Lymph Node Stations Research Articles

MA21.04 Novel Classification with Number or Zones of Involved Lymph Nodal Stations in Patients with Resected Non-Small Cell Lung Cancer

MA21.04 Novel Classification with Number or Zones of Involved Lymph Nodal Stations in Patients with Resected Non-Small Cell Lung Cancer

EP07.01-22 Identifying the Optimal Number of Lymph Node Stations for Improving Survival in Resections for Non-small Cell Lung Cancer

EP07.01-22 Identifying the Optimal Number of Lymph Node Stations for Improving Survival in Resections for Non-small Cell Lung Cancer

Impact of EUS in liver transplantation workup for patients with unresectable perihilar cholangiocarcinoma

Background and study aimsFor a highly selected group of patients with unresectable perihilar cholangiocarcinoma (pCCA) liver transplantation (LT) is a treatment option. The Dutch screening protocol comprises non-regional lymph node (LN) assessment by endoscopic ultrasound (EUS) and whenever LN metastases are identified, further LT screening is precluded. The aim of this study is to investigate the yield of EUS in patients with pCCA who are potentially eligible for LT. MethodsIn this retrospective, nationwide cohort study, all consecutive patients with suspected unresectable pCCA who underwent EUS in the screening protocol for LT were included from 2011-2021. During EUS, sampling of a ‘suspicious’ non-regional LN was performed based on the endoscopists discretion. The primary outcome was the added value of EUS, defined as number of patients who were precluded from further screening due to malignant LN. ResultsA total of 75 patients was included in whom 84 EUS procedures were performed, with EUS guided tissue acquisition confirming malignancy in LN in 3/75 (4%) patients. In the 43 who underwent surgical staging conform the protocol, non-regional LN were identified in 6 (14%) patients. Regional LN were found in 7 patients in post-LT resected specimens. ConclusionsOur current EUS screening for the detection of malignant LN in patients with pCCA eligible for LT shows a limited but clinically important yield. EUS with systematic screening of all LN stations, both regional and non-regional and sampling of ‘suspicious’ lymph nodes according to defined and set criteria could potentially increase this yield.

Optimal Lymphadenectomy in Patients with Well-Differentiated Nonfunctioning Pancreatic Neuroendocrine Neoplasms.

This study aimed to evaluate the optimal extent of lymphadenectomy in patients with nonfunctioning pancreatic neuroendocrine neoplasms. We retrospectively analyzed the clinicopathological data of patients with nonfunctioning pancreatic neuroendocrine neoplasms who underwent surgical resection. We investigated the frequency of metastases at each lymph node station according to tumor location and analyzed the factors contributing to poor overall survival (OS) and disease-free survival (DFS). Overall, data of 84 patients were analyzed. Among patients with pancreatic head tumors, metastases at stations 8, 13, and 17 were found in one (3.1%), four (12.5%), and three (9.3%) patients, respectively. However, none of the other stations showed metastases. For pancreatic body and tail tumors, metastases only at station 11 were found in two (5.1%) patients. Additionally, multivariate DFS and OS analyses showed that lymph node metastasis was the only independent prognostic factor. In conclusion, lymph node metastasis near the primary tumor was the only independent factor of poor prognosis in patients with nonfunctioning pancreatic neuroendocrine neoplasms after undergoing curative surgery. Peri-pancreatic lymphadenectomy might be recommended for nonfunctioning pancreatic neuroendocrine neoplasms.

Benefit of lymph node dissection for perihilar and distal cholangiocarcinoma according to lymph node stations.

The benefits of lymph node (LN) dissection at each station have not previously been fully investigated in perihilar cholangiocarcinoma (PHCC) and distal cholangiocarcinoma (DCC). The efficacy index (EI) was calculated in patients who underwent surgery for PHCC (n = 134) and DCC (n = 135) by multiplying the frequency of metastasis to the LN station and the 5-year overall survival (OS) rate of patients with metastasis to that station. In PHCC, the frequency of metastasis, 5-year OS rates, and the EI in para-aortic LNs (4.7%, 0%, and 0, respectively) and posterior pancreaticoduodenal LNs (8.1%, 0%, and 0, respectively) were lower than those in hepatoduodenal ligament LNs (30.1%, 24.1%, and 7.25, respectively) and LNs along the common hepatic artery (CHA) (16.2%, 15.0%, and 2.43, respectively). In DCC, these values were lower in LNs along the CHA (6.4%, 0%, and 0, respectively) than in the posterior pancreaticoduodenal LNs (31.2%, 34.5%, and 10.8, respectively), the hepatoduodenal ligament LNs (14.8%, 15.2%, and 2.25, respectively), and para-aortic (4.0%, 25.0%, and 0.99, respectively) LNs. According to the EI, this study raises concerns about the effectiveness of dissection in the posterior pancreaticoduodenal LNs in PHCC and LNs along the CHA in DCC.

Discrepancies in tumor mutation burden reporting from sequential endobronchial ultrasound transbronchial needle aspiration samples within single lymph node stations - brief report.

Tumour Mutation Burden (TMB) is a potential biomarker for immune cancer therapies. Here we investigated parameters that might affect TMB using duplicate cytology smears obtained from endobronchial ultrasound transbronchial needle aspiration (EBUS TBNA)-sampled malignant lymph nodes. Individual Diff-Quik cytology smears were prepared for each needle pass. DNA extracted from each smear underwent sequencing using large gene panel (TruSight Oncology 500 (TSO500 - Illumina)). TMB was estimated using the TSO500 Local App v. 2.0 (Illumina). Twenty patients had two or more Diff-Quik smears (total 45 smears) which passed sequencing quality control. Average smear TMB was 8.7 ± 5.0 mutations per megabase (Mb). Sixteen of the 20 patients had paired samples with minimal differences in TMB score (average difference 1.3 ± 0.85). Paired samples from 13 patients had concordant TMB (scores below or above a threshold of 10 mutations/Mb). Markedly discrepant TMB was observed in four cases, with an average difference of 11.3 ± 2.7 mutations/Mb. Factors affecting TMB calling included sample tumour content, the amount of DNA used in sequencing, and bone fide heterogeneity of node tumour between paired samples. TMB assessment is feasible from EBUS-TBNA smears from a single needle pass. Repeated samples of a lymph node station have minimal variation in TMB in most cases. However, this novel data shows how tumour content and minor change in site of node sampling can impact TMB. Further study is needed on whether all node aspirates should be combined in 1 sample, or whether testing independent nodes using smears is needed.

Radicality and safety of mediastinal lymphadenectomy in lung resection: a comparative analysis of uniportal thoracoscopic, multiportal thoracoscopic, and thoracotomy approaches.

Lung cancer poses a significant challenge with high mortality rates. Minimally invasive surgical approaches, including the uniportal thoracoscopic technique, offer potential benefits in terms of recovery and patient compliance. This study focuses on evaluating the radicality of mediastinal lymphadenectomy during uniportal thoracoscopic lung resection, specifically assessing the reachability of established lymphatic stations. A comparative study was conducted at the University Hospital Ostrava from January 2015 to July 2022, focusing on the evaluation of radicality in mediastinal lymphadenectomy across three patient subgroups: uniportal thoracoscopic approach, multiportal thoracoscopic approach, and thoracotomy approach. The study implemented the routine identification and excision of 8 lymph node stations from the respective hemithorax to assess the radicality of lymph node harvesting. A total of 428 patients were enrolled and evaluated. No significant differences were observed in the number of lymph nodes removed between the subgroups. The mean number of lymph nodes removed was 6.50 in the left hemithorax and 6.49 in the right hemithorax. The 30-day postoperative morbidity rate for the entire patient population was 27.3%, with 17.5% experiencing minor complications and 6.5% experiencing major complications. Statistically significant differences were observed in major complications between the uniportal approach and the thoracotomy approach (3.5% vs 12.0%, p = 0.002). The overall mortality rate in the study population was 3%, with a statistically significant difference in mortality between the uniportal and multiportal approaches (1.0% vs 6.4%, p = 0.020). The uniportal approach demonstrated comparable accessibility and lymph node yield to multiportal and thoracotomy techniques. It is equivalent to established methods in terms of postoperative complications, with fewer major complications compared to thoracotomy. While our study indicates a potential for lower mortality following uniportal lung resection in comparison to multiportal lung resection, and demonstrates comparable outcomes to thoracotomy, it is important to approach these findings cautiously and refrain from drawing definitive conclusions.

Long-Term Oncologic Outcomes in Robot-Assisted and Video-Assisted Lobectomies for Non-Small Cell Lung Cancer.

This study compares long-term outcomes in patients undergoing video-assisted thoracic surgery (VATS) and robotic-assisted thoracic surgery (RATS) lobectomy for non-small cell lung cancer (NSCLC); all consecutive patients who underwent RATS or VATS lobectomy for NSCLC between July 2015 and December 2021 in our center were enrolled in a single-center prospective study. The primary outcomes were overall survival (OS), disease-free survival (DFS), and recurrence rate. The secondary outcomes were complication rate, length of hospitalization (LOS), duration of chest tubes (LOD), and number of lymph node stations harvested. A total of 619 patients treated with RATS (n = 403) or VATS (n = 216) were included in the study. There was no significant difference in OS between the RATS and VATS groups (3-year OS: 75.9% vs. 82.3%; 5-year OS: 70.5% vs. 68.5%; p = 0.637). There was a statistically significant difference in DFS between the RATS and VATS groups (3-year DFS: 92.4% vs. 81.2%; 5-year DFS: 90.3% vs. 77.6%; p < 0.001). Subgroup analysis according to the pathological stage also demonstrated a significant difference between RATS and VATS groups in DFS in stage I (3-year DFS: 94.4% vs. 88.9%; 5-year DFS: 91.8% vs. 85.2%; p = 0.037) and stage III disease (3-year DFS: 82.4% vs. 51.1%; 5-year DFS: 82.4% vs. 37.7%; p = 0.024). Moreover, in multivariable Cox regression analysis, the surgical approach was significantly associated with DFS, with an HR of 0.46 (95% CI 0.27-0.78, p = 0.004) for RATS compared to VATS. VATS lobectomy was associated with a significantly higher recurrence rate compared to RATS (21.8% vs. 6.2%; p < 0.001). LOS and LOD, as well as complication rate and in-hospital and 30-day mortality, were similar among the groups. RATS lobectomy was associated with a higher number of lymph node stations harvested compared to VATS (7 [IQR:2] vs. 5 [IQR:2]; p < 0.001). In conclusion, in our series, RATS lobectomy for lung cancer led to a significantly higher DFS and significantly lower recurrence rate compared to the VATS approach. RATS may allow more extensive nodal dissection, and this could translate into reduced recurrence.

Complete dissection of right paratracheal lymph nodes (stations 2R and 4R) is critical to improve the prognosis of lung cancer patients: A retrospective cohort study.

The optimal extent of mediastinal lymph node dissection is still under debate. This study aimed to investigate the prognostic impact of complete dissection of right paratracheal lymph nodes (LNs) in right-sided non-small cell lung cancer (NSCLC) and evaluate the potential patient population who will particularly benefit from right paratracheal node dissection (RPND). Between January 2009 and December 2019, we retrospectively reviewed 2650 patients with primary right-sided NSCLC who underwent pulmonary surgery with lymphadenectomy in the Western China Lung Cancer Database. A total of 2447 patients received both 2R and 4R LNs dissection (complete RPND group), 162 patients received only 2R or 4R LNs dissection (incomplete RPND group), and 41 patients received neither 2R nor 4R LNs dissection (no RPND group). Overall survival (OS) was analyzed. The metastasis rates in stations 2R and 4R were 6.5% and 8.0%, respectively. In stage N2 patients, the frequency of involvement of stations 2R/4R was 74.8%. The complete RPND group had a significantly better survival than the incomplete and no RPND group (5-year OS, 79.5% vs. 72.7% vs. 65.5%; p < 0.001). In the multivariate analysis, status of RPND (incomplete RPND vs. complete RPND: HR 1.45, 95% CI: 1.10-1.90; p = 0.009; no RPND vs. complete RPND: HR 2.25, 95% CI: 1.37 to 3.69; p = 0.001), age, gender, tumor size, histological type, pTNM stage, pT stage, pN stage, and adjuvant treatment were independent factors for OS. Complete RPND brings survival benefits to patients with right-sided NSCLC. We suggest complete RPND as a standard procedure for patients with right-sided NSCLC.

Man vs. Machine (Learning): Comparing Speed and Cost-Effectiveness of Manual vs. Deep Learning Segmentation-Aided Volume Delineation for Head and Neck Lymph Node Targets.

The purposes of the following study were to: 1) compare the time required to delineate head and neck lymph nodal volumes using a manual versus deep learning segmentation (DLS) - aided approach and 2) investigate the potential cost-savings per scan. 10 de-identified head and neck CT simulation datasets were randomly selected for segmentation and analysis. Using published consensus definitions of 27 total lymph node regions1, 1 radiation oncologist manually segmented all 10 CT datasets. For each patient, the time required to contour and review the dataset was recorded. Next, for each dataset, the time required to generate and modify DLS-generated volumes via a proprietary software was recorded, including image export from treatment planning system (TPS), uploading to DLS software, volume generation, downloading volumes, importing volumes into the TPS, and manual edits required. Mean and standard deviations for each treatment modality were calculated. Using two-sided t-test, the statistical difference between the measured outcomes were compared. Finally, assuming a salary of $500,000 per year, average cost savings per scan were calculated. Time required to segment each dataset manually (mean = 59.32 min, SD = 9.16) versus DLS-aided (mean = 14.55 min, SD = 3.16) was statistically significant (p-value = 1.91E-07). Estimated cost required to segment each dataset manually (mean = $237.67, SD = $36.69) versus DLS-aided (mean = $58.27, SD = $12.64) was also statistically significant (p-value = 1.91E-07). The DLS-aided approach resulted in a $179.40 savings per CT dataset segmented, as well as an absolute time savings of 44.78 minutes per scan. This preliminary study shows that using a DLS-aided approach to head and neck lymph node stations can be feasibly implemented within a standard radiation oncology workflow and has the potential for significant time and cost savings.

Dissection bleeding. Left upper A1+2a+b injury during dissection, due to metastatic N1 12 station lymph nodes.

Dissection bleeding. Left upper A1+2a+b injury during dissection, due to metastatic N1 12 station lymph nodes.

Deep Learning for Automatic Prediction of Lymph Node Station Metastasis in Esophageal Cancer Patients from Contrast-Enhanced CT

The diagnosis of lymph node (LN) metastasis in computed tomography (CT) is an essential yet challenging task in esophageal cancer staging and treatment planning. Although criteria (e.g., RECIST, morphological/texture features) are proposed to predict LN metastasis, the diagnostic accuracy remains low with sensitivity <50% and specificity <75%, as reported in previous studies. Deep learning (DL) has the potential to address this issue by learning from large-scale labeled data. However, due to the practical surgery procedure in lymph node dissection, it is difficult to pair the metastasis of individual LN reported in the pathology report to the LN instance found in the CT image. Hence, in this study, we first use pathology reports to determine the LNS metastasis, then develop a multiple instance deep learning (MIDL) model to predict lymph node station (LNS) metastasis. We collected 1200 esophageal cancer patients with preoperative contrast-enhanced CT before surgery. A recently developed automatic mediastinal LNS segmentation model was first applied to segment LNS of 1 to 8 based on the IASLC protocol. For each LNS, the local CT region of interest (ROI) was cropped to generate a station-wise CT patch, where the LNS was labeled as metastatic if at least one metastatic LN was indicated in the pathology report. Using the station-wise CT patch and LNS label, we train a 3D MIDL model, MobileNetV3, to predict LNS metastasis. To better provide the LN position priors in MIDL, LN instances (with a short axis >4mm) were also segmented using an automatic LN detection algorithm and were added to the MIDL model as an auxiliary input. Five-fold cross-validation was conducted to evaluate the MIDL performance. The MIDL model's performance is summarized in Table 1. The MIDL model incorporating an additional LN instance mask demonstrated a superior overall AUC of 0.7539, surpassing the model without the LN mask input by 2.93%. The specificity was evaluated at a threshold resulting in a recall of 0.7, and the best model outperformed the CT input model in terms of specificity by 2.11%. This highlights the value of including the LN position prior to the MIDL model. Notably, when a threshold was set to result in a specificity of 75%, the best MIDL model demonstrated a significantly higher recall compared to the previously reported clinical diagnostic recall (39.7% vs. 63.21%). We developed a MIDL classification model to predict LNS metastasis using CT scans of 1200 patients. Our findings suggest that the MIDL model can substantially improve LNS metastasis prediction and has the potential to play an essential role in cancer staging, treatment planning, and prognostic analysis.

Dosimetric Comparison of Nodal Clinical Target Volume for Locally Advanced Non-Small Cell Lung Cancer: Options for Geometric Expansion vs. Lymph Node Stations

We investigated whether dosimetric differences existed in nodal clinical target volume (CTV) using options for geometric expansion and lymph node stations based on the European Society for Radiotherapy and Oncology (ESTRO) guideline for locally advanced non-small cell lung cancer (NSCLC). With treatment planning computed tomographic images in 17 patients who underwent radiotherapy for cT4N2M0 NSCLC from 2017 to 2022 at our institution, we retrospectively contoured nodal CTVs based on the guideline's options of: (1) geometric expansion, CTV including the nodal gross tumor volume plus 5 mm margin: (2) lymph node stations, CTV including the affected lymph node stations. The 5 mm margins for planning target volume (PTV) were added to the nodal and primary tumors' CTVs. Treatment planning of 60 Gy in 30 fractions to the PTV D50% was performed using volumetric modulated arc therapy; Dn% was irradiated dose to n% of volume of the structure; VnGy was percentage of volume of the structure at least irradiated n Gy. We compared dose-volume parameters between the two options using Wilcoxon rank sum test. Primary tumors were located in the right and left lobes in 12 and five patients, and in the upper and lower lobes in 13 and four patients, respectively. Median PTV size/D95% of the options for geometric expansion and lymph node stations were 569 cc (range, 149-2005 cc)/58.2 Gy (range, 57.5-58.7 Gy) and 635 cc (range, 184-2109 cc)/58.1 Gy (range, 57.5-58.7 Gy), respectively. Median mean dose of the esophagus/heart in the two options were 12.2 Gy (range, 6.6-24.9 Gy)/3.3 Gy (range, 0.6-19.1 Gy) and 16.1 Gy (range, 13.6-30.5 Gy)/4.6 Gy (range, 0.7-18.9 Gy), respectively. Median V20 Gy/mean dose of the lungs in the options for geometric expansion and lymph node stations were 20.5% (range, 14.8-33.9%)/12.2 Gy (range, 8.7-18.4 Gy) and 24.0% (range, 15.1-36.7%)/13.5 Gy (range, 9.5-19.4 Gy), respectively. In the eight patients (47%) with lymph node metastases in stations 2 or 3, a significant dosimetric difference between the two options existed on V20 Gy of the lungs; median values of the difference were 2.8% and 0.5% with and without lymph node metastases in stations 2 or 3, respectively (p = 0.027). Of the ESTRO guideline for the nodal CTV, using the option for geometric expansion might be able to reduce V20 Gy of the lungs in patients with lymph node metastases in stations 2 or 3.

5-Year Results from a Prospective Phase II Trial of Ten-Fractions Hypofractionated Radiotherapy in Locally Advanced Breast Cancer

There is a growing interest for adjuvant loco-regional hypofractionated radiotherapy (Hypo-RT) regimens in patients (pts) undergoing surgery for locally advanced breast cancer (LABC). We report the 5-year results of a phase II study on Hypo-RT targeting the primary and regional lymph nodes in ten fractions (fxs). A schedule of 34 Gy/10 fxs/2 wks to the whole breast/chest wall and to the draining lymph nodes was used; an optional single fraction 8 Gy boost was administered with electrons to the tumor bed in patients who had undergone conservative surgery. Both acute (CTCAE 4.0) and late (LENT/SOMA) toxicities were collected. All pts but those who underwent mastectomy without reconstruction or with temporary expander were also asked to rate their cosmetic outcome according to the Harvard scale. Toxicity was assessed weekly during RT and then at each follow-up (fup) examination (1, 3, 6 months and then yearly). Late toxicity was assessed starting from 3 months after the end of Hypo-RT and loco-regional toxicity was prospectively collected. Cancer related endpoints in terms of loco-regional (LR) recurrence, distant metastasis, specific disease- free survival and overall survival (OS) were evaluated from the date of RT start to the diagnosis of local relapse/distant metastases or the last fup respectively. From February 2015 to March 2019, 59 women (median age 60 yrs, IQR: 48.3-68.8 yrs) with stage II to IIIA breast cancer who underwent axillary dissection and conservative surgery (83%) or mastectomy (17%) were accrued. One patient was lost to fup immediately after the end of RT. Of the 58 evaluable pts, 56 underwent neo-adjuvant (27.5%) or adjuvant (57%) chemotherapy and 15.5% exclusive hormone therapy as well. Trastuzumab was administered concomitant to RT in HER2 positive pts (25%). All pts completed treatment as planned. No grade 2+ acute toxicity was recorded. At the median fup of 63 months (range: 25-92 mths), the cumulative incidence of any grade locoregional late toxicity estimated with the Kaplan-Meier method is 43.4% (95% CI) (30.0% and 46.1% for patients undergone mastectomy and lumpectomy, respectively). Peak 2 events have been observed for fibrosis (1 pt, 1.7%), telangiectasia (1 pts, 1.7%) and lymphoedema (1 pt, 1.7%). One patient (1.7%) experienced grade 3 breast retraction. Of all eligible patients (N = 51), patient reported cosmetic outcome was excellent, good, fair and poor in 51.7%, 22.4%, 10.3% and 3.4%, respectively. No late lung toxicity was observed. The actuarial LR control rate at 5 years is 98%; for distant metastasis-free survival, specific disease-free survival and OS rates are 89.2%, 80.8% and 93.7% respectively. Our results support the activity of a 10-fxs Hypo-RT schedule targeting the primary site as well as the draining lymph node stations after surgery for LABC.

A Radiation Therapy Contouring Atlas for Delineation of the Level I-II Axilla in the Prone Position

When patients are treated prone for whole breast irradiation (WBI), the axilla typically receives less dose than when patients are treated with WBI in the supine position. There are situations, however, where the axilla is a target as in a situation where the physician intends to treat with "high tangents" to provide good coverage of both the breast and level I-II axilla. In these scenarios, ideal target delineation when the patient is in the prone position is not well-defined. While different consensus guidelines exist for delineation of the nodal areas in the supine position, to our knowledge there are no contouring guidelines for the regional nodes in the prone position based on bone, skin, vascular and muscle landmarks. Forty-three patients treated with high tangents in the prone position from 2012-2018 were identified as representative cases. The level I and II regional nodal contours from the Radiation Therapy Oncology Group (RTOG) breast cancer atlas were adapted for prone position by a radiation oncologist and a breast radiologist based on anatomic considerations and changes observed from supine to prone positioning on diagnostic imaging. The revised nodal contours were reviewed by an expanded expert multidisciplinary panel including additional breast radiation oncologists and surgical oncologists to delineate the level I and II axilla on noncontrast computed tomography (CT) scans. We adapted the RTOG breast cancer atlas, supported by detailed figures, in order to create a CT based atlas of the level I and II axillary lymph node stations in the prone position. For the level I axilla, the cranial and caudal anatomic boundaries remain unchanged. With transition to the prone position from supine, tenting of the pectoralis major occurs displacing the muscle from the chest wall and shifting the axillary space anteromedial to the lateral border of the pectoralis major. Therefore, the anterior boundary is now defined by the plane of the anterior extent of the pectoralis major to skin. The medial boundary is defined by the plane of the lateral border of the pectoralis major and pectoralis minor including to ribs and intercostal muscles. The lateral boundary is defined by the skin, cropped by 5mm. The posterior boundary is defined by the plane of the anterior surface of the latissimus dorsi and subscapularis muscle to skin. For the level II axilla, the cranial, posterior, medial and lateral boundaries remain unchanged. With transition from supine to prone, the axilla exhibits an anterolateral shift, now laterally abutting the lateral border of the pectoralis minor. The anterior boundary is now defined as the posterior aspect of the pectoralis major muscle. The caudal boundary is where the pectoralis minor inserts into ribs. The adaptations to the RTOG breast cancer atlas for prone positioning will enable radiation oncologists to more accurately target the level I and II axilla when treating patients prone in whom the axilla is a target in addition to the breast.

Endobronchial ultrasound sonographic characteristics of mediastinal lymph node in the evaluation of lung cancer.

Endobronchial ultrasound (EBUS) and contrast-enhanced computed tomography (CECT) are essential components of lung cancer evaluation. Features of mediastinal lymph nodes on EBUS and CECT can help in predicting metastatic disease. Clinical, radiological, and EBUS data of patients with clinico-radiological suspicion of lung cancer who have undergone EBUS with no transbronchial needle aspiration (TBNA) or nonyielding EBUS-TBNA were retrospectively collected from medical records. EBUS features of lymph nodes for metastatic disease [size >1 cm, round shape, heterogeneous echotexture, indistinct margin, coagulation necrosis (CN), absence of central hilar structures (CHS), and grade II-III vascularity] were noted. CECT findings were noted from CECT films and reports to analyze and compare with EBUS findings. Scoring criteria of EBUS sonographic characteristics from previous studies for discriminating benign and malignant lymph nodes were also assessed for possible prediction. 31 patients [male: 18 (58.1%), female: 13 (41.9); age (mean ± standard deviation): 52.9±15.7 years] with CECT findings suggesting lung cancer were studied. EBUS showed mediastinal lymphadenopathy at 82 lymph node stations in 29 patients. Size >1 cm, round shape, heterogeneous echotexture, distinct margin, CN, absence of CHS and grade II-III vascularity at 33 (40%), 28 (34%), 31 (38%), 55 (67%), 3 (4%), 77 (94%), and 6 (7.3%) lymph nodes, respectively, were found. The malignant or benign status assigned to lymph nodes using different scoring criteria was highly discordant. Compared to EBUS, CECT revealed abnormal mediastinal lymph nodes in significantly fewer patients [21 (67.7%) versus 29 (93.5%), p=0.01] involving a lower number of lymph node stations (37 versus 82, p<0.001). Lymphadenopathy frequency at different LNS on EBUS and CECT showed a weak positive but significant correlation (r=0.356; p=0.0426). EBUS characteristics and related scores have limited accuracy in differentiating benign and malignant nodes. CECT underestimates lymphadenopathy in comparison to EBUS. A larger prospective study of EBUS features with cyto/histopathology correlation may elicit its clinical significance and help to create better and more composite scoring criteria.

Estadificación quirúrgica del cáncer de pulmón de células no pequeñas: ¿cuándo deberíamos realizar de rutina la resección de los ganglios supraclaviculares?

Background: Accurate staging after the diagnosis of lung carcinoma is essential to select an appropriate therapy. Objective: The aim of the present study is to describe the characteristics of patients with non-small cell lung carcinoma in whom supraclavicular lymph node resection would detect non-palpable (N3 supraclavicular disease) lymph node metastases. Material and methods: Data from patients undergoing mediastinal surgical staging for non-small cell lung cancer using cervical mediastinoscopy and resection of supraclavicular lymph nodes were collected between December 2016 and December 2019. Results: A total of 60 patients were included; 76.6% were men. Mean tumor size was 4.7 cm ad mean lymph node stations evaluated by mediastinoscopy was 2.37 ± 1.44 (SD). All the patients underwent supraclavicular lymph node resection and the result was positive for epithelial carcinoma in 21 cases (35%). Of the 21 cases with N3 supraclavicular disease, 2 patients were recorded as skip metastases and the remaining cases were association with mediastinal N2 disease (p = 0.0424). There was a significant association between central tumor and N3 supraclavicular disease (p = 0.0148). Conclusion: Supraclavicular lymph node resection may be recommended in patients with suspected or confirmed N2 lymph node disease and central tumors, before considering a multimodal therapeutic approach including surgery.

Lymphatic flow mapping using near-infrared fluorescence imaging with indocyanine green helps to predict lymph node metastasis intraoperatively in patients with esophageal or esophagogastric junction cancer not treated with neoadjuvant chemotherapy

BackgroundLymphatic flow mapping using near-infrared fluorescence (NIR) imaging with indocyanine green (ICG) has been used for the intraoperative prediction of lymph node metastasis in esophageal or esophagogastric junction cancer. However, a consistent method that yields sufficient diagnostic quality is yet to be confirmed. This study explored the diagnostic utility of our newly established lymphatic flow mapping protocol for predicting lymph node metastasis in patients with esophageal or esophagogastric junction cancer.MethodsWe injected 0.5 mL of ICG (500 μg/mL) into the submucosal layer at four peritumoral points on the day before surgery for 54 patients. We performed lymphatic flow mapping intraoperatively using NIR imaging. After determining the NIR status and presence of metastases, evaluable lymph node stations on in vivo imaging and all resected lymph nodes were divided into four categories: ICG+meta+ (true positive), ICG+meta− (false positive), ICG−meta+ (false negative), and ICG−meta− (true negative).ResultsThe distribution of ICG+ and meta+ lymph node stations differed according to the primary tumor site. Sensitivity and specificity for predicting meta+ lymph nodes among ICG+ ones were 50% (95% CI 41–59%) and 75% (73–76%), respectively. Predicting meta+ lymph node stations among ICG+ stations improved these values to 66% (54–77%) and 77% (74–79%), respectively. Undergoing neoadjuvant chemotherapy was an independent risk factor for having meta+ lymph nodes with false-negative diagnoses (odds ratio 4.82; 95% CI 1.28–18.19). The sensitivity of our technique for predicting meta+ lymph nodes and meta+ lymph node stations in patients who did not undergo neoadjuvant chemotherapy was 79% (63–90%) and 83% (61–94%), respectively.ConclusionOur protocol potentially helps to predict lymph node metastasis intraoperatively in patients with esophageal or esophagogastric junction cancer undergoing esophagectomy who did not undergo neoadjuvant chemotherapy.Graphical abstract

164. INTRAOPERATIVE LYMPHATIC FLOW MAPPING USING INDOCYANINE GREEN PREDICTS LYMPH NODE METASTASIS IN ESOPHAGEAL CANCER PATIENTS NOT TREATED WITH NEOADJUVANT CHEMOTHERAPY

Abstract Background Lymphatic flow mapping using near-infrared fluorescence (NIR) imaging with indocyanine green (ICG) has been used for the intraoperative prediction of lymph node metastasis (LNM) in various cancers. Previous studies examined the feasibility of applying this technique to patients with esophageal cancer. However, a consistent method that yields sufficient diagnostic quality has yet to be confirmed. This study explored the diagnostic utility of our established lymphatic flow mapping protocol for predicting LNM in esophageal cancer. Methods We injected 0.5 mL of ICG (500 μg/mL) into the submucosal layer at four peritumoral points on the day before surgery for 54 patients. We performed lymphatic flow mapping intraoperatively using NIR imaging. After determining the NIR status and presence of metastases, evaluable lymph node stations on intraoperative NIR imaging and all resected lymph nodes were divided into four categories: ICG + meta+ (true positive), ICG + meta− (false positive), ICG − meta+ (false negative), and ICG − meta− (true negative). Logistic regression models were used to investigate the characteristics of patients with LNs or LN stations associated with high false-negative rates. Results The distribution of ICG+ and meta+ lymph node stations differed according to the primary tumor site. Sensitivity and specificity for predicting meta+ lymph nodes among ICG+ ones were 50% and 75%, respectively. Predicting meta+ lymph node stations among ICG+ stations improved these values to 66% and 77%, respectively. Undergoing neoadjuvant chemotherapy was an independent risk factor for having meta+ lymph nodes with false-negative diagnoses (odds ratio: 4.82; 95% confidence interval: 1.28–18.19). The sensitivity of our technique for predicting meta+ lymph nodes and meta+ lymph node stations in patients who did not undergo neoadjuvant chemotherapy was 79% and 83%, respectively. Conclusion Our NIR imaging protocol potentially helps to predict lymph node metastasis intraoperatively in patients with esophageal cancer undergoing esophagectomy who had not undergone neoadjuvant chemotherapy. This technique may effectively serve as a parameter for assessing the need for dissecting LNs in each station and determining whether it is applicable to reduce the extent of lymphadenectomy.

402. LYMPH NODE METASTASIS MAPPING IN T1–2 ESOPHAGEAL SQUAMOUS CELL CARCINOMA

Abstract Background Lymph node metastasis (LNM) is a crucial factor in predicting the prognosis of patients with T1–2 esophageal squamous cell carcinoma (ESCC), but the extent of lymph node (LN) dissection remains controversial. This study aims to investigate the optimal extent of LN dissection for T1–2 ESCC by analyzing the metastasis rate, evaluating the prognostic value at each LN station, and identifying risk factors for the LN stations with high LNM rate. Methods Patients with pathological T1–2 ESCC who underwent esophagectomy with LN dissection were enrolled between January 2014 and December 2019. Kaplan–Meier and Cox proportional hazards model were used to analyze the influence of LN with different metastasis rates on prognosis, respectively. The logistic regression analysis was performed to identify risk factors for the LN stations with high LNM rate. Results In total, 386 patients with T1–2 ESCC were included with a median LN dissection number of 18.5 (range: 12–48). The LN stations with LNM rate over 5% were the station 8 (11.9%), 2 (10.9%), 17 (8.0%), 16 (7.3%), and 7 (5.2%), and patients with metastasis of these stations showed significantly worse OS (P &amp;lt; 0.001). Moreover, the BMI (OR 0.45, 95%CI: 0.27–0.75, P &amp;lt; 0.01), tumor differentiation (OR 1.66, 95%CI: 1.14–2.42, P &amp;lt; 0.01), and T stage (OR 2.05, 95%CI: 1.21–3.47, P &amp;lt; 0.01) were independent risk factors of the metastasis of stations with LNM rate over 5%. Conclusions The poor prognosis of the metastasis of LN stations with LNM rate over 5% (station 8, 2, 17, 16, and 7) in T1–2 ESCC suggests the necessity of dissection, especially for patients with lower BMI, poor tumor differentiation, and deeper infiltration.