the pleural surface were measured radiologically.Results: A median of two metastases were resected per operation (range 1–13). The median duration of postoperative air leak was 1 day (range 0–11). LAS associated postoperative minor and major complications were observed in 4 (5%) cases and 1 (1%) case, respectively; there were no mortalities. The analysis of perioperative lung function showed that mean VC 3 months after surgery was reduced by 11 %, FEV1 by 11% and median DLCO by 11% (all p < 0.0001). There was almost no recovery of lung function between 3 and 6 months in the whole cohort. Patients with two or less metastases showed a recovery of lung function after 3 months regarding DLCO (p = 0.003). Decline of DLCO in the whole cohort correlated with the number of resected metastases at 3 months (r = 0.45, p = 0.006) and at 6 months (r = 0.42, p = 0.02) as well as depth of metastases in the parenchyma at 6 months (r = 0.48, p = 0.001).Conclusions: LAS is a safe and effective method for PM even for higher numbers of metastases, with short duration of postoperative air leak and little morbidity. Number and depth, but not size of metastases affect lung function changes after resection.

Immunotherapy in malignant pleural mesothelioma: a review of literature data.

Malignant pleural mesothelioma (MPM) is a rare, aggressive cancer of the pleural surface, associated with asbestos exposure, whose incidence is still growing in some areas of the world. MPM is still considered a rare and an orphan disease with an unchanged median overall survival (OS) ranging from 8 to 14 months and no treatment advances in the last 15 years both in local and advanced disease. In the recent years, chronic inflammation of the mesothelium together with local tumor suppression plays a major role in the malignant transformation. Also, significant heterogeneity in both tumor and the microenvironment is at the basis of MPM biology. Preclinical data have demonstrated the immunogenicity and the lack of an effective antitumor response by the immune system in MPM thus paving the way to the development of immune therapeutics in this disease. Still there is no clear evidence of any predictive biomarker so that, given the close interaction between the immune infiltrate and mesothelial cells, a number of trials are ongoing to investigate the role and prognostic value of the immune microenvironment. In this review we summarize the rationale for immune therapeutics development in MPM, as well as, the relevant literature and ongoing trials of immune checkpoint inhibitors (ICIs) and vaccines used as both first-line treatment and beyond.

Correlation between pleural tags on CT and visceral pleural invasion of peripheral lung cancer that does not appear touching the pleural surface.

To evaluate the association between a sign and visceral pleural invasion (VPI) of peripheral non-small-cell lung cancer (NSCLC) that does not appear touching the pleural surface. A total of 221 consecutive patients with NSCLC that did not appear touching the pleural surface, ≤ 3 cm in solid tumor diameter, and was surgically resected between January 2009 and December 2015 were included. We focused on the flat distortion of the tumor caused by an arch-shaped linear tag between the tumor and the pleura on CT and named it a bridge tag sign. We evaluated the associations between the clinicopathological features of the tumor, including the bridge tag sign, and VPI. We also evaluated the associations between histopathological findings and the bridge tag sign. The utility of the bridge tag sign in the diagnosis of VPI was statistically assessed. The bridge tag sign was observed in 48 (20.8%) patients. VPI was positive in 9 (4.1%) patients; among these, the bridge tag sign was positive in 8 patients. In multivariate analysis, a bridge tag sign was significantly associated with VPI. The bridge tag sign was associated with longer contact length of the pleura with the tumor and trapezoid type pleural retraction. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the bridge tag sign in the diagnosis of VPI were 88.9%, 83.5%, 83.7%, 18.6%, and 99.4%, respectively. A bridge tag sign on CT might improve the accuracy of the prediction of VPI. • We present the bridge tag sign which is defined as a flat distortion of an NSCLC tumor by an arch-shaped linear tag between the tumor and chest wall or interlobar fissure. • The bridge tag sign was an independent predictive factor for visceral pleural invasion. • The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the bridge tag sign in the diagnosis of visceral pleural invasion were 88.9%, 83.5%, 83.7%, 18.6%, and 99.4%, respectively.

Multimodality Imaging of Pleuropulmonary Blastoma: Pearls, Pitfalls, and Differential Diagnosis

Pleuropulmonary blastomas are rare, potentially aggressive embryonal cancers of the lung parenchyma and pleural surfaces that account for 0.25%-0.5% of primary pulmonary malignancies in children. Pleuropulmonary blastomas are classified as cystic (type I), mixed cystic and solid (type II), and solid (type III). Pleuropulmonary blastoma occurs in the same age group (0-6 years) as other more common solid tumors such as neuroblastoma and Wilms tumor. Differential diagnosis includes metastasis from Wilms tumor and macrocystic congenital pulmonary airway malformation (CPAM). A key pathologic and genetic discriminator is the DICER1 germline mutation found in patients with pleuropulmonary blastoma. Imaging, histopathologic, and clinical data are important to use in conjunction in order to determine the diagnosis and risk stratification of pleuropulmonary blastomas. Survival varies from poor to good, depending on type. However, the spectrum of pleuropulmonary blastoma is insufficiently understood due to the variable presentation of this rare disease. We present a current review of the literature regarding pleuropulmonary blastomas in this article.

Regional and organ-level responses to local lung irradiation in sheep

Lung is a dose-limiting organ in radiotherapy. This may limit tumour control when effort is made in planning to limit the likelihood of radiation-induced lung injury (RILI). Understanding the factors that dictate susceptibility to radiation-induced pulmonary fibrosis will aid in the prevention and management of RILI, and may lead to more effective personalized radiotherapy treatment. As the interaction of regional and organ-level responses may shape the chronic consequences of RILI, we sought to characterise both aspects of the response in an ovine model. A defined volume of left pulmonary parenchyma was prescribed 5 fractions of 6 Gy within 14 days while the contralateral lung dose was constrained. Radiographic changes via computed tomography (CT) were documented to define differences in radio-exposed lung relative to non-exposed lung at d21, d63 and d171 (n = 2), and at d21, d147 and d227 (n = 2). Gross and histologic lung changes were evaluated in samples derived at necropsy examination to define the chronic pulmonary response to radiation. Irradiated lung demonstrated reduced radio-density and increased homogeneity as evidenced from texture based radiomic feature analysis, relative to the control lung. At necropsy, the radiation field was readily defined by pallor on the pleural surface, which was also evident on the cut surface of fixed lung specimens. The degree and homogeneity of pallor reflected the sparse presence of erythrocytes in alveolar septal capillaries of radiation-exposed lung. These changes contrasted with dilated and congested microvasculature in the contralateral control lung. Referencing data to measurements made in control lung volumes of sheep experiencing acute RILI indicated that interstitial collagen continues to deposit in the radio-exposed lung field. Overall lung vascularity increased during the chronic response, as evidenced by increased expression of endothelial cell marker (CD31); however, vascularity was consistently decreased in irradiated lung and was negatively correlated with lung collagen. Other organ-level responses included increased expression of alpha smooth muscle actin (ASMA), increased numbers of proliferating cells (Ki67 positive), and cells expressing the dendritic cell-lysosomal associated membrane protein (DC-LAMP) antigen. The chronic response to RILI in this model is effected at both the whole organ and local lung level. Whilst the long-term consequences of exposure to radiation involved the continued deposition of collagen in the radiation field, organ-level responses also included increased vascularization and increased expression of ASMA, Ki67 and DC-LAMP. Interrupting the interplay between these aspects may influence susceptibility to pulmonary fibrosis after radiotherapy. We advocate for the importance of large animal model systems in pursuing these opportunities to target local, organ-level and systemic mechanisms in parallel within the same subject over time.

Preoperative computer tomography-guided indocyanine green injection is associated with successful localization of small pulmonary nodules.

BackgroundLocalization of small pulmonary nodules (SPNs) is challenging in minimally invasive pulmonary resection, and it is unknown whether computer tomography (CT) guided by indocyanine green (ICG) can provide accurate localization with minimal complications.MethodsWe performed a retrospective study of patients who underwent thoracoscopic resection of pulmonary nodules after CT-guided preoperative localization with ICG from May 2019 to May 2020. Demographics, procedural data, postoperative complications, and pathologic information, were collected, and an analysis of the accuracy and complications after surgery was conducted.ResultsIn 471 patients, there was a total of 512 peripheral pulmonary nodules that were ≤2 cm in size. The average time for CT-guided percutaneous ICG injection for localization was 18 minutes, and 98.4% (504/512) of the nodules were successfully localized. The average size of the nodules was 9.1 mm, and the average depth from the pleural surface was 8.9 mm. Overall, 5.9% (28/471) of the patients had asymptomatic pneumothorax after localization, but none needed a tube thoracostomy. All the nodules were resected using video-assisted thoracoscopy technique.ConclusionsPreoperative CT-guided transthoracic ICG injection is safe and feasible for localization of small lung nodules for minimally invasive pulmonary resection. This technique should be considered for preoperative CT-guided localization of small lung nodules.

Intradialytic Hypotension in Critically Ill Patients on Hemodialysis With A-Line versus B-Line Pattern on Lung Ultrasonography

Intradialytic Hypotension in Critically Ill Patients on Hemodialysis With A-Line versus B-Line Pattern on Lung Ultrasonography

Toraks Bilgisayarlı Tomografisinde Tesadüfen Saptanan Nadir Bir Anatomik Varyasyon: Azigos Lobu

Aim: An azygos lobe is an unusual anatomical variation of the upper lobe of the right lung. During the formation of the lungs, the right azygos lobe develops as the precursor of the azygos vein, moving along the pleural surface rather than arcing forward above the origin of the lung to reach the upper vena cava, enters the apex of the right lung in the upper thoracic region. The purpose of this study was to assess the prevalence of the right azygos lobe in a sample of the Turkish population.Methods: This study was conducted from February to October 2020. Each computed tomography (CT) scan was checked for the presence of a right azygos lobe and a fissure on the axial plane. The azygos lobe was described as the convex line in the paramediastinal portion of the upper right lung on the CT scan. Our exclusion criteria were previous thoracic surgery in the right lung or parenchymal distortion on CT examinations.Results: One thousand nine hundred and sixty-five thorax CT scans were evalu¬ated retrospectively. Nine hundred and forty-five of them were from men and the remainder were from women. A total of 15 right azygos lobe variations were detected (six females, nine males). The mean age of the patients was 52.87 ± 14.604 years (30–77). The azygos lobe frequency was 0.76%.Conclusion: The azygos lobe is typically an uncommon variation of the right lung and is not really a distinct lobe. It is a very important variation that should be known about as it can mimic pathological conditions such as cysts, abscesses, or lung le¬sions. Since the azygos lobe is usually an incidental finding, radiologists and sur¬geons should be aware of this this potential anomaly during the imaging and inter¬ventional procedures.

Transpleural systemic artery-to-pulmonary artery communications in the absence of chronic inflammatory lung disease. A case series and review of the literature

To describe the causes and computed tomography (CT) and angiographic appearances of transpleural systemic artery-to-pulmonary artery shunts in patients without chronic inflammatory lung disease and determine their best management. All patients referred to a tertiary referral unit between January 2009 and January 2020 in whom a diagnosis of a systemic-to-pulmonary artery communication without underlying chronic inflammatory lung disease was subsequently made have been included in this report. Medical records and imaging findings were reviewed retrospectively. Ten patients (male: female ratio=7:3; median age 42 years [range 22-70 years]) with systemic artery-to-pulmonary artery shunts without chronic inflammatory lung disease were identified. Five were misdiagnosed as having a pulmonary arteriovenous malformation and had been referred for embolisation. In six patients, there was either a history of accidental or iatrogenic thoracic trauma or of inflammatory disease involving the pleura, and in two patients, in whom a previous medical history could not be obtained, there were CT features suggesting previous pleural inflammatory disease. Two shunts were thought to be congenital. All individuals were asymptomatic other than one with localised thoracic discomfort that dated from the time of surgery. All patients were managed conservatively and have remained well with a median follow-up of 4.5 years (range 1-11.3 years). Localised transpleural systemic artery-to-pulmonary artery shunts in the absence of chronic inflammatory lung disease are usually related to previous thoracic trauma/intervention or abdominal or pulmonary sepsis involving a pleural or diaphragmatic surface. Congenital shunts are rare. The present study and much of the literature supports conservative management.

Propensity-score-matching analysis to compare efficacy and safety between 16-gauge and 18-gauge needle in ultrasound-guided biopsy for peripheral pulmonary lesions

BackgroundDefinitive diagnosis of peripheral pulmonary lesions (PPLs) depends on the histological analysis of the pleural biopsy sample. Ultrasound (US)-guided sampling is now standard practice in the clinical setting. However, determining a suitable needle size and sampling times to improve the efficacy and safety of the biopsy remains challenging. Here, we compared the efficacy between 16- and 18-gauge core biopsy needles in US-guided percutaneous transthoracic biopsy for PPLs on histological diagnosis and procedure-related complications.Materials and methodsIn total, 1169 patients (767 men, 402 women; mean age, 59.4 ± 13.2 years) who received biopsy for PPLs between September 2011 and February 2019 were included. The propensity score matching (PSM) analysis was performed to adjust the baseline differences, and the rate of successful specimen assessment and complications were compared between the 16-gauge (249 patients) and 18-gauge (920 patients) groups. The number of pleural surfaces crossed (NOPSC) was defined as the number of times the visceral pleural surface was transgressed. Stratified analysis was performed based on NOPSC.ResultsThe overall success rate was 92.0% (1076/1169). The overall complication rate was 9.6%, including pneumothorax, hemorrhage, and vasovagal reaction, which occurred in 2.5% (29/1169), 6.6% (77/1169), and 0.5% (6/1169) of the patients, respectively. When NOPSC was 1 or > 2, the success and complication rates in the 16-gauge group were comparable to those of the 18-gauge group (all P > 0.05). When the NOPSC was 2, the success rate in the 16-gauge group was significantly higher than that in the 18-gauge group (P = 0.017), whereas the complication rate was comparable (P > 0.05).ConclusionHigher success rate could be achieved using a 16-gauge than an 18-gauge core biopsy needle in the US-guided percutaneous transthoracic biopsy for PPLs when the NOPSC was 2. We recommend using 16-gauge needles with 2 times of needle passes in biopsy for PPLs in clinical practice.

Automatic detection and segmentation of lung nodules in different locations from CT images based on adaptive α‐hull algorithm and DenseNet convolutional network

AbstractAutomatic lung nodules detection and segmentation can assist doctors in better diagnosis and treatment for lung cancer. However, precise detection and segmentation are still challenging, because lung nodules can have different contours or locations and may be attached to other tissues, such as neighboring blood vessel and pleural surface. In this study, an automatic detection and segmentation method for lung nodules in different locations has been developed. First, we apply Otsu thresholding to segment lung parenchyma. Next, a morphological opening operation is carried out to remove blood vessels. Then α‐hull operation is proposed to correct lung contours and optimal α values can be acquired adaptively. Finally, DenseNet convolutional network is applied to classify true lung nodules from all nodule candidates. We select the intersection area of at least three radiologists' annotations as ground truth and validate our method on 466 nodules including well‐circumscribed, juxta‐vascular, juxta‐pleural, and pleural tail. Our study not only concentrates on false positive reduction but also evaluates segmentation performance. To give a more comprehensive quantitative evaluation of nodule segmentation, we use evaluation metrics including Jaccard index (JI), dice similar coefficient (DSC), Hausdorff distance, under‐segmentation rate, over‐segmentation rate, sensitivity, specificity, accuracy, and false positive rate. Overall results are 0.6385 ± 0.1309, 0.7710 ± 0.1057, 3.5123 ± 3.1251, 0.1769 ± 0.1308, 0.1848 ± 0.1463, 0.7936 ± 0.1417, 0.9998 ± 0.0003, 0.9997 ± 0.0003, and 0.0002 ± 0.0003, respectively. These metrics can demonstrate segmentation performance in multiple dimensions. As a general and automatic detection and segmentation framework for lung nodules in different locations, this study achieves better performance than previous approaches in JI and DSC.

Pneumothorax Induced by Computed Tomography Guided Transthoracic Needle Biopsy: A Review for the Clinician.

Percutaneous computed tomography (CT)-guided transthoracic needle biopsy (TTNB) is a valuable procedure for obtaining tissue or cells for diagnosis, which is especially indispensable in thoracic oncology. Pneumothorax and hemoptysis are the most common complications of percutaneous needle biopsy of the lung. According to reports published over the past decades, pneumothorax incidence in patients who underwent TTNB greatly varies. The morbidity of pneumothorax after CT-guided TTNB depends on several factors, including size and depth of lesions, emphysema, the number of pleural surfaces and fissure crossed, etc. Attention to biopsy planning and technique and post-biopsy precautions help to prevent or minimize potential complications. Many measures can be taken to help prevent the progression of a pneumothorax, which in turn might reduce the number of pneumothoraces requiring chest tube placement. A multitude of therapeutic options is available for the treatment of pneumothorax, varying from observation and oxygen treatment, simple manual aspiration, to chest tube placement. When a pneumothorax develops during the biopsy procedure, it can be manually aspirated after the needle is retracted back into the pleural space or by inserting a separate needle into the pleural space. Biopsy side down positioning of the patient after biopsy significantly reduces the incidence of pneumothorax and the requirement of chest tube placement. Aspiration in biopsy side down position is also recommended for treating pneumothorax when simple manual aspiration is unsuccessful or delayed pneumothorax occurred. Chest tube placement is an important treatment strategy for patients with a large or symptomatic pneumothorax. Clinicians are encouraged to understand the development, prevention, and treatment of pneumothorax. Efforts should be made to reduce the incidence of pneumothorax in biopsy planning and post-biopsy precautions. When pneumothorax occurs, appropriate treatment should be adopted to reduce the risk of worsening pneumothorax.

WFUMB position paper on reverberation artefacts in lung ultrasound: B-lines or comet-tails?

The analysis of vertical reverberation artefacts is an essential component of the differential diagnosis in pulmonary ultra-sound. Traditionally, they are often, but not exclusively, called B-line artefacts (BLA) and/or comet tail artefacts (CTA), but this view is misleading. In this position paper we clarify the terminology and relation of the two lung reverberation artefacts BLA and CTA to spe-cific clinical scenarios. BLA are defined by a normal pleura line and are a typical hallmark of cardiogenic pulmonary edema after exclusion of certain pathologies including pneumonia or lung contusion, whereas CTAs show an irregular pleura line representing a variety of parenchymal lung diseases. The dual approach using low frequency transducers to determine BLA and high frequency transducer to determine the pleural surface is recommended.

Computerized tomography-Guided Microwave Ablation of Patients with Stage I Non-small Cell Lung Cancers: A Single-Institution Retrospective Study.

Objectives:The objective of the study was to retrospectively investigate the safety and efficacy of computerized tomography-guided microwave ablation (MWA) in the treatment of Stage I non-small cell lung cancers (NSCLCs).Material and Methods:This retrospective, single-center study evaluated 21 patients (10 males and 11 females; mean age 73.8 ± 8.2 years) with Stage I peripheral NSCLCs treated with MWA between 2010 and 2020. All patients were surveyed for metastatic disease. Clinical success was defined as absence of FDG avidity on follow-up imaging. Tumor growth within 5 mm of the original ablated territory was defined as local recurrence. Welch t-test and Fisher’s exact test were used for univariate analysis. Hazard ratio (HR) and odds ratio (OR) were determined using Cox regression and Firth logistic regression. Significance was P < 0.05. Data are expressed as mean ± standard deviation.Results:Ablated tumors had longest dimension 17.4 ± 5.4 mm and depth 19.7 ± 15.1 mm from the pleural surface. Median follow-up was 20 months (range, 0.6–56 months). Mean overall survival (OS) following lung cancer diagnosis or MWA was 26.2 ± 15.4 months (range, 5–56 months) and 23.7 ± 15.1 months (range, 3–55 months). OS at 1, 2, and 5 years was 67.6%, 61.8%, and 45.7%, respectively. Progression-free survival (PFS) was 19.1 ± 16.2 months (range, 1–55 months). PFS at 1, 2, and 5 years was 44.5%, 32.9%, and 32.9%, respectively. Technical success was 100%, while clinical success was observed in 95.2% (20/21) of patients. One patient had local residual disease following MWA and was treated with chemotherapy. Local control was 90% with recurrence in two patients following ablation. Six patients (28.6%) experienced post-ablation complications, with pneumothorax being the most common event (23.8% of patients). Female gender was associated with 90% reduction in risk of death (HR 0.1, P = 0.014). Tumor longest dimension was associated with a 10% increase in risk of death (P = 0.197). Several comorbidities were associated with increased hazard. Univariate analysis revealed pre-ablation forced vital capacity trended higher among survivors (84.7 ± 15.2% vs. 73 ± 21.6%, P = 0.093). Adjusted for age and sex, adenocarcinoma, and neuroendocrine histology trended toward improved OS (OR: 0.13, 0.13) and PFS (OR: 0.88, 0.37) compared to squamous cell carcinoma.Conclusion:MWA provides a safe and effective alternative to stereotactic brachytherapy resulting in promising OS and PFS in patients with Stage I peripheral NSCLC. Larger sample sizes are needed to further define the effects of underlying comorbidities and tumor biology.