18-fluorodeoxy-glucose positron emission computed tomography as predictive of response after chemoradiation in oesophageal cancer patients

The prognostic value of pretreatment [18F]FDG PET/CT parameters in esophageal cancer: a meta-analysis

OBJECTIVES

This study aims to evaluate the prognostic implications of pretreatment [18F]FDG-PET metrics in esophageal cancer patients through a meta-analysis of the existing literature.

METHODS

We carefully searched electronic databases, including PubMed and Embase, from inception to April 1, 2024, to identify studies describing the prognostic value of pretreatment PET metrics for advanced esophageal cancer. Clinical endpoints examined were overall survival (OS), recurrence-free survival (RFS)/disease-free survival (DFS), and progression-free survival (PFS). Hazard ratios (HRs) for PFS and OS were taken directly from the original reports.

RESULTS

Forty-seven publications, including 5504 patients, were included in our analysis. OS and PFS were analyzed in 31 and nine studies, respectively, and DFS/RFS was analyzed in 16 studies. The comprehensive pooled analysis revealed significant associations between metabolic parameters derived from positron emission tomography (PET) imaging and clinical outcomes. Expressly, the pooled HR indicated that patients with higher SUVmax were significantly associated with poor PFS (HR: 1.06; 95% CI: 1.01-1.12, p = 0.011) and poor RFS/DFS (HR: 1.09; 95% CI: 1.02-1.18, p = 0.019). Patients with higher SUVmean were significantly associated with poorer OS (HR: 1.07; 95% CI: 1.01-1.14, p = 0.025). High MTV was significantly associated with inferior OS (HR: 1.02; 95% CI: 1.00-1.05, p = 0.049). High TLG was significantly associated with poorer RFS/DFS (HR: 2.02; 95% CI: 1.11-3.68, p = 0.022).

CONCLUSION

This study unveiled pretreatment FDG-derived parameters as valuable prognostic indicators in assessing esophageal cancer outcomes. Specifically, SUVmax is associated with PFS and RFS/DFS. SUVmean and MTV were correlated with OS, and TLG was only associated with RFS/DFS.

KEY POINTS

Question Inconsistent findings on the prognostic value of pretreatment [18F]FDG PET parameters in esophageal cancer require comprehensive analysis to clarify their role in outcome prediction. Findings Higher pretreatment [18F]FDG-PET metrics (SUVmax, SUVmean, MTV, TLG) are associated with poor survival outcomes, emphasizing their potential value in enhancing prognostic assessments for esophageal cancer. Clinical relevance This study highlights the prognostic significance of pretreatment [18F]FDG-PET metrics in esophageal cancer, providing valuable insights for patient outcome prediction and potentially guiding personalized treatment strategies.

The prognostic value of positron emission tomography/magnetic resonance imaging in predicting survival in patients with adenocarcinoma of the esophagogastric junction

INTRODUCTION

In recent years, the utility of positron emission tomography/magnetic resonance imaging (PET/MRI) has become increasingly significant in diagnostic settings. This study provides a five-year follow-up on a previous pilot study that demonstrated the feasibility of PET/MRI in predicting the resectability of adenocarcinoma of the esophagogastric junction (AEG). We aimed to evaluate whether this imaging modality could further serve as a prognostic tool for survival in AEG patients.

METHODS

A total of 22 patients were included in the initial pilot study, with 17 of them undergoing surgery. All patients underwent three series of neo-adjuvant chemotherapy (NT). This follow-up study retrospectively analyzed the correlation between the apparent diffusion coefficient (ADC) and standard uptake value (SUV) measurements of the primary tumor from the original study with overall survival and recurrence. ADC and SUV values were measured prior to initiation of NT, and again 17-21 days into the first cycle of NT-administration, and the differences between the scans were calculated as ∆SUVmax, ∆ADCb0, and ∆ADCb50. Early treatment response was assessed using the Response Evaluation Criteria In Solid Tumors (RECIST). Binary logistic regression was employed to evaluate the predictive values of ADC and SUV parameters, and receiver operating characteristic (ROC) curves were generated to determine sensitivity, specificity, and area under the curve (AUC).

RESULTS

As of January 7, 2022, 8 of the 22 patients were still alive. The AUC was calculated to assess the association of imaging parameters with long-term survival: ∆SUVmax: AUC = 0.74, sensitivity, 87.5%, specificity 62.5% (p = 0.037). ∆ADCb0: AUC = 0.62, sensitivity 85.7%, specificity 57.1% (p = 0.400). ∆ADCb50: AUC = 0.78, sensitivity 78.6%, specificity 85.7% (p = 0.011). Combining all three parameters yielded an AUC of 0.81, with a sensitivity of 78.6% and a specificity of 85.7% (p = 0.002). The results for individual measurements were: SUVmax(pre-NT): AUC = 0.56, sensitivity 78.6%, specificity 50% (p = 0.646). SUVmax(post-NT): AUC = 0.81, sensitivity 85.7%, specificity 87.5% (p = 0.002). ADCb0(pre-NT): AUC = 0.55, sensitivity 71.4%, specificity 62.5% (p = 0.682). ADCb0(post-NT): AUC = 0.63, sensitivity 78.6%, specificity 57.1% (p = 0.339). ADCb50(pre-NT): AUC = 0.51, sensitivity 85.7%, specificity 37.5% (p = 0.952). ADCb50(post-NT): AUC = 0.63, sensitivity 42.9%, specificity 100% (p = 0.279). No significant correlation was found between RECIST group and survival status (p = 0.15).

CONCLUSION

Our results indicate that PET/MRI is feasible for predicting long-term survival in AEG patients. The highest AUCs were achieved when combining SUV and ADC parameters, and when using post-NT SUVmax alone.

Value of Computed Tomography Scan for Detecting Lymph Node Metastasis in Early Esophageal Squamous Cell Carcinoma

BACKGROUND

The necessity of computed tomography (CT) scan for detecting potential lymph node metastasis (LNM) in early esophageal squamous cell carcinoma (ESCC) before endoscopic and surgical treatments is under debate.

METHODS

Patients with histologically proven ESCC limited to the mucosa or submucosa were examined retrospectively. Diagnostic performance of CT for detecting LNM was analyzed by comparing original CT reports with pathology reports. The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were calculated.

RESULTS

A total of 625 patients from three tertiary referral hospitals were included. The rate of pathologically confirmed LNM was 12.5%. Based on original CT reports, the sensitivity, specificity, accuracy, PPV, and NPV of CT to determine LNM in T1 ESCC were 41.0%, 83.2%, 77.9%, 25.8%, and 90.8% respectively. For mucosal cancers (T1a), these parameters were 50.0%, 81.7%, 80.9%, 6.8%, and 98.4%, respectively. For submucosal cancers (T1b), they were 40.0%, 85.0%, 75.0%, 43.0%, and 83.3%, respectively. Additionally, the diagnostic performance of CT for LNM was relatively better for ESCC in the lower esophagus. Pathologically, 69.2% of patients with LNM did not exhibit lymphovascular invasion (LVI), and the sensitivity of CT for recognizing LNM in these patients (33.3%) was lower than those with LVI (58.3%).

CONCLUSIONS

Computed tomography can detect nearly half of the LNM cases in early ESCC with high specificity. The performance of CT further improved in LNM cases with LVI. Therefore, we conclude that routine preoperative CT for the assessment of potential LNM risk in patients with early ESCC is necessary.

[18F]AlF-NOTA-FAPI-04 PET/CT for Predicting Pathologic Response of Resectable Esophageal Squamous Cell Carcinoma to Neoadjuvant Camrelizumab and Chemotherapy: A Phase II Clinical Trial

This single-center, single-arm, phase II trial (ChiCTR2100050057) investigated the ability of 18F-labeled fibroblast activation protein inhibitor ([18F]AlF-NOTA-FAPI-04, denoted as 18F-FAPI) PET/CT to predict the response to neoadjuvant camrelizumab plus chemotherapy (nCC) in locally advanced esophageal squamous cell carcinoma (LA-ESCC). Methods: This study included 32 newly diagnosed LA-ESCC participants who underwent 18F-FAPI PET/CT at baseline, of whom 23 also underwent scanning after 2 cycles of nCC. The participants underwent surgery after 2 cycles of nCC. Recorded PET parameters included maximum, peak, and mean SUVs and tumor-to-background ratios (TBRs), metabolic tumor volume, and total lesion FAP expression. PET parameters were compared between patient groups with good and poor pathologic responses, and the predictive performance for treatment response was analyzed. Results: The good and poor response groups each included 16 participants (16/32, 50.0%). On 18F-FAPI PET/CT, the posttreatment SUVs were significantly lower in good responders than in poor responders, whereas the changes in SUVs with treatment were significantly higher (all P < 0.05). SUVmax (area under the curve [AUC], 0.87; P = 0.0026), SUVpeak (AUC, 0.89; P = 0.0017), SUVmean (AUC, 0.88; P = 0.0021), TBRmax (AUC, 0.86; P = 0.0031), and TBRmean (AUC, 0.88; P = 0.0021) after nCC were significant predictors of pathologic response to nCC, with sensitivities of 63.64%-81.82% and specificities of 83.33%-100%. Changes in SUVmax (AUC, 0.81; P = 0.0116), SUVpeak (AUC, 0.82; P = 0.0097), SUVmean (AUC, 0.81; P = 0.0116), and TBRmean (AUC, 0.74; P = 0.0489) also were significant predictors of the pathologic response to nCC, with sensitivities and specificities in similar ranges. Conclusion: 18F-FAPI PET/CT parameters after treatment and their changes from baseline can predict the pathologic response to nCC in LA-ESCC participants.

Association of dynamic contrast-enhanced MRI and 18F-Fluorodeoxyglucose PET/CT parameters with neoadjuvant therapy response and survival in esophagogastric cancer

INTRODUCTION

Better predictive markers are needed to deliver individualized care for patients with primary esophagogastric cancer. This exploratory study aimed to assess whether pre-treatment imaging parameters from dynamic contrast-enhanced MRI and 18F-fluorodeoxyglucose (18F-FDG) PET/CT are associated with response to neoadjuvant therapy or outcome.

MATERIALS AND METHODS

Following ethical approval and informed consent, prospective participants underwent dynamic contrast-enhanced MRI and 18F-FDG PET/CT prior to neoadjuvant chemotherapy/chemoradiotherapy ± surgery. Vascular dynamic contrast-enhanced MRI and metabolic 18F-FDG PET parameters were compared by tumor characteristics using Mann Whitney U test and with pathological response (Mandard tumor regression grade), recurrence-free and overall survival using logistic regression modelling, adjusting for predefined clinical variables.

RESULTS

39 of 47 recruited participants (30 males; median age 65 years, IQR: 54, 72 years) were included in the final analysis. The tumor vascular-metabolic ratio was higher in patients remaining node positive following neoadjuvant therapy (median tumor peak enhancement/SUVmax ratio: 0.052 vs. 0.023, p = 0.02). In multivariable analysis adjusted for age, gender, pre-treatment tumor and nodal stage, peak enhancement (highest gadolinium concentration value prior to contrast washout) was associated with pathological tumor regression grade. The odds of response decreased by 5% for each 0.01 unit increase (OR 0.95; 95% CI: 0.90, 1.00, p = 0.04). No 18F-FDG PET/CT parameters were predictive of pathological tumor response. No relationships between pre-treatment imaging and survival were identified.

CONCLUSION

Pre-treatment esophagogastric tumor vascular and metabolic parameters may provide additional information in assessing response to neoadjuvant therapy.

Perioperative immunotherapy for esophageal squamous cell carcinoma: Now and future

Esophageal cancer (EC) ranks among the most prevalent malignant tumors affecting the digestive tract. Esophageal squamous cell carcinoma (ESCC) stands as the prevailing pathological subtype, encompassing approximately 90% of all EC patients. In clinical stage II-IVA locally advanced ESCC cases, the primary approach to treatment involves a combination of neoadjuvant therapy and surgical resection. Despite concerted efforts, the long-term outcomes for ESCC patients remain unsatisfactory, with dismal prognoses. However, recent years have witnessed remarkable strides in immunotherapy, particularly in the second- and first-line treatment of advanced or metastatic ESCC, with the development of monoclonal antibodies that inhibit programmed death 1 or programmed death ligand 1 demonstrating encouraging responses and perioperative clinical benefits for various malignancies, including ESCC. This comprehensive review aims to present the current landscape of perioperative immunotherapy for resectable ESCC, focusing specifically on the role of immune checkpoint inhibitors during the perioperative period. Additionally, the review will explore promising biomarkers and offer insights into future prospects.

Interim position emission tomography-computed tomography during multimodality treatment of locally advanced esophageal cancer: a scoping review

Background

Among cancers, esophageal cancer (EC) has one of the highest incidences and mortality in Asia. As recognized in many national guidelines, functional imaging performed with position emission tomography is recommended for patients with locally advanced disease. This review evaluated evidence for the use of fluorodeoxyglucose (FDG) interim positron emission tomography (PETint) in bimodality (chemoradiation) and trimodality (chemoradiation followed by surgery) management of locally advanced esophageal cancer (LAEC), with a focus on its prognostic and predictive value.

Methods

The MEDLINE database was searched from January 1, 2001, to January 1, 2022, as part of a scoping review. References of selected articles were manually checked to identify other articles meeting the inclusion criteria; only original articles were included, and reviews, guidelines, letters, editorials, and case reports were excluded.

Results

A total of 63 articles were included in this review. PET-computed tomography (PET-CT) is recognized as having a significant role in the assessment of treatment response. Studies on the predictive PETint suggest that it has a certain value, particularly for early response. Identification of poor responders or nonresponders soon after commencement of multimodality treatment allows for treatment modification.

Conclusions

The scoping review indicated variable utility for the prognostic value of PETint. There is a need to improve its accuracy, which can likely be achieved through greater standardization of measurements and reporting and testing as well as combination with other promising measures of response to residual disease.

Prognostic value of [18F]FDG PET/CT on treatment response and progression-free survival of gastroesophageal cancer patients undergoing perioperative FLOT chemotherapy

PURPOSE

To evaluate the prognostic role of [¹⁸F]FDG PET/CT metabolic parameters in gastric cancer (GC) and gastroesophageal adenocarcinoma (GEJAC) patients receiving neoadjuvant chemotherapy.

METHOD

In this retrospective study, 31 patients with biopsy-proven GC or GEJAC were included between August 2016 and March 2020. [¹⁸F]FDG PET/CT was performed before the neoadjuvant chemotherapy. Primary tumours' semi-quantitative metabolic parameters were extracted. All patients received a perioperative FLOT regimen thereafter. Post-chemotherapy [¹⁸F]FDG PET/CT was performed in most patients (17/31). All patients underwent surgical resection. Histopathology response to treatment and progression-free survival (PFS) were evaluated. Two-sided p-values < 0.05 were considered statistically significant.

RESULTS

Thirty-one patients (mean age = 62 ± 8), including 21 GC and 10 GEJAC patients, were evaluated. 20/31(65%) patients were histopathology responders to neoadjuvant chemotherapy, including twelve complete and eight partial responders. During the median follow-up of 42.0 months, nine patients experienced recurrence. The median PFS was 60(95% CI:32.9-87.1) months. Pre-neoadjuvant chemotherapy SULpeak was significantly correlated with pathological response to treatment (p-value = 0.03;odds ratio = 16.75). In survival analysis, SUVmax (p-value = 0.01;hazard ratio[HR] = 1.55), SUVmean (p-value = 0.04;HR = 2.73), SULpeak (p-value < 0.001;HR = 1.91) and SULmean (p-value = 0.04;HR = 4.22) in the post-neoadjuvant chemotherapy pre-operative [¹⁸F]FDG PET/CT showed significant correlation with PFS. Additionally, aspects of staging were significantly correlated with PFS (p-value = 0.01;HR = 2.21).

CONCLUSIONS

Pre-neoadjuvant chemotherapy [¹⁸F]FDG PET/CT parameters, especially SULpeak, could predict the pathological response to treatment in GC and GEJAC patients. Additionally, in survival analysis, post-chemotherapy metabolic parameters significantly correlated with PFS. Thus, performing [¹⁸F]FDG PET/CT before chemotherapy may help to identify patients at risk for inadequate response to perioperative FLOT and, after chemotherapy, may predict clinical outcomes.

Imaging glucose metabolism to reveal tumor progression

Purpose: To analyze and review the progress of glucose metabolism-based molecular imaging in detecting tumors to guide clinicians for new management strategies. Summary: When metabolic abnormalities occur, termed the Warburg effect, it simultaneously enables excessive cell proliferation and inhibits cell apoptosis. Molecular imaging technology combines molecular biology and cell probe technology to visualize, characterize, and quantify processes at cellular and subcellular levels in vivo. Modern instruments, including molecular biochemistry, data processing, nanotechnology, and image processing, use molecular probes to perform real-time, non-invasive imaging of molecular and cellular events in living organisms. Conclusion: Molecular imaging is a non-invasive method for live detection, dynamic observation, and quantitative assessment of tumor glucose metabolism. It enables in-depth examination of the connection between the tumor microenvironment and tumor growth, providing a reliable assessment technique for scientific and clinical research. This new technique will facilitate the translation of fundamental research into clinical practice.

Neoadjuvant Strategies for Esophageal Cancer

Neoadjuvant strategies with multimodal therapy including chemotherapy and radiation are the standard of care in locally advanced esophageal cancer. The role of immunotherapy in the perioperative management of esophageal cancer is expanding, and adjuvant nivolumab for patients with residual disease following trimodality therapy has been shown to improve disease-free survival. Applications of checkpoint blockade and positron emission tomography (PET)-directed therapy in the neoadjuvant setting are under investigation in several clinical trials. We review the perioperative management of locally advanced esophageal cancer and recent evidence exploring the role of immune checkpoint inhibitors and PET in guiding neoadjuvant management.

Early prediction of residual disease after neoadjuvant chemoradiotherapy and cetuximab for locally advanced esophageal cancer using 18F-FDG PET-CT imaging: a prospective cohort study

Background

Previous studies in locally advanced esophageal cancer (LAEC) suggested that a change in the tumor's metabolic response, i.e., decrease of its interim ¹⁸F-FDG uptake compared with baseline, may predict histopathological response. We evaluated the possible predictive correlation between various PET-CT and histopathological parameters following a neoadjuvant biological-containing chemoradiotherapy (CRT) regimen.

Methods

Patients with resectable LAEC received neoadjuvant cisplatin/5-fluorouracil-based CRT and cetuximab following one cycle of induction chemotherapy and cetuximab. Changes in maximum and mean standardized uptake values (ΔSUV-max and ΔSUV-mean, respectively) and metabolic tumor volume (ΔMTV), measured by PET-CT at baseline and 2 weeks after the onset of treatment, were compared with histopathological findings at surgery. Histopathological response was defined by tumor regression grade (TRG), pathological complete response (pCR) and microscopic or macroscopic residual disease (RD).

Results

Of 18 patients, 13 (72%) with adenocarcinoma (AC) and 5 (28%) with squamous cell carcinoma (SCC), were included. None of the changes in the parameters of PET was associated with pCR; only ΔSUV-mean was associated with TRG in the AC cohort. In contrast, both ΔSUV-mean% and ΔSUV-max% were significantly associated with RD, both in the whole cohort and in the AC cohort. Changes in FDG-uptake predicted RD2 at surgery: only patients with less than 13% decrease in SUV-mean% or less than 29% decrease in SUV-max% had RD2, while all patients with RD0 or RD1 had greater reductions [100% specificity and 100% positive predictive value (PPV)].

Conclusions

Changes in ΔSUV-max and ΔSUV-mean after two weeks of onset of cetuximab-based neoadjuvant chemotherapy for LAEC may predict macroscopic RD but not TRG or pCR at surgery.

Prognostic Assessment of Interim F18-Fluorodeoxyglucose Positron Emission Tomography in Esophageal Cancer Treated With Chemoradiation With or Without Surgery

Purpose

This study aimed to evaluate if the F18-fluorodeoxyglucose positron emission tomography (F18-FDG PET) response after two weeks of chemoradiation for locoregionally advanced esophageal cancer (staged Tumor (T) 3 and/or Nodes (N)+ Metastases (M) 0) was linked to the pathologic response for patients undergoing surgery, to disease-free survival (DFS) or overall survival (OS).

Materials and Methods

Between March 2006 and September 2017, 40 patients were prospectively enrolled in our study, gave written consent, and had PET scans performed before treatment and after two weeks of chemoradiation. One patient did not undergo his two-week PET without informing study coordinators and was excluded from analyses.

Results

The median age at diagnosis was 62 years. Seventy-two percent of patients had N+ disease. Median OS for the entire group was 24 months. Five-year overall survival was 17%. Survival curves for patients with no PET response, minor PET response, or good PET response overlapped and were not statistically different. For the 25 patients who underwent surgery, the positive predictive value (PPV) of the PET response relative to the pathologic response was 75% and the negative predictive value (NPV) was 62%. In study patients, the crude recurrence rate was 68% and there was no correlation between PET response and DFS.

Conclusion

In our study, interim PET response after two weeks of chemoradiation for locoregionally advanced esophageal cancer was not predictive of outcome or pathologic response. Based on our data and current literature, interim PET should not be used to alter treatment (whether to escalate neo-adjuvant treatment or omit surgery).

Predictive value of clinical and 18F-FDG-PET/CT derived imaging parameters in patients undergoing neoadjuvant chemoradiation for esophageal squamous cell carcinoma

Aim of this study was to validate the prognostic impact of clinical parameters and baseline ¹⁸F-FDG-PET/CT derived textural features to predict histopathologic response and survival in patients with esophageal squamous cell carcinoma undergoing neoadjuvant chemoradiation (nCRT) and surgery. Between 2005 and 2014, 38 ESCC were treated with nCRT and surgery. For all patients, the ¹⁸F-FDG-PET-derived parameters metabolic tumor volume (MTV), SUVmax, contrast and busyness were calculated for the primary tumor using a SUV-threshold of 3. The parameter uniformity was calculated using contrast-enhanced computed tomography. Based on histopathological response to nCRT, patients were classified as good responders (< 10% residual tumor) (R) or non-responders (≥ 10% residual tumor) (NR). Regression analyses were used to analyse the association of clinical parameters and imaging parameters with treatment response and overall survival (OS). Good response to nCRT was seen in 27 patients (71.1%) and non-response was seen in 11 patients (28.9%). Grading was the only parameter predicting response to nCRT (Odds Ratio (OR) = 0.188, 95% CI: 0.040–0.883; p = 0.034). No association with histopathologic treatment response was seen for any of the evaluated imaging parameters including SUVmax, MTV, busyness, contrast and uniformity. Using multivariate Cox-regression analysis, the heterogeneity parameters busyness (Hazard Ratio (HR) = 1.424, 95% CI: 1.044–1.943; p = 0.026) and contrast (HR = 6.678, 95% CI: 1.969–22.643;p = 0.002) were independently associated with OS, while no independent association with OS was seen for SUVmax and MTV. In patients with ESCC undergoing nCRT and surgery, baseline ¹⁸F-FDG-PET/CT derived parameters could not predict histopathologic response to nCRT. However, the PET/CT derived features busyness and contrast were independently associated with OS and should be further investigated.

18F-FDG-PET/CT-measured parameters as potential predictors of residual disease after neoadjuvant chemoradiotherapy in patients with esophageal carcinoma

Objective

To evaluate the maximum and mean standardized uptake values, together with the metabolic tumor value and the total lesion glycolysis, at the primary tumor site, as determined by ¹⁸F-fluorodeoxyglucose positron-emission tomography/computed tomography (¹⁸F-FDG-PET/CT), performed before and after neoadjuvant chemoradiotherapy (nCRT), as predictors of residual disease (RD) in patients with esophageal cancer.

Materials and Methods

The standardized uptake values and the volumetric parameters (metabolic tumor value and total lesion glycolysis) were determined by ¹⁸F-FDG-PET/CT to identify RD in 39 patients before and after nCRT for esophageal carcinoma. We used receiver operating characteristic curves to analyze the diagnostic performance of ¹⁸F-FDG-PET/CT parameters in the definition of RD. The standard of reference was histopathological analysis of the surgical specimen.

Results

Eighteen patients (46%) presented RD after nCRT. Statistically significant areas under the curve (approximately 0.72) for predicting RD were obtained for all four of the variables evaluated after nCRT. Considering the presence of visually detectable uptake (higher than the background level) at the primary tumor site after nCRT as a positive result, we achieved a sensitivity of 94% and a specificity of 48% for the detection of RD.

Conclusion

The use of ¹⁸F-FDG-PET/CT can facilitate the detection of RD after nCRT in patients with esophageal cancer.

FAPI PET/CT research progress in digestive system tumours

¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography has been used in clinical practice for many years. This modality is of great value for tumour diagnosis, staging, and efficacy evaluations, but it has many limitations in the diagnosis and treatment of digestive system tumours. Fibroblast activation protein is highly expressed in gastrointestinal tumours. Various isotope-labelled fibroblast activation protein inhibitors are widely used in clinical research. These inhibitors have low background uptake in the brain, liver and oral/pharyngeal mucosa and show good contrast between the tumour and background, which makes up for the lack of fluorodeoxyglucose in the diagnosis of digestive system tumours. It better displays the primary tumours, metastases and regional lymph nodes of digestive system tumours, such as oesophageal cancer, gastric cancer and liver cancer, and also provides a new method for treating these tumours. Based on this background, this article introduces the current research status of fibroblast activation protein inhibitor positron emission tomography/computed tomography in various types of digestive system malignant tumours to provide more valuable information for diagnosing and treating digestive system tumours.

Baseline 18F-FDG PET/CT quantitative parameters as prognostic factors in esophageal squamous cell cancer

AIM

To determine the utility of [¹⁸F]FDG PET/CT quantitative parameters as prognostic factors for the response to neoadjuvant treatment, progression-free survival (PFS) and cancer-specific survival (CSS) in patients with esophageal squamous cell carcinoma (SCC).

MATERIAL AND METHODS

Thirty patients (29 men) diagnosed with SCC were retrospectively evaluated over a 6-year interval. Metabolic parameters were determined: maximum SUV (SUVmax), mean SUV (SUVmed), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) from baseline PET/CT study. After treatment with chemotherapy and/or radiotherapy, response to treatment and patient survival were assessed. The comparison of parameters between groups of responders and non-responders was carried out using a Mann-Whitney U test ROC curves and the Kaplan-Meier method were used for analysis of prognostic factors and survival curves.

RESULTS

The average follow-up was 22.4 months, with 22 recurrence-progressions and 25 deaths. Significant differences were demonstrated between responders and non-responders with respect to tumor size, MTV and TLG. Survival analysis found significant differences for SCE and CSS depending on these three parameters.

CONCLUSION

Metabolic parameters MTV and TLG, and tumor size were prognostic factors for neoadjuvant treatment response, PFS, and CSS in patients diagnosed with SCC. Neither SUVmax nor SUVmed were predictive for any of the evaluation criteria. Results could help to personalize patient treatment.

Trimodality therapy for locally advanced esophageal squamous cell carcinoma: the role of volume-based PET/CT in patient management and prognostication

PURPOSE

To evaluate the role of positron emission tomography/computed tomography (PET/CT) in predicting pathologic complete response (pCR) and identify relevant prognostic factors from clinico-imaging-pathologic features of locally advanced esophageal squamous cell carcinoma (eSCC) patients undergoing trimodality therapy.

METHODS

We evaluated 275 patients with eSCCs of T3-T4aN0M0 and T1-T4aN1-N3M0 who received trimodality therapy. We correlated volume-based PET/CT parameters before and after concurrent chemoradiation therapy with pCR after surgery, clinico-imaging-pathologic features, and patient survival.

RESULTS

pCR occurred in 75 (27.3%) of 275 patients, of whom 61 (80.9%) showed 5-year survival. Pre-total lesion glycolysis (pre-TLG, OR = 0.318, 95% CI 0.169 to 0.600), post-metabolic tumor volume (post-MTV, OR = 0.572, 95% CI 0.327 to 0.999), and % decrease of average standardized uptake value (% SUVavg decrease, OR = 2.976, 95% CI = 1.608 to 5.507) were significant predictors for pCR. Among them, best predictor for pCR was pre-TLG with best cutoff value of 205.67 and with AUC value of 0.591. Performance status (HR = 5.171, 95% CI 1.737 to 15.397), pathologic tumor size (HR = 1.645, 95% CI 1.351 to 2.002), pathologic N status (N1, HR = 1.572, 95% CI 1.010 to 2.446; N2, HR = 3.088, 95% CI 1.845 to 5.166), and post-metabolic tumor volume (HR = 1.506, 95% CI 1.033 to 2.195) were significant predictors of overall survival.

CONCLUSION

Pre-TLG, post-MTV, and % SUVavg decrease are predictive of pCR. Additionally, several clinico-imaging-pathologic factors are significant survival predictors in locally advanced eSCC patients undergoing trimodality therapy.

18F-FDG PET/CT Parameters for Predicting Prognosis in Esophageal Cancer Patients Treated With Concurrent Chemoradiotherapy

Background and Aims:

This study evaluated the prognostic value of ¹⁸F-fluorodeoxyglucose positron emission tomography with integrated computed tomography (¹⁸F-FDG PET/CT) performed before and after concurrent chemoradiotherapy (CCRT) in esophageal cancer.

Methods:

We analyzed the prognosis of 50 non-metastatic squamous cell esophageal cancer (T1-4N0-2) patients who underwent CCRT with curative intent at Inje University Busan Paik Hospital and Haeundae Paik Hospital from 2009 to 2019. Median total radiation dose was 54 Gy (range 34-66 Gy). Our aim was to investigate the relationship between PET/CT values and prognosis. The primary end point was progression-free survival (PFS).

Results:

The median follow-up period was 9.9 months (range 1.7-85.7). Median baseline maximum standard uptake value (SUVmax) was 14.2 (range 3.2-27.7). After treatment, 29 patients (58%) showed disease progression. The 3-year PFS and overall survival (OS) were 24.2% and 54.5%, respectively. PFS was significantly lower (P = 0.015) when SUVmax of initial PET/CT exceeded 10 (n = 22). However, OS did not reach a significant difference based on maximum SUV (P = 0.282). Small metabolic tumor volume (≤14.1) was related with good PFS (P = 0.002) and OS (P = 0.001). Small total lesion of glycolysis (≤107.3) also had a significant good prognostic effect on PFS (P = 0.009) and OS (P = 0.025). In a subgroup analysis of 18 patients with follow-up PET/CT, the patients with SUV max ≤3.5 in follow-up PET/CT showed longer PFS (P = 0.028) than those with a maximum SUV >3.5.

Conclusion:

Maximum SUV of PET/CT is useful in predicting prognosis of esophageal cancer patients treated with CCRT. Efforts to find more effective treatments for patients at high risk of progression are still warranted.

Baseline 18F-FDG PET/CT quantitative parameters as prognostic factors in esophageal squamous cell cancer

AIM

To determine the utility of 18F-FDG PET/CT quantitative parameters as prognostic factors for the response to neoadjuvant treatment, progression-free survival (PFS) and cancer-specific survival (CSS) in patients with esophageal squamous cell carcinoma (SCC).

MATERIAL AND METHODS

Thirty patients (29 men) diagnosed with SCC were retrospectively evaluated over a 6-year interval. Metabolic parameters were determined: maximum SUV (SUVmax), mean SUV (SUVmed), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) from baseline PET/CT study. After treatment with chemotherapy and/or radiotherapy, response to treatment and patient survival were assessed. The comparison of parameters between groups of responders and non-responders was carried out using a Mann-Whitney U test. ROC curves and the Kaplan-Meier method were used for analysis of prognostic factors and survival curves.

RESULTS

The average follow-up was 22.4months, with 22 recurrence-progressions and 25 deads. Significant differences were demonstrated between responders and non-responders with respect to tumor size, MTV and TLG. Survival analysis found significant differences for SCE and CSS depending on these three parameters.

CONCLUSION

Metabolic parameters MTV and TLG, and tumor size were prognostic factors for neoadjuvant treatment response, PFS, and CSS in patients diagnosed with SCC. Neither SUVmax nor SUVmed were predictive for any of the evaluation criteria. Results could help to personalize patient treatment.

Prognostic value of 18F-fluorodeoxyglucose PET/computed tomography metabolic parameters measured in the primary tumor and suspicious lymph nodes before neoadjuvant therapy in patients with esophageal carcinoma

BACKGROUND

18F-fluorodeoxyglucose PET/computed tomography (18F-FDG PET/CT) metabolic parameters are prognostic indicators in several neoplasms. This study aimed to evaluate the prognostic value of the maximum and average standardized uptake value (SUVmax and SUVavg), metabolic tumor value (MTV), and total lesion glycolysis (TLG) measured in the primary tumor and suspicious lymph nodes preneoadjuvant therapy in patients submitted to surgical resection for esophageal cancer.

METHODS

A cohort of 113 patients with esophageal cancer who performed 18F-FDG PET/CT preneoadjuvant therapy was assessed. The association of the SUV, MTV, and TLG measured in the primary tumor and in the suspicious lymph nodes with the overall survival was assessed. It was also analyzed other potentially confounding variables such as age, sex, clinical stage, and histologic subtype. The analyses were performed using Kaplan-Meier curve, log-rank test, and Cox regression.

RESULTS

The univariate analyses showed that the MTV and TLG in the primary tumor, the SUV in the suspicious lymph nodes, the age, the histologic subtype, and the clinical stage were associated with survival after surgery (P ≤ 0.05). In the Cox regression multivariate analyses, all variables identified in the univariate analyses but the clinical stage were associated with survival after surgery (P ≤ 0.05).

CONCLUSION

In esophageal cancer patients, some of the 18F-FDG PET/CT metabolic parameters measured in the primary tumor and in the suspicious lymph nodes before the neoadjuvant therapy are independent indicators of overall survival and appear to be more important than the clinical stage in the prognostic definition of this group of patients.

PET/CT-Based Response Evaluation in Cancer-a Systematic Review of Design Issues

Positron emission tomography/x-ray computed tomography (PET/CT) has long been discussed as a promising modality for response evaluation in cancer. When designing respective clinical trials, several design issues have to be addressed, especially the number/timing of PET/CT scans, the approach for quantifying metabolic activity, and the final translation of measurements into a rule. It is unclear how well these issues have been tackled in quest of an optimised use of PET/CT in response evaluation. Medline via Ovid and Science Citation Index via Web of Science were systematically searched for articles from 2015 on cancer patients scanned with PET/CT before and during/after treatment. Reports were categorised as being either developmental or evaluative, i.e. focusing on either the establishment or the evaluation of a rule discriminating responders from non-responders. Of 124 included papers, 112 (90 %) were accuracy and/or prognostic studies; the remainder were response-curve studies. No randomised controlled trials were found. Most studies were prospective (62 %) and from single centres (85 %); median number of patients was 38.5 (range 5-354). Most (69 %) of the studies employed only one post-baseline scan. Quantification was mainly based on SUVmax (91 %), while change over time was most frequently used to combine measurements into a rule (79 %). Half of the reports were categorised as developmental, the other half evaluative. Most development studies assessed only one element (35/62, 56 %), most frequently the choice of cut-off points (25/62, 40 %). In summary, the majority of studies did not address the essential open issues in establishing PET/CT for response evaluation. Reasonably sized multicentre studies are needed to systematically compare the many different options when using PET/CT for response evaluation.

Use of 18F Fluorodeoxyglucose Positron Emission Tomography Computed Tomography in Assessing Response to Neoadjuvant Chemoradiation and Its Impact on Survival in Esophageal Squamous Cell Carcinoma

BACKGROUND

To determine the accuracy of ¹⁸F-Fluorodeoxyglucose positron emission tomography computed tomography (FDG-PET CT) in predicting response to neoadjuvant chemoradiation (NACRT) in esophageal squamous cell cancer (SCC) and impact of such response on survival.

METHODS

Retrospective analysis of patients with esophageal SCC (cT2-4N0-N+M0) who underwent PET CT before and 6 weeks after NACRT followed by surgery was carried out in this study. Metabolic response was assessed by change in standardized uptake value (ΔSUV_max) after NACRT and the pathological response was graded. A receiver operating characteristic curve (ROC) was used to identify the optimal cut off value of SUV_max to predict histopathological response. The impact of metabolic response and pathological response on survival was determined.

RESULTS

Of the 73 patients analyzed, 27 had complete metabolic response, while 24 had pathological complete response (PCR). However, only 14 of the 27 complete metabolic responders actually had PCR. At 67% ΔSUV_max, the optimum balance between sensitivity (70.83%) and specificity (69.23%) was achieved and the correlation between metabolic response and pathological complete response achieved statistical significance (p = 0.0009). However, ΔSUV_max of 67% was found to have no significant association with survival (p = 0.51). PCR was the only significant determinant of improved survival (p = 0.04).

CONCLUSION

PCR which is a significant determinant of survival is not ideally predicted by ΔSUV_max on PET CT.

Total Lesion Glycolysis Assessment Identifies a Patient Fraction With a High Cure Rate Among Esophageal Adenocarcinoma Patients Treated With Definitive Chemoradiation

OBJECTIVE

We aimed to determine whether tumor metabolism could be prognostic of cure in L-EAC patients who receive definitive chemoradiation.

SUMMARY BACKGROUND DATA

Patients with inoperable localized esophageal adenocarcinoma (L-EAC) often receive definitive chemoradiation; however, biomarkers and/or imaging variables to prognosticate cure are missing.

METHODS

Two hundred sixty-six patients with L-EAC who had chemoradiation but not surgery were analyzed from the prospectively maintained EAC databases in the Department of Gastrointestinal Medical Oncology at The University of Texas MD Anderson Cancer Center (Texas, USA) between March 2002 and April 2015. Maximum standardized uptake value (SUVmax) and total lesion glycolysis (TLG) from the positron emission tomography data were evaluated.

RESULTS

Of 266 patients, 253 (95%) were men; the median age was 67 years (range 20-91 yrs) and 153 had poorly differentiated L-EAC. The median SUVmax was 10.3 (range 0-87) and the median TLG was 85.7 (range 0-3227). Both SUVmax and TLG were higher among those with: tumors >5 cm in length, high clinical stage, and high tumor and node categories by TNM staging (all P < 0.0001). Of 234 patients evaluable for cure, 60 (25.6%) achieved cure. In the multivariable logistic regression model, low TLG (but not low SUVmax) was associated with cure (continuous TLG value: odds ratio 0.70, 95% confidence interval (CI) 0.54-0.92). TLG was quantified into 4 quartile categorical variables; first quartile (Q1; <32), second quartile (Q2; 32.0-85.6), third quartile (Q3; 85.6-228.4), and fourth quartile (Q4; >228.4); the cure rate was only 10.3% in Q4 and 5.1% in Q3 but increased to 28.8% in Q2, and 58.6% in Q1. The cross-validation resulted in an average accuracy of prediction score of 0.81 (95% CI, 0.75-0.86).

CONCLUSIONS

In this cross-validated model, 59% of patients in the 1st quartile were cured following definitive chemoradiation. Baseline TLG could be pursued as one of the tools for esophageal preservation.

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.

Clinical impact of FDG PET/CT in alimentary tract malignancies: an updated review

The use of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography combined with computed tomography (PET/CT) is well established in the evaluation of alimentary tract malignancies. This review of the literature and demonstration of correlative images focuses on the current role of PET/CT in the diagnosis (including pathologic/clinical staging) and post-therapy follow-up of esophageal, gastric, and colorectal cancers. PET/CT provides utility in the management of esophageal cancer, including detection of distant disease prior to resection. In gastric cancer, PET/CT is useful in detecting solid organ metastases and in characterizing responders vs. non-responders after neoadjuvant chemotherapy, the latter of which have poorer overall survival. In patients with GIST tumors, PET/CT also determines response to imatinib therapy with greater expedience as compared to CECT. For colorectal cancer, PET/CT has proven helpful in detecting hepatic and other distant metastases, treatment response, and differentiating post-radiation changes from tumor recurrence. Our review also highlights several pitfalls in PET/CT interpretation of alimentary tract lesions.

Preoperative Prediction of Pathologic Response to Neoadjuvant Chemoradiotherapy in Patients With Esophageal Cancer Using 18F-FDG PET/CT and DW-MRI: A Prospective Multicenter Study

PURPOSE

Accurate preoperative prediction of pathologic response to neoadjuvant chemoradiotherapy (nCRT) in patients with esophageal cancer could enable omission of esophagectomy in patients with a pathologic complete response (pCR). This study aimed to evaluate the individual and combined value of ¹⁸F-fluorodeoxyglucose positron emission tomography with integrated computed tomography (¹⁸F-FDG PET/CT) and diffusion-weighted magnetic resonance imaging (DW-MRI) during and after nCRT to predict pathologic response in patients with esophageal cancer.

METHODS AND MATERIALS

In this multicenter prospective study, patients scheduled to receive nCRT followed by esophagectomy for esophageal cancer underwent ¹⁸F-FDG PET/CT and DW-MRI scanning before the start of nCRT, during nCRT, and before esophagectomy. Response to nCRT was based on histopathologic evaluation of the resection specimen. Relative changes in ¹⁸F-FDG PET/CT and DW-MRI parameters were compared between patients with pCR and non-pCR groups. Multivariable ridge regression analyses with bootstrapped c-indices were performed to evaluate the individual and combined value of ¹⁸F-FDG PET/CT and DW-MRI.

RESULTS

pCR was found in 26.1% of 69 patients. Relative changes in ¹⁸F-FDG PET/CT parameters after nCRT (Δ standardized uptake value [SUV]_mean,postP = .016, and Δ total lesion glycolysis _postP = .024), as well as changes in DW-MRI parameters during nCRT (Δ apparent diffusion coefficient [ADC]_duringP = .008) were significantly different between pCR and non-pCR. A c-statistic of 0.84 was obtained for a model with ΔADC_during, ΔSUV_mean,post, and histology in classifying patients as pCR (versus 0.82 for ΔADC_during and 0.79 for ΔSUV_mean,post alone).

CONCLUSIONS

Changes on ¹⁸F-FDG PET/CT after nCRT and early changes on DW-MRI during nCRT can help identify pCR to nCRT in esophageal cancer. Moreover, ¹⁸F-FDG PET/CT and DW-MRI might be of complementary value in the assessment of pCR.

Baseline FDG Uptake And Peripheral Lymphocyte-Monocyte Ratio For Predicting Chemoradiotherapy Response In Patients With Esophageal Squamous Cell Carcinoma

Purpose

To explore he predictive values of both the baseline SUVmax of ¹⁸F-fluorodeoxy-glucose by the primary tumor in positron emission tomography/computed tomography (PET/CT) and the lymphocyte-monocyte ratio (LMR) in peripheral blood in inoperable treated esophageal squamous cell carcinoma (ESCC) patients who received concurrent chemoradiotherapy (CCRT).

Patients and methods

Between January 2011 and December 2016, 138 newly diagnosed ESCC patients from our institution were retrospectively recruited. The optimal cut-off values for baseline SUVmax and peripheral LMR were determined by individual receiver operating characteristic curves. The predictive values of baseline SUVmax and peripheral LMR for primary tumor response were examined by chi-square and Fisher’s exact tests, as was their combined predictive value.

Results

The objective response rate (ORR) was significantly different between the high-SUVmax group and the low-SUVmax group (61.9% vs 87.8%; P=0.004), as well as between the high-LMR group and the low-LMR group (80.7% vs 52.0%; P=0.001). Furthermore, the low-SUVmax-high-LMR group achieved the best ORR (100%), which was significantly different from the ORRs of the high-SUVmax-high-LMR group (ORR: 72.1%, P=0.002), the high-SUVmax-low-LMR group (ORR: 45.7%, P=0.001), and the low-SUVmax-low-LMR group (ORR: 45.7%, P=0.001).

Conclusion

Baseline SUVmax of the primary tumor and the peripheral LMR are independent predictors of CCRT response in the primary tumors of ESCC patients. Patients who have lower FDG uptake accompanied by a higher peripheral LMR are more likely to have a better primary tumor response after CCRT.

Role of intravoxel incoherent motion parameters in gastroesophageal cancer: relationship with 18F-FDG-positron emission tomography, computed tomography perfusion and magnetic resonance perfusion imaging parameters

BACKGROUND

Identification of pretherapeutic predictive markers in gastro-esophageal cancer is essential for individual-oriented treatment. This study evaluated the relationship of multimodality parameters derived from intravoxel incoherent motion method (IVIM), 18F-FDG-positron emission tomography (PET), computed tomography (CT) perfusion and dynamic contrast enhanced magnetic resonance imaging (MRI) in patients with gastro-esophageal cancer and investigated their histopathological correlation.

METHODS

Thirty-one consecutive patients (28 males; median age 63.9 years; range 37-84 years) with gastro-esophageal adenocarcinoma (N.=22) and esophageal squamous cell carcinoma (N.=9) were analyzed. IVIM parameters: pseudodiffusion (D*), perfusion fraction (fp), true diffusion (D) and the threshold b-value (bval); PET-parameters: SUV<inf>max</inf>, metabolic tumor volume (MTV) and total lesion glycolysis (TLG); CT perfusion parameters: blood flow (BF), blood volume (BV) and mean transit time (MTT); and MR perfusion parameters: time to enhance, positive enhancement integral, time-to-peak (TTP), maximum-slope-of-increase, and maximum-slope-of-decrease were determined, and correlated to each other and to histopathology.

RESULTS

IVIM and PET parameters showed significant negative correlations: MTV and bval (r<inf>s</inf> =-0.643, P=0.002), TLG and bval (r<inf>s</inf>=-0.699, P<0.01) and TLG and fp (r<inf>s</inf>=-0.577, P=0.006). Positive correlation was found for TLG and D (r<inf>s</inf>=0.705, P=0.000). Negative correlation was found for bval and staging (r<inf>s</inf>=0.590, P=0.005). Positive correlation was found for positive enhancement interval and BV (r<inf>s</inf>=0.547, P=0.007), BF and regression index (r<inf>s</inf>=0.753, P=0.005) and for time-to-peak and staging (r<inf>s</inf>=0.557, P=0.005).

CONCLUSIONS

IVIM parameters (bval, fp, D) provide quantitative information and correlate with PET parameters (MTV, TLG) and staging. IVIM might be a useful tool for additional characterization of gastro-esophageal cancer.

Staging and Response Evaluation to Neo-Adjuvant Chemoradiation in Esophageal Cancers Using 18FDG PET/ CT with Standardized Protocol

Background: Precise staging of esophageal cancer (EC) is important for selection of optimal treatment option and prognostication. Aim of this study was to assess the role of 18FDG PET/CT in staging and response evaluation to neoadjuvant chemoradiation (nCR) in EC patients using standardized imaging protocol. Material and methods: This prospective study was conducted at PET/CT Section of Department of Radiology, Aga Khan University Hospital Karachi, Pakistan from July 2017 till February 2018. We included 34 biopsy proven EC patients who had 18FDG PET/CT and CT of neck, chest and abdomen as part of initial staging. Eleven patients had post-nCR 18FDG PET/CT using standardized imaging protocol as per EANM guidelines. CT and PET/CT based staging was compared. Based on PERCIST criteria, response evaluation was assessed using change in highest SUVmax (%ΔSUVmax) in baseline and follow-up scans (primary lesion, node or extra-nodal metastases). Results: Mean age of cohort was 57 ± 14 years (23 males and 11 females) having adenocarcinoma (AC) in 23 and squamous cell cancer (SCC) in 11 patients. Mean 18FDG dose, uptake time and hepatic SUVmean for baseline scans were 169 ±54 MBq, 65 ±10 minute and 1.91 ± 0.49 which were within ± 10%, ± 15% and ± 20% for follow-up scans in 11 patients respectively. Mean size (craniocaudal dimension in mm) and SUVmax of primary tumor was 56 ±27 mm and 13.4 ± 4.7. Based on 18FDG PET/CT findings, patients were categorized into N0 (10/34), N1 (09/34), N2 (11/34) and N3 (04/34) while 11/32 had stage IV disease. No significant difference was seen in AC and SCC groups. CT found stage IV disease in 3/34 (09%) while PET/CT found in 11/34 (32%; p value: 0.019) cases. PET/CT showed concordance with CT in 41% while discordance (all with upstaging) seen in 59%. On follow-up PET/CT, complete metabolic response was seen in 5/11 (45%) and partial metabolic response was noted in 6/11 (55% - p value non-significant) patients. Median %ΔSUVmax over primary lesions was 49.84% (-32.69 -100%) while over nodal sites it was 41.18% (-82.60 -100%). Conclusion: We conclude that 18FDG PET/CT was found a sensitive tool in initial staging of EC. Compared with CT, it had higher diagnostic accuracy for distant nodal and extra-nodal metastasis. %ΔSUVmax between baseline and post-nCR studies acquired with standardized protocol had changed management in more than half of our patients. For response evaluation in EC more studies with standardized 18FDG PET/CT imaging protocols are warranted.

Early metabolic response to chemoradiotherapy by interim FDG PET/CT is associated with better overall survival and histological response in esophageal cancers

BACKGROUND

Early assessment of response to neoadjuvant chemoradiotherapy (CRT) is crucial in determining the most suitable treatment strategy in locally advanced oesophageal cancer (LAEC).

AIMS

We evaluated the impact of early metabolic response during CRT on overall survival (OS) and histological response.

METHODS

Patients with biopsy-proven oesophageal carcinoma underwent FDG PET/CT with evaluation of the standardized uptake value (SUV) before any treatment and during CRT after 20 Gy.

RESULTS

116 patients (Male: 66.4%, Median age: 63; squamous cell carcinomas (SCC): 70%) met inclusion criteria. Median OS was 21.7 months. There was a significant positive correlation between interim metabolic response and OS. In multivariate analysis, only metabolic response using the 50% cut-off value remained significantly associated with OS (IC95% = 0.28-0.73; p = 0.001). In this statistical analysis, surgery (p = 0.007) and T stage (p = 0.023) were also correlated with OS. There was a significant correlation between early metabolic response and local recurrence (Chi-squared test p = 0.0001).

CONCLUSIONS

Early metabolic response using FDG PET/CT is associated with better OS, disease-free survival, local control and pathological response in patients treated by CRT for LAEC.

Confirmation of the prognostic value of pretherapeutic tumor SUR and MTV in patients with esophageal squamous cell carcinoma

PURPOSE

The prognosis for patients with inoperable esophageal carcinoma is still poor and the reliability of individual therapy outcome prediction based on clinical parameters is not convincing. In a recent publication, we were able to show that PET can provide independent prognostic information in such a patient group and that the tumor-to-blood standard uptake ratio (SUR) can improve the prognostic value of tracer uptake values. The present investigation addresses the question of whether the distinctly improved prognostic value of SUR can be confirmed in a similar patient group that was examined and treated at a different site.

METHODS

¹⁸F-FDG PET/CT was performed in 147 consecutive patients (115 male, 32 female, mean age: 62 years) with newly diagnosed esophageal squamous cell carcinoma prior to definitive radiochemotherapy. In the PET images, the metabolic active volume (MTV) of the primary tumor was delineated with an adaptive threshold method. For the resulting ROIs, SUV_max and total lesion glycolysis (TLG = MTV × SUV_mean) were computed. The blood SUV was determined by manually delineating the aorta in the low-dose CT. SUR values were computed as ratio of tumor SUV and blood SUV. Univariate Cox regression and Kaplan-Meier analysis with respect to overall survival (OS), distant-metastases-free survival (DM), and locoregional control (LRC) was performed. Additionally, a multivariate Cox regression including clinically relevant parameters was performed.

RESULTS

Univariate Cox regression revealed MTV, TLG, and SUR_max as significant prognostic factors for OS. MTV as well as TLG were significant prognostic factors for LRC while SUR_max showed only a trend for significance. None of the PET parameters was prognostic for DM. In univariate analysis, SUV_max was not prognostic for any of the investigated clinical endpoints. In multivariate analysis (T-stage, N-stage, MTV, and SUR_max), MTV was an independent prognostic factor for OS and showed a trend for significance for LRC. SUR_max was not an independent predictor for OS or LRC. When including the PET parameters separately in multivariate analysis, MTV as well as SUR_max were prognostic factors for OS indicating that SUR_max is independent from the clinical parameters but not from MTV. In addition, MTV was an independent prognostic factor for LRC in this separate analysis.

CONCLUSIONS

Our study revealed a clearly improved prognostic value of tumor SUR compared to tumor SUV and confirms our previously published findings regarding OS. Furthermore, SUR delivers prognostic information beyond that provided by the clinical parameters alone, but does not add prognostic information beyond that provided by MTV in this patient group. Therefore, our results suggest that pretherapeutic MTV is the parameter of choice for PET-based risk stratification in the considered setting but further investigations are necessary to demonstrate that this suggestion is correct.

Interobserver variability of image-derived arterial blood SUV in whole-body FDG PET

Background

Today, the standardized uptake value (SUV) is essentially the only means for quantitative evaluation of static [¹⁸F-]fluorodeoxyglucose (FDG) positron emission tomography (PET) investigations. However, the SUV approach has several well-known shortcomings which adversely affect the reliability of the SUV as a surrogate of the metabolic rate of glucose consumption. The standard uptake ratio (SUR), i.e., the uptake time-corrected ratio of tumor SUV to image-derived arterial blood SUV, has been shown in the first clinical studies to overcome most of these shortcomings, to decrease test-retest variability, and to increase the prognostic value in comparison to SUV. However, it is unclear, to what extent the SUR approach is vulnerable to observer variability of the additionally required blood SUV (BSUV) determination. The goal of the present work was the investigation of the interobserver variability of image-derived BSUV.

Methods

FDG PET/CT scans from 83 patients (72 male, 11 female) with non-small cell lung cancer (N = 46) or head and neck cancer (N = 37) were included. BSUV was determined by 8 individuals, each applying a dedicated delineation tool for the BSUV determination in the aorta. Two of the observers applied two further tools. Altogether, five different delineation tools were used. With each used tool, delineation was performed for the whole patient group, resulting in 12 distinct observations per patient. Intersubject variability of BSUV determination was assessed using the fractional deviations for the individual patients from the patient group average and was quantified as standard deviation (SD _is), 95% confidence interval, and range.

Interobserver variability of BSUV determination was assessed using the fractional deviations of the individual observers from the observer-average for the considered patient and quantified as standard deviations (SD _p, SD _d) or root mean square (RMS), 95% confidence interval, and range in each patient, each observer, and the pooled data respectively.

Results

Interobserver variability in the pooled data amounts to RMS = 2.8% and is much smaller than the intersubject variability of BSUV (SD _is= 16%). Averaged over the whole patient group, deviations of individual observers from the observer average are very small and fall in the range [ − 0.96, 1.05]%. However, interobserver variability partly differs distinctly for different patients, covering a range of [0.7, 7.4]% in the investigated patient group.

Conclusion

The present investigation demonstrates that the image-based manual determination of BSUV in the aorta is sufficiently reproducible across different observers and delineation tools which is a prerequisite for accurate SUR determination. This finding is in line with the already demonstrated superior prognostic value of SUR in comparison to SUV in the first clinical studies.

Early response evaluation of neoadjuvant therapy with PET/MRI to predict resectability in patients with adenocarcinoma of the esophagogastric junction

STUDY DESIGN AND PURPOSE

Positron emission tomography (PET)/magnetic resonance imaging (MRI) is a new modality that has showed promising results for various clinical indications. Currently, evaluation of neoadjuvant therapy (NT) among patients with adenocarcinoma of the esophagogastric junction has primarily been reserved for PET/computed tomography. Our aim was to evaluate if early response evaluation by PET/MRI is a feasible method to predict resectability.

METHODS AND MATERIALS

Patients with untreated adenocarcinoma of the esophagogastric junction (Siewert types I/II) and fit for NT with no contraindications for PET/MRI were considered eligible. A baseline scan was performed prior to NT induction and an evaluation scan 3 weeks later. For histopathological response evaluation, the Mandard tumor regression grade score was applied. Response on PET/MRI was evaluated with Response Evaluation Criteria in Solid Tumors (RECIST 1.1), and change in ADC and SUV_max values.

RESULTS

Twenty-eight patients were enrolled, and 22 completed both scans and proceeded to final analyses. Seventeen patients were found resectable versus five who were found unresectable. PET/MRI response evaluation had a sensitivity 94%, specificity 80%, and AUC = 0.95 when predicting resectability in patients with adenocarcinoma of the esophagogastric junction. No association with histopathological response (tumor regression grade) was found nor was RECIST correlated with resectability.

CONCLUSION

Response evaluation using PET/MRI was a feasible method to predict resectability in patients with adenocarcinoma of the esophagogastric junction in this pilot study. However, larger studies are warranted to justify the use of the modality for this indication.

Treatment response assessment in [18F]FDG-PET/CT oncology scans: Impact of count statistics variation and reconstruction protocol

PURPOSE

To investigate influences of reconstruction algorithms and count statistics variation on quantification and treatment response assessment in cancer patients, by using a large field of view-FOV scanner.

METHODS

54 cancer patients underwent PET/CT scan: 1) at baseline: 1.5 min/FOV, reconstructed by ordered-subset expectation maximization + point-spread-function-OSEM-PSF and bayesian penalised-likelihood-BPL algorithm 2) at restaging: 2 min/FOV, reconstructed also at 1.5 and 1 min/FOV, using OSEM-PSF and BPL. SUL (lean-body mass SUV) peak and max were measured for each target-lesion (n = 59). Differences in quantification obtained from datasets with different reconstruction algorithms and different time/FOV were evaluated. For any pair of PET datasets, metabolic response was assessed by using SULpeak, with a threshold of 30% in variation considered as significant.

RESULTS

Both at baseline and restaging, SULpeak and max values were higher in BPL reconstructions than in OSEM-PSF (p < 0.0001). SULpeak at different time/FOV reconstructions showed no statistically significant differences both with OSEM-PSF and BPL; SULmax depended on acquisition time (p < 0.05). In 56/59 lesions (95%) therapy response was concordant regardless count statistics variation and reconstruction algorithm; 2/59 (3%) showed different responses according to count statistics, both for OSEM-PSF and BPL; in 1/59 lesion (2%) response was different depending on reconstruction algorithm used.

CONCLUSIONS

BPL provided higher SULpeak and max than OSEM-PSF. With a large FOV/high sensitivity scanner, variation of time/FOV in restaging PET scans gave stable and reproducible results in terms of SULpeak, both for OSEM-PSF and BPL. Thus, metabolic response defined by SULpeak variation proved to be quite independent from count statistics.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Multimodal Imaging of Pathologic Response to Chemoradiation in Esophageal Cancer

PURPOSE

To examine the value of early changes in quantitative diffusion-weighted imaging and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) for discriminating complete pathologic response (pCR) to chemoradiation in esophageal cancer.

METHODS AND MATERIALS

Twenty esophageal cancer patients treated with chemoradiation followed by surgery were prospectively enrolled. Patients underwent magnetic resonance imaging and FDG-PET/CT scans at baseline, interim (2 weeks after chemoradiation start), and first follow-up. On the basis of pathologic findings at surgery, patients were categorized into tumor regression groups (TRG1, TRG2, and TRG3+). Distributions of summary statistics in apparent diffusion coefficient (ADC) and FDG-PET at baseline and relative changes at interim and follow-up scans were compared between pCR/TRG1 and non-pCR/TRG2+ groups and across readers. Receiver operating characteristics were evaluated for summary measures to characterize discrimination of pCR from non-pCR.

RESULTS

Relative changes in tumor volume ADC (ΔADC) mean and 25th and 10th percentiles from baseline to interim were able to completely discriminate (area under the curve = 1, P < .0011) between pCR and non-pCR (thresholds = 27.7%, 29.2%, and 32.1%, respectively) and were found to have high interreader reliability (95% limits of agreement of 1.001, 0.944, and 0.940, respectively). Relative change in total lesion glycolysis (TLG) from baseline to interim was significantly different among pCR and non-pCR groups (P=.0117) and yielded an area under the curve of 0.947 (95% confidence interval 0.8505-1.043). An optimal threshold of 59% decrease in TLG provided optimal sensitivity (specificity) of 1.000 (0.867). Changes in ADC summary measures were negatively correlated with that of TLG (Spearman, -0.495, P=.027).

CONCLUSIONS

Quantitative volume ΔADC and TLG during treatment may serve as early imaging biomarkers for discriminating pathologic response to chemoradiation in esophageal cancer. Validation of these data in larger, prospective, multicenter studies is essential.

Intratreatment Response Assessment With 18F-FDG PET: Correlation of Semiquantitative PET Features With Pathologic Response of Esophageal Cancer to Neoadjuvant Chemoradiotherapy

PURPOSE

This prospective study seeks to extract semiquantitative positron emission tomography (PET) features from 18F-fluorodeoxyglucose PET scans performed before and during neoadjuvant chemoradiotherapy for esophageal cancer and to compare their accuracy in predicting histopathologic response.

METHODS AND MATERIALS

From 2012 to 2016, 26 patients with esophageal cancer underwent pretreatment and intratreatment PET scans during chemoradiotherapy followed by surgery. Median patient age was 63 years (interquartile range, 58-68 years); 26 patients had esophageal adenocarcinoma, and 3 had esophageal squamous cell carcinoma. The intratreatment PET scan was performed at a median of 32.4 Gy (interquartile range, 30.6-32.4 Gy). PET features of the primary site including maximum standardized uptake value (SUV), SUV mean, metabolic tumor volume, and total lesion glycolysis were extracted from the pretreatment and intratreatment PET scans. Patients were histopathologic responders if there was complete or near-complete tumor response by modified Ryan scheme. Mean values of PET features were compared between histopathologic responders and nonresponders. The area under the receiver operating characteristic curve (AUC) was used to compare the accuracy of PET features in predicting histopathologic response.

RESULTS

Eleven patients (42%) were histopathologic responders. PET features most discriminatory of histopathologic response on AUC analysis were volumetric PET features from the intratreatment PET including metabolic tumor volume based on manual contour (AUC, 0.73; 95% confidence interval, 0.52-0.93) and total lesion glycolysis based on semiautomatic 40% SUV threshold (AUC, 0.73; 95% confidence interval, 0.53-0.94).

CONCLUSIONS

Volumetric PET features from the intratreatment PET were the most accurate predictors of histopathologic response.

Patterns of Failure Following Dose-escalated Chemoradiotherapy for Fluorodeoxyglucose Positron Emission Tomography Staged Squamous Cell Carcinoma of the Oesophagus

AIMS

To analyse outcomes and patterns of failure following dose-escalated definitive chemoradiotherapy (CRT) for oesophageal squamous cell carcinoma using fluorodeoxyglucose positron emission tomography for staging and treatment planning.

MATERIALS AND METHODS

A retrospective review of patients with oesophageal squamous cell carcinoma receiving definitive CRT to a dose of ≥56 Gy was conducted. Patient and tumour characteristics, treatment received and first sites of relapse were analysed.

RESULTS

Between 2003 and 2014, 72 patients were treated with CRT to a median dose of 60 Gy (range 56-66 Gy). The median age was 63 years; most (61%) were stage III/IVa. The median follow-up was 57 months. Three year in-field control, relapse-free survival and overall survival was 64% (95% confidence interval 50-75%), 38% (95% confidence interval 27-50%) and 42% (95% confidence interval 30-53%), respectively. Of the 41 failures prior to death or at last follow-up date, isolated locoregional relapse occurred in 16 patients (22%) with isolated in-field recurrence in 11 patients (15%). Distant failure as first site of relapse was present in 25 patients (35%). No in-field failures occurred in the 11 patients with cT1-2, N0-1 tumours. The median survival for cT4 tumours was 8 months, with five of eight patients developing local progression within the first 6 months.

CONCLUSIONS

Dose-escalated radiotherapy was associated with promising rates of in-field local control, with the exception of cT4 tumours. Distant failure remains a significant competing risk. Our data supports the need for current trials re-examining the role of dose escalation in the modern era.

Increased evidence for the prognostic value of FDG uptake on late-treatment PET in non-tumour-affected oesophagus in irradiated patients with oesophageal carcinoma

PURPOSE

¹⁸F-FDG uptake in irradiated non-tumour-affected oesophagus (NTO) on restaging PET is a potential surrogate for the measurement of radiation-induced inflammation. Radiation-induced inflammation itself has been shown to be of high prognostic relevance in patients undergoing preoperative radiochemotherapy (RCT) for locally advanced oesophageal cancer. We assessed the prognostic relevance of FDG uptake in the NTO in an independent cohort of patients treated with definitive RCT.

METHODS

This retrospective evaluation included 72 patients with oesophageal squamous cell carcinoma treated with definitive RCT with curative intent. All patients underwent pretreatment and restaging FDG PET after receiving a radiation dose of 40-50 Gy. Standardized uptake values (SUV_max/SUV_mean), metabolic tumour volume (MTV) and relative changes from pretreatment to restaging PET (∆SUV_max/∆SUV_mean) were determined within the tumour and NTO. Univariate Cox regression with respect to overall survival (OS), local control (LC), distant metastases (DM) and treatment failure (TF) was performed. Independence of parameters was tested by multivariate Cox regression.

RESULTS

∆SUV_max NTO and MTV were prognostic factors for all investigated clinical endpoints (OS, LC, DM, TF). Inclusion of clinical and PET tumour parameters in multivariate analysis showed that ∆SUV_max NTO was an independent prognostic factor. Furthermore, multivariate analysis of ∆SUV_max NTO using previously published cut-off values from preoperatively treated patients revealed that ∆SUV_max NTO was independent prognostic factor for OS (HR = 1.88, p = 0.038), TF (HR = 2.11, p = 0.048) and DM (HR = 3.02, p = 0.047).

CONCLUSION

NTO-related tracer uptake during the course of treatment in patients with oesophageal carcinoma was shown to be of high prognostic relevance. Thus, metabolically activity of NTO measured in terms of ∆SUV_max NTO is a potential candidate for future treatment individualization (i.e. organ preservation).

Glucose transporter 1 expression as a marker of prognosis in oesophageal adenocarcinoma

BACKGROUND

The current TNM staging system for oesophageal adenocarcinoma (OAC) has limited ability to stratify patients and inform clinical management following neo-adjuvant chemotherapy and surgery.

RESULTS

Functional genomic analysis of the gene expression data using Gene Set Enrichment Analysis (GSEA) identified GLUT1 as putative prognostic marker in OAC.In the discovery cohort GLUT1 positivity was observed in 114 patients (80.9%) and was associated with poor overall survival (HR 2.08, 95% CI 1.1-3.94; p=0.024) following multivariate analysis. A prognostic model incorporating GLUT1, CRM and nodal status stratified patients into good, intermediate and poor prognosis groups (p< 0.001) with a median overall survival of 16.6 months in the poorest group.In the validation set 182 patients (69.5%) were GLUT1 positive and the prognostic model separated patients treated with neo-adjuvant chemotherapy and surgery (p<0.001) and surgery alone (p<0.001) into three prognostic groups.

PATIENTS AND METHODS

Transcriptional profiling of 60 formalin fixed paraffin-embedded (FFPE) biopsies was performed. GLUT1 immunohistochemical staining was assessed in a discovery cohort of 141 FFPE OAC samples treated with neo-adjuvant chemotherapy and surgery at the Northern Ireland Cancer Centre from 2004-2012. Validation was performed in 262 oesophageal adenocarcinomas collected at four OCCAMS consortium centres. The relationship between GLUT1 staining, T stage, N stage, lymphovascular invasion and circumferential resection margin (CRM) status was assessed and a prognostic model developed using Cox Proportional Hazards.

CONCLUSIONS

GLUT1 staining combined with CRM and nodal status identifies a poor prognosis sub-group of OAC patients and is a novel prognostic marker following potentially curative surgical resection.

Personalized therapy based on image for esophageal or gastroesophageal junction adenocarcinoma

Preoperative therapy is the gold standard for esophageal or gastroesophageal junction adenocarcinoma. Positron emission tomography (PET) is not only essential for tumor staging, but changes in glucose consumption correspond with response to therapy and correlated with prognosis. Therefore, with further refinement, PET parameter can serve as a tool for personalized therapy. For instance, the Municon trials suggested the possibility of PET-response guided therapy for esophageal adenocarcinoma (EAC) patients, however there are limitations. New PET parameters such as total lesion glycolysis (TLG) or magnetic resonance imaging (MRI) may provide better response prediction. Furthermore, PET parameters combined with genomic profiling might enhance better treatment selection, prediction, and prognostication. Here, we summarized the current state of understanding and future possibilities.

18F-fluorodeoxyglucose positron emission computed tomography for monitoring tumor response in esophageal carcinoma treated with concurrent chemoradiotherapy

The aim of the present study was to explore the value of ^18F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET) in monitoring the early tumor response of esophageal squamous cell carcinoma (ESCC) treated with concurrent chemoradiotherapy (CRT). A total of 48 patients with pathologically proven ESCC were retrospectively analyzed. All patients underwent two serial ¹⁸F-FDG PET scans at baseline (pre-CRT) and 40 Gy/4 weeks of starting radiation therapy (inter-CRT). All patients received intensity-modulated radiotherapy (with a total radiation dose of 59.6 Gy) concurrently with cisplatin-based chemotherapy. The maximum standardized uptake value (SUV_max) and metabolic tumor volume (MTV) were measured using ¹⁸F-FDG PET. The percentage changes (Δ) in SUV_max and MTV between two serial scans were calculated and were revealed to be associated with the objective tumor response (oTR), according to the Response Evaluation Criteria in Solid Tumors 1.1. Among the 48 patients, 20.8% achieved a complete response, 68.8% exhibited a partial response and the oTR rate was 89.6%. On the pre-CRT PET scans, the mean SUV_max and MTV were 14.1±5.8 and 58.2±25.4 cm³, respectively. Following 40 Gy irradiation over 4 weeks, the mean SUV_max and MTV significantly decreased to 4.3±3.5 and 19.0±12.1 cm³, respectively (P<0.001). A significantly higher ΔSUV_max and ΔMTV was observed in the responders compared with that in the non-responders [0.71±0.16 vs. 0.51±0.26 (P=0.015); and 0.64±0.13 vs. 0.42±0.09 (P=0.001), respectively]. Univariate analysis revealed that ΔSUV_max and ΔMTV were significantly associated with oTR (P=0.010 and P=0.001, respectively). ΔMTV was used as a predictor and a cut-off value of 54% discriminated responders from non-responders with a sensitivity of 69.8% and a specificity of 100% (P=0.001). The area under the receiver operating characteristic curve was 0.837 (95% confidence interval, 0.702-0.928). The results of the present study indicated that interim ¹⁸F-FDG PET scans may provide early prognostic value for determining oTR in patients with ESCC undergoing treatment with CRT.

Interim 18F-FDG-PET/CT during chemo-radiotherapy in the management of oesophageal cancer patients. A systematic review

Oesophageal cancer is an aggressive disease. The possibility to early stratify patients as responsive and non-responsive with a non-invasive method is extremely appealing. The uptake of Fluorodeoxyglucose (¹⁸F-FDG) in tumours, provided by positron emission tomography (PET) images, has been proved to be useful to assess the initial staging of the disease, recurrence, and response to chemotherapy and chemo-radiotherapy (CRT). In the last years, efforts have been focused on the possibility to use ad interim ¹⁸F-FDG-PET/CT (PET_int) to evaluate response during radiation therapy. However, controversial findings have been reported, although some relevant results would support its use for individual therapeutic decision. The present review assembles the comprehensive literature of the last decade to evaluate whether and in which cases PET_int may offer predictive potential in oesophageal cancer. All the analysed studies (13 studies, 697 patients) denoted PET_int as a challenging examination for early assessment of outcomes during CRT. In particular, 8 studies advocated the predictivity of PET_int, whilst 5 did not find any correlation between the interim variation of PET parameters and the pathological complete response and/or the clinical outcome. The reasons that possibly have caused contradictions among the studies demand further research with prospective and uniform protocols and methods of analysis to assess the predictive and prognostic value of PET_int in oesophageal cancer.

Pathological complete response in patients with esophageal cancer after the trimodality approach: The association with baseline variables and survival-The University of Texas MD Anderson Cancer Center experience

BACKGROUND

Reports are limited regarding clinical and pretreatment features that might predict a pathological complete response (pathCR) after treatment in patients with esophageal cancer (EC). This might allow patient selection for different strategies. This study examines the association of a pathCR with pretreatment variables, overall survival (OS), recurrence-free survival (RFS), and patterns of recurrence in a large cohort from a single institution.

METHODS

The baseline clinical features of 911 consecutive patients with EC who were treated with trimodality therapy from January 2000 to November 2013 were analyzed. A pathCR was defined as a surgical specimen with no residual carcinoma (primary or nodes). Logistic regressions were used to identify independent baseline features associated with a pathCR. We applied log-rank testing and Cox models to determine the association between a pathCR and the time-to-event outcomes (OS and RFS).

RESULTS

Of 911 patients, 218 (23.9%) achieved a pathCR. The pathCR rate was 23.1% for adenocarcinoma and 32.2% for squamous cell carcinoma. A lower pathCR rate was observed for 1) older patients (>60 years), 2) patients with poorly differentiated tumors, 3) patients with signet ring cells (SRCs), and 4) patients with a higher T stage. Patients with a pathCR had longer OS and RFS than those without a pathCR (P = .0021 and P = .0011, respectively). Recurrences occurred more in non-pathCR patients. Distant metastases were the most common type of recurrence. PathCR patients developed brain metastases at a marginally higher rate than non-pathCR patients (P = .051).

CONCLUSIONS

In this large cohort study, a pathCR is confirmed to be associated with better OS and RFS. The presence of a poorly differentiated tumor or SRCs reduces the likelihood of a pathCR. Future research should focus on molecular classifiers. Cancer 2017;123:4106-4113. © 2017 American Cancer Society.

Increased FDG uptake on late-treatment PET in non-tumour-affected oesophagus is prognostic for pathological complete response and disease recurrence in patients undergoing neoadjuvant radiochemotherapy

PURPOSE

Early side effects including oesophagitis are potential prognostic factors in patients undergoing radiochemotherapy (RCT) for locally advanced oesophageal cancer (LAEC). We assessed the prognostic value of ¹⁸F-fluorodeoxyglucose (FDG) uptake within irradiated non-tumour-affected oesophagus (NTO) during restaging positron emission tomography (PET) as a surrogate for inflammation/oesophagitis.

METHODS

This retrospective evaluation included 64 patients with LAEC who had completed neoadjuvant RCT and had successful oncological resection. All patients underwent FDG PET/CT before and after RCT. In the restaging PET scan maximum and mean standardized uptake values (SUV_max, SUV_mean) were determined in the tumour and NTO. Univariate Cox regression with respect to overall survival, local control, distant metastases and treatment failure was performed. Independence of clinically relevant parameters was tested in a multivariate Cox regression analysis.

RESULTS

Increased FDG uptake, measured in terms of SUV_mean in NTO during restaging was significantly associated with complete pathological remission (p = 0.002) and did not show a high correlation with FDG response of the tumour (rho < 0.3). In the univariate analysis, increased SUV_max and SUV_mean in NTO was associated with improved overall survival (p = 0.011, p = 0.004), better local control (p = 0.051, p = 0.044), a lower rate of treatment failure (p < 0.001 for both) and development of distant metastases (p = 0.012, p = 0.001). In the multivariate analysis, SUV_max and SUV_mean in NTO remained a significant prognostic factor for treatment failure (p < 0.001, p = 0.004) and distant metastases (p = 0.040, p = 0.011).

CONCLUSIONS

FDG uptake in irradiated normal tissues measured on restaging PET has significant prognostic value in patients undergoing neoadjuvant RCT for LAEC. This effect may potentially be of use in treatment personalization.

Recent advances in preoperative management of esophageal adenocarcinoma

Esophageal cancer is an aggressive malignancy with increasing incidence, and the prognosis of patients treated by surgery alone remains dismal. Preoperative treatment can modestly prolong overall survival. Preoperative chemotherapy or chemoradiation is the standard of care for resectable esophageal cancer (greater than clinical stage I and less than clinical stage IV). One of the challenges is to predict complete response in the surgical specimen from preoperative therapy and to avoid surgery in some patients but also predict ineffectiveness of preoperative therapy if the tumor is resistant and avoid such therapies altogether. In-depth understanding of the molecular biology could lead to personalized therapy, and in the future, clinical trials designed according to molecular features are expected. Here, we summarize preoperative treatment for esophageal adenocarcinoma and their potential.

A study about different findings of PET-CT between neoadjuvant and non-neoadjuvant therapy: SUVmax is not a reliable predictor of lymphatic involvement after neoadjuvant therapy for esophageal cancer

BACKGROUND

No definitive findings or established guidelines have been published for the evaluation of esophageal tumors (tumor) and regional lymph nodes (LN) using positron emission tomography computed tomography (PET-CT) in patients with esophageal cancer. In addition, it remains unclear whether PET-CT findings vary between neoadjuvant (NT) and non-neoadjuvant (non-NT) therapy cases. Therefore, preoperative evaluation using PET-CT might provide unreliable information and influence the management plan for esophageal cancer. The purpose of the present study is to clarify the different findings of PET-CT between NT and non-NT in surgical esophageal cancer cases and to predict LN metastasis.

METHODS

We retrospectively reviewed the medical records of 192 consecutive cases that met this study's inclusion criteria from January 2009 to December 2014. All patients underwent curative and complete esophagectomy for intra-thoracic esophageal cancer at the department of thoracic and cardiovascular surgery in a single tertiary Korean hospital. We compiled and analyzed maximum standard uptake values (SUVmax) of tumor and LNs with other clinical information (chronic lung disease, history of previous other primary cancer, sex, pathological findings, NT, and other clinical data).

RESULTS

(I) In NT, a positive correlation between T stage and SUVmax was found (tumor SUVmax P<0.001, LN SUVmax P=0.010); however, no relationship between N stage and SUVmax was found. In non-NT, a positive correlation between pathological stage (T and N stage) and SUVmax was found (T stage, tumor SUVmax P<0.001, LN SUVmax P=0.001; N stage, tumor SUVmax P=0.003, LN SUVmax P=0.021); (II) In NT, the low SUVmax group had higher disease-free survival (DFS) and overall survival (OS) than the high SUVmax group (DFS, tumor SUVmax P<0.001, LN SUVmax P=0.142; OS, tumor SUVmax P<0.001, LN SUVmax P=0.002). In non-NT, the low SUVmax group also had higher DFS and OS than the high SUVmax group (DFS, tumor SUVmax P<0.001, LN SUVmax P=0.008; OS, tumor SUVmax P=0.029, LN SUVmax P=0.016). SUVmax values being equal, non-NT had significantly higher DFS and OS than NT (P=0.011, P=0.009, respectively), despite the absence of significant differences in pathological stage; (III) Tumor SUVmax had a positive correlation with LN SUVmax in both NT and non-NT (P=0.006, P<0.001, respectively); (IV) In NT, there were no diagnostic findings of LN metastases using SUVmax. However, in non-NT, significant cutoff values for diagnosis of LN metastases using both tumor and LN SUVmax were found (tumor SUVmax cutoff value 4.9, P=0.008; LN SUVmax cutoff value 2.5, P=0.045); (V) In NT, there was no significant difference in LN SUVmax between pathologically negative and positive LNs. However, in non-NT, the LN SUVmax of pathologically positive LNs was significantly higher than that of pathologically negative LNs (P=0.042); (VI) There were no significant differences in tumor and LN SUVmax according to various factors, including chronic lung disease (COPD, bronchiectasis), age, previous cancers, and sex, regardless of NT.

CONCLUSIONS

This study showed that there were some different findings of PET-CT using SUVmax between NT and non-NT. These findings should be clarified for further evaluation and management, especially of surgery, which should not be withheld out of ignorance of these different PET-CT findings and should be considered carefully in conjunction with other conditions. In addition, further studies about the effects of NT on PET-CT findings are required to improve the utility of PET-CT to evaluate the LNs in esophageal cancer.