Meta-analysis of 18FDG PET-CT for nodal staging in patients with esophageal cancer

Validation of the Node Reporting and Data System (Node-RADS) for standardized CT evaluation of regional lymph nodes in esophageal squamous cell carcinoma patients

OBJECTIVES

The accurate identification of positive lymph nodes in esophageal squamous cell carcinoma (ESCC) influences patient risk assessment and treatment decisions, but there is no standardized approach for radiological evaluation. The aim of this study was to verify the diagnostic performance of the new Node Reporting and Data System 1.0 (Node-RADS) in the assessment of lymph node metastasis in patients with ESCC, as verified by final histopathology.

METHODS

Node-RADS is a scoring system composed of different criteria for evaluating lymph node metastasis, with scores ranging from 1 to 5, corresponding to the degree of suspicion of lymph node involvement. In this single-center study, Node-RADS was used to retrospectively evaluate regional lymph nodes in 173 ESCC patients who underwent computed tomography (CT) before radical resection. In addition, the area under the ROC curve (AUC), accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for the Node-RADS score and individual criteria.

RESULTS

Node-RADS outperformed the individual assessment criteria (AUC: 94.3%, sensitivity: 96.5%, specificity: 92.0%), with scores ≥ 3 indicating the maximum diagnostic effectiveness. The diagnostic efficiency of the highest Node-RADS score surpassed that of the short axis score (AUC: 94.3% vs. 81.9%, p < 0.001). Our results indicated that the best diagnostic cut-off points for the short axis, long axis and short axis/long axis ratio were 9 mm, 11 mm, and 0.74, respectively.

CONCLUSION

Node-RADS has emerged as a practical, repetitive method for the early identification of high-risk metastatic lymph nodes, providing therapeutic guidance and predicting disease prognosis in ESCC patients.

KEY POINTS

Question How does the Node Reporting and Data System 1.0 (Node-RADS) perform in the assessment of lymph node metastasis in patients with esophageal squamous cell carcinoma (ESCC)? Findings The maximum diagnostic efficiency was achieved with a Node-RADS score of ≥ 3. Clinical relevance The Node-RADS has improved diagnostic efficiency for distinguishing lymph node metastasis in patients with ESCC.

Diagnostic Accuracy and Reliability of CT-based Node-RADS for Esophageal Cancer

BACKGROUND/AIM

The recently published Node-Reporting and Data System (Node-RADS) can aid the characterization of lymph nodes in cross-sectional imaging. This study investigated the Node-RADS system in computed tomography (CT) to characterize lymph nodes in esophageal cancer.

PATIENTS AND METHODS

Overall, 126 patients (15 female, 11.9%) with a mean age of 62.1±10.4 years comprised the patient sample. All patients underwent resection with curative intent and the lymph nodes were histopathologically analyzed during clinical routine. For every patient, the locoregional lymph nodes were scored in accordance with the Node-RADS classification. For statistical analysis, receiver-operating characteristics (ROC) with area under the curve (AUC) were used to test for diagnostic accuracy; inter-reader variability was assessed with Cohen's kappa.

RESULTS

Overall, 54 patients were nodal positive (42.9%), 72 patients were nodal negative (57.1%). Inter-reader agreement was substantial for the overall Node-RADS scoring ([Formula: see text]=0.65, p<0.001). ROC curve analysis for lymph node discrimination (N0 versus N1-3) showed an AUC of 0.69 (95% confidence interval=0.59-0.79). A threshold score of more than 2 resulted in a sensitivity of 0.77 and a specificity of 0.55 for correctly predicting nodal positivity. Node-RADS 1 category had a malignancy rate of 30%, Node-RADS 2 of 14%, Node-RADS 3 of 81%, Node-RADS 4 of 90.1% and Node-RADS 5 of 86.5%.

CONCLUSION

The Node-RADS score on staging CT is associated with the malignancy rate of lymph nodes in patients with EC with only moderate diagnostic accuracy. The inter-reader variability is moderate, which could pose difficulties for translation into clinical routine.

Imaging in Esophageal Cancer: A Comprehensive Review

Esophageal cancer is one of the common cancers. Risk factors are well recognized and lead most commonly to two distinct histological subtypes (squamous cell carcinoma and adenocarcinoma). The diagnosis is based on endoscopic evaluation. The most challenging aspect of management is accurate staging as it guides appropriate management. Endoscopic ultrasound, computed tomography (CT), positron emission tomography-CT, and magnetic resonance imaging are the imaging tests employed for the staging. Each imaging test has its own merits and demerits. Imaging is also critical to evaluate posttreatment complication and for response assessment. In this review article, we discuss in detail the risk factors, anatomical aspects, and role of imaging test in staging and evaluation of complications and response after treatment.

Upper Mediastinal Lymphadenectomy Utilizing Prone-Position Thoracoscopy for Esophageal and Gastroesophageal Junction Cancers

Background/Objectives: Esophagectomy is the mainstay of treatment in esophageal cancer. Minimally invasive esophagectomy (MIE) remains a challenging procedure and has been associated with a high rate of complications and mortality. Routine lymphadenectomy includes two-field lymphadenectomy for distal-esophageal or gastroesophageal junction Siewert I-II tumors. Superior mediastinal lymphadenectomy (SML) refers to an extended two-field lymphadenectomy or total mediastinal lymphadenectomy during MIE for cancer. The exact benefits of SML have been the subject of prolonged debate, with no conclusive evidence indicating improved clinical and oncological results. Herein, we aim to present our surgical technique of thoracoscopic SML during MIE in the prone position, with short-term clinical and oncological outcomes. Methods: About 150 consecutive patients underwent totally MIE within 3 years period (2016-2019). SML included right-paratracheal nodes and nodes along the right-recurrent laryngeal nerve throughout its mediastinal route in cases of extended two-field lymphadenectomy, as well as left-paratracheal nodes and nodes along the left recurrent laryngeal nerve during total mediastinal lymphadenectomy. Eligible patients underwent SML during two-stage or three-stage MIE. Results: Twenty consecutive patients underwent SML during the study period. The 30- and 90-day mortality rates were 0. Pulmonary complications were observed in 16.5% of the patients. There was 1 right recurrent laryngeal nerve palsy noted. The median length of stay was 9 days. The median number of resected lymph nodes was 45, with the median SML nodes count being 8. The median follow-up was 24 months. Conclusions: SML during prone position thoracoscopy for esophageal cancer is safe and feasible, although technically demanding. Minimally invasive esophagectomy with SML may offer meaningful benefits in oncological outcomes without introducing additional significant morbidity. Further comparative studies are needed to better elucidate our results.

Advances in the Imaging of Esophageal and Gastroesophageal Junction Malignancies

Accurate imaging is key for the diagnosis and treatment of esophageal and gastroesophageal junction cancers . Current imaging modalities, such as computed tomography (CT) and 18F-FDG (2-deoxy-2-[18F]fluoro-D-glucose) positron emission tomography (PET)/CT, have limitations in accurately staging these cancers. MRI shows promise for T staging and residual disease assessment. Novel PET tracers, like FAPI, FLT, and hypoxia markers, offer potential improvements in diagnostic accuracy. 18F-FDG PET/MRI combines metabolic and anatomic information, enhancing disease evaluation. Radiomics and artificial intelligence hold promise for early detection, treatment planning, and response assessment. Theranostic nanoparticles and personalized medicine approaches offer new avenues for cancer therapy.

Association between prognosis and lymph node status using 18F-fluorodeoxyglucose-positron emission tomography in esophageal squamous cell carcinoma treated with esophagectomy post-neoadjuvant chemotherapy

BACKGROUND

There are few reports on the associations between lymph node (LN) status, determined by preoperative 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET), and prognosis in patients with locally advanced esophageal squamous cell carcinoma (ESCC) who underwent esophagectomy post-neoadjuvant chemotherapy (NCT). Additionally, details on the diagnostic performance of LN metastasis determination based on pathological examination versus FDG-PET have not been reported. In this study, we aimed to evaluate the associations among LN status using FDG-PET, LN status based on pathological examination, and prognosis in patients with locally advanced ESCC who underwent esophagectomy post-NCT.

METHODS

We reviewed the data of 124 consecutive patients with ESCC who underwent esophagectomy with R0 resection post-NCT between December 2008 and August 2022 and were evaluated pre- and post-NCT using FDG-PET. The associations among LN status using FDG-PET, LN status based on pathological examination, and prognosis were assessed.

RESULTS

Station-by-station analysis of PET-positive LNs pre- and post-NCT correlated significantly with pathological LN metastases (sensitivity, specificity, and accuracy pre- and post-NCT: 51.6%, 96.0%, and 92.1%; and 28.2%, 99.5%, and 93.1%, respectively; both p < 0.0001). Using univariate and multivariate analyses, LN status determined using PET post-NCT was a significant independent predictor of both recurrence-free survival and overall survival.

CONCLUSION

The LN status assessed using FDG-PET post-NCT was significantly associated with the pathological LN status and prognosis in patients with ESCC who underwent esophagectomy post-NCT. Therefore, FDG-PET is a useful diagnostic tool for preoperatively predicting pathological LN metastasis and survival in these patients and could provide valuable information for selecting individualized treatment strategies.

A novel tumor staging system incorporating cN status for stratifying early stage esophageal squamous cell carcinoma patients after trimodal therapy

BACKGROUNDS

The aim of this study is to investigate the prognostic value of cN status for early stage esophageal squamous cell carcinoma (ESCC) patients after neoadjuvant chemoradiotherapy (nCRT) and construct a new staging model for individual survival prediction.

METHODS

Patients with ESCC who underwent nCRT and esophagectomy were included in this study. Both the Akaike Information Criterion (AIC) and the Bayesian Information Criterion (BIC) were meticulously ascertained to assess the cogency of each oncological staging system. A discernible abatement in the values of AIC and BIC signifies a model endowed with enhanced predictive prowess and exemplary veracity.

RESULTS

A new staging model was established based on ypTNM stage and cN status by precisely stratifying ypI ESCC patients. The novel ypTNM-cN staging demonstrated superior overall survival trend alignment over the AJCC 8th ypTNM staging, with a notably lower AIC of 3143.014 versus 3149.950. This superiority was supported by a BIC of 3146.605 against 3153.541. In the context of disease-free survival outcomes, the emergent ypTNM-cN staging, with an AIC value registering at 3196.057 and a BIC value at 3199.648, distinctively eclipsed the AJCC 8th ypTNM staging, which documented values of 3203.853 and 3207.444, respectively.

CONCLUSION

We constructed a new staging system based on ypTNM stage and cN status to precisely stratify the patients with ypI stage. Our new ypTNM-cN staging system provides new insights for classifying stage ypI ESCC and shows reliable classification efficacy for all ESCC patients after nCRT and surgery.

The Value of Paratracheal Lymphadenectomy in Esophagectomy for Adenocarcinoma of the Esophagus or Gastroesophageal Junction: A Systematic Review of the Literature

BACKGROUND

The role of upper mediastinal lymphadenectomy for distal esophageal or gastroesophageal junction (GEJ) adenocarcinomas remains a matter of debate. This systematic review aims to provide a comprehensive overview of evidence on the incidence of nodal metastases in the upper mediastinum following transthoracic esophagectomy for distal esophageal or GEJ adenocarcinoma.

METHODS

A literature search was performed using Medline, Embase and Cochrane databases up to November 2020 to include studies on patients who underwent transthoracic esophagectomy with upper mediastinal lymphadenectomy for distal esophageal and/or GEJ adenocarcinoma. The primary endpoint was the incidence of metastatic nodes in the upper mediastinum based on pathological examination. Secondary endpoints were the definition of upper mediastinal lymphadenectomy, recurrent laryngeal nerve (RLN) palsy rate and survival.

RESULTS

A total of 17 studies were included and the sample sizes ranged from 10-634 patients. Overall, the median incidence of upper mediastinal lymph node metastases was 10.0% (IQR 4.7-16.7). The incidences of upper mediastinal lymph node metastases were 8.3% in the 7 studies that included patients undergoing primary resection (IQR 2.0-16.6), 4,4% in the 1 study that provided neoadjuvant therapy to the full cohort, and 10.6% in the 9 studies that included patients undergoing esophagectomy either with or without neoadjuvant therapy (IQR 8.9-15.8%). Data on survival and RLN palsy rates were scarce and inconclusive.

CONCLUSIONS

The incidence of upper mediastinal lymph node metastases in distal esophageal adenocarcinoma is up to 10%. Morbidity should be weighed against potential impact on survival.

Variants and Pitfalls in PET/CT Imaging of Gastrointestinal Cancers

In the past two decades, PET/CT has become an essential modality in oncology increasingly used in the management of gastrointestinal (GI) cancers. Most PET/CT tracers used in clinical practice show some degree of GI uptake. This uptake is quite variable and knowledge of common patterns of biodistribution of various radiotracers is helpful in clinical practice. 18F-Fluoro-Deoxy-Glucose (FDG) is the most commonly used radiotracer and has quite a variable uptake within the bowel. 68Ga-Prostate specific membrane antigen (PSMA) shows intense uptake within the proximal small bowel loops. 11C-methyl-L-methionine (MET) shows high accumulation within the bowels, which makes it difficult to assess bowel or pelvic diseases. One must also be aware of technical artifacts causing difficulties in interpretations, such as high attenuation oral contrast material within the bowel lumen or misregistration artifact due to patient movements. It is imperative to know the common variants and benign diseases that can mimic malignant pathologies. Intense FDG uptake within the esophagus and stomach may be a normal variant or may be associated with benign conditions such as esophagitis, reflux disease, or gastritis. Metformin can cause diffuse intense uptake throughout the bowel loops. Intense physiologic uptake can also be seen within the anal canal. Segmental bowel uptake can be seen in inflammatory bowel disease, radiation, or medication induced enteritis/colitis or infection. Diagnosis of appendicitis or diverticular disease requires CT correlation, as normal appendix or diverticulum can show intense uptake. Certain malignant pathologies are known to have only low FDG uptake, such as early-stage esophageal adenocarcinoma, mucinous tumors, indolent lymphomas, and multicystic mesotheliomas. Response assessment, particularly in the neoadjuvant setting, can be limited by post-treatment inflammatory changes. Post-operative complications such as abscess or fistula formation can also show intense uptake and may obscure underlying malignant pathology. In the absence of clinical suspicion or rising tumor marker, the role of FDG PET/CT in routine surveillance of patients with GI malignancy is not clear.

Meta-analysis of prognostic factors of overall survival in patients undergoing oesophagectomy for oesophageal cancer

INTRODUCTION

Currently, the American Joint Commission on Cancer (AJCC) staging system is used for prognostication for oesophageal cancer. However, several prognostically important factors have been reported but not incorporated. This meta-analysis aimed to characterize the impact of preoperative, operative, and oncological factors on the prognosis of patients undergoing curative resection for oesophageal cancer.

METHODS

This systematic review was performed according to PRISMA guidelines and eligible studies were identified through a search of PubMed, Scopus, and Cochrane CENTRAL databases up to 31 December 2018. A meta-analysis was conducted with the use of random-effects modeling to determine pooled univariable hazard ratios (HRs). The study was prospectively registered with the PROSPERO database (Registration: CRD42018157966).

RESULTS

One-hundred and seventy-one articles including 73,629 patients were assessed quantitatively. Of the 122 factors associated with survival, 39 were significant on pooled analysis. Of these. the strongly associated prognostic factors were 'pathological' T stage (HR: 2.07, CI95%: 1.77-2.43, P < 0.001), 'pathological' N stage (HR: 2.24, CI95%: 1.95-2.59, P < 0.001), perineural invasion (HR: 1.54, CI95%: 1.36-1.74, P < 0.001), circumferential resection margin (HR: 2.17, CI95%: 1.82-2.59, P < 0.001), poor tumor grade (HR: 1.53, CI95%: 1.34-1.74, P < 0.001), and high neutrophil:lymphocyte ratio (HR: 1.47, CI95%: 1.30-1.66, P < 0.001).

CONCLUSION

Several tumor biological variables not included in the AJCC 8th edition classification can impact on overall survival. Incorporation and validation of these factors into prognostic models and next edition of the AJCC system will enable personalized approach to prognostication and treatment.

Role of precision imaging in esophageal cancer

Esophageal cancer is a major cause of morbidity and mortality worldwide. Recent advancements in the management of esophageal cancer have allowed for earlier detection, improved ability to monitor progression, and superior treatment options. These innovations allow treatment teams to formulate more customized management plans and have led to an increase in patient survival rates. For example, in order for the most effective management plan to be constructed, accurate staging must be performed to determine tumor resectability. This article reviews the multimodality imaging approach involved in making a diagnosis, staging, evaluating treatment response and detecting recurrence in esophageal cancer.

Discordant nodal staging identifies intermediate-risk group for overall survival in patients with cT3 oesophageal adenocarcinoma

OBJECTIVES

Oesophageal adenocarcinoma has a poor prognosis and relies on multi-modality assessment for accurate nodal staging. The aim of the study was to determine the prognostic significance of nodal concordance between PET/CT and EUS in oesophageal adenocarcinoma.

METHODS

Consecutive patients with oesophageal adenocarcinoma staged between 2010 and 2016 were included. Groups comprising concordant node-negative (C-ve), discordant (DC), and concordant node-positive (C+ve) patients were analysed. Survival analysis using log-rank tests and Cox proportional hazards model was performed. The primary outcome was overall survival. A p value < 0.05 was considered statistically significant.

RESULTS

In total, 310 patients (median age = 66.0; interquartile range 59.5-72.5, males = 264) were included. The median overall survival was 23.0 months (95% confidence intervals (CI) 18.73-27.29). There was a significant difference in overall survival between concordance groups (X² = 44.91, df = 2, p < 0.001). The hazard ratios for overall survival of DC and C+ve patients compared with those of C-ve patients with cT3 tumours were 1.21 (95% CI 0.81-1.79) and 1.79 (95% CI 1.23-2.61), respectively. On multivariable analysis, nodal concordance was significantly and independently associated with overall survival (HR 1.44, 95% CI 1.12-1.83, p = 0.004) and performed better than age at diagnosis (HR 1.02, 95% CI 1.003-1.034, p = 0.016) and current cN-staging methods (HR 1.20, 95% CI 0.978-1.48, p = 0.080).

CONCLUSIONS

Patients with discordant nodal staging on PET/CT and EUS represent an intermediate-risk group for overall survival. This finding was consistent in patients with cT3 tumours. These findings will assist optimum treatment decisions based upon perceived prognosis for each patient.

KEY POINTS

• Clinicians are commonly faced with results of discordant nodal staging in oesophageal adenocarcinoma. • There is a significant difference in overall survival between patients with negative, discordant, and positive lymph node staging. • Patients with discordant lymph node staging between imaging modalities represent an intermediate-risk group for overall survival.

Siewert type I and II oesophageal adenocarcinoma: sensitivity/specificity of computed tomography, positron emission tomography and endoscopic ultrasound for assessment of lymph node metastases in groups of thoracic and abdominal lymph node stations

OBJECTIVES

In Siewert type I/II oesophageal adenocarcinoma, the sensitivity and specificity of computed tomography (CT), positron emission tomography (PET)-CT and endoscopic ultrasound (EUS) for assessment of the N descriptor in defined groups of lymph nodes were investigated.

METHODS

CT, PET/CT, EUS images and the pathological data of 101 oesophageal adenocarcinomas submitted to primary resection were compared. The lymph nodes were identified as (a) right paratracheal/subcarinal/pulmonary ligament; (b) paraoesophageal; (c) paracardial; (d) left gastric artery, lesser curvature; (e) coeliac trunk, hepatic/splenic artery.

RESULTS

Of the 2451 lymph nodes identified, 273 (11.1%) were histologically positive. Overall sensitivity, specificity and negative and positive predictive value for detection of lymph nodes metastatic were respectively: CT sensitivity 39%, specificity 86%, negative 58% and positive 74% predictive value; PET/CT sensitivity 30%, specificity 98%, negative 58% and positive 93% predictive value; EUS sensitivity 50%, specificity 81%, negative 72% and positive 62% predictive value. The sensitivity of CT, PET/CT and EUS in the thoracic nodal groups (a) and (b) was, respectively, 58.3%, 7.1% and 87.5% and 33.3%, 20% and 80%. Sensitivity was below 47% for all tests in the abdominal nodal groups. In contrast, specificity (88.6-100%) was super imposable in all nodal groups. The strength of agreement among the 3 imaging techniques was poor (kappa < 0.30) for the thoracic anatomical groups of interest: (a) lower paratracheal/subcarinal/pulmonary ligament and (b) paraoesophageal; it was moderate/good (kappa >0.30) for the abdominal N groups of interest: c, d and e.

CONCLUSIONS

The diagnostic performance of CT, PET and EUS for assessing the N descriptor in the paracardial and abdominal stations close to the primary tumour is not satisfactory. EUS can efficiently assess the presence/absence of nodal metastases in the thoracic stations.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov number: NCT03529968.

Improved detection of metastatic lymph nodes in oesophageal squamous cell carcinoma by combined interpretation of fluorine-18-fluorodeoxyglucose positron-emission tomography/computed tomography

Background

We sought to evaluate the diagnostic performance of fluorine-18-fluorodeoxyglucose positron-emission tomography/computed tomography (¹⁸F-FDG PET/CT) in the detection of metastatic lymph nodes by combined interpretation of PET/CT images in patients with oesophageal squamous cell carcinoma.

Methods

Two hundred three patients with oesophageal squamous cell carcinoma underwent ¹⁸F-FDG PET/CT before oesophagectomy and lymph node dissection. Maximum standardized uptake value (SUV_max), mean Hounsfield unit (HU), short axis diameter (size), and visual CT attenuation (high, iso-, low) were evaluated on noncontrast CT and PET images following PET/CT scan. In this combined interpretation protocol, the high attenuated lymph nodes were considered benign, even if the SUV_max value was high. The diagnostic accuracy of each method was compared using the postoperative histologic result as a reference standard.

Results

A total of 1099 nodal stations were dissected and 949 nodal stations were proven to demonstrate metastasis. SUV_max and size of the malignant lymph nodes were higher than those of the benign nodes, and visual CT attenuation was significantly different among the two groups (P < 0.001). Using cutoff values of 2.6 for SUV_max and 10.2 mm for size, the combined interpretation of an SUV_max of more than 2.6 with iso- or low CT attenuation [area under the curve (AUC): 0.846, 95% confidence interval (CI): 0.824–0.867] showed significantly better diagnostic performance for detecting malignant lymph nodes than SUV_max only (AUC: 0.791, 95% CI: 0.766–0.815) and size (AUC: 0.693, 95% CI: 0.665–0.720) methods (P < 0.001) in a receiver operating characteristic curve analysis.

Conclusions

The diagnostic accuracy of PET/CT for nodal metastasis in oesophageal squamous cell carcinoma was improved by the combined interpretation of ¹⁸F-FDG uptake and visual CT attenuation pattern.

Failure patterns after adjuvant chemoradiotherapy following endoscopic resection for superficial esophageal squamous cell carcinoma

Background

This study evaluated the locations of lymph node recurrence and their association with irradiation fields used for radiotherapy after adjuvant chemoradiotherapy following endoscopic resection for superficial esophageal squamous cell carcinoma.

Methods

Medical records of 96 consecutive patients with superficial esophageal squamous cell carcinoma who underwent adjuvant chemoradiotherapy following endoscopic resection were reviewed. Computed tomography was used to identify whether nodal recurrences were within the elective nodal irradiation field. The cumulative incidence of recurrence was calculated, accounting for death as a competing risk. Univariate and multivariate analyses identified factors predicting nodal recurrence.

Results

The median follow‐up period was 61 months (range: 6‐137 months). Seven patients (7.3%) developed lymph node recurrence only; two patients (2.1%) developed nodal plus local recurrence. Six of the seven cases without local recurrence involved the elective nodal irradiation field, with five cases involving the recurrent nerve lymph nodes. The 5‐year cumulative incidence of lymph node recurrence was higher for T1b tumors with lymphovascular invasion than for T1a tumors with lymphovascular invasion (17.6% vs 6.2%, P = 0.086; HR: 3.74, 95% CI: 0.80‐17.52, P = 0.094) and T1b tumors without lymphovascular invasion (17.6% vs 3.3%, P = 0.031; HR: 6.78, 95% CI: 0.80‐57.63, P = 0.080).

Conclusions

Lymph node recurrence frequently involved the elective nodal irradiation field, with recurrent nerve lymph nodes being common metastasis sites. The high incidence of nodal recurrence for T1b tumors with lymphovascular invasion highlights a need for new strategies for treating this subset of superficial esophageal squamous cell carcinomas.

Clinical Significance of 18F-Fluorodeoxyglucose-Positron Emission Tomography-Positive Lymph Nodes to Outcomes of Trimodal Therapy for Esophageal Squamous Cell Carcinoma

BACKGROUND

The clinical significance of lymph node (LN) status determined by preoperative ¹⁸F-fluorodeoxyglucose-positron emission tomography (FDG-PET) has not been investigated in patients with locally advanced esophageal squamous cell carcinoma (ESCC) treated with neoadjuvant chemoradiotherapy (NCRT) followed by surgery (trimodal therapy).

METHODS

This study reviewed 132 consecutive patients with ESCC who had been preoperatively evaluated using FDG-PET before and after NCRT to analyze associations among LN status according to PET findings, pathologic LN metastasis, and prognosis of ESCC after trimodal therapy.

RESULTS

Lymph nodes that were PET-positive both before and after NCRT comprised significant predictive markers of pathologic LN metastasis in station-by-station analyses (sensitivity, specificity, and accuracy respectively 41.7%, 95.0%, and 92.7% before, and 12.0%, 99.4%, and 95.6% after NCRT; both p < 0.0001). The numbers of LNs evaluated using PET before and after NCRT were significantly associated with those of pathologic metastatic LNs. Uni- and multivariable analyses selected LN status determined by PET before NCRT as a significant independent predictor of both recurrence-free [LN-negative vs LN-positive: hazard ratio (HR) 1.90; 95% confidence interval (CI) 1.02-3.23; p = 0.045] and overall survival (HR 2.62; 95% CI 1.29-5.30; p = 0.01).

CONCLUSIONS

The status of LN determined by preoperative FDG-PET is significantly associated with pathologic LN status and the prognosis of ESCC with trimodal therapy. Thus, FDG-PET is a useful diagnostic tool for preoperative prediction of pathologic LN metastasis and survival among patients with ESCC.

Nodal FDG-PET/CT uptake influences outcome and relapse location among esophageal cancer patients submitted to chemotherapy or radiochemotherapy

PURPOSE

Our aim was investigate whether lymph node uptake is associated with survival and regional relapses, and relapse patterns with respect to the radiotherapy fields in esophageal cancer (EC).

MATERIALS AND METHODS

The FDG-PET/CT image datasets of 56 patients were analyzed. All patients underwent definitive or neoadjuvant radio/chemotherapy (RCT). All patients suffering from persistent or recurrent local/regional-only disease after RCT were considered for salvage resection. Patients with adenocarcinoma without metastatic disease were considered for planned resection (usually within 3 months of treatment).

RESULTS

Patients with PET-positive lymph nodes before treatment had a worse overall survival and a shorter disease-free survival than those without PET-positive nodes. They also had worse node and metastatic relapse-free survival. N2 patients had statistically significant poorer outcomes than N1-N0 patients and a better survival if the involved nodes were closer to the esophageal tumor. Involved node location by PET/CT also affected global, nodal and metastatic relapses. In addition, an increment of SUVmax value increased relative risk of death and increased relative risk of node and metastatic relapses. The first site of relapse was metastatic recurrence and, second, local recurrence. The most frequent were "in-field" loco/regional recurrence. We observed a relationship between patients classified-N1 and out-field nodal recurrence (p = 0.024), and between patients-N2 and in-field nodal recurrence. The number of PET-positive nodes was an independent significant prognostic predictor for relapse (p < 0.001).

CONCLUSION

Our study shows that only FDG-PET/CT can provide prognostic information in EC. Nodal PET/CT uptake influences outcome and relapse location among EC patients.

Diagnostic value of 18F-fluorodeoxyglucose positron-emission tomography/computed tomography for preoperative lymph node metastasis of esophageal cancer: A meta-analysis

OBJECTIVE

We determined the value of F-fluorodeoxyglucose positron-emission tomography/computed tomography (FDG PET/CT) for the assessment of preoperative lymph node metastases in patients with esophageal cancer.

METHODS

We searched electronic database indexes for articles on PET/CT assessment of lymph node status. Information including true positives, false positives, false negatives, and true negatives was obtained. Based on these data, the pooled sensitivity, specificity, diagnostic odds ratio, and likelihood ratio were calculated using bivariate models and receiver operating characteristic curves (ROCs) were drawn.

RESULTS

Patients without neoadjuvant treatment had a pooled sensitivity and specificity (95% confidence interval [CI]) of 0.57 (0.45-0.69) and 0.91 (0.85-0.95), respectively. Patients who received neoadjuvant treatment had a pooled sensitivity and specificity of 0.53 (0.35-0.70) and 0.96 (0.86-0.99), respectively.

CONCLUSIONS

The PET/CT has a high diagnostic specificity but its diagnostic sensitivity is low; thus, its diagnosis findings cannot accurately reflect the lymph node status.

Novel imaging techniques in staging oesophageal cancer

The survival of oesophageal cancer is poor as most patients present with advanced disease. Radiological staging of oesophageal cancer is complex but is fundamental to clinical management. Accurate staging investigations are vitally important to guide treatment decisions and optimise patient outcomes. A combination of baseline computed tomography (CT), endoscopic ultrasound (EUS) and positron emission tomography (PET) are currently used for initial treatment decisions. The potential value of these imaging modalities to re-stage disease, monitor response and alter treatment is currently being investigated. This review presents an essential update on the accuracy of oesophageal cancer staging investigations, their use in re-staging after neo-adjuvant therapy and introduces evolving imaging techniques, including novel biomarkers that have clinical potential in oesophageal cancer.

Systematic review and meta-analysis of the accuracy of 18F-FDG PET/CT for detection of regional lymph node metastasis in esophageal squamous cell carcinoma

Background

We performed a systematic review and meta-analysis to assess the accuracy of 18F-fluorodeoxyglucose positron emission tomography with computer tomography (18F-FDG PET/CT) for detection of regional lymph node metastasis in esophageal squamous cell carcinoma in per-patient and per-nodal station basis.

Methods

Electronic databases were researched for studies assessing the sensitivity and specificity of PET/CT to detect the regional lymph node metastasis published between January 2006 and December 2017 on esophageal squamous cell carcinoma. STATA software was performed to assess the sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odd ratio (DOR) and summary receiver operating characteristic (SROC) curve. The Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) and Deeks' Funnel Plot Asymmetry Test were performed to evaluate the study quality and publication bias of included studies.

Results

Nineteen studies were eligible for meta-analysis, comprising 1,089 patients with esophageal cancer who underwent 18F-FDG PET/CT before surgery. According to the content of the article, we divided the selected studies into per-patient basis group and per-nodal basis group (one of the articles was involved in both groups). For the per-nodal station basis group (12 studies, 5,681 stations), the pooled sensitivity and specificity estimates of 18F-FDG PET/CT for detecting regional lymph node metastasis were 66% [95% confidence interval (CI): 51-78%] and 96% (95% CI: 92-98%), respectively. The corresponding values on a per-patient basis group (8 studies; 506 patients) were 65% (95% CI: 49-78%) and 81% (95% CI: 69-89%) in sensitivity and specificity, respectively.

Conclusions

Overall, 18F-FDG PET/CT have a moderate to low sensitivity and a high to moderate specificity for detection of regional nodal metastasis in esophageal cancer. Therefore, since the false rate is considerable, extending the extent of lymph node dissection or radiotherapy target volume is necessary after diagnosis of regional nodal metastasis by 18F-FDG PET/CT.

Positron Emission Tomography/Computed Tomography in Esophageal Carcinoma: Applications and Limitations

Squamous cell carcinoma and adenocarcinoma represent approximately 98% of esophageal malignant tumors. During the last 30 years, the incidence of adenocarcinoma has increased in Western countries (including the USA) where adenocarcinoma currently represents more than 60% of esophageal malignancies, although, worldwide, squamous cell carcinoma continues to be the predominant histologic type. Integrated positron emission tomography or computed tomography with 2-[fluorine18] fluro-2-deoxy-d-glucose is used in many institutions routinely as a tool in the initial staging and then repeated after therapy for the assessment of response to neoadjuvant therapy and detection of recurrent disease in patients with esophageal carcinoma. As with any other imaging modality, 2-[fluorine18] fluro-2-deoxy-d-glucose-positron emission tomography or computed tomography has strengths and limitations that should be understood in order to maximize its utility.

PET/Computed Tomography Scanning and Precision Medicine: Esophageal Cancer

Esophageal cancer commonly has a poor prognosis, which requires an accurate diagnosis and early treatment to improve outcome. Other modalities for staging, such as endoscopic ultrasound imaging and computed tomography (CT) scans, have a role in diagnosis and staging. However, PET with fluorine-18 fluoro-2-deoxy-d-glucose/CT (FDG PET/CT) scanning allows for improved detection of distant metastatic disease and can help to prevent unnecessary interventions that would increase morbidity. FDG PET/CT scanning is valuable in the neoadjuvant chemotherapy assessment and predicting survival outcomes subsequent to surgery. FDG PET/CT scanning detects recurrent disease and metastases in follow-up.

Early clinical esophageal adenocarcinoma (cT1): Utility of CT in regional nodal metastasis detection and can the clinical accuracy be improved?

INTRODUCTION

Treatment of early esophageal cancer depends on the extent of the primary tumor and presence of regional lymph node metastasis.(RNM). Short axis diameter>10mm is typically used to detect RNM. However, clinical determination of RNM is inaccurate and can result in inappropriate treatment. Purpose of this study is to evaluate the accuracy of a single linear measurement (short axis>10mm) of regional nodes on CT in predicting nodal metastasis, in patients with early esophageal cancer and whether using a mean diameter value (short axis+long axis/2) as well as nodal shape improves cN designation.

METHODS

CTs of 49 patients with cT1 adenocarcinoma treated with surgical resection alone were reviewed retrospectively. Regional nodes were considered positive for malignancy when round or ovoid and mean size>5mm adjacent to the primary tumor and>7mm when not adjacent. Results were compared with pN status after esophagectomy.

RESULTS

18/49 patients had pN+ at resection. Using a single short axis diameter>10mm on CT, nodal metastasis (cN) was positive in 7/49. Only 1 of these patients was pN+ at resection (sensitivity 5%, specificity 80%, accuracy 53%). Using mean size and morphologic criteria, cN was positive in 28/49. 11 of these patients were pN+ at resection (sensitivity 61%, specificity 45%, accuracy 51%). EUS with limited FNA of regional nodes resulted in 16/49 patients with pN+ being inappropriately designated as cN0.

CONCLUSIONS

Evaluation of size, shape and location of regional lymph nodes on CT improves the sensitivity of cN determination compared with a short axis measurement alone in patients with cT1 esophageal cancer, although clinical utility is limited.

Application of PET/CT in gastrointestinal cancers

Fluorine-18 fluoro-2-deoxy-D-glucose positron emission tomography (¹⁸F-FDG PET) is an imaging tool which reflects tumor metabolism. The integration of PET with computed tomography (CT) can provide precise anatomical information along with metabolic data. Here, we review the application and potential role of ¹⁸F-FDG PET/CT imaging in staging, evaluation of chemoradiation therapy, and detection of recurrence in gastrointestinal cancers.

Distribution of FDG-avid nodes in esophageal cancer: implications for radiotherapy target delineation

PURPOSE

Clinical target volumes (CTV) for radiotherapy (RT) in esophageal cancer (EC) are based on standard expansions of primary tumor volume. Data is needed to define regions at highest risk for occult disease, based on histology and location of the primary tumor. We therefore reviewed PET scans in EC patients to characterize the location of FDG-avid lymph node metastases (LNM).

MATERIALS AND METHODS

We identified 473 EC patients with reviewable pre-treatment PET-CT scans. Tumors were classified by histology and location; 85% were distal or GE junction tumors and 71% were adenocarcinoma. FDG-avid LNM were classified using standard radiographic nodal atlases, and distances from primary tumor to paraesophageal LNM were also measured.

RESULTS

The most common LNM in upper EC were supraclavicular, retrotracheal and paratracheal. The most common LNM in lower EC were paraesophageal and in the gastrohepatic space. Overall, 55% of paraesophageal LNM were adjacent to primary tumor. Of upper esophageal tumors with paraesophageal LNM, 87% were adjacent to the tumor and none were >6 cm from tumor. However, 57% of lower esophageal tumors with paraesophageal LNM had non-adjacent paraesophageal nodes, 24% of which were >8 cm from the tumor.

CONCLUSION

A more data-driven and individualized approach to CTV delineation could improve the therapeutic ratio of RT in esophageal cancer. These results can guide CTV delineation by indicating the potential distribution of nodal involvement in esophageal cancer.

Accuracy of ultrasound for the diagnosis of cervical lymph node metastasis in esophageal cancer: a systematic review and meta-analysis

BACKGROUND

Esophageal cancer is considered a serious malignancy with respect to its prognosis and mortality rate. Cervical lymph node status is one of the keys to determining prognosis and treatment methods. However, published data vary regarding the accuracy of ultrasound in the diagnosis of cervical lymph node metastasis. We performed a meta-analysis to assess the efficacy of ultrasound for detecting cervical lymph node metastasis in patients with esophageal cancer.

METHODS

The PubMed/MEDLINE, EMBASE, Web of Science, and Cochrane Library databases were searched to identify studies related to cervical lymph node metastasis, and 22 studies comprising 3,513 patients met our inclusion criteria. We used a bivariate meta-analysis following a random effects model to summarize the data. We also explored reasons for statistical heterogeneity using meta-regression, subgroup, and sensitivity analyses. Publication bias was assessed with a Deeks funnel plot.

RESULTS

The area under the receiver operating characteristic curve was 0.97 [95% confidence interval (CI): 0.95-0.98], and the pooled diagnostic odds ratio was 121.00 (95% CI: 47.57-307.79). With cut-off values of 5 mm and >5 mm for cervical lymph node size, the sensitivities and specificities (95% confidence interval) for ultrasound detection of cervical lymph node metastasis were 84% (67-93%) and 93% (90-95%); and 94% (76-98%) and 98% (89-100%), respectively.

CONCLUSIONS

We show for the first time the diagnostic accuracy of ultrasound for predicting cervical lymph node-positive metastasis in esophageal cancer. Our analysis shows that ultrasonography may be an effective and reliable approach to detect cervical lymph node metastasis in esophageal cancer. However, to accommodate heterogeneity, high-quality studies are needed to further verify the efficacy of ultrasound detection.

Stage-directed individualized therapy in esophageal cancer

Esophageal cancer is the eighth most common cancer worldwide, and the incidence of esophageal carcinoma is rapidly increasing. With the advent of new staging and treatment techniques, esophageal cancer can now be managed through various strategies. A good understanding of the advances and limitations of new staging techniques and how these can guide in individualizing treatment is important to improve outcomes for esophageal cancer patients. This paper outlines the recent progress in staging and treatment of esophageal cancer, with particularly attention to endoscopic techniques for early-stage esophageal cancer, multimodality treatment for locally advanced esophageal cancer, assessment of response to neoadjuvant treatment, and the role of cervical lymph node dissection. Furthermore, advances in robot-assisted surgical techniques and postoperative recovery protocols that may further improve outcomes after esophagectomy are discussed.

Identification of a predictive factor for distant metastasis in esophageal squamous cell carcinoma after definitive chemoradiotherapy

BACKGROUND AND PURPOSE

Distant metastasis (DM) after definitive chemoradiotherapy has not been a focus of research in esophageal carcinoma. At present, local-regional control is improving following advances in salvage treatments after definitive chemoradiotherapy. There is a need to focus on suppressing the development of DM. The aim of this study was to identify pre-treatment factors associated with DM after definitive chemoradiotherapy.

MATERIALS AND METHODS

This study included 144 patients with thoracic esophageal squamous cell carcinoma (Stage I/II/III/IV; 35/17/69/23) (TNM 7th) who underwent definitive chemoradiotherapy; >50 Gy was prescribed to all gross tumors with concurrent administration of 5-fluorouracil ± platinum. Pre-treatment factors included age, gender, performance status, tumor location, T/N/M status, tumor length, size of metastatic lymph nodes (LN size), and the presence of intramural metastasis or multiple primary tumors. The effects of pre-treatment factors on overall survival (OS) and DM were evaluated.

RESULTS

The median follow-up period was 48 months. DM occurred as an initial progression in 21 % of patients, and LN size correlated with DM development (hazard ratio [HR] = 5.12; p = 0.0013) and poor OS (HR = 2.20; p = 0.0076) in univariate and multivariate analyses.

CONCLUSIONS

LN size is a quantitative pre-treatment prognostic factor that should be assessed prior to definitive chemoradiotherapy. Patients with large metastatic lymph nodes are at high risk of DM and should be monitored.

Association between the inflammatory biomarker, C-reactive protein, and the response to radiochemotherapy in patients with esophageal cancer

Locally advanced esophageal cancer has been treated by a multimodality regimen encompassing combined radiochemotherapy (RCT). The tumor response to neoadjuvant RCT is a major determinant of further therapeutic strategies, whether surgery or a continuation of RCT, and therefore, also of the patient's overall prognosis. The present study included patients with histologically proven squamous cell esophageal carcinoma. The C-reactive protein (CRP) level was measured prior to and following the completion of neoadjuvant RCT. Only CRP measurements taken within 2 weeks of the start of RCT were analyzed. Further measurements were then taken at 6, 12, 18, 24, 30, 36 and 40 weeks following RCT. CRP levels were high prior to treatment; however, eventually decreased and normalized following the therapy. In univariate analysis, pre-therapeutic CRP levels had a significant influence on the response rate (P=0.033), whilst post-therapeutic CRP levels had no significant influence (P=0.383). Pre-therapeutic CRP levels, however, not post-therapeutic CRP levels were significantly correlated with the response rate (P=0.045 and P=0.444, respectively), and no association was observed between CRP levels and survival. This preliminary data indicated that the pre-therapeutic serum CRP level is a possible indicator of treatment response to RCT.

FDG-PET nodal staging does not correlate with histopathological nodal stage for oesophageal cancers

OBJECTIVE

To investigate whether pre-operative N-stage (nodal stage) based on FDG-PET for oesophageal cancers, correlates with final histopathology. Additionally, we assessed if N-stage differs for squamous cell cancers compared with adenocarcinomas and if neoadjuvant therapy alters these results.

BACKGROUND

Our current understanding of oesophageal cancer biology means that personalisation of multimodality therapy is based on accurate clinical staging, allied with patient co morbidities and patient preference.

METHODS

We conducted a retrospective review of consecutive oesophagectomy cases performed over a ten year period (between 2002 and 2013) from a single tertiary centre. A total of 161 patients were identified in the study period.

RESULTS

Overall, 103 specimens with 1402 lymph nodes were included. For both Adenocarcinomas (AC) and Squamous Cell Carcinomas (SCC), there was no significant difference between the N-stage determined by CT vs. FDG-PET (p > 0.05). For AC, there was statistically significant under-reporting of the N-stage by PET compared with the final histopathology (p < 0.01). Subgroup analysis showed that neoadjuvant therapy vs. adjuvant therapy alone did not alter the bias for under-reporting of the N-stage for adenocarcinoma by PET-CT (Bland-Altman bias 0.76 vs. bias 0.75).

CONCLUSION

There is little doubt that PET-CT provides useful information in determining metastatic disease however its use in evaluating nodal burden is limited. Theoretically, this should not preclude patients from receiving definitive surgical management but the decision regarding neoadjuvant treatment based on locoregional disease may be affected.

Clinical staging of patients with early esophageal adenocarcinoma: does FDG-PET/CT have a role?

BACKGROUND

Esophageal carcinoma is a significant worldwide health problem and the incidence is increasing faster than that of any other malignancy. 18F-2-deoxy-D-glucose (FDG)-positron emission tomography/computed tomography (PET/CT) is important in the management of patients with potentially resectable esophageal cancer and is useful in initial staging of locally advanced cancer and after neoadjuvant therapy. The purpose of this study is to determine the utility of FDG-PET/CT in the clinical staging of early-stage esophageal cancer.

METHODS

Subjects in this retrospective study were 79 consecutive patients with cTisN0 (high-grade dysplasia) and cT1N0 primary esophageal adenocarcinoma diagnosed by endoscopy and endoscopic ultrasound biopsy that were evaluated with preoperative FDG-PET/CT and had not received neoadjuvant therapy. Seventh edition American Joint Committee on Cancer cTNM and FDG-PET/CT were compared with postoperative pTNM staging. pT1 was subdivided into intramucosal cancers with lamina propria or muscularis mucosa invasion (pT1a) and submucosal cancers (pT1b).

RESULTS

In pT staging, the frequency of FDG uptake increased with increasing pT, from pT1a 21 of 39 (53.8%) to pT1b 19 of 22 (55.8%). pTis was three of five (60.0%). Similarly, the maximum standardized uptake value of FDG-avid lesions increased with increasing pT, with median values of 3.7 for pTis, 3.8 for pT1a and 4.2 for T1b. In cN staging, FDG-PET/CT was negative in 76 patients and positive in three patients. All three patients with FDG-avid nodes on FDG-PET/CT were negative for metastatic disease on biopsy. In 12 patients with pN1 and in one patient with N2, FDG-PET/CT was falsely negative. Sensitivity and positive predictive value for pN disease were 0% and accuracy was 82%. There were no distant metastases. In cM staging, FDG-PET/CT was falsely positive in five patients (FDG avid nodules n = 3, distant nodal metastasis n = 2) and resulted in unwarranted biopsy in four patients.

CONCLUSION

FDG-PET/CT is not useful in the TNM staging of primary adenocarcinoma of the esophagus when endoscopy and biopsy indicate cTis and cT1. In fact, FDGPET/CT can be detrimental to patient management. Because regional nodal metastases are uncommon and distant metastases rare, and as FDG-PET/CT can result in inappropriate clinical care, FDG-PET/CT should not be performed in the evaluation of early-stage esophageal cancer.

Usefulness of positron emission tomography-computed tomography in pre-operative evaluation of intra-thoracic esophageal cancer

Background

The purpose of the study was to clarify the usefulness of positron emission tomography-computed tomography (PET-CT) for pre-operative evaluation of intra-thoracic esophageal cancer, especially in terms of regional lymph node status.

Methods

Medical records of 93 consecutive cases from July 2007 to October 2012 were retrospectively reviewed. All patients underwent curative and complete esophagectomies for intra-thoracic esophageal cancer. We compared pre-operative maximum standard uptake values (SUVmax) of esophageal tumors and regional lymph nodes (LN) with other variables (chronic obstructive pulmonary disease, history of previous other primary cancer, gender, differentiation, and neoadjuvant therapy). In addition, the SUVmax of tumors and LNs were analyzed with pathologic findings.

Results

There was no significant difference of each tumor and LN SUVmax according to factors including chronic lung disease, age, history of previous other cancer, differentiation, and gender. Pre-operative evaluations by PET-CT were not accurate (tumor sensitivity 76.4%, specificity 25%; LN sensitivity 45.2%, specificity 54.8%). Receiver operating characteristic analysis showed that LN metastasis could not be appropriately diagnosed with SUVmax (P = 0.871). There was no difference in SUVmax between pathologically positive and negative LN subgroups. Tumor SUVmax correlated with the progression of esophageal cancer in patients without neoadjuvant therapy (P < 0.001). However, LN SUVmax had no correlation with overall pathologic stage. After neoadjuvant therapy, there were significant decreases in SUVmax in both pathologically positive and negative LN subgroups (P = 0.043, P = 0.008).

Conclusion

 Surgery should not be withheld in N-stage according to PET-CT findings and carefully considered in conjunction with other conditions.

Positron Emission Tomography (PET) in Oncology

Since its introduction in the early nineties as a promising functional imaging technique in the management of neoplastic disorders, FDG-PET, and subsequently FDG-PET/CT, has become a cornerstone in several oncologic procedures such as tumor staging and restaging, treatment efficacy assessment during or after treatment end and radiotherapy planning. Moreover, the continuous technological progress of image generation and the introduction of sophisticated software to use PET scan as a biomarker paved the way to calculate new prognostic markers such as the metabolic tumor volume (MTV) and the total amount of tumor glycolysis (TLG). FDG-PET/CT proved more sensitive than contrast-enhanced CT scan in staging of several type of lymphoma or in detecting widespread tumor dissemination in several solid cancers, such as breast, lung, colon, ovary and head and neck carcinoma. As a consequence the stage of patients was upgraded, with a change of treatment in 10%-15% of them. One of the most evident advantages of FDG-PET was its ability to detect, very early during treatment, significant changes in glucose metabolism or even complete shutoff of the neoplastic cell metabolism as a surrogate of tumor chemosensitivity assessment. This could enable clinicians to detect much earlier the effectiveness of a given antineoplastic treatment, as compared to the traditional radiological detection of tumor shrinkage, which usually takes time and occurs much later.