FDG-PET/CT lymph node staging after neoadjuvant chemotherapy in patients with adenocarcinoma of the esophageal-gastric junction

The diagnostic value of dual-layer CT in the assessment of lymph nodes in lymphoma patients with PET/CT as a reference standard

This study aimed to evaluate the diagnostic performances of dual-layer CT (DLCT) for the identification of positive lymph nodes (LNs) in patients with lymphoma and retrospectively included 1165 LNs obtained by biopsy from 78 patients with histologically proven lymphoma, who underwent both pretreatment DLCT and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). According to 18F-FDG PET/CT findings as a reference standard, cases were categorized into the LN-negative and LN-positive groups. LNs were then randomly divided at a ratio of 7:3 into the training (n = 809) and validation (n = 356) cohorts. The patients' clinical characteristics and quantitative parameters including spectral curve slope (λHU), iodine concentration (IC) on arterial phase (AP) and venous phase (VP) images were compared between the LN-negative and LN-positive groups using Chi-square test, t-test or Mann-Whitney U test for categorical variables or quantitative parameters. Multivariate logistic regression analysis with tenfold cross-validation was performed to establish the most efficient predictive model in the training cohort. The area under the curve (AUC) was used to evaluate the diagnostic value of the predictive model, and differences in AUC were determined by the DeLong test. Moreover, the predictive model was validated in the validation cohort. Repeatability analysis was performed for LNs using intraclass correlation coefficients (ICCs). In the training cohort, long diameter (LD) had the highest AUC as an independent factors compared to other parameter in differentiating LN positivity from LN negativity (p = 0.006 to p < 0.001), and the AUC of predictive model jointly involving LD and λHU-AP was significantly elevated (AUC of 0.816, p < 0.001). While the AUC of predictive model in the validation cohort was 0.786. Good to excellent repeatability was observed for all parameters (ICC > 0.75). The combination of DLCT with morphological and functional parameters may represent a potential imaging biomarker for detecting LN positivity in lymphoma.

18F-FDG-PET/CT Imaging for Gastrointestinal Malignancies

Gastrointestinal malignancies encompass a variety of primary tumor sites, each with different staging criteria and treatment approaches. In this review we discuss technical aspects of 18F-FDG-PET/CT scanning to optimize information from both the PET and computed tomography components. Specific applications for 18F-FDG-PET/CT are summarized for initial staging and follow-up of the major disease sites, including esophagus, stomach, hepatobiliary system, pancreas, colon, rectum, and anus.

Hypofractionated Radiotherapy in Combination With Chemotherapy Improves Outcome of Patients With Esophageal Carcinoma Tracheoesophageal Groove Lymph Node Metastasis

This study investigated the efficiency and safety of hypofractionated radiotherapy (HFR) combined with paclitaxel chemotherapy for the treatment of postsurgery tracheoesophageal groove lymph node (TGLN) metastasis in patients with esophageal cancer (EC). Fifty-three EC patients with TGLN metastasis after surgery admitted to the Yancheng Third People's Hospital from January 2013 to June 2015 were included in this study. They were randomly divided into the HFR group (n = 25) and conventional fractioned radiotherapy (CFR) group (n = 28) based on the random grouping method. Patients in the HFR group received treatment with radiation of 60 Gy (5 fractions per week, total 20 fractions) combined with paclitaxel chemotherapy at a dose of 50 mg once per week for 4 weeks. Patients in the CFR group received radiation of 60 Gy (5 fractions per week, total 30 fractions) combined with paclitaxel chemotherapy at a dose of 50 mg once per week for 6 weeks. The adverse events and treatment outcomes in these two groups were analyzed. It was found that there was no significant difference in the incidence of radiation esophagitis in the HFR group compared with that of the CFR group (grades 3-4, 44.0 vs. 25.0%; P = 0.149). There was no statistical difference in the incidence of radiation pneumonitis between these two groups (grades 3-4, 16.0 vs. 7.1%; P = 0.314). No statistical difference was noticed in complete response (CR), partial response (PR), and no response (NR) between these two groups. The median overall survival (OS) in the HRF group was significantly longer compared with that of the CRF group (24.2 months (95% CI, 16.2-32.1 months) vs. 11.8 months (95% CI, 9.2-14.4 months); P = 0.024). Our results indicated that the combination of HFR and chemotherapy improved the prognosis of EC patients with TGLN metastasis with no increased adverse events.

Predicting lymph node metastases with endoscopic resection in cT2N0M0 oesophageal cancer: A systematic review and meta-analysis

Background

Despite modern imaging modalities, staging of clinically staged T2N0M0 (cT2N0M0) oesophageal cancer is suboptimal, often leading to overtreatment. Endoscopic resection – the first-line therapy for early localised tumours – could be used to improve staging and to attain predictors of nodal upstaging enabling more stage-guided treatment decisions.

Objective

A systematic literature review and a meta-analysis were conducted to assess the prevalence and the pathological risk factors of lymph node metastases in cT2N0M0 oesophageal cancer.

Methods

Databases of PUBMED, EMBASE and Cochrane were searched for literature. The primary outcome was lymph node metastases determined after primary surgical resection.

Results

Nine studies with a total of 1650 cT2N0M0 patients were included. The prevalence of lymph node metastases was 43% (95% confidence interval: 35–50%) with heterogeneity being high across studies (I² = 0.86, p < 0.001). Factors potentially attainable by endoscopic resection and having a significant association with lymph node metastases were invasion depth, differentiation grade, tumour size, depth of invasion in the muscularis propria and lymphovascular invasion.

Conclusions

Clinical lymph node staging is inaccurate in almost half of cT2N0M0 oesophageal cancer. Endoscopic resection is a promising diagnostic modality that might even be a valid alternative to surgery in selected patients without high-risk features, but further evidence is warranted.

[18F]Fluorodeoxyglucose PET/CT and prediction of histopathological response to neoadjuvant chemotherapy for adenocarcinoma of the oesophagus and oesophagogastric junction

Background

The aim of this prospective study was to assess whether [18F]fluorodeoxyglucose PET can be used to predict histopathological response early in the course of neoadjuvant chemotherapy in patients with adenocarcinoma of the oesophagus and oesophagogastric junction.

Methods

Following the PET response criteria in solid tumours (PERCIST 1.0) as a standardized method for semiquantitative assessment of metabolic response, FDG-PET/CT was performed before (PET1) and after (PET2) initiation of the first cycle of chemotherapy. The relative changes in the peak standardized uptake value (ΔSUL) and total lesion glycolysis (ΔTLG) between PET1 and PET2 were correlated with histopathological response, defined as less than 50 per cent viable tumour cells in the resection specimen. A receiver operating characteristic (ROC) curve analysis was used to identify the optimal cut-off value with the highest accuracy of histopathological response prediction.

Results

PET2 was performed a median of 16 (range 12–22) days after the start of chemotherapy. Some 27 of 90 patients who underwent surgery had a histopathological response. There was no association between the median ΔSUL or median ΔTLG and the histopathological response. A post hoc analysis in 47 patients with PET2 performed 16 days or less after the start of chemotherapy showed that ΔTLG, but not ΔSUL, was associated with the histopathological response (P = 0·009). The optimal cut-off value of ΔTLG was 66 per cent or more.

Conclusion

FDG-PET/CT after the first cycle of chemotherapy does not predict histopathological response in patients with adenocarcinoma of the oesophagus and oesophagogastric junction.

Significance of baseline FDG-PET/CT scan as a method of staging regional lymph nodes in patients with operable distal oesophageal or gastroesophageal junction adenocarcinoma

BACKGROUND

The new American Joint Committee on Cancer eighth edition (AJCC8) staging is the first to describe separate clinical and pathology staging systems, but still has low performance to predict prognosis in patients with oesophageal/gastroesophageal junction (O/GOJ) adenocarcinoma, who are candidates for surgery. Recent studies have demonstrated that O/GOJ cancer patients with 18F-fluorodeoxyglucose (FDG) avid regional lymph nodes (RLNs) may have poor prognosis. The aim of our study was to examine whether the baseline assessment of the FDG uptake of RLN improves the prognostic accuracy of the new AJCC8 staging.

PATIENTS AND METHODS

This single-centre retrospective study included patients with operable FDG avid O/GOJ adenocarcinoma treated with perioperative chemotherapy. All patients were reclassified according to the new AJCC8 clinical staging. Prognostic factors for time-to-progression (TTP) and overall survival (OS) were explored.

RESULTS

Of 430 patients included in the study, 180 (41.9%) had FDG avid RLN at baseline PET/CT scan before starting perioperative chemotherapy. The presence of FDG avid RLN was significantly and independently associated with shorter TTP and OS, especially in clinical stage III patients (p < .001 in both cases). Stage III patients with FDG avid RLN had similar TTP and OS to those with stage IVA. Classifying stage III patients with FDG avid RLN into stage IVA led to a significant improvement of the prognostic accuracy of the new AJCC8 clinical staging system (Harrell's concordance index improved from 0.555 to 0.588, p < .001). Of 430 patients starting perioperative chemotherapy, 332 underwent radical tumour resection. The presence of FDG avid RLN before starting perioperative chemotherapy could additionally predict a significantly shorter postoperative time-to-relapse and OS (p < .001 in both cases).

CONCLUSIONS

We propose that the incorporation of RLN status (by FDG PET/CT scan) into the AJCC8 staging system of O/GOJ adenocarcinoma improves its prognostic accuracy and may also improve treatment stratification.