PET/CT of esophageal cancer: its role in clinical management

Correlation between metabolic response determined with [18F]FDG PET/CT and pathological response after neoadjuvant treatment and surgery in patients with esophageal cancer

AIM

To assess the correlation between the result of the PET/CT study with [18F]FDG and the histological outcome in patients with esophageal cancer undergoing chemoradiotherapy and subsequent surgery.

MATERIAL AND METHODS

41 patients (35 men) diagnosed with esophageal cancer during a 10-year interval were retrospectively evaluated. PERCIST criteria and SULpeak (ΔSULpeak) variation between pre- and post-treatment PET/CT studies were used. After neoadjuvant treatment and subsequent surgery, histological response and patient survival were determined, correlating the findings with the result of the metabolic study. Different parameters related to patient and tumors lesion characteristics were compared with respect to histologic response. ROC curves and the Kaplan-Meier method were applied for the analysis of prognostic factors and survival curves.

RESULTS

The mean follow-up was 34.9 months, with 21 relapses-progressions and 25 deaths. Significant differences were demonstrated between histologic responses regarding PERCIST criteria and ΔSULpeak. Both showed adequate sensitivity and moderate specificity in relation to their histological correlation. No significant differences were found with respect to other parameters studied. Survival analysis showed significantly different progression-free survival curves for the ΔSULpeak and histologic outcome.

CONCLUSION

PERCIST criteria and ΔSULpeak differentiated between patients with and without histological response. ΔSULpeak and histological results proved to be prognostic factors. The results could help to personalize treatment and, together with other determinations, allow an active surveillance approach could be contemplated.

Advancing Esophageal Cancer Staging and Restaging: The Role of MRI in Precision Diagnosis

This review provides an in-depth analysis and comprehensive overview of recent advancements in MRI techniques for evaluating esophageal cancer (EC). It discusses the specific MRI acquisition protocols and parameters that enhance image quality and diagnostic accuracy. The review highlights MRI's role and performance in the initial TNM staging and its potential to refine treatment strategies by improving tumor delineation and characterization. Additionally, the paper explores MRI utility in restaging after NAT, focusing on its accuracy in assessing treatment response and detecting residual or recurrent disease. Comparisons with other imaging modalities currently used-such as endoscopic ultrasound (EUS), contrast-enhanced computed tomography (CE-CT), and 18F-fluorodeoxyglucose (FDG) positron emission tomography/CT (PET/CT)-are included to highlight the strengths and limitations of each method. Illustrated with numerous Figures, this article proposes a novel MRI-based strategy for EC staging and restaging. It aims to integrate MRI into clinical practice by leveraging its superior soft-tissue contrast and functional imaging capabilities to enhance diagnostic precision and improve patient outcomes. Through this comprehensive evaluation, the review underscores the potential of MRI to become a cornerstone in the precision diagnosis and management of EC.

A Canadian algorithm for upper gastrointestinal cancer management

Recent advances in immunotherapy have changed the treatment landscape for cancers of the upper gastrointestinal (GI) system. Immune checkpoint inhibitors can lead to better survival and improved quality of life for affected individuals. Adopting new treatment strategies in real-world practice can be challenging, and algorithms that are easy to implement in Canadian oncology practices would benefit clinicians and patients. In this study, we present expert opinion on best practices for upper GI cancer management, including a new algorithm that integrates the latest evidence for screening, workup, diagnosis, treatment, and survivorship. The algorithm is based on a novel approach comprising a case-based, accredited educational program with asynchronous discussion among clinicians practicing across Canada, with the input of expert medical oncologists and gastroenterologists. A needs assessment was employed to determine current areas of educational need in the field of upper GI cancers, and a patient representative provided insights into patient concerns and priorities. The best practices described here include seeking patient input throughout treatment, integrating immune checkpoint inhibitors into systemic therapy for both localized and advanced disease, and providing comprehensive supportive care throughout the treatment and survivorship journey.

Definition and Predictors of Early Recurrence in Neoadjuvantly Treated Esophageal and Gastroesophageal Adenocarcinoma: a Dual-Center Retrospective Cohort Study

ABSTARCT

BACKGROUND: Early recurrence after esophagectomy is often used as a surrogate for aggressive tumor biology and treatment failure. However, there is no standardized definition of early recurrence, and predictors for early recurrence are unknown. Therefore, we aimed to define an evidence-based cutoff to discriminate early and late recurrence and assess the influence of neoadjuvant treatment modalities for patients with esophageal or gastroesophageal-junction adenocarcinoma (EAC).

PATIENTS AND METHODS

This dual-center retrospective cohort study included patients who underwent esophagectomy for stage II-III EAC after neoadjuvant treatment with chemotherapy using 5-fluorouracil, leucovorin, oxaliplatin, and docetaxel (FLOT) or radiochemotherapy according to the Chemoradiotherapy for Esophageal Cancer followed by Surgery Study (CROSS) protocol from 2012 to 2022. The optimal cutoff for early versus late recurrence was calculated by using the most significant difference in survival after recurrence (SAR). Multivariable logistic regression was used to identify variables associated with early recurrence.

RESULTS

Of 334 included patients, 160 (47.9%) were diagnosed with recurrence. Most patients had systemic (60.5%) or multiple sites of recurrence (21.1%), whereas local-only recurrence (9.2%) and carcinomatosis (9.2%) were rare. The optimal interval between surgery and recurrence for distinguishing early and late recurrence was 18 months (median SAR: 9.1 versus 17.8 months, p = 0.039) with only 24% of recurrences diagnosed after the calculated cutoff. Advanced pathologic tumor infiltration (ypT3-4, p = 0.006), nodal positivity (p = 0.013), poor treatment response (>10% residual tumor, p = 0.015), and no adjuvant treatment (p = 0.048) predicted early recurrence.

CONCLUSION

Early recurrence can be defined as recurrent disease within 18 months. Hallmarks for early recurrence are poor response to neoadjuvant therapy with persisting advanced disease. In those patients, adjuvant therapy and closer follow-up should be considered.

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.

Therapy response monitoring in blood plasma from esophageal adenocarcinoma patients using cell-free DNA methylation profiling

Esophageal adenocarcinoma (EAC) is an aggressive cancer characterized by a high risk of relapse post-surgery. Current follow-up methods (serum carcinoembryonic antigen detection and PET-CT) lack sensitivity and reliability, necessitating a novel approach. Analyzing cell-free DNA (cfDNA) from blood plasma emerges as a promising avenue. This study aims to evaluate the cost-effective and genome-wide cell-free reduced representation bisulfite sequencing (cfRRBS) method combined with computational deconvolution for effective disease monitoring in EAC patients. cfDNA methylation profiling with cfRRBS was performed on 162 blood plasma samples from 33 EAC cancer patients and 28 blood plasma samples from 20 healthy donors. The estimated tumor fraction for EAC patients at the time of diagnosis was significantly different from the healthy donor plasma samples (one-sided Wilcoxon rank-sum test: p-value = 0.032). Tumor fractions above 15% and focal gains/amplifications in MYC (chr8), KRAS (chr12), EGFR (chr7) and NOTCH2 (chr1) were observed in four samples of distinct patients at the time metastatic disease was detected. This study showed feasibility to estimate tumor fractions in blood plasma of EAC patients based on cfDNA methylation using cfRRBS and computational deconvolution. Nevertheless, in this study only cancer patients with evidence of metastatic disease show high tumor fractions and copy number alterations.

Circumferential resection margin rates in esophageal cancer resection: oncological equivalency and comparable clinical outcomes between open versus minimally invasive techniques - a retrospective cohort study

BACKGROUND

Radical surgery for esophageal cancer requires macroscopic and microscopic clearance of all malignant tissue. A critical element of the procedure is achieving a negative circumferential margin (CRM) to minimize local recurrence. The utility of minimally invasive surgery poses challenges in replicating techniques developed in open surgery, particularly for hiatal dissection in esophago-gastrectomy. In this study, the technical approach and clinical and oncological outcomes for open and laparoscopic esophago-gastrectomy are described with particular reference to CRM involvement.

MATERIALS AND METHODS

This cohort study included all patients undergoing either open or laparoscopic esophago-gastrectomy between January 2004 and June 2022 in a single tertiary center. A standard surgical technique for hiatal dissection of the esophago-gastric junction developed in open surgery was adapted for a laparoscopic approach. Clinical parameters, length of stay (LOS), postoperative complications, and mortality data were collected and analyzed by a Mann-Whitney U or Fisher's exact method.

RESULTS

Overall 447 patients underwent an esophago-gastrectomy in the study with 219 open and 228 laparoscopic procedures. The CRM involvement was 18.8% in open surgery and 13.6% in laparoscopic surgery. The 90-day-mortality for open surgery was 4.1 compared with 2.2% for laparoscopic procedures. Median Intensive care unit (ITU), inpatient LOS and 30-day readmission rates were shorter for laparoscopic compared with open esophago-gastrectomy (ITU: 5 versus 8 days, P= 0.0004; LOS: 14 versus 20 days, P= 0.022; 30-day re-admission 7.46 versus 10.50%). Postoperative complication rates were comparable across both cohorts. The rates of starting adjuvant chemotherapy were 51.8 after open and 74.4% in laparoscopic esophago-gastrectomy.

CONCLUSION

This study presents a standardized surgical approach to hiatal dissection for esophageal cancer. The authors present equivalence between open and laparoscopic esophago-gastrectomy in clinical, oncological, and survival outcomes with similar rates of CRM involvement. The authors also observe a significantly shorter hospital length of stay with the minimally invasive approach.

False Liver Metastasis by Positron Emission Tomography/Computed Tomography Scan after Chemoradiotherapy for Esophageal Cancer-Potential Overstaged Pitfalls of Treatment

In patients with esophageal cancer undergoing neoadjuvant chemoradiotherapy (nCRT), subsequent restaging with F-18-fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET-CT) can reveal the presence of interval metastases, such as liver metastases, in approximately 10% of cases. Nevertheless, it is not uncommon in clinical practice to observe focal FDG uptake in the liver that is not associated with liver metastases but rather with radiation-induced liver injury (RILI), which can result in the overstaging of the disease. Liver radiation damage is also a concern during distal esophageal cancer radiotherapy due to its proximity to the left liver lobe, typically included in the radiation field. Post-CRT, if FDG activity appears in the left or caudate liver lobes, a thorough investigation is needed to confirm or rule out distant metastases. The increased FDG uptake in liver lobes post-CRT often presents a diagnostic dilemma. Distinguishing between radiation-induced liver disease and metastasis is vital for appropriate patient management, necessitating a combination of imaging techniques and an understanding of the factors influencing the radiation response. Diagnosis involves identifying new foci of hepatic FDG avidity on PET/CT scans. Geographic regions of hypoattenuation on CT and well-demarcated regions with specific enhancement patterns on contrast-enhanced CT scans and MRI are characteristic of radiation-induced liver disease (RILD). Lack of mass effect on all three modalities (CT, MRI, PET) indicates RILD. Resolution of abnormalities on subsequent examinations also helps in diagnosing RILD. Moreover, it can also help to rule out occult metastases, thereby excluding those patients from further surgery who will not benefit from esophagectomy with curative intent.

Abdominal Positron Emission Tomography/Magnetic Resonance Imaging

Hybrid positron emission tomography (PET)/magnetic resonance imaging (MRI) is highly suited for abdominal pathologies. A precise co-registration of anatomic and metabolic data is possible thanks to the simultaneous acquisition, leading to accurate imaging. The literature shows that PET/MRI is at least as good as PET/CT and even superior for some indications, such as primary hepatic tumors, distant metastasis evaluation, and inflammatory bowel disease. PET/MRI allows whole-body staging in a single session, improving health care efficiency and patient comfort.

The Prognostic Value of Sequential 18 F-FDG PET/CT Metabolic Parameters in Outcomes of Upper-Third Esophageal Squamous Cell Carcinoma Patients Treated with Definitive Chemoradiotherapy

Objective  The aim of this study is to determine prognostic values of sequential 18 F-FDG PET/CT metabolic parameters in locally advanced esophageal squamous cell carcinoma (ESCC) patients treated with definitive chemoradiotherapy. Materials and Methods  Forty locally advanced ESCC patients treated with definitive chemoradiotherapy (dCRT) who received pre-treatment 18 F-FDG PET/CT (PET1) and 3-months post-treatment 18 F-FDG PET/CT (PET2) were enrolled in the prospective study. 18 F-FDG PET parameters of the primary tumor including maximum and mean standardized uptake values (SUVmax, SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were calculated on PET delineated primary tumor. Using Kaplan-Meier curves to estimated overall survival (OS), progression-free survival (PFS), and local-regional control (LRC). Cox regression analysis was performed to find significant prognostic factors for survival. Results  With a median follow-up of 13.5 months, the 4-year OS, PFS, and LRC rates were 67.3%, 52.6%, and 53.4% respectively. Patients with MTV 2 > 5.7 had lower OS, PFS, and LRC rates than the lower MTV 2 group (p < 0.05). Univariate Cox regression analysis showed that MTV2 was a significant prognostic factor for OS, PFS, and LRC (p < 0.05). Conclusion  MTV parameter of sequential 18 F-FDG PET/CT could be used as a prognostic factor for OS, PFS, and LRC in locally advanced ESCC patients treated with dCRT.

Progress of magnetic resonance imaging radiomics in preoperative lymph node diagnosis of esophageal cancer

Esophageal cancer, also referred to as esophagus cancer, is a prevalent disease in the cardiothoracic field and is a leading cause of cancer-related mortality in China. Accurately determining the status of lymph nodes is crucial for developing treatment plans, defining the scope of intraoperative lymph node dissection, and ascertaining the prognosis of patients with esophageal cancer. Recent advances in diffusion-weighted imaging and dynamic contrast-enhanced magnetic resonance imaging (MRI) have improved the effectiveness of MRI for assessing lymph node involvement, making it a beneficial tool for guiding personalized treatment plans for patients with esophageal cancer in a clinical setting. Radiomics is a recently developed imaging technique that transforms radiological image data from regions of interest into high-dimensional feature data that can be analyzed. The features, such as shape, texture, and waveform, are associated with the cancer phenotype and tumor microenvironment. When these features correlate with the clinical disease outcomes, they form the basis for specific and reliable clinical evidence. This study aimed to review the potential clinical applications of MRI-based radiomics in studying the lymph nodes affected by esophageal cancer. The combination of MRI and radiomics is a powerful tool for diagnosing and treating esophageal cancer, enabling a more personalized and effectual approach.

Liver Injury in Patients With Distal Esophageal Carcinoma After Precision Radiation Therapy: Systematic Review of FDG-PET/CT Patterns

OBJECTIVE

To determine the incidence and various patterns of radiation-induced liver injury (RILI) and its temporal evolution on fluorodeoxiglucose-positron emission tomography/computed tomography (FDG-PET/CT) after neoadjuvant chemoradiation using precision radiation in patients with esophageal carcinoma.

MATERIAL AND METHODS

We evaluated 639 patients with locally advanced esophageal carcinoma who had serial FDG-PET/CTs after neoadjuvant chemoradiation. Two readers reviewed the imaging studies in consensus and recorded the cases where new foci of increased FDG uptake were identified within the radiated liver parenchyma. RILI was confirmed by follow-up imaging or percutaneous biopsy.

RESULTS

FDG-avid RILI developed in 39/639 (6%) of patients. The caudate and left hepatic lobe were involved in all cases. There were various patterns of increased FDG uptake: 38% of patients had a single focus of increased FDG uptake and 62% had 2 regions of increased FDG uptake, which were focal nodular or diffuse or a combination of focal nodular and diffuse FDG uptake. On CT, 72% of patients had a poorly-marginated region of low attenuation and 28% had a well-defined region of low attenuation with sharp, well-defined linear borders in the location of the radiation, as confirmed by the treatment plan.

CONCLUSION

The caudate and left hepatic lobes were involved in all cases of RILI. The various imaging patterns of RILI on FDG-PET/CT include 1 or 2 regions of increased FDG uptake with a nodular, diffuse, or combined appearance. Awareness of this potential complication of radiation therapy and knowledge of the imaging manifestations of RILI is important to avoid misinterpretation as a metastasis.

Acceptance and disparities of PET/CT use in patients with esophageal or gastro-esophageal junction cancer: Evaluation of mature registry data

Background/rationale

PET/CT plays a crucial role in esophageal (EC) and gastroesophageal junction cancer (GEJ) diagnosis and management. Despite endorsement in clinical guidelines, variation in acceptance of PET/CT exists. The aim of this study was to assess the early use of PET/CT among EC and GEJ patients in a regionalized setting and identify factors contributing to disparity in access.

Materials and methods

Retrospective cohort study of adults with EC or GEJ between 2012 and 2014 from the Population Registry of Esophageal and Stomach Tumours of Ontario and Ontario Health (Cancer Care Ontario). Receipt of PET/CT and relevant demographics were collected, and statistical analysis performed. Continuous data were analysed with t-tests and Wilcoxon rank sum test. Categorical data were analysed with chi-square test. Kaplan-Meier methods were used to estimate median survival.

Results

Fifty-five percent of patients diagnosed with EC or GEJ between 2012 and 2014 received PET/CT (1321/2390). Eighty-four percent of patients underwent surgical resection (729/870), and 80% receiving radical treatment (496/622) underwent PET/CT. The use of PET/CT increased from 2012 to 2014. Male patients received more PET/CT than females (85% vs.78% p < 0.001).Median survival for the overall cohort was 11.1 months, 17.2 vs. 5.2 months among those who did and did not receive PET/CT and 35 vs. 27 months among the surgical cohort (p = 0.16).

Conclusions

We found that PET/CT use increased from 2012 to 2014 and that the majority of EC/GEJ patients being considered for curative therapy received PET/CT. There were also gender disparities identified. PET/CT appears to confer a potential survival benefit in our study, although our assessment is limited. Our findings may serve as learned lessons for other new imaging modalities, new indications for PET/CT or even for the introduction of new radiopharmaceuticals for PET/CT.

CT-Guided Survival Prediction of Esophageal Cancer

Survival prediction of esophageal cancer is an essential task for doctors to make personalized cancer treatment plans. However, handcrafted features from medical images need prior medical knowledge, which is usually limited and not complete, yielding unsatisfying survival predictions. To address these challenges, we propose a novel and efficient deep learning-based survival prediction framework for evaluating clinical outcomes before concurrent chemoradiotherapy. The proposed model consists of two key components: a 3D Coordinate Attention Convolutional Autoencoder (CACA) and an uncertainty-based jointly Optimizing Cox Model (UOCM). The CACA is built upon an autoencoder structure with 3D coordinate attention layers, capturing latent representations and encoding 3D spatial characteristics with precise positional information. Additionally, we designed an Uncertainty-based jointly Optimizing Cox Model, which jointly optimizes the CACA and survival prediction task. The survival prediction task models the interactions between a patient's feature signatures and clinical outcome to predict a reliable hazard ratio of patients. To verify the effectiveness of our model, we conducted extensive experiments on a dataset including computed tomography of 285 patients with esophageal cancer. Experimental results demonstrated that the proposed method achieved a C-index of 0.72, outperforming the state-of-the-art method.

Pretreatment 18F-FDG PET/CT-Derived Parameters in Predicting Clinical Outcomes of Locally Advanced Upper Third Esophageal Squamous Cell Carcinoma After Definitive Chemoradiation Therapy

Purpose

The aim of this study was to investigate whether standard uptake values (SUVs) of pretreatment ¹⁸F-FDG PET/CT were the surrogate parameters for predicting the outcomes in locally advanced esophageal squamous cell carcinoma patients treated with definitive chemoradiotherapy.

Materials and Methods

Sixty patients with esophageal squamous cell carcinoma underwent pretreatment ¹⁸F-FDG PET/CT and received definitive chemoradiotherapy. ¹⁸F-FDG metabolic parameters including SUVmax, SUVmean, SULpeak, total lesion glycolysis (TLG), and metabolic tumor volume (MTV) of primary tumor were calculated. The receiver-operating characteristic (ROC) curve was used to determine the optimal cutoff value of FDG PET/CT-derived parameters that associated with treatment response. Estimating progression-free survival (PFS) and overall survival (OS) was analyzed by using Kaplan-Meier methods. Univariate and multivariate analysis for PFS and OS was performed using Cox regression.

Results

Complete response was achieved in 38.3%. The 4-year OS and PFS rates were 48.6% and 44.4%, respectively. SUVmean with a cutoff value of 6.1 could predict complete response with sensitivity of 69.6%, specificity of 78.4%, and accuracy of 75%. Cox multi-factor regression analyses revealed SUVmean > 6.1 as an independent prognostic factor for OS (HR = 6.74, p = 0.02) and PFS (HR = 6.53, p < 0.001).

Conclusions

Our study suggests that SUVmean of the primary tumor in pretreatment ¹⁸F-FDG PET/CT may be used as an independent predictor in esophageal squamous cell carcinoma patients treated with definitive chemoradiotherapy.

Role of dual-time point 18F-FDG PET/CT imaging in the primary diagnosis and staging of hilar cholangiocarcinoma

PURPOSE

The aim of this study was to evaluate the role of dual-time point 18F-FDG PET/CT imaging in the primary diagnosis and staging of hilar cholangiocarcinoma (HCCA).

METHODS

Dual-time point FDG PET/CT findings, including early phase whole-body scanning and abdominal delayed phased performed 1 and 2 h after radiotracer injection, respectively, were retrospective reviewed in 69 patients conformed HCCA by histology. PET/CT was evaluated based on visual interpretation and the semiquantitative index of SUVmax and tumor-to-normal liver tissue ratio (TNR) for both early and delayed images.

RESULTS

For all 69 HCCA patients, the mean SUVmax of the lesion and TNR in delayed phase was significantly higher than that in early phase (6.1 ± 4.7, 2.2 ± 1.7, vs 5.1 ± 3.4, 1.6 ± 1.1; P < 0.001). The sensitivity and accuracy value of detection primary lesions was 69.6% and 70% in early phase vs 76.8% and 76.8% in delay phase, respectively. There was a significant correlation between lesion SUVmax and Ki67 index in both dual-time imaging (r = 0.462, P < 0.001 in early phase vs r = 0.47, P < 0.001 in delay phase). The sensitivity, specificity and accuracy value of metastatic lymph nodes prediction was 50%, 67.3% and 71% in early phase vs 62.5%, 73.3% and 76.8% in delayed phase, respectively. The sensitivity, specificity and accuracy of FDG PET/CT in detecting distant metastasis in our study was 75%, 100% and 97.1%. There was no difference of predicting distant metastasis between early phase and delayed phase.

CONCLUSION

Delayed phase in dual-time point 18F-FDG PET/CT scan provides additional usefulness for detection primary tumor and lymph nodes metastases in HCCA, but there was no added benefit of delayed PET/CT imaging in detection of distant metastases in this study. SUVmax in early and delayed phase could be used to assess tumor aggressiveness in pre-treatment HCCA.

Human Gut Microbiota-associated Gastrointestinal Malignancies: A Comprehensive Review

The human gastrointestinal tract houses trillions of microbes. The gut and various types of microorganisms, including bacteria, viruses, fungi, and archaea, form a complex ecosystem known as the gut microbiota, and the whole genome of the gut microbiota is referred to as the gut microbiome. The gut microbiota is essential for homeostasis and the overall well-being of a person and is increasingly considered an adjunct "virtual organ," with a complexity level comparable to that of the other organ systems. The gut microbiota plays an essential role in nutrition, local mucosal homeostasis, inflammation, and the mucosal immune system. An imbalanced state of the gut microbiota, known as dysbiosis, can predispose to development of various gastrointestinal malignancies through three speculated pathogenic mechanisms: (a) direct cytotoxic effects with damage to the host DNA, (b) disproportionate proinflammatory signaling inducing inflammation, and (c) activation of tumorigenic pathways or suppression of tumor-suppressing pathways. Several microorganisms, including Helicobacter pylori, Epstein-Barr virus, human papillomavirus, Mycoplasma species, Escherichia coli, and Streptococcus bovis, are associated with gastrointestinal malignancies such as esophageal adenocarcinoma, gastric adenocarcinoma, gastric mucosa-associated lymphoid tissue lymphoma, colorectal adenocarcinoma, and anal squamous cell carcinoma. Imaging plays a pivotal role in diagnosis and management of microbiota-associated gastrointestinal malignancies. Appropriate use of probiotics, fecal microbiota transplantation, and overall promotion of the healthy gut are ongoing areas of research for prevention and treatment of malignancies. Online supplemental material is available for this article. ^©RSNA, 2021.

Esophageal Cancer: Tumor-Node-Metastasis Staging

Esophageal cancer is an uncommon malignancy that ranks sixth in terms of mortality worldwide. Squamous cell carcinoma is the predominant histologic subtype worldwide whereas adenocarcinoma represents the majority of cases in North America, Australia, and Europe. Esophageal cancer is staged using the American Joint Committee on Cancer and the International Union for Cancer Control TNM system and has separate classifications for the clinical, pathologic, and postneoadjuvant pathologic stage groups. The determination of clinical TNM is based on complementary imaging modalities, including esophagogastroduodenoscopy/endoscopic ultrasound; endoscopic ultrasound-fine-needle aspiration; computed tomography of the chest, abdomen, and pelvis; and fluorodeoxyglucose PET/computed tomography.

Diagnostic Performance and Prognostic Relevance of FDG Positron Emission Tomography/Computed Tomography for Patients with Extrahepatic Cholangiocarcinoma

OBJECTIVE

We aimed to evaluate the diagnostic value and prognostic relevance of FDG positron emission tomography/computed tomography (PET-CT) in extrahepatic cholangiocarcinoma patients.

MATERIALS AND METHODS

This study included 234 extrahepatic cholangiocarcinoma patients who underwent FDG PET-CT between June 2008 and February 2016. The diagnostic performance of FDG PEG-CT was compared to that of contrast-enhanced multidetector row CT (MDCT) and MRI. Independent prognosticators for poor survival were also assessed.

RESULTS

The sensitivity of FDG PET-CT for detecting primary tumor and regional lymph node metastases was lower than that of MDCT or MRI (p < 0.001), whereas the specificity and positive predictive value for detecting regional lymph nodes metastases was significantly better in FDG PET-CT compared to MDCT and MRI (all p < 0.001). There was no significant difference in the diagnostic yield of distant metastases detection among three diagnostic imaging techniques. In a multivariate analysis, maximum standardized uptake values (SUVmax) of the primary tumor (adjusted hazard ratio [HR], 1.75; 95% confidence interval [CI], 1.13-2.69) and of the metastatic lesions ≥ 5 (adjusted HR, 8.10; 95% CI, 1.96-33.5) were independent contributors to poor overall survival in extrahepatic cholangiocarcinoma patients. In a subgroup analysis of 187 patients with periductal infiltrating type of cholangiocarcinoma, an SUVmax of the primary tumor ≥ 5 was associated with an increased risk of regional lymph node (adjusted odds ratio [OR], 1.60; 95% CI, 0.55-4.63) and distant metastases (adjusted OR, 100.57; 95% CI, 3.94-2567.43) at diagnosis as well as with poor overall survival (adjusted HR, 1.81; 95% CI, 1.04-3.15).

CONCLUSION

FDG PET-CT showed lower sensitivity for detecting primary tumor and regional lymph node involvement than MDCT and MRI. However, the SUVmax of primary tumors and metastatic lesions derived from FDG PET-CT could have significant implications for predicting prognoses in extrahepatic cholangiocarcinoma patients.

Incremental value of endoscopic brush cytology in response assessment after chemo-irradiation for Esophageal cancer

BACKGROUND

Response assessment after chemo-radiotherapy (CTRT) in locally advanced esophageal cancer is usually performed using a PET-CT scan, an upper GI endoscopy (UGIE) and histological correlation with biopsy or cytology. We aim to study the incremental value of brush cytology in addition to PET-CT for response assessment.

MATERIALS AND METHODS

In this retrospective analysis, 40 patients with Stage II- IV carcinoma esophagus treated with radical intent between June 2015 and August 2019 were included. Patients were treated with either upfront concurrent CTRT or neo-adjuvant chemotherapy followed by CTRT. All patients underwent PET-CT and UGIE for initial staging and response assessment on follow-up. Patients with esophageal stricture (disease related or treatment induced) had brush cytology done during UGIE. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of brush cytology were calculated considering serial clinical follow-up as gold standard.

RESULTS

Twenty-three male (57.5%) and 17 (42.5%) female patients with median age of 57 years (range: 27 - 79 years) were analyzed. Concurrent CTRT was delivered in 52.5%; 75% patients were treated with intensity-modulated radiotherapy (IMRT); median RT dose was 63 Gy (range- 41.4 to 64 Gy). At a median follow-up of 16 months (range 6- 54 months), 20 patients (55.5%) were clinically controlled, 9 (25%) had local recurrence, 5 (13.8%) had loco-regional recurrence and 2 had distant metastasis. Considering clinical follow-up as the gold standard, sensitivity, PPV and NPV of PET-CT combined with brush cytology improved compared to PET-CT alone and was found to be 75%, 90%, 85.7% and 81.8% respectively.

CONCLUSION

We found that brush cytology on endoscopy is a simple tool with high specificity which adds value to the findings of response assessment PET-CT scan and thereby can increase the confidence of the treating oncologist in making clinical decisions.

Role of 18F-FDG PET/CT in restaging of esophageal cancer after curative-intent surgical resection

OBJECTIVE

The aim of the study was to evaluate diagnostic performance of FDG PET-CT in suspected recurrence of carcinoma esophagus after curative-intent surgical resection and impact of FDG PET-CT on intended management.

MATERIAL AND METHODS

This was retrospective study of patients with clinical or radiological suspicion of recurrent esophageal carcinoma who were referred for PET-CT from January 2006 to December 2017. Diagnostic performance of PET-CT was evaluated for disease recurrence and its impact on management decisions. PET-CT findings were confirmed with tissue diagnosis. When tissue diagnosis was not available clinical and radiological follow-up was used as reference standard.

RESULTS

Relevant clinical data were available in 68 patients which were considered for analysis. In 91% (62/68) patients FDG PET-CT findings were suggestive of disease recurrence. Histopathological confirmation was available in 43 patients, whereas in remaining patients recurrence was confirmed by radiological and clinical follow-up. Forty percent (28/68) patients were detected with distant metastases. Sensitivity, specificity, positive and negative predictive values of FDG PET-CT was found to be 98.4, 80, 98 and 80% with accuracy of 97%. Change in management was observed in 41% (28/68) of patients from salvage radiotherapy/surgery to palliative chemotherapy/best supportive care based on evidence of distant metastases seen on FDG PET-CT.

CONCLUSION

FDG PET-CT is highly sensitive in detection of recurrent disease in esophageal cancer patients after surgical resection. It can detect distant metastases in high proportion of patients thus changing the intent of management from radical salvage to palliative chemotherapy/best supportive care.

Phantom simulation of liver metastasis on a positron emission tomography with computed tomography scan after neoadjuvant chemoradiotherapy for distal esophageal cancer: a case report

Background

Neoadjuvant chemoradiotherapy is currently the gold standard treatment for esophageal cancer prior to surgery. This radiation therapy will sometimes lead to liver damage parallel to esophageal lesions, which mimics liver metastasis visualized by ¹⁸F-fluorodeoxyglucose positron emission tomography with computed tomography. In this report, we publish virtual radiation-induced liver damage images obtained during surgery, along with the coherent pathology, in order to confirm the false-positive result through an optimally decisive radiological examination.

Case presentation

We report a case of a Asian male patient with distal esophageal cancer who had undergone neoadjuvant chemoradiotherapy (5000 cGy). Subsequently, a new lesion was discovered during a positron emission tomography with computed tomography scan 6 weeks later, near the left caudate lobe of the liver during tumor restaging. To exclude the possibility of liver metastasis, serial imaging was conducted, which included liver sonography, computed tomography, and magnetic resonance imaging for a more intimate probe. The patient’s condition was verified as being liver inflammation change, as seen by the liver magnetic resonance imaging presentation. Thoracoscopic esophagectomy was performed with cervical esophagogastrostomy via the retrosternal route, along with a feeding jejunostomy. The procedure was performed smoothly, with an intraoperative liver biopsy also being conducted 2 weeks later, after positron emission tomography with computed tomography restaging. The pathology report revealed esophageal cancer in the form of poorly differentiated squamous cell carcinoma, pT3N1M0. The liver biopsy revealed obvious inflammation change after radiation therapy, which elucidated sinusoidal congestion with the attenuated hepatic cords and filled with erythrocytes. There was no evidence of liver metastasis. The patient recovered uneventfully and was discharged with his oral intake performing smoothly, and a stable condition was observed during 12 months of outpatient department follow-up.

Conclusions

New foci of increased ¹⁸F-fluorodeoxyglucose avidity are commonly seen in the caudate and left hepatic lobes of the liver during neoadjuvant chemoradiation for distal esophageal cancer, and these findings generally reflect radiation-induced liver disease rather than metastatic disease. Awareness of the pitfalls of a high ¹⁸F-fluorodeoxyglucose uptake in radiation-induced liver injury is crucial in order to avoid misinterpretation and overstaging. Except for the location of ¹⁸F-fluorodeoxyglucose uptake, the shape of the lesion, and an maximum standardized uptake value (> 10/h), a convincing liver magnetic resonance imaging scan or even a liver biopsy can provide accurate information for distinguishing radiotherapy-induced liver injury from liver metastasis.

Clinical response assessment on DW-MRI compared with FDG-PET/CT after neoadjuvant chemoradiotherapy in patients with oesophageal cancer

PURPOSE

In about 30% of patients treated with neoadjuvant chemoradiotherapy (nCRT) followed by surgical resection for locally advanced oesophageal cancer no vital tumour is found in the resection specimen. Accurate clinical response assessment is critical if deferral from surgery is considered in complete responders. Our study aimed to compare the performance of MRI and of FDG-PET/CT for the detection of residual disease after nCRT.

METHODS

Patients with oesophageal cancer eligible for nCRT and oesophagectomy were prospectively included. All patients underwent FDG-PET/CT and MRI before and between 6 and 8 weeks after nCRT. Two radiologists scored the MRI scans, and two nuclear medicine physicians scored the FDG-PET/CT scans using a 5-point score for residual disease. Histopathology after oesophagectomy represented the reference standard. Sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) were calculated for detection of residual tumour (ypT+), residual nodal disease (ypN+), and any residual disease (ypT+Nx/ypT0N+).

RESULTS

Seven out of 33 (21%) patients had a pathological complete response. The AUCs for individual readers to detect ypT+ were 0.71/0.70 on diffusion-weighted (DW)-MRI and 0.54/0.57 on FDG-PET/CT, and to detect ypN+ were 0.89/0.81 on DW-MRI and 0.75/0.71 on FDG-PET/CT. The AUCs/sensitivities/specificities for the individual readers to detect any residual disease were 0.74/92%/57% and 0.70/96%/43% on MRI; these were 0.49/69%/29% and 0.60/69%/43% on FDG-PET/CT, respectively.

CONCLUSION

MRI reached higher diagnostic accuracies than FDG-PET/CT for the detection of residual tumour in oesophageal cancer patients at 6 to 8 weeks after nCRT.

The flow-metabolism ratio might predict treatment response and survival in patients with locally advanced esophageal squamous cell carcinoma

Background

Perfusion CT can offer functional information about tumor angiogenesis, and ¹⁸F-FDG PET/CT quantifies the glucose metabolic activity of tumors. This prospective study aims to investigate the value of biologically relevant imaging biomarkers for predicting treatment response and survival outcomes in patients with locally advanced esophageal squamous cell cancer (LA ESCC).

Methods

Twenty-seven patients with pathologically proven ESCC were included. All patients had undergone perfusion CT and ¹⁸F-FDG PET/CT using separate imaging systems before receiving definitive chemoradiotherapy (dCRT). The perfusion parameters included blood flow (BF), blood volume (BV), and time to peak (TTP), and the metabolic parameters included maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG). The flow-metabolism ratio (FMR) was defined as BF divided by SUVmax. Statistical methods used included Spearman’s rank correlation, Mann–Whitney U test or two-sample t test, receiver operating characteristic (ROC) curve analysis, the Kaplan–Meier method, and Cox proportional hazards models.

Results

The median overall survival (OS) and progression-free survival (PFS) were 18 and 11.6 months, respectively. FMR was significantly positively correlated with BF (r = 0.886, p < 0.001) and negatively correlated with SUVmax (r = − 0.547, p = 0.003) and TTP (r = − 0.462, p = 0.015) in the tumors. However, there was no significant correlation between perfusion and PET parameters. After dCRT, 14 patients (51.9%) were identified as responders, and another 13 were nonresponders. The BF and FMR of the responders were significantly higher than those of the nonresponders (42.05 ± 16.47 vs 27.48 ± 8.55, p = 0.007; 3.18 ± 1.15 vs 1.84 ± 0.65, p = 0.001). The ROC curves indicated that the FMR [area under the curve (AUC) = 0.846] was a better biomarker for predicting treatment response than BF (AUC = 0.802). Univariable Cox analysis revealed that of all imaging parameters, only the FMR was significantly correlated with overall survival (OS) (p = 0.015) and progression-free survival (PFS) (p = 0.017). Specifically, patients with a lower FMR had poorer survival. Multivariable analysis showed that after adjusting for age, clinical staging, and treatment response, the FMR remained an independent predictor of OS (p = 0.026) and PFS (p = 0.014).

Conclusions

The flow-metabolism mismatch demonstrated by a low FMR shows good potential in predicting chemoradiotherapy sensitivity and prognosis in ESCC.

Benefits of 18F-FDG PET/CT for the preoperative characterisation or staging of disease in the ampullary and duodenal papillary

OBJECTIVES

Diagnosing ampullary and duodenal papillary carcinomas (ADPCs) is challenging. In the present study, we investigated the application value of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) in the preoperative evaluation of these tumours.

METHODS

¹⁸F-FDG PET/CT images of 58 patients with ADPC and 28 patients with benign disease were retrospectively analysed. Preoperative ¹⁸F-FDG PET/CT was compared to contrast-enhanced (CE) CT and magnetic resonance imaging (MRI) in terms of diagnostic efficacy, certainty, staging and impact on treatment decisions.

RESULTS

¹⁸F-FDG PET/CT showed a high sensitivity (93.1%) and a medium specificity (78.6%) for diagnosing ADPC. Compared to CE CT/MRI, ¹⁸F-FDG PET/CT had a higher diagnostic specificity (78.6 vs. 35.7%, p = 0.001) but a similar sensitivity (93.1 vs. 89.6%, p = 0.508). ¹⁸F-FDG PET/CT provided a much higher diagnostic certainty than CE CT/MRI (definite reports, 88.4 vs. 50.0%, χ² = 29.698, p < 0.001), especially for small tumours ≤ 1.5 cm, and found distant metastases in five patients. The ¹⁸F-FDG PET/CT findings affected the treatment plans of 11 patients and improved the confidence in the diagnoses of 28 patients.

CONCLUSIONS

The present study demonstrated that ¹⁸F-FDG PET/CT can supplement CE CT/MRI to provide a more accurate diagnosis for ADPC, and thus, plays an important role in the decision-making process before complicated pancreaticoduodenectomy procedures.

KEY POINTS

• It is a challenge for CT and MRI to diagnose ampullary carcinoma, especially at their early stage. • Our study demonstrated that the benefit of PET/CT was improving the diagnostic confidence for ampullary and duodenal papillary carcinomas. • ¹⁸F-FDG PET/CT can change the treatment decision for ampullary and duodenal papillary carcinomas.

Surgically Resected Esophageal Squamous Cell Carcinoma: Patient Survival and Clinicopathological Prognostic Factors

We aimed to report patients' survival after surgical resection of eSCC and to ascertain the clinical, imaging, and pathological factors related to patient prognosis. This retrospective study included 435 patients with eSCC of <stage T2 (median follow-up period, 49.3 months). A total of 103 (23.7%) patients died, and 89 (20.5%) experienced recurrence during follow-up. The maximum standardized uptake value (SUV_max) on positron emission tomography (PET)/computed tomography (CT) of the primary tumor was significantly correlated with tumor length, nodal metastasis, and pathologic T stage in a positive linear fashion. In the multivariate analysis, higher SUV_max on PET/CT was a negative prognostic factor for both disease-free survival (DFS) and overall survival (OS). Contrarily, the presence of nodal metastasis was a prognostic factor only for DFS, and pathologic T stage only for OS. By applying SUVmax cut-off, both DFS and OS were significantly different among three groups when divided by cut-off values (A: SUVmax ≤ 3.05, B: SUVmax 3.06 - 5.64, C: SUVmax ≥ 5.65). In patients with a surgically resectable eSCC, measuring the SUV_max of the primary tumor during PET/CT can help predict patient survival. Additionally, PET/CT renders triage criterion for endoscopic submucosal dissection (ESD; T1a cancer and SUVmax, ≤3.05).

Prediction of lymph node metastasis by PET/CT metabolic parameters in patients with esophageal squamous cell carcinoma

OBJECTIVE

The aim of this study was to investigate the capability of F-FDG PET/computed tomography (CT)-related metabolic parameters to predict lymph node metastasis (LNM) and occult lymph node metastasis (OLNM) in patients with esophageal squamous cell carcinoma (ESCC).

METHODS

Totally 84 patients undergoing curative esophagectomy with lymph node dissection were enrolled in this study. Metabolic tumor volume (MTV) was measured using threshold-based methods with a threshold of 40% maximum standardized uptake value (SUVmax). The derivative of the volume (V)-threshold (T) function (volume difference/threshold difference) was defined as the heterogeneity factor (HF). In addition, SUVmax, SUVmean, total lesion glycolysis (TLG), maximum tumor-to-blood SUV ratio (SURmax), SURmean and several clinicopathologic parameters were analyzed to identify risk factors of LNM and OLNM.

RESULTS

SUVmax, SUVmean, MTV, TLG, SURmax, SURmean and HF were significantly different between LNM (+) and LNM (-). The optimal cut-off values of those parameters were 12.5, 8.34, 15.01, 117.185, 7.885, 4.855 and 0.300, respectively. Logistic regression analysis showed that MTV (OR = 1.127, P = 0.04) and SURmax (OR = 1.446, P = 0.004) were independent predictors of LNM, with sensitivity and specificity were 51.2%, 83.7% vs. 53.7%, 79.1%. In univariate and multivariate analysis, MTV was the sole parameter associated with OLMN (P = 0.024).

CONCLUSION

MTV and SURmax were statistically significant predictors of LNM in patients with ESCC, while MTV was a predictor of OLNM. High SURmax and MTV may indicate that the treatment planning should be tailored, which may improve patient prognosis.

Using positron-emission tomography-computed tomography for predicting radiotherapy-induced tumor regression in carcinoma esophagus in an Indian population

Carcinoma esophagus is a common malignancy of the Indian subcontinent. The role of positron-emission tomography–computed tomography (PET-CT) in the assessment of response to radiotherapy has been widely studied and accepted. However, its precise use as a predictive tool for actual histopathological response to radiotherapy needs further evaluation, especially in an Indian population. The aim of this study was to identify a quantum of metabolic response on PET-CT that can also predict for a good pathological response. Forty-four patients of carcinoma esophagus treated with neoadjuvant chemoradiotherapy followed by surgery were included in the study. All patients underwent a PET-CT before starting treatment as well as at 4–6 weeks after completion of radiotherapy. The percentage change in pre and posttreatment maximum standardized uptake value (SUV_max) value (ΔSUV%) of the primary tumor was correlated against histopathological tumor regression grade (TRG) as per the Mandard's system. Seventy-five percent of the patients with a significant metabolic response, i.e., a ΔSUV% of 60% or more, also had a good pathological response to treatment. Thus, by considering a ΔSUV% of 60%, we could predict for a good pathological response (TRG of 1 or 2) to chemoradiotherapy in our patient set with a sensitivity of 95.45% and a specificity of 72.72%.

Phase II randomized clinical trial of endosonography and PET/CT versus clinical assessment only for follow-up after surgery for upper gastrointestinal cancer (EUFURO study)

Background

Upper gastrointestinal malignancies have a poor prognosis. There is no consensus on how patients should be followed after surgery. The authors hypothesized that a structured follow-up programme including endoscopic ultrasonography (EUS) and [18F]fluorodeoxyglucose (FDG) PET/CT would detect cancer recurrences, leading to more patients being eligible for therapy.

Methods

After surgery with curative intent for adenocarcinomas in the gastro-oesophageal junction, stomach or pancreas, patients were randomized 1 : 1 to standard clinical assessment in the outpatient clinic at 3, 6, 9, 12, 18 and 24 months after operation, or clinical assessment plus imaging including [18F]FDG PET/CT and EUS. The primary endpoint was number of patients receiving oncological treatment for recurrence. Secondary endpoints were overall and progression-free survival, survival after recurrence detection of isolated locoregional recurrences and risk factors affecting survival.

Results

In total, 183 patients were enrolled, including 93 who underwent standard follow-up and 90 who had follow-up plus imaging. A recurrence was detected in 84 patients within 2 years after surgery (42 in each group), including 33 of 42 patients in the imaging group who were asymptomatic. Some 25 of 42 patients in the imaging group and 14 of 42 in the standard group received chemotherapy (P = 0·028). Although survival after detection of recurrence in asymptomatic patients was significantly longer than that for symptomatic patients (P &lt; 0·001), overall survival from date of surgery in the two treatment groups was comparable.

Conclusion

Follow-up after surgery for upper gastrointestinal cancer with EUS and PET/CT leads to detection of more asymptomatic cancer recurrences and patients referred for treatment without prolonging overall survival. Registration number: NCT02209415 (http://www.clinicaltrials.gov).

Clinical implication of the innovations of the 8th edition of the TNM classification for esophageal and esophago-gastric cancer

Epidemiology of esophageal cancer and esophagogastric junction (EGJ) has deeply changed for the past two decades with a dramatically increase of adenocarcinoma whereas squamous cell carcinoma (SCC) has slowly decreased. Moreover, the two histological types differ in a number of features including risks factors, tumor location, tumor biology and outcomes. In acknowledgement of these differences, the newest 8^th edition of the American Joint Committee on Cancer (AJCC) tumor, node and metastasis (TNM) staging classification of epithelial cancers of the esophagus and EGJ has refined this histology-specific disease stage with incorporation of new anatomic and non-anatomic categories. Based on data-driven of patients collected through the Worldwide Esophageal Cancer Collaboration (WECC) group, the 8^th edition database encompasses a six-continent cohort of 22,654 patients among 33 institutions including patients treated with surgery alone and, for the first time, patients treated after neoadjuvant treatment. Anatomic categories include T descriptors (tumor invasion), N descriptors (regional lymph node invasion) and M descriptors (distant site). Non anatomic categories include grade differentiation (G descriptors) and tumor location (L descriptors). Category descriptors are currently assessed by endoscopy with biopsy, by endoscopy ultrasound fine-needle aspiration (EUS-FNA), by thoracic-abdominal-pelvic computed tomography (CT) and whole body flurodeoxyglucose positron emission tomography (FDG-PET) fused with CT. The new 8^th edition considers separate and temporally related cancer classification based on the treatment strategy: clinical cTNM (before any treatment), pathologic pTNM (after surgery alone) and postneoadjuvant pathologic ypTNM (after neoadjuvant treatment followed by surgery). The 8th edition permits a more robust and reliable random forest-based machine learning analysis. Refinement of each T, N, M categories and subcategories makes the 8^th edition more accurate and more adaptable to the current practice including neoadjuvant regimen. The main objective of this review is to examine the current staging of esophageal cancer and the new aspects of the 8^th edition with its applications to clinical practice.

Prediction and diagnosis of interval metastasis after neoadjuvant chemoradiotherapy for oesophageal cancer using 18F-FDG PET/CT

OBJECTIVE

During neoadjuvant chemoradiotherapy for oesophageal cancer, or in the interval prior to surgery, some patients develop systemic metastasis. This study aimed to evaluate the diagnostic performance of ¹⁸F-FDG PET/CT for the detection of interval metastasis and to identify predictors of interval metastases in a large cohort of oesophageal cancer patients.

METHODS

In total, 783 consecutive patients with potentially resectable oesophageal cancer who underwent chemoradiotherapy and pre- and post-treatment ¹⁸F-FDG PET/CT between 2006 and 2015 were analyzed from a prospectively maintained database. Diagnostic accuracy measures were calculated on a per-patient basis using histological verification or clinical follow-up as a reference standard. Multivariable logistic regression analysis was performed to determine pre-treatment predictors of interval metastasis. A prediction score was developed to predict the probability of interval metastasis.

RESULTS

Of 783 patients that underwent ¹⁸F-FDG PET/CT restaging, 65 (8.3%) were found to have interval metastasis and 44 (5.6%) were deemed to have false positive lesions. The resulting sensitivity and specificity was 74.7% (95% CI: 64.3-83.4%) and 93.7% (95% CI: 91.6-95.4%), respectively. Multivariable analysis revealed that tumor length, cN status, squamous cell tumor histology, and baseline SUV_max were associated with interval metastasis. Based on these criteria, a prediction score was developed with an optimism adjusted C-index of 0.67 that demonstrated accurate calibration.

CONCLUSIONS

¹⁸F-FDG PET/CT restaging detects distant interval metastases in 8.3% of patients after chemoradiotherapy for oesophageal cancer. The provided prediction score may stratify risk of developing interval metastasis, and could be used to prioritize additional restaging modalities for patients most likely to benefit.

18F-deoxyglucose positron emission tomography/computed tomography to predict local failure in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) patients are at risk for local failure (LF) following treatment. Predicting tumor regions at high risk for local failure before radiotherapy may increase treatment efficacy by permitting an escalated radiation dose specifically to those regions critical for tumor control. Forty-one patients with non-resectable locally advanced ESCC underwent ¹⁸F-deoxyglucose positron emission tomography/computed tomography (FDG PET/CT) imaging before concurrent chemoradiotherapy (CCRT). After CCRT, a second (failure) FDG PET/CT was performed in cases of relapse. Failure FDG PET/CT scans were fused to pre-treatment scans to identify tumor regions at high risk for LF. Within a median follow-up time of 26 months, 20 patients (48.8%) had LF. In 19 patients, the failure occurred within a pre-treatment high FDG uptake region; the failure occurred outside these regions in only one patient. Pre-treatment metabolic tumor volume (MTV) was independently associated with LF (P<0.001, HR 1.128, 95% CI: 1.061–1.198). LF was more likely in patients with MTVs ≥27 cm³. In initial PET/CT images, when 50% maximum standardized uptake value (SUV_max) was used as the threshold, delineated subvolumes overlapped LF regions. These results confirm that LF occurs most commonly within pre-treatment high FDG uptake regions.

Survival based radiographic-grouping for esophageal squamous cell carcinoma may impact clinical T stage

Most patients diagnosed with thoracic esophageal squamous cell carcinoma (ESCC) have progressed beyond surgical resection as a therapeutic option. Difficulties in the proper assessment of tumor invasion depth before treatment complicate determination of the type and extent of therapy. Therefore, accurate tumor clinical staging is a necessity for identifying treatment options and aiding in patient prognosis. We investigated radiographic factors as prognostic indicators for survival in ESCC. Between July 2006 - July 2010, 324 thoracic ESCC patients who underwent surgery were selected. All patients received contrast enhanced preoperative chest CT scans and esophageal barium swallow examinations. Measurement of maximal lesion cross-sectional area, the largest long diameter, largest short diameter, CT-indicated lesion length, barium-indicated lesion length and the length of pericardial fat reduction were performed. Relationships between these indicators and post-surgical survival time and the cutoff values of related factors were analyzed. Maximum long diameter, maximum lesion area and lesion length, as measured by CT imaging, were correlated with survival. Survival effects were clearly associated with group intervals, calculated by a genetic algorithm, and tumor stages. Risk-stratification intervals of esophageal lesions from radiographic imaging included: maximum long diameter < 28.7, 28.7-34.6mm, 34.6-41.4mm and >41.4mm; maximum lesion area < 355.8mm2, 355.8-568.0mm2, 568.0-907.3mm2 and >907.3mm2; and CT-indicated lesion length <30.9mm, 30.9-57.3mm, 57.3-70.6mm and > 70.6mm. The reasonable stratification of maximum esophageal lesion area, largest long diameter and lesion length measured in CT is valuable for clinical T staging of ESCC. Radiographic parameters may have prognostic clinical value in the staging of esophageal carcinoma.

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.

FDG PET/CT in 2 Cases of Renal Metastasis From Esophageal Squamous Cell Carcinoma

Clinically, renal metastasis from esophageal squamous cell carcinoma is uncommon. We present 2 cases of renal metastasis from esophageal squamous cell carcinoma with enhanced CT and FDG PET/CT findings. In the first case, right kidney and right renal hilum were the only known metastatic sites. In the second case, bilateral kidneys were the only known metastatic sites. All the renal metastatic tumors appeared as hypovascular and hypoattenuating masses involving both the renal cortex and medulla on enhanced CT and intense FDG uptake on FDG PET/CT.

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.

Impact of Endoscopic Ultrasonography on 18F-FDG-PET/CT Upfront Towards Patient Specific Esophageal Cancer Treatment

INTRODUCTION

In patients with potentially resectable esophageal cancer (EC), the value of endoscopic ultrasonography (EUS) after fluorine-18 labeled fluorodeoxyglucose positron emission tomography with computed tomography (¹⁸F-FDG-PET/CT) is questionable. Retrospectively, we assessed the impact of EUS after PET/CT on the given treatment in EC patients.

METHODS

During the period 2009-2015, 318 EC patients were staged as T1-4aN0-3M0 with hybrid ¹⁸F-FDG-PET/CT or ¹⁸F-FDG-PET with CT and EUS if applicable in a nonspecific order. We determined the impact of EUS on the given treatment in 279 patients who also were staged with EUS. EUS had clinical consequences if it changed curability, extent of radiation fields or lymph node resection (AJCC stations 2-5), and when the performed fine-needle aspiration (FNA) provided conclusive information of suspicious lymph node.

RESULTS

EUS had an impact in 80 (28.7%) patients; it changed the radiation field in 63 (22.6%), curability in 5 (1.8%), lymphadenectomy in 48 (17.2%), and FNA was additional in 21 (7.5%). In patients treated with nCRT (n = 194), EUS influenced treatment in 53 (27.3%) patients; in 38 (19.6%) the radiation field changed, in 3 (1.5%) the curability, in 35 (18.0%) the lymphadenectomy, and in 17 (8.8%) FNA was additional. EUS influenced both the extent of radiation field and nodal resection in 31 (16.0%) nCRT patients.

CONCLUSIONS

EUS had an impact on the given treatment in approximately 29%. In most patients, the magnitude of EUS found expression in the extent of radiotherapy target volume delineation to upper/high mediastinal lymph nodes.

Staging Early Esophageal Cancer

Staging esophageal cancer provides a standardized measure of the extent of disease that can be used to inform decisions about therapy and guide prognosis. For esophageal cancer, the treatment pathways vary greatly depending on stage of disease, and accurate staging is therefore crucial in ensuring the optimal therapy for each patient. For early esophageal cancer (T1 lesions), endoscopic resection can be curative and simultaneously gives accurate staging of depth of invasion. For tumors invading the submucosa or more advanced disease, comprehensive investigation is required to accurately stage the tumor and assess suitability for curative resection. A combined imaging approach of computed tomography (CT), positron emission tomography (PET), and endoscopic ultrasound (EUS) offers complementary diagnostic information and gives the greatest chance of accurate staging. Staging laparoscopy can identify peritoneal disease and small superficial liver lesions that could be missed on CT or PET, and alters management in up to 20 % of patients. Optical diagnostic techniques offer the prospect of further extending the possibilities of endoscopic staging in real time. Optical coherence tomography can image superficial lesions and could provide information on depth of invasion for these lesions. Real-time lymph node analysis using optical diagnostics such as Raman spectroscopy could be used to support immediate endoscopic therapy without waiting for results of cytology or further investigations.

Impact of PET/CT on radiation treatment in patients with esophageal cancer: A systematic review

PURPOSE

With the advances in radiotracers, positron emission tomography/computed tomography (PET/CT) is recognized as a useful adjunct to anatomic imaging with CT, MRI and endoscopic ultrasonography (EUS). The objective of this review was to comprehensively analyze the roles of PET/CT for the radiotherapy of esophageal cancer.

METHODS

In this review, we focused on issues concerning the application of PET/CT in TNM staging, target volume delineation and response to therapy, both for the primary tumor and regional lymph nodes. Furthermore, the following questions were addressed: how does PET/CT guide appropriate treatment protocols, how does it allow accurate tumor delineation and how does it guide prognosis and future treatment decisions.

RESULTS AND CONCLUSION

For the staging of esophageal cancer, PET/CT played a crucial role in exploring distant malignant lymph nodes and metastasis with high sensitivity, specificity and accuracy. PET/CT using different radiotracer provided a serial of thresholding methods based on standardized uptake value (SUV) to assist in auto-contouring the gross tumor volume (GTV). The change in SUV may offer a potential paradigm of personalized treatment to definitive chemoradiotherapy (CRT). In total, PET/CT has sought to further optimize radiotherapy treatment planning for patients with esophageal cancer.

Esophageal Cancer

Esophageal cancer carries a poor prognosis among gastrointestinal malignancies. Although esophageal squamous cell carcinoma predominates worldwide, Western nations have seen a marked rise in the incidence of esophageal adenocarcinoma that parallels the obesity epidemic. Efforts directed toward early detection have been difficult, given that dysplasia and early cancer are generally asymptomatic. However, significant advances have been made in the past 10 to 15 years that allow for endoscopic management and often cure in early stage esophageal malignancy. New diagnostic imaging technologies may provide a means by which cost-effective, early diagnosis of dysplasia allows for definitive therapy and ultimately improves the overall survival among patients.

Esophageal cancer: anatomic particularities, staging, and imaging techniques

Cancer of the esophagus is a tumor with aggressive behavior that is usually diagnosed in advanced stages. The absence of serosa allows it to spread quickly to neighboring mediastinal structures, and an extensive lymphatic drainage network facilitates tumor spread even in early stages. The current TNM classification, harmonized with the classification for gastric cancer, provides new definitions for the anatomic classification, adds non-anatomic characteristics of the tumor, and includes tumors of the gastroesophageal junction. Combining endoscopic ultrasound, computed tomography, positron emission tomography, and magnetic resonance imaging provides greater accuracy in determining the initial clinical stage, and these imaging techniques play an essential role in the selection, planning, and evaluation of treatment. In this article, we review some particularities that explain the behavior of this tumor and we describe the current TNM staging system; furthermore, we discuss the different imaging tests available for its evaluation and include a diagnostic algorithm.

Role of 18F-FDG PET/CT Imaging in Intrahepatic Cholangiocarcinoma

PURPOSE

Although intrahepatic cholangiocarcinoma (ICC) is the second most common primary hepatic malignancy after hepatocellular carcinoma, there are limited data available on PET/CT imaging in ICC. This retrospective study analyzed the role of PET/CT imaging in the evaluation of ICC.

METHODS

FDG PET/CT findings were reviewed in 65 patients with histologically confirmed ICC. PET/CT was evaluated based on visual interpretation and the semiquantitative index of SUVmax and tumor-to-normal liver tissue ratio (TNR), which were consequently further analyzed and correlated with tumor localization, differentiation, size, and serum levels of tumor markers. Forty-five cases also underwent abdominal MRI examinations.

RESULTS

Nineteen patients had hilar ICC, whereas 46 patients had peripheral ICC. Sixty cases of ICC showed elevated FDG uptake with an average SUVmax of 8.3 ± 4.7 and TNR of 3.1 ± 1.7. Five cases located in the hilum were false negative on PET/CT imaging. Compared with hilar ICC, SUVmax and TNR of peripheral ICC were significantly higher (P < 0.05). FDG accumulation correlated with the degree of ICC differentiation. SUVmax and TNR correlated with tumor size, whereas there was no correlation observed with serum levels of carbohydrate antigen 19-9. The sensitivity, specificity, and accuracy of PET/CT and MRI in the diagnosis of regional lymph node metastases were 70.0% versus 50%, 91.7% versus 83.3%, and 81.8% versus 68.2%, respectively. PET/CT upstaged 12.3% and downstaged 3.1% of cases and had no impact on patient management in the remaining 84.6% of cases.

CONCLUSIONS

Combination of FDG PET/CT and abdominal MRI might improve the diagnostic accuracy for ICC.

Role of Pre-therapeutic (18)F-FDG PET/CT in Guiding the Treatment Strategy and Predicting Prognosis in Patients with Esophageal Carcinoma

OBJECTIVES

The present study aimed to evaluate the role of pre-therapeutic (18)fluorine-fluorodeoxyglucose positron emission tomography-computed tomography ((18)F-FDG PET-CT) and maximum standardized uptake value (SUVmax) in guiding the treatment strategy and predicting the prognosis of esophageal carcinoma, using the survival data of the patients.

METHODS

The present retrospective, cohort study was performed on 40 consecutive patients with esophageal carcinoma (confirmed by endoscopic biopsy), who underwent pre-operative (18)F-FDG PET-CT staging between January 2009 and June 2014. All the patients underwent contrast-enhanced CT and non-contrasted (18)F-FDG PET-CT evaluations. The patients were followed-up over 12 months to assess the changes in therapeutic strategies. Survival analysis was done considering the primary tumor SUVmax, using the Kaplan-Meier product-limit method.

RESULTS

In a total of 40 patients, (18)F-FDG PET-CT scan led to changes in disease stage in 26 (65.0%) cases, with upstaging and downstaging reported in 10 (25.0%) and 16 (40.0%) patients, respectively. The management strategy changed from palliative to curative in 10 out of 24 patients and from curative to palliative in 7 out of 16 cases. Based on the (18)F-FDG PET-CT scan alone, the median survival of patients in the palliative group was 4.0 (95% CI 3.0-5.0) months, whereas the median survival in the curative group has not been reached, based on the 12-month follow-up. Selection of treatment strategy on the basis of (18)F-FDG PET/CT alone was significantly associated with the survival outcomes at nine months (P=0.03) and marginally significant at 12 months (P=0.03). On the basis of SUVmax, the relation between survival and SUVmax was not statistically significant.

CONCLUSION

(18)F-FDG PET/CT scan had a significant impact on stage stratification and subsequently, selection of a stage-specific treatment approach and the overall survival outcome in patients with esophageal carcinoma. However, pre-treatment SUVmax failed to stablish its usefulness in the assessment of patient prognosis and survival outcome.

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.