Positron emission tomography for assessment of the response to induction radiochemotherapy in locally advanced oesophageal cancer

Treatment Response to Neoadjuvant Therapy in Squamous Esophageal Cancer-Correlation Between Metabolic Response and Histopathology

PURPOSE

Esophageal cancer is among the leading causes of cancer-related mortality worldwide. Patients presenting with localized and loco-regionally advanced cancer without distant metastases have reasonable survival with multimodality management. Adequate and comprehensive staging is the backbone for proper selection of patients fit for curative treatment. Positron emission tomography (PET) in combination with contrast-enhanced computed tomography (CECT) is utilized as the standard staging modality. Multimodality treatment has been able to achieve evaluable tumor responses including pathological complete response (pCR). It is, therefore, necessary to understand whether the impact of neoadjuvant therapy can be evaluated on imaging, i.e., standardized uptake value (SUV) on PET scan done for response assessment and if this can be correlated with histopathological response and later, with survival. Squamous cell carcinoma (SCC) is more common globally and in the Indian subcontinent; hence, we chose this subgroup to evaluate our hypothesis.

METHODS

This is a single institution, retrospective study. Out of the 1967 patients who were treated between 2009 and 2019, 1369 (78.54%) patients had SCC. Out of these, 44 received NACTRT, whereas 1325 received NACT followed by curative surgery. The standardized uptake value (SUV) of 18-fluorodeoxyglucose was recorded during pre- and post-neoadjuvant treatment (NAT) using positron emission tomography (PET). The histopathology of the final resection specimen was evaluated using the Mandard tumor regression grade (TRG) criteria with response being graded from 0 to 5 as no residual tumor (NRT), scanty residual tumor (SRT), and residual tumor We attempted to find a cut-off value of the post neoadjuvant SUV of the primary tumor site which correlated with achievement of better histopathological response.

RESULTS

Out of 1325 patients of SCC esophagus who underwent surgery, 943 patients had available data of TRG, and it was categorized into the 0-2 category which had 325 patients (34.5%) and 3-5 category, 618 patients (65.5%). The SUV was taken only from the PET scans done at our institution, so as to achieve a more homogenous cohort, and this was available for 186 patients, 151 from the NACT group and 35 from the NACTRT group. The ROC method was used to find the cut-off for SUV (5.05) in the NACT cohort, which depicted significant difference in the outcome. Out of these, 93 patients who underwent NACT had SUV > 5.05 and 58 had SUV < 5.05. It was found that the subjective and objective histopathological scores correlated at a p value of < 0.0001. Specifically, the majority of cases with SRT tended to be in the 3-5 category of TRG, whereas cases with NRT are predominantly in the 0-2 category. In the ≥ 5.05 category of SUV, there were 76 cases with SRT. In the NACT cohort, the < 5.05 category of SUV, there are 26 cases with SRT and 32 cases with NRT. Among cases with SRT, 74.5% had SUV ≥ 5.05, while 25.5% had SUV < 5.05. Among cases with NRT, 34.7% had SUV ≥ 5.05, while 65.3% had SUV < 5.05 (p value 0.007). No significant association was found in the radio-pathological correlation in the NACTRT group.

CONCLUSION

Our study confirms the correlation of post neoadjuvant chemotherapy PET SUV with histopathological response, the cut-off of SUV being 5.05 in our cohort. This confirms the predictive value of FDG PET as demonstrated in other studies. Furthermore, its prognostic value with respect to survival has been verified in multiple other studies. With larger scale randomized studies, we may be able to identify the group of patients who have borderline operability anatomically as well as physiologically, where alternative treatment regimens may be indicated to improve outcomes.

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

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

Tata Memorial Centre Evidence Based Use of Nuclear medicine diagnostic and treatment modalities in cancer

ABSTRACT

PET/CT and radioisotope therapy are diagnostic and therapeutic arms of Nuclear Medicine, respectively. With the emergence of better technology, PET/CT has become an accessible modality. Diagnostic tracers exploring disease-specific targets has led the clinicians to look beyond FDG PET. Moreover, with the emergence of theranostic pairs of radiopharmaceuticals, radioisotope therapy is gradually making it's way into treatment algorithm of common cancers in India. We therefore would like to discuss in detail the updates in PET/CT imaging and radionuclide therapy and generate a consensus-driven evidence based document which would guide the practitioners of Oncology.

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).

Intrapatient variability of 18F-FDG uptake in normal tissues

Objectives

To investigate the effect of serum glucose level and other confounding factors on the variability of maximum standardized uptake value (SUVmax) in normal tissues within the same patient on two separate occasions and to suggest an ideal reference tissue.

Materials and Methods

We retrospectively reviewed 334 18F-FDG PET/CT scans of 167 cancer patients including 38 diabetics. All patients had two studies, on average 152 ± 68 days apart. Ten matched volumes of interest were drawn on the brain, right tonsil, blood pool, heart, lung, liver, spleen, bone marrow, fat, and iliopsoas muscle opposite third lumber vertebra away from any pathological 18F-FDG uptake to calculate SUVmax.

Results

SUVmax of the lungs and heart were significantly different in the two studies (P = 0.003 and P = 0.024 respectively). Only the brain uptake showed a significant moderate negative correlation with the level of blood glucose in diabetic patients (r = −0.537, P = 0.001) in the first study, while the SUVmax of other tissues showed negligible or weak correlation with the level of blood glucose in both studies.

The liver showed significant moderate positive correlation with body mass index (BMI) in both studies (r = .416, P = <0.001 versus r = 0.453, P = <0.001, respectively), and blood pool activity showed significant moderate positive correlation with BMI in the first study only (r = 0.414, P = <0.001). The liver and blood pool activities showed significant moderate negative correlation with 18F-FDG uptake time in first study only (r = −0.405, P-value = <0.001; and r = −0.409, P-value = <0.001, respectively).

In the multivariate analysis, the liver showed a consistent effect of the injected 18F-FDG dose and uptake duration on its SUVmax on the two occasions. In comparison, spleen and muscle showed consistent effect only of the injected dose on the two occasions.

Conclusion

The liver, muscle, and splenic activities showed satisfactory test/retest stability and can be used as reference activities. The spleen and muscle appear to be more optimal reference than the liver, as it is only associated with the injected dose of 18F-FDG.

Prognostic Value of 18F-FDG PET/CT Volume-Based Metabolic Parameters in Patients with Node-Negative Stage II Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is a major cancer prevalent in Asian males. Pretreatment tumor burden can be prognostic for ESCC. We studied the prognostic value of metabolic parameters of 2-deoxy-2-[¹⁸F] fluoro-D-glucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) and the serum squamous cell carcinoma antigen (SCC-Ag) level in node-negative stage II ESCC patients. Eighteen males underwent staging evaluation were included. The volume-based metabolic parameters derived from ¹⁸F-FDG PET/CT, including metabolic tumor volume (MTV) and total lesion glycolysis (TLG), were obtained using the PET Volume Computer Assisted Reading application. The Spearman correlation coefficients were calculated to assess the relationship between metabolic parameters and pretreatment serum SCC-Ag levels. Based on the 5-year follow-up, patients were sub-divided into the demised and the stable groups. Potential prognostic value was assessed by independent t-test and the Mann–Whitney U test. The association of overall survival was assessed using univariate and multivariate Cox regression analyses. The demised group showed significant higher values in serum SCC-Ag, as well as in MTV and TLG, but not SUVmax and SUVmean. The SUVmax, MTV, TLG, and serum SCC-Ag showed significant association with overall survival. Our findings suggest potential usage of pretreatment volume-based metabolic parameters of ¹⁸F-FDG PET/CT and serum SCC-Ag as prognostic factors for node-negative stage II ESCC patients.

SUVmax reduction predicts long-term survival in patients of non-pCR both in the tumor and lymph nodes after neoadjuvant chemoradiotherapy in esophageal squamous cell carcinoma

Background

A pathological complete response (pCR) after neoadjuvant chemoradiotherapy (NACRT) ensures long-term survival in esophageal squamous cell carcinoma (ESCC) patients following esophagectomy, but pCR patients are a minority. The aim here was to identify prognostic factors in patients with non-pCR ESCC after NACRT.

Methods

This is a retrospective study. Investigated were 5-year overall survival (OS), disease-specific survival (DSS), and relapse-free survival (RFS) among non-pCR ESCC patients divided into pT0N0, primary site pCR (pT0N+), lymph node pCR (pT+N0), and non-pCR in both the tumor and lymph node (pT+N+) subgroups after NACRT and esophagectomy. Focusing on the SUV_max reduction rate in the primary tumor in 88 patients who underwent FDG-PET before and after NACRT, we used univariate and multivariate Cox proportional hazard models to identify prognostic factors.

Results

Although there were no significant survival differences among non-pCR ESCC patients with pT0N+, pT+N0, or pT+N+, survival rate among pT+N+patients was the poorest. After setting a 60% cutoff for the SUV_max reduction rate in the tumor, RFS curves for non-pCR patients significantly differed between patients above the cutoff and those below it. For pT+N+ patients, the SUV_max reduction rate (<60% vs ≥ 60%) was an independent prognostic factor of OS, DSS, and RFS.

Conclusion

Because ESCC patients with SUV_max reduction rates of <60% in the tumor after NACRT and categorized as pT+N+ after NACRT had significantly poorer prognoses, even after esophagectomy, a change in treatment strategy may be an option to improve survival.

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Use of endoscopic ultrasound in pre-treatment staging of esophageal cancer did not alter management plan

Background

Initial staging of esophageal cancer relies on EUS in addition to FDG-PET/CT. It is our hypothesis that with the advancement of FDG-PET/CT staging, endoscopic ultrasound may not be required for initial staging in all cases. The purpose of this study is to analyze whether EUS affects initial treatment stratification in patients diagnosed with esophageal cancer.

Methods

A retrospective database at the University of Virginia was queried for patients diagnosed with esophageal squamous cell carcinoma and adenocarcinoma who underwent EGD with EUS and FDG-PET/CT at their initial evaluation from 10/2013 to 5/2017. Two thoracic surgeons were asked to determine appropriate management for each case. Options included surgical resection, neoadjuvant chemoradiotherapy followed by resection, definitive chemoradiotherapy, or chemotherapy with or without palliative radiation. Both surgeons received the FDG-PET/CT report along with the EGD report. For each case, one or both surgeons were randomly allocated to review EUS results in addition to the clinical information. The treatment decisions of each thoracic surgeon were compared to determine if EUS reports impacted clinical management. Simple and weighted correlation coefficients (kappa) were calculated to compare agreement of treatment choices between the two surgeons using McNemars test. Conditional logistic regression was used to assess the influence of EUS on the treatment recommendations.

Results

A total of 50 patients (44 male and 6 female) were enrolled and data was collected. The thoracic surgeons agreed on treatment decisions in 39 cases and disagreed on 11 cases. Agreement between surgeons was good despite lack of EUS information for one surgeon on each case (weighted Kappa =0.73, 95% CI: 0.57-0.89). Using conditional logistic regression, EUS did not have a statistically independent association with agreement on treatment plan (P for model =0.17).

Conclusions

EUS did not have a statistically independent association with agreement on treatment plan for newly diagnosed esophageal cancer (P for model =0.17). Our findings suggest that EUS may not be necessary in the algorithm for the initial staging of every case of esophageal cancer. Selective, rather than mandatory use of EUS seems warranted.

Staging laparoscopy in gastric cancer surgery. A population-based cohort study in patients undergoing gastrectomy with curative intent

BACKGROUND

Studies on the value of a staging laparoscopy in detecting metastases in gastric cancer patients show great variation. This study investigates the avoidable surgery rate in patients with and without a staging laparoscopy scheduled for surgery with curative intent.

METHODS

This population-based cohort study included all patients with an intentional resection for a potentially curable gastric adenocarcinoma, between 2011 and 2016, registered in the Dutch Upper GI Cancer audit. Patients with and without a staging laparoscopy were compared. The primary outcome was the avoidable surgery rate (detection of metastases and/or locoregional non-resectable tumor during intentional gastrectomy). Secondary outcomes were the negative predictive value, postoperative morbidity and pathology parameters.

RESULTS

2849 patients who underwent an intentional gastrectomy were included. 414 of 2849 (14.5%) patients underwent a staging laparoscopy before initiation of treatment. The avoidable surgery rate was 16.2% in the staging laparoscopy group, compared to 8.5% in the non-staging group (P < 0.001), resulting in a negative predictive value of 83.8%. The avoidable surgery rate remained significantly different after correction for possible confounders. The main reason for not executing the gastrectomy was the presence of distant metastasis in both groups. cT and cN stage were significantly higher in patients who underwent a staging laparoscopy.

CONCLUSIONS

The staging laparoscopy group had a higher cTN and pTN stage, implicating selection of patients with more advanced disease for a staging laparoscopy. Despite the staging laparoscopy, a higher rate of avoidable surgery was found, suggesting a low sensitivity for detecting metastases or locoregional non-resectability in this patient group.

Novel 5-point 18-FDG-PET/CT visual scoring system for assessing treatment response in patients with oesophageal or gastro-oesophageal junction carcinoma

INTRODUCTION

The purpose of this study was to investigate the prognostic utility and reproducibility of a qualitative 5-point 18-fluorodeoxyglucose (FDG)-PET primary visual score (PVS) in patients with oesophageal and gastro-oesophageal junction (GOJ) cancer.

METHODS

This was a retrospective review of patients with histologically proven oesophageal or GOJ cancer who received curative intent therapy. Clinical, pathological and imaging data were extracted from electronic medical records. Patients were required to have pre-treatment and post-treatment FDG-PET scans, that were evaluated with a 5-point primary visual score (prePVS, postPVS). The changes in PVS (ΔPVS) were correlated with progression-free survival and overall survival. Interobserver variability was assessed using Cohen's Kappa intraclass correlation and agreement.

RESULTS

Sixty-seven patients were retrospectively identified. Two (3%), 36 (54%) and 29 (43%) of the patients had stage I, II and III disease respectively. Twenty-five (37%) patients had squamous cell carcinoma. Thirty-seven (55%) patients proceeded onto surgical resection. postPVS was associated with both PFS (P = 0.013) and OS (P = 0.0002). ΔPVS predicted for PFS (P = 0.002) and OS (P = 0.0003). When thresholds of response were considered, agreement was 80.6% (K = 0.78) and 74.6% (K = 0.69) for postPVS and ΔPVS respectively.

CONCLUSION

Qualitative assessment of oesophageal and GOJ cancers utilising FDG-PET is reproducible and may be able to prognosticate outcomes in patients undergoing treatment. Prospective validation is required.

Accuracy of Detecting Residual Disease After Neoadjuvant Chemoradiotherapy for Esophageal Cancer: A Systematic Review and Meta-analysis

OBJECTIVE

The aim of this study was to perform a meta-analysis on the accuracy of endoscopic biopsies, EUS, and 18F-FDG PET(-CT) for detecting residual disease after neoadjuvant chemoradiotherapy (nCRT) for esophageal cancer.

SUMMARY OF BACKGROUND DATA

After nCRT, one-third of patients have a pathologically complete response in the resection specimen. Before an active surveillance strategy could be offered to these patients, clinically complete responders should be accurately identified.

METHODS

Embase, Medline, Cochrane, and Web-of-Science were searched until February 2018 for studies on accuracy of endoscopic biopsies, EUS, or PET(-CT) for detecting locoregional residual disease after nCRT for squamous cell- or adenocarcinoma. Pooled sensitivities and specificities were calculated using random-effect meta-analyses.

RESULTS

Forty-four studies were included for meta-analyses. For detecting residual disease at the primary tumor site, 12 studies evaluated endoscopic biopsies, 11 qualitative EUS, 14 qualitative PET, 8 quantitative PET using maximum standardized uptake value (SUVmax), and 7 quantitative PET using percentage reduction of SUVmax (%ΔSUVmax). Pooled sensitivities and specificities were 33% and 95% for endoscopic biopsies, 96% and 8% for qualitative EUS, 74% and 52% for qualitative PET, 69% and 72% for PET-SUVmax, and 73% and 63% for PET-%ΔSUVmax. For detecting residual nodal disease, 11 studies evaluated qualitative EUS with a pooled sensitivity and specificity of 68% and 57%, respectively. In subgroup analyses, sensitivity of PET-%ΔSUVmax and EUS for nodal disease was higher in squamous cell carcinoma than adenocarcinoma.

CONCLUSIONS

Current literature suggests insufficient accuracy of endoscopic biopsies, EUS, and 18F-FDG PET(-CT) as single modalities for detecting residual disease after nCRT for esophageal cancer.

Prognostic Value of Lymph Node-To-Primary Tumor Standardized Uptake Value Ratio in Esophageal Squamous Cell Carcinoma Treated with Definitive Chemoradiotherapy

We aimed to investigate the prognostic value of the relative maximum standardized uptake value (SUV) of metastatic lymph node (LN) compared with that of primary tumor (SUV_LN / SUV_Tumor) based on a pretreatment [¹⁸F]-FDG PET/CT scan in patients with clinically node-positive esophageal squamous cell carcinoma (cN+ ESCC) treated with definitive chemoradiotherapy (dCRT). We retrospectively evaluated cN+ ESCC patients who underwent a PET/CT scan before dCRT. Time-dependent receiver operating characteristics analysis was performed to identify the optimal cutoff value for SUV_LN / SUV_Tumor. Prognostic influences of SUV_LN / SUV_Tumor on distant metastasis-free survival (DMFS) and overall survival (OS) were evaluated using the Kaplan-Meier method and log-rank test for univariate analysis and Cox's proportional hazards regression model for multivariate analysis. We identified 112 patients with newly diagnosed cN+ ESCC. After a median follow-up of 32.0 months, 50 (44.6%) patients had distant failure and 84 (75.0%) patients died. Patients with high SUV_LN / SUV_Tumor (≥ 0.39) experienced worse outcomes than low SUV_LN / SUV_Tumor (< 0.39) (two-year DMFS: 26% vs. 70%, p < 0.001; two-year OS: 21% vs. 48%, p = 0.001). Multivariate analysis showed that SUV_LN / SUV_Tumor was an independent prognostic factor for both DMFS (adjusted HR 2.24, 95% CI 1.34-3.75, p = 0.002) and OS (adjusted HR 1.61, 95% CI 1.03-2.53, p = 0.037). Pretreatment of SUV_LN / SUV_Tumor is a simple and useful marker for prognosticating DMFS and OS in cN+ ESCC patients treated with dCRT, which may help in tailoring treatment and designing future clinical trials.

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

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

Post-Treatment/Pre-operative PET Response Is Not an Independent Predictor of Outcomes for Patients With Gastric and GEJ Adenocarcinoma

OBJECTIVE

To determine whether changes in positron emission tomography (PET) avidity correlated with histologic response and were independently associated with outcome.

BACKGROUND

The implications of metabolic response to neoadjuvant therapy as measured by repeat PET imaging remain ill-defined for patients with gastric and gastroesophageal junction (GEJ) cancers.

METHODS

We identified patients with gastric and GEJ adenocarcinoma who were evaluated with PET imaging before and following neoadjuvant treatment, and subsequently underwent curative resections. Spearman rank correlation and Cox proportional hazards regression were used to evaluate standardized uptake value (SUV) and histologic response, pathologic parameters, and disease-specific survival (DSS).

RESULTS

From 2002 to 2013, 192 patients met our inclusion criteria. The median SUVmax response was 57.3% (range: -110% to 100%) for patients with GEJ cancers, with a corresponding median pathologic treatment response of 80% (range: 0% to 100%). The median SUVmax response was 32.5% (-230% to 100%) for patients with gastric cancers, with a corresponding median pathologic treatment response of 35% (range: 0% to 100%). The Spearman correlation between SUVmax response and histologic response was significant for patients with GEJ (rho = 0.19, P = 0.04) and gastric (rho = 0.44, P < 0.0001) cancers. For patients with GEJ (P <0.0001 to 0.046) and gastric cancers (P = 0.0003 to 0.016), histopathologic response and tumor staging predicted DSS. SUVmax response failed to demonstrate a relationship with DSS when entered into multivariable models containing conventional pathologic variables.

CONCLUSION

Following completion of neoadjuvant therapy for gastric and GEJ adenocarcinoma, histopathologic staging remains the best predictor of outcome. Repeat post-treatment/preoperative PET imaging for the purpose of prognostication is of limited value.

Detecting Pathological Complete Response in Esophageal Cancer after Neoadjuvant Therapy Based on Imaging Techniques: A Diagnostic Systematic Review and Meta-Analysis

INTRODUCTION

Up to 32% of patients with esophageal cancer show a pathological complete response (ypCR) after neoadjuvant therapy. To prevent overtreatment, the indication to perform esophagectomy in these patients should be reconsidered. Implementing an organ-preserving strategy for patients with ypCR requires an accurate assessment of residual disease after neoadjuvant treatment. The aim of this study was to systematically review the effectiveness of imaging techniques used for detection of ypCR after neoadjuvant therapy but before resection in patients with esophageal cancer.

METHODS

A systematic literature search of the Medline, Embase, and Cochrane Library databases was performed from January 1, 2000, to December 13, 2017. Eligible studies were diagnostic studies that compared results of imaging modalities after neoadjuvant therapy to histopathological findings in the resection specimen after esophagectomy. Methodological quality was assessed by the Cochrane Quality Assessment of Diagnostic Accuracy Studies, version 2, model. Primary outcome measures were true positive, false-positive, false-negative, and true negative values of imaging techniques predicting ypCR. A meta-analysis was performed by pooling sensitivities and specificities by using a bivariate model.

RESULTS

A total of 4420 articles were identified. After exclusion of irrelevant titles and abstracts, 360 articles were reviewed in full text. In total, four imaging modalities (computed tomography [CT], positron emission tomography [PET-CT], endoscopic ultrasound [EUS], and magnetic resonance imaging [MRI]) were used for restaging. The meta-analysis was conducted with data from 56 studies involving 3625 patients. The pooled sensitivities of CT, PET-CT, EUS, and MRI for detecting ypCR were 0.35, 0.62, 0.01 and 0.80, respectively, whereas the pooled specificities were 0.83, 0.73, 0.99, and 0.83, respectively. The positive predictive value in detecting ypCR was 0.47 for CT, 0.41 for PET-CT, not applicable for EUS, and 0.61 for MRI.

CONCLUSION

Current imaging modalities such as CT, PET-CT, and EUS seem to be insufficiently accurate to identify complete responders. More accurate diagnostic tests are needed to improve restaging accuracy for patients with esophageal cancer.

Tumor Remission and Tumor-Infiltrating Lymphocytes During Chemoradiation Therapy: Predictive and Prognostic Markers in Locally Advanced Esophageal Squamous Cell Carcinoma

PURPOSE

Clinical tools are unavailable for accurate prediction of pathologic responses to chemoradiation therapy (CRT) among patients with esophageal squamous cell carcinoma (ESCC) before surgery. We evaluated tumor remission and tumor-infiltrating lymphocytes (TILs) during CRT as predictors of pathologic response and prognostic markers for patients with locally advanced ESCC treated with neoadjuvant CRT (neo-CRT) or definitive CRT.

METHODS AND MATERIALS

We analyzed patients with locally advanced ESCC (N = 164) who underwent neo-CRT (N = 48) or definitive CRT (N = 116). Patients underwent endoscopic ultrasonography and biopsies when induction CRT finished. Tumor remission characteristics were designated minor (-/+) to excellent remission (ER) (+++). TILs were determined in 10% increments. Tumor remission, TILs, or both were associated with pathologic complete response (pCR) and survival in the neo-CRT group and then analyzed in the definitive CRT group.

RESULTS

ER and lymphocyte-predominant ESCC (LPE; ≥60% TILs) were identified according to the pCR rate and disease-free survival. We built a prediction model for pCR incorporating ER and LPE. The area under the receiver operating characteristic curve was 0.877, and sensitivity and specificity were 86.7% and 90.9%, respectively. Furthermore, this model identified pathologic response with an excellent calibration. Disease-free survival of patients with ER and LPE tumors was significantly longer than that of other patients.

CONCLUSIONS

When we included tumor remission and TILs during CRT, our model predicted pCR with high probability and helped stratify prognostic subgroups, thereby guiding future therapy decisions for patients with locally advanced ESCC. Validation of this model in larger, prospective, multicenter studies is essential.

Adjuvant therapy for pathological T3N0M0 esophageal squamous cell carcinoma

Background

Tumors invading the depth of adventitia (T3) are the most common pathological type of esophageal squamous cell carcinoma (ESCC). For patients without lymph nodes metastasis, the role of adjuvant therapy is uncertain. This study was intended to retrospectively analyze the survival effects of postoperative adjuvant therapy in such patients.

Methods

A total of 200 patients with pathological T3N0M0 (pT3N0M0) ESCC from January 2012 to September 2014 were enrolled, including a surgery-alone group (Group S) of 111 patients and a surgery followed with adjuvant chemo/radiation/chemoradiation therapy group (Group S + aCRT) of 89 patients.

Results

There was no significant difference in preoperative basic characteristics and postoperative complications between the two groups. Among all patients, 5-year overall survival (OS) rate was 56.6% and the 5-year disease-free survival (DFS) rate was 51.1%, respectively. The 5-year OS rate was 47.2% in Group S, and 68.4% in Group S + aCRT (P=0.004). The 5-year DFS rate was 44.4% in Group S and 59.3% in Group S + aCRT (P=0.036). The 5-year OS and DFS were improved by adjuvant chemoradiotherapy in the subgroups of males, tumor located at the middle of thoracic esophagus, moderate differentiation, number of resected lymph nodes <15. Multivariate analysis showed that adjuvant chemoradiotherapy and female were associated with improved survival.

Conclusions

In our study, the adjuvant therapy was associated with improved survival for patients with pT3N0M0 ESCC.

Correlation Between Standardized Uptake Value in Preneoadjuvant and Postneoadjuvant Chemoradiotherapy and Tumor Regression Grade in Patients With Locally Advanced Esophageal Cancer

PURPOSE

To investigate whether positron emission tomography/computed tomography (PET/CT) initial and restaging imaging predicts for pathologic response measured by tumor regression grade (TRG) after preoperative chemoradiotherapy (CRT) in patients with locally advanced esophageal cancer.

METHODS

A retrospective review of 220 patients with stage II-III esophageal cancer treated with neoadjuvant CRT followed by surgery was performed. In total, 187 patients were eligible for statistical analysis. Pretreatment and posttreatment PET/CT scans were reviewed. Maximum standard uptake value (SUV) at the site of the primary tumor was recorded before and 6 weeks after neoadjuvant therapy. Upon completion of surgery, TRG was determined by a specialized site-specific gastrointestinal pathologist. Spearman correlation was used to compare pre, post, and change in maximum SUV, TRG, and overall survival.

RESULTS

The median follow-up was 24 months. Although no significant correlation was found between pretreatment SUV and TRG (r=0.073, P=0.32), post-CRT SUV, however, showed a significant positive correlation with TRG (r=0.374, P<0.01). There was no significant correlation between the absolute change in fluorodeoxyglucose uptake after CRT and TRG (r=0.057, P=0.44); however, the rate of SUV change showed a significant correlation with TRG (r=0.178, P=0.017). Similar to previous studies, our study showed a significant difference in overall survival between TRG groups (log-rank test, P=0.019). Patients with TRG 3 showed prominently worse survival with median survival of 27.4 months. Patients with favorable pathologic responses were those whose scans demonstrated a metabolic response defined as a decrease in SUV≥70%.

CONCLUSIONS

Changes in SUV uptake on PET/CT scans after CRT have prognostic value in predicting pathologic response of esophageal cancer after neoadjuvant therapy. Further studies are needed to validate the integration of PET/CT as a decision-making tool.

Detection of distant interval metastases after neoadjuvant therapy for esophageal cancer with 18F-FDG PET(/CT): a systematic review and meta-analysis

Restaging after neoadjuvant therapy aims to reduce the number of patients undergoing esophagectomy in case of distant (interval) metastases. The aim of this study is to systematically review and meta-analyze the diagnostic performance of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) and 18F-FDG PET/CT for the detection of distant interval metastases after neoadjuvant therapy in patients with esophageal cancer. PubMed/MEDLINE, Embase, and the Cochrane library were systematically searched. The analysis included diagnostic studies reporting on the detection of distant interval metastases with 18F-FDG PET(/CT) in patients with esophageal cancer who received neoadjuvant therapy and both baseline staging and restaging after neoadjuvant therapy with 18F-FDG PET(/CT) imaging. The primary outcome measure was the proportion of patients in whom distant interval metastases were detected by 18F-FDG PET(/CT) as confirmed by pathology or clinical follow-up (i.e. true positives). The secondary outcome measure was the proportion of patients in whom 18F-FDG PET(/CT) restaging was false positive for distant interval metastases (i.e. false positives). Risk of bias and applicability concerns were assessed using the QUADAS-2 tool. Random-effect models were used to estimate pooled outcomes and examine potential sources of heterogeneity. Fourteen studies were included comprising a total of 1,110 patients who received baseline staging with 18F-FDG PET(/CT) imaging of whom 1,001 (90%) underwent restaging with 18F-FDG PET(/CT) imaging. Studies were generally of moderate quality. The pooled proportion of patients in whom true distant interval metastases were detected by 18F-FDG PET(/CT) restaging was 8% (95% confidence interval [CI]: 5-13%). The pooled proportion of patients in whom false positive distant findings were detected by 18F-FDG PET(/CT) restaging was 5% (95% CI: 3-9%). In conclusion,18F-FDG PET(/CT) restaging after neoadjuvant therapy for esophageal cancer detects true distant interval metastases in 8% of patients. Therefore, 18F-FDG PET(/CT) restaging can considerably impact on treatment decision-making. However, false positive distant findings occur in 5% of patients at restaging with 18F-FDG PET(/CT), underlining the need for pathological confirmation of suspected lesions.

Isocitrate dehydrogenase gene mutations and 2-hydroxyglutarate accumulation in esophageal squamous cell carcinoma

Isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) are key metabolic enzymes that convert isocitrate to α-ketoglutarate. Somatic point mutations in IDH1/2 confer a gain-of-function in cancer cells, resulting in overproduction of an oncometabolite, 2-hydroxyglutarate (2HG). 2HG interferes with cellular metabolism and epigenetic regulation, contributing to oncogenesis. Given that IDH1 and IDH2 are attracting attention as promising therapeutic targets, better evaluation of the incidence of IDH1 and IDH2 mutations and 2HG level in human cancers is clinically important. This is the first study to assess their incidence in esophageal squamous cell carcinomas (ESCCs). First, we established pyrosequencing assays for IDH1 and IDH2 mutations and revealed that these mutations were absent in 10 ESCC cell lines and 96 ESCC tissues. Second, utilizing IDH1 and IDH2 overexpression vectors, we demonstrated that LC-MS/MS assays can accurately evaluate 2HG level and found that some ESCC cases presented a high level of 2HG. In conclusion, IDH1 or IDH2 mutations play a limited role in the development of ESCC. 2HG is potentially synthesized to high levels in the absence of IDH1 and IDH2 mutations, and this may correlate with progression of ESCCs.

Neoadjuvant chemoradiotherapy for resectable oesophageal cancer

At present, treatment of potentially curable oesophageal cancer includes neoadjuvant chemoradiotherapy followed by oesophagectomy. Alternatively, neoadjuvant chemotherapy is used. To date, strong evidence on the superiority of one modality over the other has not been provided. Currently, up to one-third of patients show a pathologically complete response after neoadjuvant chemoradiotherapy. To optimise the efficacy of neoadjuvant treatment for individual patients, prediction of response to neoadjuvant treatment is highly desired. Therefore, several clinical diagnostic modalities have been investigated for early response evaluation, of which positron emission tomography (PET) has been studied most extensively. To identify patients who might benefit from postponing or even omitting surgery, recent advances have been made in evaluating response after completion of neoadjuvant chemoradiotherapy. This review provides an overview of current evidence and recent advances in neoadjuvant chemoradiotherapy for oesophageal cancer and discusses the use of neoadjuvant chemotherapy compared to chemoradiotherapy. Moreover, clinical response evaluation to neoadjuvant chemoradiotherapy is reviewed.

18F-fluorodeoxyglucose positron emission tomography/computed tomography for the prediction of survival in patients with advanced esophageal cancer who have undergone neoadjuvant chemotherapy

Neoadjuvant chemotherapy (NAC) is a promising treatment strategy for advanced esophageal cancer. However, measures of NAC response assessment and prognostic prediction have not yet been established. The aim of this study was to evaluate the usefulness of combined ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT). A total of 77 patients with stage IB-IV esophageal cancer who were treated with NAC followed by curative resection were retrospectively analyzed. PET/CT was performed before and after NAC and 56 patients were clinical responders. The pretreatment maximal standardized uptake value (pre-SUV_max), post-SUV_max and %SUV_max were 11.3±5.8, 5.1±4.8 and 49.0±35.1%, respectively, for the main tumors (T) and 4.3±2.8, 2.5±1.9 and 67.0±39.6%, respectively, for the metastatic nodes (N). Among the preoperatively available factors, clinical response (P=0.018), post-SUV_max-N (P=0.0001) and %SUV_max-T (P=0.0031) were significant prognostic factors by univariate analysis. The multivariate analysis identified post-SUV_max-N as the only significant prognostic predictor (P=0.0254). Patients with a post-SUV_max-N of <3.0 exhibited significantly fewer pathological metastatic nodes and better disease-free survival compared with patients with a post-SUV_max-N >3.0. Therefore, post-SUV_max-N may be a useful prognostic predictor in patients with advanced esophageal cancer who are treated with NAC followed by surgery.

Neoadjuvant chemoradiation for esophageal cancer : Surgery improves locoregional control while response based on FDG-PET/CT predicts survival

INTRODUCTION

To retrospectively analyze the outcome of patients with esophageal cancer treated with neoadjuvant chemoradiation.

METHODS

A total of 41 patients received neoadjuvant intent chemoradiation for esophageal cancer. Most patients had a locally advanced disease (T3/4: 82%, N+: 83%, M0: 100%) and squamous cell carcinoma (83%). All patients received concurrent chemotherapy with cisplatin/5-fluorouracil or mitomycin/5-fluorouracil. Median radiation dose was 50.4 Gy in the 25 patients who proceeded to surgery and 57.4 Gy in 16 patients who did not undergo surgery. FDG-PET/CT was used for treatment planning in 24 patients. A second FDG-PET/CT was available for response evaluation in 18 patients.

RESULTS

Median follow-up was 16 months in all patients and 30 months in survivors. Radiotherapy was completed without interruptions >3 days in 90% of patients, and chemotherapy was carried out to >80% in 85% of patients. The 2‑year locoregional control rate was 60%, distant control rate 54% and overall survival rate 50%. Hematological toxicity grade 3/4 was observed in 34%/10% of patients and non-hematological toxicity grade 3/4 in 46%/2% of patients. Perioperative 30-day mortality was 4%. Subgroup analyses revealed that surgery significantly improved locoregional control (74% vs. 39%, p = 0.034), but not the 2‑year survival rate (54% vs. 43%, p = 0.246). In contrast, response based on FDG-PET/CT prior and after chemoradiation significantly predicted improved overall survival (2-year overall survival 61% vs. 40%, p = 0.048).

CONCLUSION

Outcomes of our cohort were comparable to other series using similar treatments. Surgery significantly improved locoregional control but not survival. Response based on FDG-PET/CT predicted survival and might be used for treatment stratification.

Pilot study of serial FLT and FDG-PET/CT imaging to monitor response to neoadjuvant chemoradiotherapy of esophageal adenocarcinoma: correlation with histopathologic response

OBJECTIVE

The aim of this prospective pilot study was to investigate the potential of serial FLT-PET/CT compared to FDG-PET/CT to provide an early indication of esophageal cancer response to concurrent neoadjuvant chemoradiation therapy.

METHODS

Five patients with biopsy-proven esophageal adenocarcinomas underwent neoadjuvant chemoradiation (Tx) prior to minimally invasive esophagectomy. The presence of residual tumor was classified histologically using the Mandard et al. criteria, categorizing patients as pathologic responders and non-responders. Participants underwent PET/CT imaging 1 h after intravenous administration of FDG and of FLT on two separate days within 48 h of each other. Each patient underwent a total of 3 scan "pairs": (1) pre-treatment, (2) during treatment, and (3) post-treatment. Image-based response to therapy was measured in terms of changes in SUVmax (ΔSUV) between pre- and post-therapeutic FLT- and FDG-PET scans. The PET imaging findings were correlated with the pathology results after surgery.

RESULTS

All tumors were FDG and FLT avid at baseline. Lesion FLT uptake was lower than with FDG. Neoadjuvant chemoradiation resulted in a reduction of tumor uptake of both radiotracers in pathological responders (n = 3) and non-responders (n = 2). While the difference in the reduction in mean tumor FLT uptake during Tx between responders (ΔSUV = - 55%) and non-responders (ΔSUV = - 29%) was significant (P = 0.007), for FDG it was not, [responders had a mean ΔSUV = - 39 vs. - 31% for non-responders (P = 0.74)]. The difference in the reduction in tumor FLT uptake at the end of treatment between responders (ΔSUV = - 62%) and non-responders (ΔSUV = - 57%) was not significant (P = 0.54), while for FDG there was a trend toward significance [ΔSUV of responders = - 74 vs. - 52% in non-responders (P = 0.06)].

CONCLUSION

The results of this prospective pilot study suggest that early changes in tumor FLT uptake may be better than FDG in predicting response of esophageal adenocarcinomas to neoadjuvant chemoradiation. These preliminary results support the need to corroborate the value of FLT-PET/CT in a larger cohort.

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

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

Preoperative T Staging of Potentially Resectable Esophageal Cancer: A Comparison between Free-Breathing Radial VIBE and Breath-Hold Cartesian VIBE, with Histopathological Correlation

PURPOSE

To compare the T staging of potentially resectable esophageal cancer using free-breathing radial VIBE (r-VIBE) and breath-hold Cartesian VIBE (C-VIBE), with pathologic confirmation of the T stage.

MATERIALS AND METHODS

Fifty patients with endoscopically proven esophageal cancer and indeterminate T1/T2/T3 stage by CT scan were examined on a 3-T scanner. The MRI protocol included C-VIBE at 150 seconds post-IV contrast, immediately followed by a work-in-progress r-VIBE with identical spatial resolution (1.1 mm × 1.1 mm × 3.0 mm). Two independent readers assigned a T stage on MRI according to the 7th edition of UICC-AJCC TNM Classification, and postoperative pathologic confirmation was considered the gold standard. Interreader agreement was also calculated.

RESULTS

The T staging agreement between both VIBE techniques and postoperative pathologic T staging was 52% (26/50) for C-VIBE, 80% (40/50) for r-VIBE for reader 1, and 50% (25/50), 82% (41/50) for reader 2, respectively. For the esophageal cancer with invading lamina propria, muscularis mucosae, or submucosa (T1 stage), r-VIBE achieved 86% (12/14) agreement for both readers 1 and 2. For invasion of muscularis propria (T2 stage), r-VIBE achieved 83% (25/30) for both readers 1 and 2, whereas for the invasion of adventitia (T3 stage), r-VIBE could only achieve agreement in 50% (3/6) and 67% (4/6) for readers 1 and 2, respectively.

CONCLUSION

Contrast-enhanced free-breathing r-VIBE is superior to breath-hold CVIBE in T staging of potentially resectable esophageal cancer, especially for T1 and T2.

Identification of Metabolic Biomarkers Using Serial 18F-FDG PET/CT for Prediction of Recurrence in Advanced Epithelial Ovarian Cancer

PURPOSE

To evaluate the prognostic value of metabolic parameters derived from serial ¹⁸F fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in patients with advanced epithelial ovarian cancer (EOC).

METHODS

Thirteen patients with advanced EOC who received surgical staging and adjuvant platinum-based combination chemotherapy were prospectively enrolled. ¹⁸F-FDG PET/CT was performed before and after the surgical staging, and after third cycle of chemotherapy. Tumor glucose metabolism at baseline and its change after operation and third cycle of chemotherapy such as changes of maximum standardized uptake values (ΔSUV_max) via ¹⁸F-FDG PET/CT were measured, and assessed regarding their ability to predict recurrence.

RESULTS

Median duration of progression-free survival (PFS) was 25 months (range, 13-34), and although optimal debulking was performed in 10 patients, 5 (38.5%) patients experienced recurrence. Univariate analyses showed significant associations between recurrence and low ΔSUV_max after surgical staging, and low SUV_max change after third cycle of chemotherapy. Multivariate analysis identified low ΔSUV_max after third cycle of chemotherapy as an independent risk factor for recurrence (P=.047, hazard ratio (HR) 16.375, 95% CI 1.041-257.536). Kaplan-Meier survival curves showed that PFS significantly differed in groups categorized based on ΔSUV_max after chemotherapy (P=.001, log-rank test).

CONCLUSIONS

¹⁸F-FDG PET/CT allows for prediction of treatment response by the level of FDG uptake in terms of SUV at baseline and after chemotherapy. The metabolic response measured as ΔSUV_max after third cycle of chemotherapy appears to be promising predictor of recurrence in patients with advanced EOC.

Follow up results of a prospective study to evaluate the impact of FDG-PET on CT-based radiotherapy treatment planning for oesophageal cancer

Background

This prospective study aims to determine the impact of PET/CT on radiotherapy planning and outcomes in patients with oesophageal cancer.

Methods

All patients underwent PET/CT scanning in the radiotherapy treatment position, and received treatment planned using the PET/CT dataset. GTV was defined separately on PET/CT (GTV-PET) and CT (GTV-CT) datasets. A corresponding PTV was generated for each patient. Volumetric and spatial analysis quantified the proportion of FDG-avid disease not included in CT-based volumes. Clinical data was collected to determine locoregional control and overall survival rates.

Results

13 (24.1%) of 57 accrued patients had metastatic disease detected on PET. Median follow up was 4 years. FDG-avid disease would have been excluded from GTV-CT in 29 of 38 patients (76%). In 5 patients, FDG-avid disease would have been completely excluded from the PTV-CT. GTV-CT underestimated the cranial and caudal extent of FDG-avid tumour in 14 (36%) and 10 (26%) patients. 4-Year overall survival and locoregional failure free survival were 37% and 65%.

Conclusions

PET/CT altered the delineation of tumour volumes when compared to CT alone, and should be considered standard for treatment planning. Although clinical outcomes were not improved with PET/CT planning, it did allow the use of smaller radiotherapy volumes.

Radiation Therapy for Locally Advanced Esophageal Cancer

The treatment of locally advanced esophageal cancer is controversial. For patients who are candidates for surgical resection, multiple prospective clinical trials have demonstrated the advantages of neoadjuvant chemoradiation. For patients who are medically inoperable, definitive chemoradiation is an alternative approach with survival rates comparable to trimodality therapy. Although trials of dose escalation are ongoing, the standard radiation dose remains 50.4 Gy. Modern radiotherapy techniques such as image-guided radiation therapy with motion management and intensity-modulated radiation therapy are strongly encouraged with a planning objective to maximize conformity to the intended target volume while reducing dose delivered to uninvolved normal tissues.

Radiotherapy response evaluation using FDG PET-CT-established and emerging applications

Radiation therapy is a common component of curative cancer treatment. However, there is a significant incidence of treatment failure. In these cases, salvage surgical options are sometimes appropriate. Accurate assessment of response and early recognition of treatment success or failure is therefore critical to guide treatment decisions and impacts on survival and the morbidity of treatment. Traditionally, treatment response has depended upon the anatomical measurement of disease. However, this may not correlate well with the presence of disease, especially after radiotherapy. Combined positron emission tomography (PET) and CT imaging employs radioactive tracers to identify molecular characteristics of tissues. PET imaging exploits the fact that malignancies have characteristic molecular profiles which differ compared with surrounding tissues. The complementary anatomical and functional information facilitates accurate non-invasive assessment of surrogate biomarkers of disease activity.

Prognostic value of metabolic response measured by 18F-FDG-PET in oesophageal cancer patients treated with definitive chemoradiotherapy

BACKGROUND

This study aimed to assess the efficacy of fluorine-18 fluorodeoxyglucose (F-FDG)-PET for predicting overall survival (OS) and disease-free survival (DFS) in oesophageal cancer patients after definitive chemoradiotherapy (CRT) and prognostic importance of metabolic response detected by post-treatment PET at least 3 months after completing CRT.

MATERIALS AND METHODS

Data from 58 oesophageal cancer patients receiving definitive CRT were retrospectively analysed. Post-treatment F-FDG-PET was delivered at a median of 3.2 (range, 3.0-6.4) months after CRT. The impact of metabolic response determined by post-treatment F-FDG-PET, maximum post-treatment standardized uptake value (SUVmax) and percent SUV change (pretreatment to post-treatment) on survival was analysed.

RESULTS

The median follow-up was 19.7 (range, 4.2-91.9) months for all patients and 28.2 (range, 13.7-91.9) months for survivors. The mean pretreatment and post-treatment SUVmax and the median percent SUV decrease were 18.6±6.4, 6.2±4.6 and -73% (+13 to -100%). Pretreatment SUVmax was higher in patients with locoregional or distant failure than in those without (P<0.001). Pretreatment SUVmax was lower in patients with a complete response (CR) than in those without a CR (P=0.006). Two-year OS and DFS were higher in patients with CR compared with those without CR (P<0.001). CR rates detected by post-treatment F-FDG-PET were lower in patients with lymph node metastases or longer tumours than in those with shorter tumours or no metastases. During multivariate analysis, post-treatment SUVmax was a significant predictor for OS, and post-treatment SUVmax, percent SUV decrease and tumour length were significant prognostic factors for DFS.

CONCLUSION

Metabolic response assessed by post-treatment F-FDG-PET at least 3 months after CRT showed that post-treatment SUVmax and percent SUV change were important survival predictors.

Potentially Curable Cancers of the Esophagus and Stomach

Gastric and gastroesophageal adenocarcinomas continue to be a major health burden globally and collectively represent the third leading cause of cancer death. Among patients with metastatic disease, most die of their cancer because of the limited number of modestly effective treatment regimens available today. The progress against these cancers has been slow compared with many other solid tumors despite many attempts. In-depth molecular profiling has also not been completed. Even when these cancers are localized, they impose considerable challenges for the patient, relatives, and treatment team alike. Localized gastric or gastroesophageal cancer is best managed with a multidisciplinary approach. This review focuses on the management of localized cancers by reviewing the current literature and explaining certain principles that help guide therapy for these patients. The future, however, will afford numerous opportunities, including exploitation of initial data from The Cancer Genome Atlas, to identify novel targets and drugs, harness the prowess of the immune system, and customize therapy for each patient.

Change in chemotherapy during concurrent radiation followed by surgery after a suboptimal positron emission tomography response to induction chemotherapy improves outcomes for locally advanced esophageal adenocarcinoma

BACKGROUND

A positron emission tomography (PET) scan after induction chemotherapy before preoperative chemoradiation and surgery for esophageal adenocarcinoma predicts outcomes. Some patients with progression on PET after induction chemotherapy had long-term overall survival (OS) when they were changed to alternative chemotherapy during radiation.

METHODS

This study retrospectively reviewed esophageal adenocarcinoma patients who received induction chemotherapy and chemoradiation before planned surgery; all had undergone a PET scan before and after induction chemotherapy.

RESULTS

There were 201 patients, and 113 (56%) were PET responders (≥35% decrease in the maximum standardized uptake value of the tumor). All PET responders received the same chemotherapy during radiation, whereas 38 of the 88 PET nonresponders (43%) changed chemotherapy. Among the 152 patients who underwent surgery, the pathologic complete response rate was 15% for PET responders and 3% for PET nonresponders who did not change chemotherapy (P = .046). The median progression-free survival (PFS; 18.9 vs 10.0 months, P < 0.01) and OS (37 vs 25.3 months, P = .02) were significantly better for PET responders versus PET nonresponders who did not change chemotherapy. The median PFS for PET nonresponders who changed chemotherapy was 17.9 months, and it was superior to the median PFS for PET nonresponders who did not change chemotherapy (P = .01). For PET nonresponders, the 5-year OS rates were 37% for those who changed chemotherapy and 25% for those who did not change chemotherapy (P = .18).

CONCLUSIONS

A PET scan after induction chemotherapy predicts outcomes for locally advanced esophageal adenocarcinoma patients who undergo chemoradiation and surgery. The median PFS is improved, and trends toward improved OS appear possible in PET nonresponders who change chemotherapy during radiation. The fully accrued Cancer and Leukemia Group B 80803 study (NCT01333033) is evaluating this strategy. Cancer 2016;122:2083-90. © 2016 American Cancer Society.

The 100 most cited articles investigating the radiological staging of oesophageal and junctional cancer: a bibliometric analysis

Objectives

Accurate staging of oesophageal cancer (OC) is vital. Bibliometric analysis highlights key topics and publications that have shaped understanding of a subject. The 100 most cited articles investigating radiological staging of OC are identified.

Methods

The Thomas Reuters Web of Science database with search terms including “CT, PET, EUS, oesophageal and gastro-oesophageal junction cancer” was used to identify all English language, full-script articles. The 100 most cited articles were further analysed by topic, journal, author, year and institution.

Results

A total of 5,500 eligible papers were returned. The most cited paper was Flamen et al. (n = 306), investigating the utility of positron emission tomography (PET) for the staging of patients with potentially operable OC. The most common research topic was accuracy of staging investigations (n = 63). The article with the highest citation rate (38.00), defined as the number of citations divided by the number of complete years published, was Tixier et al. investigating PET texture analysis to predict treatment response to neo-adjuvant chemo-radiotherapy, cited 114 times since publication in 2011.

Conclusion

This bibliometric analysis has identified key publications regarded as important in radiological OC staging. Articles with the highest citation rates all investigated PET imaging, suggesting this modality could be the focus of future research.

Main Messages

• This study identifies key articles that investigate radiological staging of oesophageal cancer.

• The most common topic was accuracy of staging investigations.

• The article with the highest citation rate investigated the use of texture analysis in PET images.

Relationship between the Temporal Changes in Positron-Emission-Tomography-Imaging-Based Textural Features and Pathologic Response and Survival in Esophageal Cancer Patients

PURPOSE

Although change in standardized uptake value (SUV) measures and PET-based textural features during treatment have shown promise in tumor response prediction, it is unclear which quantitative measure is the most predictive. We compared the relationship between PET-based features and pathologic response and overall survival with the SUV measures in esophageal cancer.

METHODS

Fifty-four esophageal cancer patients received PET/CT scans before and after chemoradiotherapy. Of these, 45 patients underwent surgery and were classified into complete, partial, and non-responders to the preoperative chemoradiation. SUVmax and SUVmean, two cooccurrence matrix (Entropy and Homogeneity), two run-length matrix (RLM) (high-gray-run emphasis and Short-run high-gray-run emphasis), and two size-zone matrix (high-gray-zone emphasis and short-zone high-gray emphasis) textures were computed. The relationship between the relative difference of each measure at different treatment time points and the pathologic response and overall survival was assessed using the area under the receiver-operating-characteristic curve (AUC) and Kaplan-Meier statistics, respectively.

RESULTS

All Textures, except Homogeneity, were better related to pathologic response than SUVmax and SUVmean. Entropy was found to significantly distinguish non-responders from the complete (AUC = 0.79, p = 1.7 × 10(-4)) and partial (AUC = 0.71, p = 0.01) responders. Non-responders can also be significantly differentiated from partial and complete responders by the change in the run-length and size-zone matrix textures (AUC = 0.71-0.76, p ≤ 0.02). Homogeneity, SUVmax, and SUVmean failed to differentiate between any of the responders (AUC = 0.50-0.57, p ≥ 0.46). However, none of the measures were found to significantly distinguish between complete and partial responders with AUC <0.60 (p = 0.37). Median Entropy and RLM textures significantly discriminated patients with good and poor survival (log-rank p < 0.02), while all other textures and survival were poorly related (log-rank p > 0.25).

CONCLUSION

For the patients studied, temporal changes in Entropy and all RLM were better correlated with pathological response and survival than the SUV measures. The hypothesis that these metrics can be used as clinical predictors of better patient outcomes will be tested in a larger patient dataset in the future.

An investigation of the relation between tumor-to-liver ratio (TLR) and tumor-to-blood standard uptake ratio (SUR) in oncological FDG PET

Background

The standardized uptake value (SUV) is the nearly exclusive means for quantitative evaluation of clinical [18F-]fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) whole body investigations. However, the SUV methodology has well-known shortcomings. In this context, it has been recognized that at least part of the problems can be eliminated if tumor SUV is normalized to the SUV of a reference region in the liver (tumor-to-liver [TLR] ratio). In recent publications, we have systematically investigated the tumor-to-blood SUV ratio (SUR) for normalization of tumor SUVs which in our view offers principal advantages in comparison to TLR. The aim of this study was a comprehensive comparison of TLR and SUR in terms of quantification of tumor lesions.

Methods

18F-FDG PET/CT was performed in 424 patients (557 scans) with different tumor entities prior to radio(chemo)therapy. In the PET images, SUV_max of the primary tumor was determined. SUV_liver was calculated in the inferior right lobe of the liver. SUV_blood was determined by manually delineating the aorta in the low-dose CT. TLR and SUR were computed and scan time corrected to 60 min p.i. (TLR_tc and SUR_tc). Correlation analysis was performed for SUV_liver vs. SUV_blood, TLR vs. SUR, SUV_liver/SUV_blood vs. SUV_blood,SUR_tc/TLR vs. SUR_tc, and SUR_tc/TLR_tc vs. SUR_tc. Variability of the respective ratios was assessed via histogram analysis. The prognostic value of TLR and TLR_tc for distant metastases-free survival (DM) was investigated with univariate Cox regression in a homogeneous subgroup (N = 130) and compared to previously published results for SUV and SUR_tc.

Results

Correlation analysis revealed a linear correlation of SUV_liver vs. SUV_blood (R ²=0.83) and of TLR vs. SUR_tc (R²=0.92). The SUV_liver/SUV_blood ratio (mean ± s.d.) was 1.47 ± 0.18. For the SUR_tc/TLR ratio, we obtained 1.14 ± 0.21 and for the SUR_tc/TLR_tc ratio 1.38 ± 0.17. Survival analysis revealed TLR and TLR_tc as significant prognostic factors for DM (hazard ratio [HR] = 3.3 and HR = 3, respectively). Both hazard ratios are lower than that of SUR_tc (HR = 4.1) although this reduction does not reach statistical significance for the given limited group size. HRs of TLR and SUR_tc are both significantly higher than HR of SUV (HR = 2.2).

Conclusions

Suitability of the liver as surrogate of arterial tracer supply for SUV normalization via TLR computation is limited. Further studies in sufficiently large patient groups are required to better characterize the relative performance of SUV, TLR, and SUR in different settings.

18F-FDG PET-CT after Neoadjuvant Chemoradiotherapy in Esophageal Cancer Patients to Optimize Surgical Decision Making

BACKGROUND

Prognosis of esophageal cancer patients can be significantly improved by neoadjuvant chemoradiotherapy (nCRT). Given the aggressive nature of esophageal tumors, it is conceivable that in a significant portion of patients treated with nCRT, dissemination already becomes manifest during the period of nCRT. The aim of this retrospective study was to determine the value and diagnostic accuracy of PET-CT after neoadjuvant chemoradiotherapy to identify patients with metastases preoperatively in order to prevent non-curative surgery.

METHODS

From January 2011 until February 2013 esophageal cancer patients deemed eligible for a curative approach with nCRT and surgical resection underwent a PET-CT after completion of nCRT. If abnormalities on PET-CT were suspected metastases, histological proof was acquired. A clinical decision model was designed to assess the cost-effectiveness of this diagnostic strategy.

RESULTS

156 patients underwent a PET-CT after nCRT. In 31 patients (19.9%) PET-CT showed abnormalities suspicious for dissemination, resulting in 17 cases of proven metastases (10.9%). Of the patients without proven metastases 133 patients were operated. In 6 of these 133 cases distant metastases were detected intraoperatively, corresponding to 4.5% false-negative results. The standard introduction of a post-neoadjuvant therapy PET-CT led to a reduction of overall health care costs per patient compared to a scenario without restaging with PET-CT ($34,088 vs. $36,490).

CONCLUSION

In 10.9% of esophageal cancer patients distant metastases were detected by standard PET-CT after neoadjuvant chemoradiotherapy. To avoid non-curative resections we advocate post-neoadjuvant therapy PET-CT as a cost-effective step in the standard work-up of candidates for surgery.

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

INTRODUCTION

The purpose of this study was to evaluate if a baseline, an interim or a post-chemoradiation (CTRT) 18-fluorodeoxy-glucose positron emission computed tomography (18F-FDG PET/CT) studies could provide information on pathologic response to CTRT and overall survival (OS).

MATERIALS AND METHODS

Thirty-one patients with histologically proven adenocarcinoma or squamous cell carcinoma of the oesophagus, fit for trimodality therapy were prospectively enrolled. Most were men (93.5%), and had a stage III cancer (74.2%). Chemotherapy consisted of oxaliplatin/5-fluorouracil (45.2%) and taxane/5-fluorouracil (54.8%). All patients underwent a baseline, an interim (performed 12 ± 2 days after the onset of CTRT) and a post-CTRT 18F-FDG PET/CT study. The 18F-FDG PET/CT variables evaluated were at baseline, interim and post-CTRT studies maximum standardised uptake value (SUV max) and total lesion glycolysis (TLG). Clinical and 18F-FDG PET/CT parameters were correlated with pathologic complete response (pathCR) and OS.

RESULTS

Among the 31 patients studied, 61.3% achieved a clinical complete response (cCR) and 87.1% had surgery. The median OS was 35.1 months (95% confidence interval (CI): 19.9-NA). PathCR rate was 22.2%. There was only a marginal association between cCR and pathCR (p = 0.06). None of the other variables was predictive of pathCR. There was association between OS and baseline TLG (p = 0.03) at the optimal cutoff TLG value of 75.15. Additionally, TLG and ΔTLG post-CTRT were also associated with OS (p = 0.01 and 0.03, respectively).

CONCLUSION

None of the PET parameters is predictive of pathCR but TLG at baseline and post-CTRT are prognostic of OS.

The role of PET and PET-CT scanning in assessing response to neoadjuvant therapy in esophageal carcinoma

BACKGROUND

The response to neoadjuvant (radio-)chemotherapy for esophageal carcinoma is often assessed with the aid of positron-emission tomography (PET), either alone or in combination with computed tomography (PET-CT). In this review, we discuss the diagnostic validity and clinical benefit of these imaging techniques.

METHODS

We systematically searched the Medline, Embase, and Cochrane Library databases for randomized controlled trials (RCTs) and controlled clinical trials (CCTs) comparing PET-CT with conventional techniques such as endosonography and CT. We then determined the diagnostic validity of these methods on the basis of information from published systematic reviews, updated with further information from more recent primary studies.

RESULTS

We did not find any RCTs that addressed the question of the patient-relevant benefit of PET-CT. We found 20 studies of diagnostic methods, carried out on a total of 854 patients, of whom 82.2% were male. These studies had a high potential for bias. In two of them, PET-CT was directly compared with endosonography or CT. Estimates of sensitivity and specificity varied widely across studies. 54% of all patients (median value across studies) had no histopathological response to therapy at the end of treatment. Taking a reduction of the standard uptake value (SUV) by at least 35% as a threshold criterion, we found that the median negative predictive value of PET across all studies was 86.5.

CONCLUSION

There is no robust evidence for a patient-relevant benefit of PET and PET-CT in patients with esophageal carcinoma. PET could potentially be used to distinguish treatment responders from non-responders after the first cycle of treatment. RCTs with patient-relevant endpoints will be needed in order to determine whether this is useful.

Accuracy of Detecting Residual Disease After Cross Neoadjuvant Chemoradiotherapy for Esophageal Cancer (preSANO Trial): Rationale and Protocol

BACKGROUND

Results from the recent CROSS trial showed that neoadjuvant chemoradiotherapy (nCRT) significantly increased survival as compared to surgery alone in patients with potentially curable esophageal cancer. Furthermore, in the nCRT arm 49% of patients with a squamous cell carcinoma (SCC) and 23% of patients with an adenocarcinoma (AC) had a pathologically complete response in the resection specimen. These results provide a rationale to reconsider and study the timing and necessity of esophagectomy in (all) patients after application of the CROSS regimen.

OBJECTIVE

We propose a "surgery as needed" approach after completion of nCRT. In this approach, patients will undergo active surveillance after completion of nCRT. Surgical resection would be offered only to those patients in whom residual disease or a locoregional recurrence is highly suspected or proven. However, before a surgery as needed approach in oesophageal cancer patients (SANO) can be tested in a randomized controlled trial, we aim to determine the accuracy of detecting the presence or absence of residual disease after nCRT (preSANO trial).

METHODS

This study is set up as a prospective, single arm, multicenter, diagnostic trial. Operable patients with potentially curable SCC or AC of the esophagus or esophagogastric junction will be included. Approximately 4-6 weeks after completion of nCRT all included patients will undergo a first clinical response evaluation (CRE-I) including endoscopy with (random) conventional mucosal biopsies of the primary tumor site and of any other suspected lesions in the esophagus and radial endo-ultrasonography (EUS) for measurement of tumor thickness and area. Patients in whom no locoregional or disseminated disease can be proven by cytohistology will be offered a postponed surgical resection 6-8 weeks after CRE-I (ie, approximately 12-14 weeks after completion of nCRT). In the week preceding the postponed surgical resection, a second clinical response evaluation (CRE-II) will be planned that will include a whole body PET-CT, followed again by endoscopy with (random) conventional mucosal biopsies of the primary tumor site and any other suspected lesions in the esophagus, radial EUS for measurement of tumor thickness and area, and linear EUS plus fine needle aspiration of PET-positive lesions and/or suspected lymph nodes. The main study parameter is the correlation between the clinical response assessment during CRE-I and CRE-II and the final pathological response in the resection specimen.

RESULTS

The first patient was enrolled on July 23, 2013, and results are expected in January 2016.

CONCLUSIONS

If this preSANO trial shows that the presence or absence of residual tumor can be predicted reliably 6 or 12 weeks after completion of nCRT, a randomized trial comparing nCRT plus standard surgery versus chemoradiotherapy plus "surgery as needed" will be conducted (SANO trial).

TRIAL REGISTRATION

Netherlands Trial Register: NTR4834; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=4834 (archived by Webcite at http://www.webcitation.org/6Ze7mn67B).

A nomogram that predicts pathologic complete response to neoadjuvant chemoradiation also predicts survival outcomes after definitive chemoradiation for esophageal cancer

BACKGROUND

Pathologic complete response (pCR) to neoadjuvant chemoradiation for esophageal cancer is associated with improved outcomes. We evaluated whether a nomogram designed to predict who would have a pCR after trimodality therapy could also predict outcome after definitive chemoradiation.

METHODS

Patients in this retrospective, single-institution analysis had received chemoradiation without surgery for esophageal cancer from 1998 through 2010; 333 such patients had complete information on all variables required for the pCR nomogram: sex; T status (by endoscopic sonography); tumor grade; tumor avidity on positron emission tomography (PET); and esophagogastroduodenoscopy (EGD)-directed biopsy results after chemoradiation. We used multivariate Cox regression to test potential associations between clinical outcomes [overall survival (OS), locoregional recurrence, and distant metastasis] and patient or treatment factors and the pCR nomogram score; the component variables of the nomogram were not reintroduced into the multivariate analysis.

RESULTS

The median follow-up time for all patients (median age 66 years) was 18.2 months (30.7 months for those alive at the time of analysis). Patients with nomogram scores ≤125 (median for all patients) had significantly worse outcomes than patients with scores >125: median OS time 19.7 vs. 48.2 months; disease-free survival (DFS) time 6.1 vs. 31.1 months; locoregional failure-free survival time 17.7 months vs. not reached; and distant metastasis-free survival time 11.7 months vs. not reached (all P<0.001). Multivariate Cox regression analysis indicated that nomogram score independently predicted each survival outcome, along with other patient and disease factors.

CONCLUSIONS

The pCR nomogram score predicted survival outcomes in patients receiving definitive chemoradiation for esophageal cancer. Although this nomogram requires further validation, it may prove useful for stratifying patients for clinical trials designed to intensify treatments for patients at the highest risk of relapse.

Clinical tools to predict outcomes in patients with esophageal cancer treated with definitive chemoradiation: are we there yet?

Definitive chemoradiation (CRT) is a well-established treatment for esophageal cancer, but disease recurrence is common and many patients do not achieve initial remission with CRT alone. Predictors of outcome with CRT are needed to guide prognosis and further treatment decisions, in particular the need for post-CRT surgery. We review the role of baseline clinical factors, such as histology and tumor bulk, in predicting response to CRT. Post-CRT assessments, particularly PET imaging, may provide further information about the likelihood of complete response and survival, but the predictive power of clinical assessments remains limited. Emerging research on biomarkers holds promise for more tailored and accurate prediction of outcome with definitive CRT.