Concordance of positron emission tomography and computed tomography in patients with locally advanced gastric and esophageal cancer

ACR Appropriateness Criteria® Staging and Follow-Up of Esophageal Cancer

This document provides recommendations regarding the role of imaging in the staging and follow-up of esophageal cancer. For initial clinical staging, locoregional extent and nodal disease are typically assessed with esophagogastroduodenoscopy and esophageal ultrasound. FDG-PET/CT or CT of the chest and abdomen is usually appropriate for use in initial clinical staging as they provide additional information regarding distant nodal and metastatic disease. The detection of metastatic disease is critical in the initial evaluation of patients with esophageal cancer because it will direct patients to a treatment pathway centered on palliative radiation rather than surgery. For imaging during treatment, particularly neoadjuvant chemotherapy, FDG-PET/CT is usually appropriate, because some studies have found that it can provide information regarding primary lesion response, but more importantly it can be used to detect metastases that have developed since the induction of treatment. For patients who have completed treatment, FDG-PET/CT or CT of the chest and abdomen is usually appropriate for evaluating the presence and extent of metastases in patients with no suspected or known recurrence and in those with a suspected or known recurrence. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Endoscopic Ultrasound/Fine Needle Aspiration Is Effective for Lymph Node Staging in Patients With Cholangiocarcinoma

BACKGROUND AND AIMS

Presence of malignant regional lymph nodes (MRLNs) precludes curative oncological resection or liver transplantation for cholangiocarcinoma (CCA). Limited data support the utility of endoscopic ultrasound (EUS)/fine needle aspiration (FNA) for detection of MRLNs in extrahepatic CCA, but there are no data for its role in intrahepatic CCA (iCCA). The aim of this study is to evaluate the staging impact of EUS for CCA, including analysis by subtype.

APPROACH AND RESULTS

We identified consecutive patients with CCA who underwent EUS staging at a single tertiary care center from October 2014 to April 2018. Among this cohort, we abstracted clinical demographic, radiographical, procedural, cytopathological, and surgical data. STATA 15 software was used for comparative analysis calculations (StataCorp LP, College Station, TX). The study cohort included 157 patients; 24 (15%), 124 (79%), and 9 (6%) with intrahepatic, perihilar, and distal CCA, respectively. EUS was able to identify regional lymph nodes (RLNs) in a higher percentage of patients compared to cross-sectional imaging (86% vs. 47%; P < 0.001). FNA was performed in 133 (98.5%) patients with RLNs, with a median of three passes per node. EUS-FNA identified MRLN in 27 of 31 (87.1%) patients ultimately found to have MRLNs. For iCCA, EUS detected a higher percentage of RLN compared to cross-sectional imaging (83% vs. 50%; P = 0.048), with MRLNs identified in 4 (17%) patients. Among the entire cohort, identification of at least one MRLN by EUS was associated with lower median survival (353 vs. 1,050 days; P < 0.001) and increased risk of death (hazard ratio = 4.1; P < 0.001).

CONCLUSIONS

EUS-FNA is effective for identifying MRLN in patients with CCA, and should be routinely incorporated into staging of all CCA subtypes given the impact of MRLN on prognosis and management decisions.

The Utility of PET/Computed Tomography for Radiation Oncology Planning, Surveillance, and Prognosis Prediction of Gastrointestinal Tumors

At present, the strongest evidence for the use of PET/computed tomography (CT) in gastrointestinal (GI) malignancies is to rule out distant metastatic disease at diagnosis, radiation treatment planning for anal malignancies, and disease recurrence monitoring in colorectal and anal malignancies. Use of PET/CT for GI malignancies continues to evolve over time, with new studies evaluating prognostic abilities of PET/CT and with increasing sensitivity and spatial resolution of more modern PET/CT scanners. The authors encourage future applications and prospective evaluation of the use of PET/CT in the staging, prognostication, and recurrence prediction for GI malignancies.

Should 18F-FDG PET/CT Be Routinely Performed in the Clinical Staging of Locally Advanced Gastric Adenocarcinoma?

PURPOSE

The aim of this study was to evaluate F-FDG PET/CT compared with conventional imaging techniques in the clinical management of patients with locally advanced gastric cancer (LAGC).

METHODS

A prospective study between January 2010 and December 2011 in patients with suspected LAGC was conducted in our hospital. F-FDG PET/CT, contrast-enhanced CT (CECT), endoscopic ultrasound, and laparoscopy were performed in all cases. Standard whole-body F-FDG PET/CT images were obtained centered on the stomach at 1 and 2 hours after injection of 4.0 MBq/kg of F-FDG. Findings were confirmed by histopathology or by imaging follow-up in nonoperable patients.

RESULTS

Fifty consecutive patients with confirmed LAGC (20 women, 30 men) with a mean ± SD age of 65.7 ± 12.1 years were included. Using Lauren classification, 24 patients were intestinal subtype, and 26 were diffuse subtype. Thirty-five patients with locoregional lymph node involvement and 22 with distant metastases were confirmed as peritoneal metastases (n = 15), retroperitoneal (n = 2) or mediastinal lymph nodes (n = 1), and liver (n = 3) or bone metastases (n = 1). Patients with signet ring carcinoma showed significantly less F-FDG uptake (P = 0.001). SUVmax correlated with tumor grading (P < 0.05). Standard and delayed F-FDG PET/CT and CECT images identified LAGC in 24, 27, and 28 of 30 patients, respectively. The sensitivity and specificity for F-FDG PET/CT and CECT to detect metastases were 68% and 100% and 64% and 93%, respectively. Contrast-enhanced CT and F-FDG PET/CT diagnosed only 6 of the 15 patients with confirmed peritoneal metastases. The impact in therapeutic management of F-FDG PET/CT and CECT was 24% and 22%, respectively. Kaplan-Meier survival curves for the LGAC showed a significant correlation between SUVmax and overall survival using an SUVmax threshold of less than 3.96 (P = 0.04).

CONCLUSIONS

F-FDG PET/CT should be recommended for staging of LAGC; however, F-FDG PET/CT and CECT cannot replace laparoscopy to rule out peritoneal metastases. Delayed F-FDG PET/CT images show an increase of F-FDG uptake in most cases, improving LAGC detection. The grade of F-FDG uptake represents a significant prognostic tool in this series.