Evaluation Of Mediastinal Nodes Research Articles

Preoperative evaluation of mediastinal lymph nodes in non-small cell lung cancer using [68Ga]FAPI-46 PET/CT: a prospective pilot study.

Mediastinal nodal staging is crucial for surgical candidate selection in non-small cell lung cancer (NSCLC), but conventional imaging has limitations often necessitating invasive staging. We investigated the additive clinical value of fibroblast activation protein inhibitor (FAPI) PET/CT, an imaging technique targeting fibroblast activation protein, for mediastinal nodal staging of NSCLC. In this prospective pilot study, we enrolled patients scheduled for surgical resection of NSCLC based on specific criteria designed to align with indications for invasive staging procedures. Patients were included when meeting at least one of the following: (1) presence of FDG-positive N2 lymph nodes, (2) clinical N1 stage, (3) central tumor location or tumor diameter of ≥ 3 cm, and (4) adenocarcinoma exhibiting high FDG uptake. [68Ga]FAPI-46 PET/CT was performed before surgery after a staging workup including [18F]FDG PET/CT. The diagnostic accuracy of [68Ga]FAPI-46 PET/CT for "N2" nodes was assessed through per-patient visual assessment and per-station quantitative analysis using histopathologic results as reference standards. Twenty-three patients with 75 nodal stations were analyzed. Histopathologic examination confirmed that nine patients (39.1%) were N2-positive. In per-patient assessment, [68Ga]FAPI-46 PET/CT successfully identified metastasis in eight patients (sensitivity 0.89 (0.52-1.00)), upstaging three patients compared to [18F]FDG PET/CT. [18F]FDG PET/CT detected FDG-avid nodes in six (42.8%) of 14 N2-negative patients. Among them, five were considered non-metastatic based on calcification and distribution pattern, and one was considered metastatic. In contrast, [68Ga]FAPI-46 PET/CT correctly identified all non-metastatic patients solely based on tracer avidity. In per-station analysis, [68Ga]FAPI-46 PET/CT discriminated metastasis more effectively compared to [18F]FDG PET/CT-based (AUC of ROC curve 0.96 (0.88-0.99) vs. 0.68 (0.56-0.78), P < 0.001). [68Ga]FAPI-46 PET/CT holds promise as an imaging tool for preoperative mediastinal nodal staging in NSCLC, with improved sensitivity and the potential to reduce false-positive results, optimizing the need for invasive staging procedures.

Pathologic Nodal Staging Before SBRT for Early-stage NSCLC Does Not Impact Overall Survival: A Propensity Score-matched NCDB Analysis.

Stereotactic body radiation therapy (SBRT) for early-stage non-small cell carcinoma of the lung (NSCLC) is increasingly utilized. We sought to assess overall survival (OS) for early-stage NSCLC patients receiving SBRT depending on staging method. Early-stage NSCLC patients treated with definitive SBRT were identified in the National Cancer Database (NCDB), and OS was determined based on method of staging. Patient, disease, and treatment characteristics were also analyzed. A total of 12,106 patients were included; 865 (7%) received invasive staging (nodal sampling, NS) and 11,241 (93%) had no nodal sampling (NNS). From this larger dataset, a propensity score matching (1:1 without replacement) was performed, which yielded 839 patients for each group (NNS and NS). With a median follow-up time of 3.12 years, median survival for all patients included in the matched dataset was 2.75 years (95% CI: 2.55-2.93y), with 2- and 5-year OS estimated at 63.9% and 25.7%, respectively. In a multivariable analysis on matched data, there was no difference in mortality risk between the NNS and NS groups (hazard ratio=1.08, 95% CI: 0.94-1.24, P =0.25). Negative prognostic factors identified in the multivariable analysis of the matched data included: age more than 65, male sex, Charlson-Deyo Score ≥1, and tumor size ≥3cm. SBRT use in early-stage NSCLC steadily increased over the study period. Most patients proceeded to SBRT without nodal staging, conflicting with National Comprehensive Cancer Network (NCCN) guidelines which recommend pathologic mediastinal lymph node evaluation for all early-stage NSCLC cases, except stage IA. Our findings suggest similar OS in patients with early-stage NSCLC treated with SBRT irrespective of nodal staging. Furthermore, we highlight patient-related, disease-related, and treatment-related prognostic factors to consider when planning therapy for these patients.

Dual targeting PET tracer [68Ga]Ga-FAPI-RGD in patients with lung neoplasms: a pilot exploratory study.

Rationale: Early discovery, accurate diagnosis, and staging of lung cancer is essential for patients to receive appropriate treatment. PET/CT has become increasingly recognized as a valuable imaging modality for these patients, but there remains room for improvement in PET tracers. We aimed to evaluate the feasibility of using [68Ga]Ga-FAPI-RGD, a dual-targeting heterodimeric PET tracer that recognizes both fibroblast activation protein (FAP) and integrin αvβ3 for detecting lung neoplasms, by comparing it with [18F]FDG and single-targeting tracers [68Ga]Ga-RGD and [68Ga]Ga-FAPI. Methods: This was a pilot exploratory study of patients with suspected lung malignancies. All 51 participants underwent [68Ga]Ga-FAPI-RGD PET/CT, of which: 9 participants received dynamic scans, 44 participants also underwent [18F]FDG PET/CT scan within two weeks, 9 participants underwent [68Ga]Ga-FAPI PET/CT scan and 10 participants underwent [68Ga]Ga-RGD PET/CT scan. The final diagnosis was made based on histopathological analyses and clinical follow-up reports. Results: Among those who underwent dynamic scans, the uptake of pulmonary lesions increased over time. The optimal timepoint for a PET/CT scan was identified to be 2 h post-injection. [68Ga]Ga-FAPI-RGD had a higher detection rate of primary lesions than [18F]FDG (91.4% vs. 77.1%, p < 0.05), higher tumor uptake (SUVmax, 6.9 ± 5.3 vs. 5.3 ± 5.4, p < 0.001) and higher tumor-to-background ratio (10.0 ± 8.4 vs. 9.0 ± 9.1, p < 0.05), demonstrated better accuracy in mediastinal lymph node evaluation (99.7% vs. 90.9%, p < 0.001), and identified more metastases (254 vs. 220). There was also a significant difference between the uptake of [68Ga]Ga-FAPI-RGD and [68Ga]Ga-RGD of primary lesions (SUVmax, 5.8 ± 4.4 vs. 2.3 ± 1.3, p < 0.001). Conclusion: In our small scale cohort study, [68Ga]Ga-FAPI-RGD PET/CT gave a higher primary tumor detection rate, higher tracer uptake, and improved detection of metastases compared with [18F]FDG PET/CT, and [68Ga]Ga-FAPI-RGD also had advantages over [68Ga]Ga-RGD and was non-inferior to [68Ga]Ga-FAPI. We thus provide proof-of-concept for using [68Ga]Ga-FAPI-RGD PET/CT for diagnosing lung cancer. With the stated advantages, the dual-targeting FAPI-RGD should also be explored for therapeutic use in future studies.

SPACES: Our team's experience in lung tumor microwave ablation.

The standard treatment of stage I nonsmall cell lung cancer is lobectomy with systematic mediastinal lymph node evaluation. Unfortunately, up to 25% of patients with stage I nonsmall cell lung cancer are not candidates for surgery due to severe medical comorbidities (poor cardiopulmonary function). Image-guided thermal ablation is an alternative for those patients, includes radiofrequency ablation, microwave ablation (MWA), cryoablation, and laser ablation. Compared to them, MWA is a relatively new technique with some potential advantages, such as faster heating times, higher intralesional temperatures, larger ablation zones, less procedural pain, relative insensitivity to "heat sinks," and less sensitivity to tissue types. However, some advantages of MWA mentioned above (such as higher intralesional temperatures, larger ablation zones) also have potential risks and problems, and an innovative and standardized guidance system is needed to avoid and solve these risks and problems. This article combs our team's clinical experience over the past decade, summarizes a systematic and standardized guidance system, and names it SPACES (Selection, Procedure, Assessment, Complication, Evaluation, Systemic therapy). Both primary and metastatic pulmonary tumors can be efficiently treated with image-guided thermal ablation in selected candidates. The selection and use of ablation techniques should consider the size and location of the target tumor, the risk of complications, and the expertise and skills of the professionals, among which the size of the target tumor (<3 mm) is a major factor determining the success of ablation.

A Comparison of Surgical Mediastinal Lymph Node Evaluation in Clinical N0 Non-small Cell Lung Cancer between Video-Assisted Thoracoscopic Lobectomy and Open Lobectomy

Background: Video-assisted thoracoscopic surgery (VATS) for lobectomy is increasingly a procedure for early-stage lung cancer surgery, but the controversy remains on the adequacy of the lymph node evaluation. Objective: To compare the completeness of surgical mediastinal lymph node evaluation between VATS lobectomy and open lobectomy in clinical N0 non-small cell lung cancer (NSCLC). Material and Methods: Between January 2015 and August 2020, 312 patients who underwent lobectomy for clinical N0 NSCLC at Central Chest Institute of Thailand were reviewed, including 149 patients in VATS lobectomy and 163 patients in open lobectomy. Patient characteristics, surgical outcomes, and lymphadenectomy results were analyzed and compared. Results: VATS lobectomy had prolonged operative time minute at 198.4±46.8 versus 160.9±73.6 (p≤0.001) but less blood loss at 100 versus 150 (p=0.034) than open lobectomy. The sampling procedure was more frequently performed in the open lobectomy at 44.2% versus 19.5% (p≤0.001), but the VATS lobectomy used the systematic dissection procedure mainly at 67.1% versus 42.9% (p≤0.001). The median overall number of lymph nodes at 19 versus 12 (p≤0.001) and the number of stations N2 nodes at 12 versus 6 (p≤0.001), especially in station 7 were dissected higher in the VATS lobectomy at 130 versus 100 (p≤0.001), but the number of stations N1 nodes was similar. The rate of lymph node upstaging was not significantly different between the two groups (p=0.176). The risk factor for lymph node upstaging was only the tumor size. There were no differences in complication and mortality. Conclusion: The completeness of mediastinal lymph node evaluation for patients with clinical N0 NSCLC operated on by an experienced surgeon in VATS lobectomy was comparable with the open lobectomy. Keywords: Video-assisted thoracic surgery; Open thoracotomy; Mediastinal lymph node assessment; Non-small cell lung cancer

Endobronchial ultrasound-guided transbronchial needle aspiration in diagnosing mediastinal lymphadenopathy: Experience from a tertiary care centre

BackgroundThe evaluation of mediastinal lymphadenopathy and masses poses a diagnostic challenge because of a myriad of possible etiologic causes; their proximity to numerous vital structures and the difficulty of access for biopsy. Computed tomography is an excellent modality for the initial evaluation of mediastinal lymph nodes (LNs). Tissue diagnosis is of paramount importance to confirm the diagnosis of mediastinal lymphadenopathy. Of various modalities including CT-guided biopsy, mediastinoscopy is considered a gold standard for tissue acquisition, but it is associated with considerable morbidity. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive method of sampling of mediastinal LNs and its role has been established in malignant cause of LN enlargement. However, its role in diagnosing benign diseases has not been studied much. MethodsIn a cross-sectional observational study, we performed EBUS-TBNA of 116 patients, and the sample was evaluated by various pathological modalities. ResultsMost common LN sampled was subcarinal (68%). MTB gene Xpert was positive in 45 cases, and resistance was detected in 3 cases. Most common diagnosis was tuberculous lymphadenitis (67.9%). Only five of our patients had post-operative bronchospasm, while four had peri-operative hypoxia, which was managed with oxygen therapy. ConclusionEBUS-TBNA is an excellent modality for sampling mediastinal LNs, which is very safe and can be done on an OPD basis.

Mediastinal lymph node evaluation, especially at station 4L, in left upper lobe lung cancer.

BackgroundMediastinal lymph node (LN) dissection during lung resection is essential for accurate staging. Station 4L dissection is anatomically difficult. Therefore, care should be taken to avoid complications. We investigated the importance of mediastinal LN dissection in left upper lobe lung cancer and evaluated intraoperative videos to identify relevant steps during dissection.MethodsWe retrospectively reviewed 151 consecutive patients with left upper lobe lung cancer. Finally, 139 patients were enrolled to examine the survival effects of clinical factors of metastatic LN stations. The association between risk factors or surgical procedures and recurrent laryngeal nerve palsy was analyzed.ResultsLN dissection of the left upper lobe revealed station 4L LN metastasis in nine patients, three of whom were node-negative on mediastinoscopy. Station 4L LN status was confirmed intraoperatively in 12 of 33 patients. Twenty patients had recurrent laryngeal nerve palsy, four of whom were complicated with aspiration pneumonia. Station 4L LN dissection was an independent risk factor for recurrent laryngeal nerve palsy (P=0.03). The use of an energy device near the recurrent laryngeal nerve was a significant risk factor for recurrent laryngeal nerve palsy. Incidentally, pathological N stage ≥2 was an independent prognostic factor for disease-free survival (DFS) (P=0.005) herein.ConclusionsIn patients with left upper lobe lung cancer, pathological N2 disease is an important predictor of recurrence. Therefore, accurate mediastinal LN dissection, including at station 4L, should be performed. We propose to standardize the dissection procedure at each institution to avoid complications, such as recurrent laryngeal nerve palsy.

Biphasic split-bolus injection protocol for routine contrast-enhanced chest CT: comparison with conventional early-phase single bolus technique.

To present a routine contrast-enhanced chest CT protocol with a split-bolus injection technique achieving combined early- and delayed phase images with a single aquisition, and to compare this technique with a conventional early-phase single-bolus chest CT protocol we formerly used at our institution, in terms of attenuation of great thoracic vessels, pleura, included hepatic and portal venous enhancement, contrast-related artifacts, and image quality. A total of 202 patients, who underwent routine contrast-enhanced chest CT examination aquired with either conventional early-phase single-bolus technique (group A,n = 102) or biphasic split-bolus protocol (group B,n = 100), were retrospectively included. Attenuation measurements were made by two radiologists independently on mediastinal window settings using a circular ROI at the following sites: main pulmonary artery (PA) at its bifurcation level, thoracal aorta (TA) at the level of MPA bifurcation,portal vein (PV) at porta hepatis, left and right hepatic lobe, and if present, thickened pleura (>2 mm) at the level with the most intense enhancement. Respective normalized enhancement values were also calculated. Contrast-related artifacts were graded and qualitative evaluation of mediastinal lymph nodes was performed by both reviewers independently. Background noise was measured and contrast-to-noise ratios (CNRs) of the liver and TA were calculated. While enhancement of thoracic vessels and normalised MPA enhancement did not differ significantly between both groups (p > 0.05), enhancement and normalised enhancement of pleura, liver parenchyma and PV was significantly greater in group B (p < 0.001). Perivenous artifacts limiting evaluation were less frequent in group B than in A and mediastinal lymph nodes were judged to be evaluated worse in group A than in group B with an excellent agreement between both observers. No significant difference was detected in CNRTA (p = 0.633), whereas CNR liver was higher in group B (p < 0.001). Our split-bolus chest CT injection protocol enables simultaneous enhancement for both vascular structures and soft tissues, and thus, might raise diagnostic confidence without the need of multiple acquisitions. We think that this CT protocol might also be a promising alternative in lung cancer staging, where combined contrast-enhanced CT of the chest and abdomen is indicated. We therefore suggest to further evaluate its diagnostic utility in this setting, in particular in comparison with a late delayed chest-upper abdominal CT imaging protocol.

Role of endoscopic ultrasound guided fine needle aspiration/biopsy in the evaluation of intra-abdominal lymphadenopathy due to tuberculosis.

BACKGROUNDIntra-abdominal lymphadenopathy due to tuberculosis (TB) poses a diagnostic challenge due to difficulty in tissue acquisition. Although endoscopic ultrasound guided fine needle aspiration/biopsy (EUS-FNA/B) has shown promise in the evaluation of mediastinal lymph nodes, its role in the evaluation of intra-abdominal lymphadenopathy is not clear. AIMTo assess the role of EUS-FNA/B in the evaluation of intra-abdominal lymphadenopathy due to TB.METHODSThis was a retrospective study where patients with intra-abdominal lymphadenopathy who underwent evaluation with EUS-FNA/B were included. TB was diagnosed if the patient had any one of the following: (1) Positive acid fast bacilli (AFB) stain/TB GeneXpert/TB-polymerase chain reaction/AFB culture of tissue sample; and (2) Positive Mantoux test and response to anti-tubercular therapy. EUS-FNA reports, clinical reports and imaging characteristics of patients were recorded for a detailed analysis of patients with TB. RESULTSA total of 149 patients underwent an EUS-FNA/B from lymph nodes (mean age 51 ± 17 years, M:F = 1.2). Benign inflammatory reactive changes were seen in 45 patients (30.2%), while 54 patients (36.2%) showed granulomatous inflammation with/without caseation. Among these, 51 patients (94.4%) were confirmed to have TB as per pre-defined criteria. Patients with TB were more likely to have hypoechoic and matted nodes [40 patients (67.7%)]. EUS-FNA/B was found to have a sensitivity and specificity of 86% and 93% respectively, with a diagnostic accuracy of 88% in the evaluation of intra-abdominal lymphadenopathy due to TB.CONCLUSIONEUS-FNA/B has a high diagnostic yield with a good sensitivity and specificity in the evaluation of intra-abdominal lymphadenopathy due to TB. However, the validity of these findings in populations with low prevalence of TB needs further evaluation.

P59.28 Protocol Adaptation for gDNA Extraction of FFPE Samples of Lung Adenocarcinoma Tissue and Related Mediastinal Lymph Nodes

Lung adenocarcinoma, the most common subtype of non-small-cell lung carcinoma (NSCLC), is characterized by low response to treatment with 50% rate of metastases at diagnosis and low five-year survival. To associate the molecular evaluation of mediastinal lymph nodes (MLN) obtained by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) to the histological examination could improve TNM staging and diagnosis. Our objective is to adapt and optimize the genomic DNA (gDNA) extraction protocol to be used in formalin-fixed paraffin-embedded (FFPE) samples from tumor tissue and mediastinal lymph nodes for molecular analysis. The gDNA from 28 paired samples of primary tumor (PT) obtained by transthoracic biopsy or tumor resection, and MLN obtained by EBUS-TBNA were extracted with GeneRead DNA FFPE kit (Qiagen). Fourteen paired samples were submitted to the manufacturer's protocol (MP- one 10 μm cut of FFPE samples incubated in deparafinization solution for 3 minutes at 56° C, followed by incubation in proteinase K, RNAse free water and FTB buffer for 1 hour at 56°C); eight paired FFPE samples were submitted to an adapted protocol (AP-no use of deparafinization solution, 3-4 10 μm cuts of directly incubated in a mix containing proteinase K, RNAse free water and FTB buffer for 3 hours at 56ºC), and 6 paired samples were submitted to both protocols (MP-AP). The gDNA quantification was performed in the Qubit 3.0 fluorometer (Thermo Fisher Scientific). Paired t test was applied, considering statistically significant p≤0.05. The range of gDNA yield obtained in the MP was 0.121-8.51 ng/μL for tumor samples and 0.025-1.14 ng/μL for MLN samples, and 1.04-26.0 ng/μL and 0.065-3.11 ng/μL, respectively, in the AP. In the paired samples extracted using both protocols, the range of gDNA obtained was 0.121-2.65 ng/μL and 1.04-4.95 ng/μL for PT samples (p=0.030) and 0.043-0.054 ng/μL and 0.065-3.11 ng/μL for MLN samples (p = 0.071). To obtain purified gDNA from FFPE samples is a laborious process, especially in archived samples over 5 years old and in samples with scarce cellularity, as are the small fragments of lung tissue obtained by transthoracic biopsy, or MLN fragments obtained by EBUS/TBNA. We observed a significant improving in the gDNA extraction for tumor samples using the AP protocol and a trend in improving for MLN samples, probably due to the small sample size. Changes in commercial protocols are frequently required to ensure better molecular results in these types of samples.

Rapid On-site Evaluation and Final Cytologic Diagnoses Correlation During Endobronchial Ultrasonography.

The cost-effectiveness and low rate of inadequate sampling with the use of rapid on-site evaluation (ROSE) along with endobronchial ultrasonography (EBUS) is well established. Our aim in this study was to evaluate the correlation of ROSE during EBUS and final cytologic diagnosis and also to see if ROSE might predict the subtype of lung cancer. All consecutive subjects who attended our clinic between January 2016 and January 2019 for the evaluation of pathologic mediastinal and/or hilar lymph nodes (LNs)/mass using EBUS were enrolled into our prospective study. ROSE was performed in the same operating room with EBUS. ROSE results during EBUS were recorded. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of ROSE compared with the final cytologic diagnosis were evaluated. We enrolled 684 LN/mass lesions belonging to 328 patients into this study. When we compared ROSE results and final cytologic diagnosis, these procedures agreed on 91.6% of the LNs (P<0.001). The sensitivity of ROSE and final cytologic diagnosis for granulomatous inflammation was 72.5%, and for lung cancer, it was 89.2% (P<0.001). The sensitivity of ROSE for the adenocarcinoma subtype of lung cancer was 67.7%, and it was 70% for small cell lung cancer. ROSE may help to recognize non-small cell lung cancer during EBUS, especially the adenocarcinoma subtype of lung cancer, which will help ensure having sufficient material for molecular analysis.

Mesotelioma

Mesothelioma is an insidious neoplasm that arises from the mesothelial surfaces of the pleural cavities. The predominant cause of malignant mesothelioma is exposure to asbestos through inhalation. The diagnosis of malignant pleural mesothelioma is established by morphological and immunohistochemical characteristics of a cytological or surgical specimen. The initial evaluation is accompanied by contrast-enhanced chest CT, thoracentesis of the existing pleural effusion, and positron emission tomography (PET) in the evaluation of mediastinal lymph nodes. In cases of localized disease, surgery is combined with radiation therapy to improve local control of the disease and chemotherapy to reduce the risk of local recurrence and systemic metastases. Combination chemotherapy according to the cisplatin-pemetrexed regimen has become the most widely used regimen in patients with unresectable malignant pleural mesothelioma.

MRI-based differentiation between lymphoma and sarcoidosis in mediastinal lymph nodes.

ABSTRACTObjective:Evaluation of enlarged mediastinal lymph nodes is crucial for patient management. Malignant lymphoma and sarcoidosis are often difficult to differentiate. Our objective was to determine the diagnostic accuracy of MRI for differentiating between sarcoidosis and malignant lymphoma. Methods:This was a retrospective study involving 47 patients who underwent chest MRI and were diagnosed with one of the diseases between 2017 and 2019. T1, T2, and diffusion-weighted signal intensity were measured. Apparent diffusion coefficients (ADCs) and T2 ratios were calculated. The diagnostic performance of MRI was determined by ROC analysis. Results:Mean T2 ratio was significantly lower in the sarcoidosis group than in the lymphoma group (p = 0.009). The T2-ratio cutoff value that best differentiated between lymphoma-related and sarcoidosis-related enlarged lymph nodes was 7.1, with a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 58.3%, 95.6%, 76.5%, 93.3%, and 68.7%, respectively. The mean ADC was significantly lower in the lymphoma group than in the sarcoidosis group (p = 0.002). The ADC cutoff value that best differentiated between lymphoma-related and sarcoidosis-related enlarged lymph nodes was 1.205, with a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 87.5%, 82.6%, 85.1%, 84.0% and 86.3%, respectively. No significant differences were found between the two groups regarding T1 signal intensity, T2 signal intensity, and lymph node diameter. Conclusions:MRI parameters such as ADC, diffusion, and T2 ratio can be useful in the differentiation between sarcoidosis and lymphoma in the evaluation of enlarged lymph nodes.

Diagnostic accuracy, indications, and negative predictive value of EBUS-TBNA procedure: retrospective observational study from a referral cancer institute

Background: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is minimally invasive procedure for the evaluation of mediastinal mass and lymph nodes. Aim: This study was conducted as an internal audit to determine diagnostic accuracy, false-negative rate of a costly, invasive procedure EBUS-TBNA performed under conscious sedation or deep/general anesthesia. Methods: Forty-nine patients who underwent EBUS-TBNA procedure at our institute were included in this retrospective study. Sensitivity, diagnostic accuracy, and negative predictive values were calculated considering clinical radiological assessment till 6 months as gold standard. Results: Forty-nine patients (27 females and 22 males) with mean age of 47.88 years underwent EBUS-TBNA during a period of 8 months. The most common indication was extrathoracic malignancy metastasis in 26 (53.1%) patients. EBUS-TBNA was performed for diagnosing malignancy lung in 11 patients, granulomatous disease in 8 patients, and mediastinal mass in 4 patients. A total of 74 nodes were sampled in 49 patients. Adequate samples were obtained in 46 patients (93.9%). Diagnostic accuracy was overall 91.8%. There were no procedure-related complications or mortality noted in any patient. Out of 17 negative cases, false negatives were 4, and negative-predictive value was 76.5%. The diagnostic accuracy, sensitivity, and negative predictive value were higher in procedures performed under deep sedation/general anesthesia. Conclusion: Diagnosing extrathoracic malignancy metastasis and malignancy lung are major indications for the EBUS-TBNA procedure at our institute. The diagnostic accuracy overall was 91.8%. The negative-predictive value, diagnostic accuracy, and sensitivity were higher for procedures performed under deep sedation/general anesthesia versus conscious sedation.

The use of 18F-FDG positron emission tomography to detect mediastinal lymph nodes in metastatic breast cancer

BackgroundTo assess the predictive value of 18F-fluorodeoxyglucose positron-emission tomography (FDG–PET/CT) in detecting mediastinal lymph node metastasis with histopathologic verification in breast cancer (BC) patients. Materials and methodsBetween February 2012 and October 2019, 37 BC patients who underwent histopathological verification for FDG-PET positive mediastinal lymph nodes were retrospectively analyzed. Nine patients (24%) were screened before beginning treatment, while 27 (76%) were screened at the time of disease progression, an average of 39 months after completion of initial treatment. ResultsThe histopathologic diagnosis revealed lymph node metastasis from BC in 15 patients (40%) and benign disease in 22 patients (60%). The standardized uptake value (SUVmax) of mediastinal lymph nodes was significantly higher in patients with lymph node metastasis compared to those with benign histology (9.0 ± 3.5 vs. 5.9 ± 2.4; P = 0.007). The cut-off value of SUVmax after the ROC curve analysis for pathological lymph node metastasis was 6.4. Two of the 15 patients with mediastinal SUVmax ≤ 6.4 and 13 of the 22 patients with SUVmax > 6.4 had lymph node metastasis. Age and pathological findings were prognostic factors for overall survival in univariate analysis. The treatment decision was changed in 19 patients (51%) after mediastinoscopic evaluation of the entire cohort. ConclusionsThis is the first study to support the need for pathologic confirmation of a positive PET/CT result following evaluation of mediastinal lymph nodes for staging BC, either at initial diagnosis or at the time of progression. Treatment decisions were consequently altered for nearly half of the patients.

Image‐guided percutaneous microwave ablation of early‐stage non–small cell lung cancer

Although surgical lobectomy with systematic mediastinal lymph node evaluation is considered as the "gold standard" for management ofearly stage non-small cell lung cancer (NSCLC), image-guided percutaneous thermalablationhas been increasingly used for medically inoperable patients. Radiofrequency ablation (RFA) is a research-based technique that has the most studies for medically inoperable early-stage NSCLC. Other thermal ablation techniques used to treat pulmonary tumors include microwave ablation (MWA), cryoablation and laser ablation. MWA has several advantages over RFA including reduced procedural time, reduced heat-sink effect, large ablation zones, decreased susceptibility to tissue impedance, and simultaneous use of multiple antennae. This review article highlights the most relevant updates of MWA for the treatment of early-stage NSCLC, including mechanism of action, clinical outcomes, potential complications, the existing technique problems and future directions.

Mediastinal ve hiler lenfadenopatilerde endobronşiyal ultrason eşliğinde kullanılan power Doppler modunun benign ve malign lenf nodu ayırımına katkısı

Aim: The aim of this study was to investigate the contribution of power Doppler mode used in the differentiation of malignant and benign lymph nodes in patients with mediastinal and hilar lymphadenopathies undergoing diagnostic fine needle aspiration under the guidance of convex probe endoscopic ultrasound (EBUS).Material and Methods: Medical files of patients who underwent EBUS between March 2018 and February 2019 were retrospectively analyzed. A total of 143 lymph nodes of 85 patients were included in the study. The demographic characteristics of the patients with a definite diagnosis and EBUS radiological and sonographic characteristics of the sampled lymph nodes were recorded. As a result of the evaluation of mediastinal lymph nodes with EBUS, the sensitivity, specificity, negative and positive predictive values were calculated for power Doppler mode in the detection of malignant lymph nodes.Results: Of a total of 85 patients, 62 (73%) were males and 23 (27%) were females with a mean age of 62±10.4 (range, 37 to 80) years. In the vascular pattern evaluation, 87 (60.8%) lymph nodes were negative and 56 (39.2%) were positive for malignancy. Comparing final diagnoses and vascular pattern analysis results revealed a statistically significant difference between benign and malignant lymph nodes in favor of power Doppler mode under the guidance of EBUS (p &amp;lt;0.01).Conclusion: Convex probe EBUS can identify the first lymph node to be sampled based on sonographic characteristics of lymph nodes and allow simultaneous imaging and transbronchial fine needle aspiration procedures. Therefore, it may shorten the procedural time and reduce the amount of anesthesia to be used.

MS06.04 Approaches to Overcoming the Nodal Staging Quality Gap

MS06.04 Approaches to Overcoming the Nodal Staging Quality Gap

908 Diagnostic Value of Semi-Quantitative Endoscopic Ultrasound Elastography in the Evaluation of Mediastinal and Abdominal Lymph Nodes

INTRODUCTION: An accurate differentiation between benign and malignant lymph nodes (LN) is crucial for staging, risk stratification and treatment selection in patients with gastrointestinal malignancies. Endoscopic ultrasound (EUS) elastography can offer additional information that enables a better tissue characterization, enhancing the diagnostic power of EUS. The aim of this study was to evaluate the accuracy of the qualitative elasticity scores (ES) and semi-quantitative strain ratio (SR) for the diagnosis of abdominal and mediastinal LNs. METHODS: Consecutive patients referred for EUS evaluation of a mediastinal or abdominal LN by a single endosonographer (MSB) at a tertiary cancer center between January 2018 and May 2019 were included in the study. Elasticity scores (Table 1) and SR were determined during EUS exam. The final diagnosis was obtained by EUS-FNA cytology evaluation, surgical pathologic examination or clinical follow up. RESULTS: A total of 45 patients undergoing EUS evaluation of 70 LNs (40 benign, 30 malignant) were included in the analysis. According to the qualitative ES, the elastography images were interpreted as benign in 18 cases, malignant in 33 cases and indeterminate in 19. ES alone had a sensitivity of 100% and a specificity of 60% (Table 1). Based on the ROC curve analysis results, the best cut-off of SR to obtain the maximum area under the curve was 18.9, with a sensitivity of 47% and specificity of 85%. When both ES and SR were considered, the sensitivity was 100% with a specificity of 60% and negative predictive value of 100%. CONCLUSION: EUS elastography represents a promising method that allows the differential diagnosis of benign and malignant LN and it is complimentary to EUS-FNA. Given the high negative predictive value, EUS-elastography can decrease the number of unnecessary biopsies. The elasticity score and SR may be useful in patients with negative EUS-FNA results or in case in which a biopsy is not feasible.

Methylation Assessment for the Prediction of Malignancy in Mediastinal Adenopathies Obtained by Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration in Patients with Lung Cancer.

The evaluation of mediastinal lymph nodes is critical for the correct staging of patients with lung cancer (LC). Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive technique for mediastinal staging, though unfortunately lymph node micrometastasis is often missed by cytological analysis. The aim of this study was to evaluate the predictive capacity of methylation biomarkers and provide a classification rule for predicting malignancy in false negative EBUS-TBNA samples. The study included 112 patients with a new or suspected diagnosis of LC that were referred to EBUS-TBNA. Methylation of p16/INK4a, MGMT, SHOX2, E-cadherin, DLEC1, and RASSF1A was quantified by nested methylation-specific qPCR in 218 EBUS-TBNA lymph node samples. Cross-validated linear regression models were evaluated to predict malignancy. According to EBUS-TBNA and final diagnosis, 90 samples were true positives for malignancy, 110 were true negatives, and 18 were false negatives. MGMT, SHOX2, and E-cadherin were the methylation markers that better predicted malignancy. The model including sex, age, short axis diameter and standard uptake value of adenopathy, and SHOX2 showed 82.7% cross-validated sensitivity and 82.4% specificity for the detection of malignant lymphadenopathies among negative cytology samples. Our results suggest that the predictive model approach proposed can complement EBUS-TBNA for mediastinal staging.