FDG-PET in the prediction of pathologic response after neoadjuvant chemoradiotherapy in locally advanced, resectable esophageal cancer

Nomogram for predicting pathologic complete response following preoperative chemoradiotherapy in patients with esophageal squamous cell carcinoma

Background

In patients with esophageal squamous cell carcinoma (ESCC), accurately predicting a pathologic complete response (pCR) to preoperative chemoradiotherapy (PCRT) has the potential to enable an active surveillance strategy without esophagectomy. We aimed to establish a reliable multiparameter nomogram model that combines tumor characteristics, imaging modalities, and hematologic markers to predict pCR in patients with ESCC who underwent PCRT and esophagectomy.

Methods

We retrospectively reviewed the medical records of 457 patients with ESCC who received PCRT followed by esophagectomy between January 2005 and October 2020. The nomogram model was developed using logistic regression analysis with a training cohort and externally validated with a validation cohort.

Results

In the training and validation cohorts, 44.2% (126/285) and 48.3% (83/172) of patients, respectively, achieved pCR after PCRT. The 5-year rates of overall survival, progression-free survival, and freedom from local progression in the training cohort were 51.6%, 48.5%, and 77.6%, respectively. The parameters included in the nomogram were histologic grade, clinical N stage, maximum standardized uptake value on positron emission tomography, and post-PCRT biopsy. Hematologic markers were significantly associated with survival outcomes but not with pCR. The area under the receiver operating characteristic curve of the nomogram was 0.717, 0.704, and 0.707 for the training cohort, internal validation cohort, and external validation cohort, respectively.

Conclusion

Our nomogram model based on four parameters obtained from standard clinical practice demonstrated good performance in both the training and validation cohorts and could be useful to aid clinical decision-making to determine whether surgery or active surveillance strategy should be pursued.

Association between prognosis and lymph node status using 18F-fluorodeoxyglucose-positron emission tomography in esophageal squamous cell carcinoma treated with esophagectomy post-neoadjuvant chemotherapy

BACKGROUND

There are few reports on the associations between lymph node (LN) status, determined by preoperative 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET), and prognosis in patients with locally advanced esophageal squamous cell carcinoma (ESCC) who underwent esophagectomy post-neoadjuvant chemotherapy (NCT). Additionally, details on the diagnostic performance of LN metastasis determination based on pathological examination versus FDG-PET have not been reported. In this study, we aimed to evaluate the associations among LN status using FDG-PET, LN status based on pathological examination, and prognosis in patients with locally advanced ESCC who underwent esophagectomy post-NCT.

METHODS

We reviewed the data of 124 consecutive patients with ESCC who underwent esophagectomy with R0 resection post-NCT between December 2008 and August 2022 and were evaluated pre- and post-NCT using FDG-PET. The associations among LN status using FDG-PET, LN status based on pathological examination, and prognosis were assessed.

RESULTS

Station-by-station analysis of PET-positive LNs pre- and post-NCT correlated significantly with pathological LN metastases (sensitivity, specificity, and accuracy pre- and post-NCT: 51.6%, 96.0%, and 92.1%; and 28.2%, 99.5%, and 93.1%, respectively; both p < 0.0001). Using univariate and multivariate analyses, LN status determined using PET post-NCT was a significant independent predictor of both recurrence-free survival and overall survival.

CONCLUSION

The LN status assessed using FDG-PET post-NCT was significantly associated with the pathological LN status and prognosis in patients with ESCC who underwent esophagectomy post-NCT. Therefore, FDG-PET is a useful diagnostic tool for preoperatively predicting pathological LN metastasis and survival in these patients and could provide valuable information for selecting individualized treatment strategies.

Pathologic complete response in patients with esophageal cancer receiving neoadjuvant chemotherapy or chemoradiation: A systematic review and meta-analysis

BACKGROUND

Neoadjuvant chemoradiation and chemotherapy are recommended for the treatment of nonmetastatic esophageal cancer. The benefit of neoadjuvant treatment is mostly limited to patients who exhibit pathologic complete response (pCR). Existing estimates of pCR rates among patients receiving neoadjuvant therapy have not been synthesized and lack precision.

METHODS

We conducted an independently funded systematic review and meta-analysis (PROSPERO CRD42023397402) of pCR rates among patients diagnosed with esophageal cancer treated with neoadjuvant chemo(radiation). Studies were identified from Medline, EMBASE, and CENTRAL database searches. Eligible studies included trials published from 1992 to 2022 that focused on nonmetastatic esophageal cancer, including the gastroesophageal junction. Histology-specific pooled pCR prevalence was determined using the Freeman-Tukey transformation and a random effects model.

RESULTS

After eligibility assessment, 84 studies with 6451 patients were included. The pooled prevalence of pCR after neoadjuvant chemotherapy in squamous cell carcinomas was 9% (95% CI: 6%-14%), ranging from 0% to 32%. The pooled prevalence of pCR after neoadjuvant chemoradiation in squamous cell carcinomas was 32% (95% CI: 26%-39%), ranging from 8% to 66%. For adenocarcinoma, the pooled prevalence of pCR was 6% (95% CI: 1%-12%) after neoadjuvant chemotherapy, and 22% (18%-26%) after neoadjuvant chemoradiation.

CONCLUSIONS

Under one-third of patients with esophageal cancer who receive neoadjuvant chemo(radiation) experience pCR. Patients diagnosed with squamous cell carcinomas had higher rates of pCR than those with adenocarcinomas. As pCR represents an increasingly utilized endpoint in neoadjuvant trials, these estimates of pooled pCR rates may serve as an important benchmark for future trial design.

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.

Analysis of trimodal and bimodal therapy in a selective-surgery paradigm for locally advanced oesophageal squamous cell carcinoma

BACKGROUND

Long-term survival outcomes of trimodal therapy (TMT; chemoradiation plus surgery) and bimodal therapy (BMT; chemoradiation) have seldom been analysed. In a selective-surgery paradigm, the benefit of TMT in patients with a complete clinical response is controversial. Factors associated with survival in patients with a clinical complete response to chemoradiation were evaluated.

METHODS

Patients with stage II-III oesophageal squamous cell carcinoma treated with TMT or BMT from 2002 to 2017 were evaluated. The BMT group consisted of patients who were otherwise eligible for surgery but underwent chemoradiation alone followed by observation. This group included patients who later had salvage oesophagectomy. Survival was evaluated and compared between TMT and BMT groups. Elastic net regularization was performed to select co-variables for Cox multivariable survival analysis in patients with a clinical complete response.

RESULTS

Of 143 patients, 60 (41.9 per cent) underwent TMT and 83 (58.0 per cent) BMT. Patients who underwent TMT had longer median overall survival than those who had BMT (77 versus 33 months; P = 0.019). For patients with a clinical complete response, TMT achieved longer median overall survival than BMT (123 versus 55 months; P = 0.04). BMT had a high locoregional recurrence rate (48 versus 6 per cent; P < 0.001); 26 of 29 patients with locoregional recurrence in the BMT groupunderwent salvage resection. Cox multivariable analysis demonstrated that upper-mid oesophageal tumour location (hazard ratio (HR) 2.04; P = 0.024) and tumour length (HR 1.18; P = 0.046) were associated with worse survival. Although TMT was not associated with survival, it was a predictor of reduced recurrence (HR 0.28; P = 0.028). The maximum standardized uptake value after chemoradiation also predicted recurrence (HR 1.33; P < 0.001).

CONCLUSION

In patients who achieve a clinical complete response, TMT reduces locoregional recurrence but may not prolong survival. The differences in survival outcomes may be due to patient selection; therefore, a selective-surgery strategy in oesophageal squamous cell carcinoma is a reasonable approach.

Utility of positron emission-computed tomography for predicting pathological response in resectable oesophageal squamous cell carcinoma after neoadjuvant chemoradiation

OBJECTIVES

For patients with locally advanced oesophageal cancer, improved complete pathological response after neoadjuvant chemoradiation (nCRT) and the detrimental effects on the quality of life related to oesophagectomy have led to the need for a reliable method to select patients who have achieved complete pathological response and do not need surgery. The reliability of 18F-fluorodeoxyglucose positron emission-computed tomography (PET-CT) for predicting the pathological response after nCRT was evaluated.

METHODS

Patients with locally advanced oesophageal cancer who were treated with nCRT and oesophagectomy from July 2010 to February 2017 were analysed. On the post-nCRT PET-CT, a complete metabolic response was defined as all tumourous lesions demonstrating maximum standardized uptake value (SUVmax) ≤2.5. To minimize the effect of radiation-induced oesophagitis, complete metabolic response was also defined as no viable lesion distinguishable from the background with diffuse uptake. The sensitivity, specificity, positive predictive value and negative predictive value were analysed for SUVmax, [X]ΔSUVmax and %ΔSUVmax.

RESULTS

A total of 158 patients with oesophageal squamous cell carcinoma were analysed. The rate of complete pathological response was 27.8%, and that of complete metabolic response was 7.6%. The sensitivity, specificity, positive predictive value and negative predictive value based on SUVmax ≤2.5 and visual normalization were 95%, 14%, 74% and 50%, respectively. Analysis for [X]ΔSUVmax and %ΔSUVmax using the optimal cut-off values determined by the receiver operating characteristic curves did not show an improved predictive efficacy.

CONCLUSIONS

PET-CT is not a reliable tool for predicting pathological response. Patients diagnosed with resectable oesophageal cancer who underwent neoadjuvant therapy should not be exempt from surgery based on PET-CT results.

Tumor SUVs on 18F-FDG PET/CT and Aggressive Pathological Features in Esophageal Squamous Cell Carcinoma

PURPOSE

Considerable discrepancies are observed between clinical staging and pathological staging after surgical resection in patients with esophageal squamous cell carcinoma (ESCC). In this study, we examined the relationships between tumor SUVs on FDG PET/CT and aggressive pathological features in resected ESCC patients.

METHODS

A total of 220 patients with surgically resected clinical stage I-II ESCC without neoadjuvant treatment were retrospectively analyzed. SUVmax of the primary tumor was measured on pretreatment FDG PET/CT. Pathological features included depth of tumor invasion, lymph node metastasis, tumor differentiation, lymphatic vessel tumor embolus, perineural invasion, Ki-67 index, and p53 protein expression. Receiver operating characteristic curve analysis was used to determine an optimal cutoff of SUVmax to predict pathologically advanced disease. Differences in pathological features associated with SUVmax were examined by t test or χ test.

RESULTS

The number of patients upstaged from clinical stage I-II to pathological stage III-IV was 43 (19.5%). Receiver operating characteristic curve analysis showed that the optimal cutoff SUVmax of 4.0 had good performance for predicting locally advanced disease (area under the receiver operating characteristic curve = 0.844, P < 0.001). Higher tumor SUVmax was significantly associated with advanced depth of tumor invasion (deeper than submucosa, P < 0.001), positive lymph node metastasis (P < 0.001), presence of lymphatic vessel tumor embolus (P < 0.001), presence of perineural invasion (P < 0.001), higher Ki-67 index (P = 0.025), and poor tumor differentiation (P = 0.039).

CONCLUSIONS

SUVmax measured on pretreatment FDG PET/CT is significantly associated with aggressive pathological features and may help clinicians identify patients at risk of advanced disease.

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.

Bio-physic constraint model using spatial registration of delta 18F-fluorodeoxyglucose positron emission tomography/computed tomography images for predicting radiation pneumonitis in esophageal squamous cell carcinoma patients receiving neoadjuvant chemoradiation

PURPOSE

This study integrated clinical outcomes and radiomics of advanced thoracic esophageal squamous cell carcinoma patients receiving neoadjuvant concurrent chemoradiotherapy (NACCRT) to establish a novel constraint model for predicting radiation pneumonitis (RP).

PATIENTS AND METHODS

We conducted a retrospective review for thoracic advanced esophageal cancer patients who received NACCRT. From 2013 to 2018, 89 patients were eligible for review. Staging workup and response evaluation included positron emission tomography/computed tomography (PET/CT) scans and endoscopic ultrasound. Patients received RT with 48 Gy to gross tumor and 43.2 Gy to elective nodal area in simultaneous integrated boost method divided in 24 fractions. Weekly platinum-based chemotherapy was administered concurrently. Side effects were evaluated using CTCAE v4. Images of 2-fluoro-2-deoxyglucose PET/CT before and after NACCRT were registered to planning CT images to create a region of interest for dosimetry parameters that spatially matched RP-related regions, including V10, V20, V50%, V27, and V30. Correlation between bio-physic parameters and toxicity was used to establish a constraint model for avoiding RP.

RESULTS

Among the investigated cohort, clinical downstaging, complete pathological response, and 5-year overall survival rates were 59.6%, 40%, and 34.4%, respectively. Multivariate logistic regression analysis demonstrated that each individual set standardized uptake value ratios (SUVRs), neither pre- nor post-NACCRT, was not predictive. Interestingly, cutoff increments of 6.2% and 8.9% in SUVRs (delta-SUVR) in registered V20 and V27 regions were powerful predictors for acute and chronic RP, respectively.

CONCLUSION

Spatial registration of metabolic and planning CT images with delta-radiomics analysis using fore-and-aft image sets can establish a unique bio-physic prediction model for avoiding RP in esophageal cancer patients receiving NACCRT.

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.

Clinical Significance of 18F-Fluorodeoxyglucose-Positron Emission Tomography-Positive Lymph Nodes to Outcomes of Trimodal Therapy for Esophageal Squamous Cell Carcinoma

BACKGROUND

The clinical significance of lymph node (LN) status determined by preoperative ¹⁸F-fluorodeoxyglucose-positron emission tomography (FDG-PET) has not been investigated in patients with locally advanced esophageal squamous cell carcinoma (ESCC) treated with neoadjuvant chemoradiotherapy (NCRT) followed by surgery (trimodal therapy).

METHODS

This study reviewed 132 consecutive patients with ESCC who had been preoperatively evaluated using FDG-PET before and after NCRT to analyze associations among LN status according to PET findings, pathologic LN metastasis, and prognosis of ESCC after trimodal therapy.

RESULTS

Lymph nodes that were PET-positive both before and after NCRT comprised significant predictive markers of pathologic LN metastasis in station-by-station analyses (sensitivity, specificity, and accuracy respectively 41.7%, 95.0%, and 92.7% before, and 12.0%, 99.4%, and 95.6% after NCRT; both p < 0.0001). The numbers of LNs evaluated using PET before and after NCRT were significantly associated with those of pathologic metastatic LNs. Uni- and multivariable analyses selected LN status determined by PET before NCRT as a significant independent predictor of both recurrence-free [LN-negative vs LN-positive: hazard ratio (HR) 1.90; 95% confidence interval (CI) 1.02-3.23; p = 0.045] and overall survival (HR 2.62; 95% CI 1.29-5.30; p = 0.01).

CONCLUSIONS

The status of LN determined by preoperative FDG-PET is significantly associated with pathologic LN status and the prognosis of ESCC with trimodal therapy. Thus, FDG-PET is a useful diagnostic tool for preoperative prediction of pathologic LN metastasis and survival among patients with ESCC.

Novel endoscopic categorization for prediction of chemoradiotherapy response in locally advanced esophageal cancer

BACKGROUND AND AIM

Preoperative chemoradiotherapy (CRT) followed by esophagectomy is a well-known treatment modality for patients with locally advanced esophageal cancer (EC). This study developed an algorithm to predict pathological complete response (CR) in these patients using post-CRT endoscopic category with biopsy and validated the proposed algorithm.

METHODS

A retrospective review of 141 consecutive patients who completed preoperative CRT and underwent surgical resection for locally advanced EC was performed. The post-CRT endoscopic findings of each patient were stratified into five categories.

RESULTS

The distribution of post-CRT endoscopic categories was significantly different between the pathological CR and non-pathological CR groups (P < 0.001). About 76.8% (73/95) of patients in category 0, 1, or 2 achieved pathological CR. In contrast, 91.3% (42/46) of endoscopic categories 3 and 4 patients did not achieve pathological CR. Sensitivity of post-CRT biopsy was 11.1%. Therefore, an algorithm combining biopsy results and dichotomized post-CRT endoscopic category (category 0, 1, or 2 vs category 3 or 4) was developed. The sensitivity, specificity, and accuracy in predicting pathological CR by the proposed algorithm were 64.8%, 95.9%, and 82.8%, respectively. In the multivariate analysis, the proposed algorithm remained a significant negative factor of survival (P < 0.001).

CONCLUSIONS

Algorithm using post-CRT endoscopic category with biopsy may help identify locally advanced EC patients who achieved pathological CR after preoperative CRT. Modalities to accurately detect subepithelial remnant EC may further aid in predicting pathological CR.

Rectal cancer MRI: protocols, signs and future perspectives radiologists should consider in everyday clinical practice

Abstract

Magnetic resonance imaging (MRI) allows to non-invasively evaluate rectal cancer staging and to assess the presence of “prognostic signs” such as the distance from the anorectal junction, the mesorectal fascia infiltration and the extramural vascular invasion. Moreover, MRI plays a crucial role in the assessment of treatment response after chemo-radiation therapy, especially considering the growing interest in the new conservative policy (wait and see, minimally invasive surgery). We present a practical overview regarding the state of the art of the MRI protocol, the main signs that radiologists should consider for their reports during their clinical activity and future perspectives.

Teaching Points

• MRI protocol for rectal cancer staging and re-staging.

• MRI findings that radiologists should consider for reports during everyday clinical activity.

• Perspectives regarding the development of latest technologies.

Preoperative prediction of a pathologic complete response of esophageal squamous cell carcinoma to neoadjuvant chemoradiotherapy

BACKGROUND

The accurate prediction of a pathologic complete response (ypT0N0M [LYM] 0 ypStage 0) before operation is essential for selecting appropriate strategies for treating esophageal cancer after neoadjuvant chemoradiotherapy.

METHODS

We reviewed 130 consecutive patients with esophageal squamous cell carcinoma who were evaluated preoperatively using upper gastrointestinal endoscopy, computed tomography, and 18F-fluorodeoxyglucose-positron emission tomography after neoadjuvant chemoradiotherapy and subsequently underwent esophagectomy. Our aim was to determine the diagnostic abilities of computed tomography, 18F-fluorodeoxyglucose-positron emission tomography, and endoscopy to predict preoperatively a pathologic complete response of the primary site of the locally advanced esophageal squamous cell carcinoma and associated lymph nodes to trimodal neoadjuvant chemoradiotherapy. Associations between clinical complete response (ycT0N0M [LYM] 0 ycStage 0) and pathologic complete response were investigated preoperatively.

RESULTS

Twenty-nine (22.3%) and 43 (33.1%) patients, respectively, achieved clinical complete response and pathologic complete response, which were associated (P=.001). The sensitivity and specificity, as well as the positive and negative predictive values of clinical complete response to define pathologic complete response were 39.5%, 86.2%, 58.6%, and 74.3%, respectively. Univariate and multivariate analyses selected clinical complete response as the sole independent preoperative predictor of pathologic complete response (clinical complete responses versus non-clinical complete responses: odds ratio: 0.26, 95% confidence interval, 0.10-0.65, P=.004). Recurrence-free and overall survival (OS) rates were better in patients with than in those without clinical complete response (5-year recurrence-free and overall survival: 69.0% vs 41.4% and 75.9% vs 45.0%, respectively, both P=.02). Furthermore, clinical complete response was an independent preoperative predictor of recurrence-free survival (clinical complete response versus nonclinical complete response: hazard ratio: 2.20, 95% confidence interval, 1.08-4.45, P=.03).

CONCLUSION

Although pathologic complete response was predictable preoperatively to some extent, the accuracy was somewhat low. Considerable caution should be exercised when selecting the watch-and-wait approach with operation as needed and omitting planned operative intervention even for patients who achieve clinical complete response after neoadjuvant chemoradiotherapy.

Serial imaging using [18F]Fluorodeoxyglucose positron emission tomography and histopathologic assessment in predicting survival in a population of surgically resectable distal oesophageal and gastric adenocarcinoma following neoadjuvant therapy

Background and objectives

We retrospectively evaluated the value of PET/CT in predicting survival and histopathological tumour-response in patients with distal oesophageal and gastric adenocarcinoma following neoadjuvant treatment.

Methods

Twenty-one patients with resectable distal oesophageal adenocarcinoma and 14 with gastric adenocarcinoma between January 2002 and December 2011, who had undergone serial PET before and after neoadjuvant therapy followed by surgery, were enrolled. Maximum standard uptake value (SUVmax) and metabolic tumour volume were measured and correlated with tumour regression grade and survival.

Results

Histopathological tumour response (PR) is a stronger predictor of overall and disease-free survival compared to metabolic response. ∆%SUVmax ≥70% was the only PET metric that predicted PR (82.4% sensitivity, 61.5% specificity, p = 0.047). Histopathological non-responders had a higher risk of death (HR 8.461, p = 0.001) and recurrence (HR 6.385, p = 0.002) and similarly in metabolic non-responders for death (HR 2.956, p = 0.063) and recurrence (HR 3.614, p = 0.028). Ordinalised ∆%SUVmax showed a predictive trend for OS and DFS, but failed to achieve statistical significance.

Conclusions

PR was a stronger predictor of survival than metabolic response. ∆%SUVmax ≥70% was the best biomarker on PET that predicted PR and survival in oesophageal and gastric adenocarcinoma. Ordinalisation of ∆%SUVmax was not helpful in predicting primary outcomes.

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.

Sequential PET/CT with [18F]-FDG Predicts Pathological Tumor Response to Preoperative Short Course Radiotherapy with Delayed Surgery in Patients with Locally Advanced Rectal Cancer Using Logistic Regression Analysis

Previous studies indicate that FDG PET/CT may predict pathological response in patients undergoing neoadjuvant chemo-radiotherapy for locally advanced rectal cancer (LARC). Aim of the current study is evaluate if pathological response can be similarly predicted in LARC patients after short course radiation therapy alone. Methods: Thirty-three patients with cT2-3, N0-2, M0 rectal adenocarcinoma treated with hypo fractionated short course neoadjuvant RT (5x5 Gy) with delayed surgery (SCRTDS) were prospectively studied. All patients underwent 3 PET/CT studies at baseline, 10 days from RT end (early), and 53 days from RT end (delayed). Maximal standardized uptake value (SUVmax), mean standardized uptake value (SUVmean) and total lesion glycolysis (TLG) of the primary tumor were measured and recorded at each PET/CT study. We use logistic regression analysis to aggregate different measures of metabolic response to predict the pathological response in the course of SCRTDS. Results: We provide straightforward formulas to classify response and estimate the probability of being a major responder (TRG1-2) or a complete responder (TRG1) for each individual. The formulas are based on the level of TLG at the early PET and on the overall proportional reduction of TLG between baseline and delayed PET studies. Conclusions: This study demonstrates that in the course of SCRTDS it is possible to estimate the probabilities of pathological tumor responses on the basis of PET/CT with FDG. Our formulas make it possible to assess the risks associated to LARC borne by a patient in the course of SCRTDS. These risk assessments can be balanced against other health risks associated with further treatments and can therefore be used to make informed therapy adjustments during SCRTDS.

FDG PET using SUVmax for preoperative T-staging of esophageal squamous cell carcinoma with and without neoadjuvant chemoradiotherapy

BACKGROUND

Accurate T-staging is pivotal for predicting prognosis and selecting appropriate therapies for esophageal squamous cell carcinoma (ESCC). The diagnostic performance of fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for its T-staging is uncertain. We investigated use of FDG PET/CT for preoperative T-staging of patients with ESCC.

METHODS

Patients with ESCC given preoperative FDG PET/CT scans, either with (CRT[+] group) or without (CRT[-] group) neoadjuvant chemoradiotherapy, were retrospectively reviewed. Maximal standardized uptake value (SUVmax) of the primary tumors on FDG PET/CT scans were measured, and histopathological results were used as the reference standard. The associations between pathological T-stage and potential factors of age, tumor location, tumor grade, tumor size, and tumor SUVmax were analyzed. The cut-off levels of SUVmax for predicting different T-stages and for residual viable tumors after neoadjuvant chemoradiotherapy were determined using receiver operating characteristic analyses.

RESULTS

We enrolled 103 patients (45 in the CRT[-] group; 58 in the CRT[+] group). SUVmax, an independent predictive factor, positively correlated with the pathological T-stage in both groups (CRT[-] group: ρ = 0.736, p < 0.001; and CRT[+] group: ρ = 0.792, p < 0.001). The overall accuracy of the PET/CT with thresholded SUVmax for predicting the pathological T-stage was 73.3% in the CRT[-] group (SUVmax of T0: 0-1.9, T1: 2.0-4.4, T2: 4.5-6.5, T3: 6.6-13.0, T4: >13.0) and 67.2% in the CRT[+] group (SUVmax of T0: 0-3.4, T1: 3.5-3.9, T2: 4.0-5.5, T3: 5.6-6.2, T4: > 6.2). For CRT[-] group, the accuracy using an SUVmax cut-off of 4.4 to differentiate early (T0-1) from locally advanced disease (T2-4) was 82.2% (95% CI, 71.1-93.4%). For CRT[+] group, the accuracy using an SUVmax cut-off of 3.4 to predict residual viable tumors (non-T0) after completion of chemoradiotherapy was 82.8% (95% CI, 73.0-92.5%).

CONCLUSIONS

The FDG avidity of a primary esophageal tumor significantly positively correlated with the pathological T-stage. PET/CT with thresholded SUVmax was useful for predicting T-stage and differentiating residual viable tumors.

The predictive value of 18F-FDG PET for pathological response of primary tumor in patients with esophageal cancer during or after neoadjuvant chemoradiotherapy: a meta-analysis

OBJECTIVE

We want to review the value of 18-fluoro-deoxy-glucose positron emission tomography for response prediction of primary tumor in patients with esophageal cancer during or after neoadjuvant chemoradiotherapy.

METHODS

Studies were searched in Pubmed, Embase and Cochrane Library with specific search strategy. The published articles were included according to the criteria established in advance. The included studies were divided into two groups according to the time of the repeat positron emission tomography: during (Group A) or after neoadjuvant chemoradiotherapy (Group B). The studies that performed the repeat positron emission tomography after neoadjuvant chemoradiotherapy were graded Quality Assessment of Diagnostic Accuracy Studies. The pooled sensitivity, specificity and diagnostic odds ratio were obtained for both groups on the basis of no-existing of threshold effect.

RESULTS

Fifteen studies were included in the present study. The threshold effect did not exist in both groups. The pooled sensitivity, specificity and diagnostic odds ratio were 85%, 59%, 6.82 with 95% confidence interval 76-91%, 48-69%, 2.25-20.72 in Group A. The equivalent values were 67%, 69%, 6.34 with 95% confidence interval 60-73%, 63-74%, 2.08-19.34 in Group B. The pooled sensitivity was 90% in four studies that enrolled patients with esophageal squamous cell carcinoma merely in Group B.

CONCLUSIONS

According to the present data, positron emission tomography should not be used routinely to guide treatment strategy in esophageal cancer patients. We speculated that positron emission tomography could be used as a tool to predict treatment response after neoadjuvant chemoradiotherapy in patients with esophageal squamous cell carcinoma.

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

PURPOSE

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

METHODS

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

RESULTS AND CONCLUSION

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

Ability of Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography to Predict Outcomes of Neoadjuvant Chemoradiotherapy Followed by Surgical Treatment for Esophageal Squamous Cell Carcinoma

BACKGROUND

Responses of esophageal cancer to neoadjuvant therapy and patient prognosis are difficult to predict preoperatively. This study aimed to determine the ability of fluorine-18 fluorodeoxyglucose ((18)FDG) positron emission tomography (FDG-PET) to predict outcomes of trimodal therapy on esophageal squamous cell carcinoma (ESCC).

METHODS

The responses of 111 patients with ESCC were monitored using FDG-PET before and after neoadjuvant chemoradiotherapy (nCRT) followed by surgical treatment. Associations between the maximum standardized uptake value (SUVmax) and pathologic responses (PRs) and prognosis were analyzed.

RESULTS

Responses were significantly associated with SUVmax after nCRT (post-SUVmax) and with the rate of decreases in the SUVmax (%ΔSUVmax) of the primary tumor. The optimal cutoffs for post-SUVmax and %ΔSUVmax determined from receiver operating characteristic (ROC) curves were 2.7 (area under the curve [AUC], 0.68; 95% confidence interval [CI], 0.58-0.78; p = 0.001) and 75 (AUC, 0.64; 95% CI, 0.54-0.75; p = 0.01) for predicting a pathologic complete response (pCR) and 3.7 (AUC, 0.76; 95% CI, 0.63-0.89; p < 0.001) and 70 (AUC, 0.65; 95% CI, 0.52-0.78; p = 0.02) for predicting a good response according to Japan Esophageal Society response criteria. These values reliably separated patients into groups with and without pCR and with and without a good response. Multivariate analysis showed that %ΔSUVmax (≤70 and >70) was an independent prognostic factor for disease-specific survival (hazard ratio [HR], 0.45; 95% CI, 0.21-0.98; p = 0.04).

CONCLUSIONS

SUVmax is a valuable preoperative predictor of tumor response and survival among patients who undergo trimodal therapy for ESCC.

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.

Superiority of Deformable Image Co-registration in the Integration of Diagnostic Positron Emission Tomography-Computed Tomography to the Radiotherapy Treatment Planning Pathway for Oesophageal Carcinoma

AIMS

To investigate the use of image co-registration in incorporating diagnostic positron emission tomography-computed tomography (PET-CT) directly into the radiotherapy treatment planning pathway, and to describe the pattern of local recurrence relative to the PET-avid volume.

MATERIALS AND METHODS

Fourteen patients were retrospectively identified, six of whom had local recurrence. The accuracy of deformable image registration (DIR) and rigid registration of the diagnostic PET-CT and recurrence CT, to the planning CT, were quantitatively assessed by comparing co-registration of oesophagus, trachea and aorta contours. DIR was used to examine the correlation between PET-avid volumes, dosimetry and site of recurrence.

RESULTS

Positional metrics including the dice similarity coefficient (DSC) and conformity index (CI), showed DIR to be superior to rigid registration in the co-registration of diagnostic and recurrence imaging to the planning CT. For diagnostic PET-CT, DIR was superior to rigid registration in the transfer of oesophagus (DSC=0.75 versus 0.65, P<0.009 and CI=0.59 versus 0.48, P<0.003), trachea (DSC=0.88 versus 0.65, P<0.004 and CI=0.78 versus 0.51, P<0.0001) and aorta structures (DSC=0.93 versus 0.86, P<0.006 and CI=0.86 versus 0.76, P<0.006). For recurrence imaging, DIR was superior to rigid registration in the transfer of trachea (DSC=0.91 versus 0.66, P<0.03 and CI=0.83 versus 0.51, P<0.02) and oesophagus structures (DSC=0.74 versus 0.51, P<0.004 and CI=0.61 versus 0.37, P<0.006) with a non-significant trend for the aorta (DSC=0.91 versus 0.75, P<0.08 and CI=0.83 versus 0.63, P<0.06) structure. A mean inclusivity index of 0.93 (range 0.79-1) showed that the relapse volume was within the planning target volume (PTVPET-CT); all relapses occurred within the high dose region.

CONCLUSION

DIR is superior to rigid registration in the co-registration of PET-CT and recurrence CT to the planning CT, and can be considered in the direct integration of PET-CT to the treatment planning process. Local recurrences occur within the PTVPET-CT, suggesting that this is a suitable target for dose-escalation strategies.

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.

Total Lesion Glycolysis Using ¹⁸F-FDG PET/CT as a Prognostic Factor for Locally Advanced Esophageal Cancer

Standardized uptake value (SUV), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) have been considered prognostic factors for survival in many cancers. However, their prognostic value for radiotherapy-treated squamous esophageal cancer has not been evaluated. In this study, SUV, MTV, and TLG were measured to predict their prognostic role in overall survival (OS) in 38 esophageal cancer patients who had undergone (18)F-FDG PET/CT before radiotherapy. TLG demonstrated higher sensitivity and specificity for predicting OS than MTV and SUV; and a better OS was observed in patients with low TLG compared to those with high TLG in locally advanced disease (OS, 46.9 months; 95% confidence interval [CI], 33.50-60.26 vs. 25.3 months; 95% CI, 8.37-42.28; P=0.003). Multivariate analyses in these patients determined that TLG and the use of combination chemotherapy were the independent prognostic factors for OS (hazard ratio [HR], 7.12; 95% CI, 2.038-24.857; P=0.002 and HR, 6.76; 95% CI, 2.149-21.248; P=0.001, respectively). These results suggest that TLG is an independent prognostic factor for OS and a better predictor of survival than MTV and SUV in patients with locally advanced esophageal cancer treated with radiotherapy.

Integration of imaging into clinical practice to assess the delivery and performance of macromolecular and nanotechnology-based oncology therapies

Functional and molecular imaging has become increasingly used to evaluate interpatient and intrapatient tumor heterogeneity. Imaging allows for assessment of microenvironment parameters including tumor hypoxia, perfusion and proliferation, as well as tumor metabolism and the intratumoral distribution of specific molecular markers. Imaging information may be used to stratify patients for targeted therapies, and to define patient populations that may benefit from alternative therapeutic approaches. It also provides a method for non-invasive monitoring of treatment response at earlier time-points than traditional cues, such as tumor shrinkage. Further, companion diagnostic imaging techniques are becoming progressively more important for development and clinical implementation of targeted therapies. Imaging-based companion diagnostics are likely to be essential for the validation and FDA approval of targeted nanotherapies and macromolecular medicines. This review describes recent clinical advances in the use of functional and molecular imaging to evaluate the tumor microenvironment. Additionally, this article focuses on image-based assessment of distribution and anti-tumor effect of nano- and macromolecular systems.

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).

Role of fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography in gastrointestinal cancers

Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) has become a routine imaging modality for many malignancies and its use is currently increasing. In the present review article, we will summarize the evidence for FDG-PET/CT use in digestive cancers (excluding neuroendocrine tumours), and review the existing recommendations. While PET/CT is nowadays considered to be an important tool in the initial workup of oesophageal and anal cancers, new data are emerging regarding its use in assessing therapeutic efficacy, radiotherapy treatment planning, and detection of recurrence in case of isolated tumour marker elevation. Moreover, PET/CT may help decision making by detecting distant metastatic sites especially in potentially resectable metastatic colorectal cancer and, to a lesser extent, in localized gastric and pancreatic cancers. Finally, incidental focal colonic FDG uptakes require exploration by colonoscopy, as they are often associated with premalignant or malignant lesions.

State-of-the-art molecular imaging in esophageal cancer management: implications for diagnosis, prognosis, and treatment

Molecular imaging techniques are increasingly being used in addition to standard imaging methods such as endoscopic ultrasound (EUS) and computed tomography (CT) for many cancers including those of the esophagus. In this review, we will discuss the utility of the most widely used molecular imaging technique, (18)F-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET). (18)F-FDG PET has a variety of potential applications ranging from improving staging accuracy at the time of initial diagnosis to assisting in radiation target volume delineation. Furthermore, (18)F-FDG PET can be used to evaluate treatment response after completion of neoadjuvant therapy or potentially during neoadjuvant therapy. Finally, we will also discuss other novel molecular imaging techniques that have potential to further improve cancer care.

Value of CT–PET after neoadjuvant chemoradiation in the prediction of histological tumour regression, nodal status and survival in oesophageal adenocarcinoma

Background

The role of CT–PET after neoadjuvant chemoradiation (nCRT) for prediction of pathological response and oncological outcome in oesophageal and junctional adenocarcinoma (OAC) is unclear. The relationship between complete metabolic response (cMR), pathological complete response (pCR) and nodal status has not been clarified.

Methods

Patients with locally advanced OAC selected to receive nCRT and surgery with curative intent, on the basis of staging that included CT–PET positivity, were included. Repeat scanning (PET2) with an identical protocol was performed 2–4 weeks after completion of nCRT (cisplatin and 5-fluorouracil plus 44 Gy radiation). Changes in [18F]fluorodeoxyglucose uptake, considered as either a maximum standardized uptake value (SUVmax) or a relative reduction (%ΔSUVmax), and PET-predicted nodal status following nCRT were compared with histopathological response, histological node positivity and survival.

Results

One hundred consecutive patients with PET-positive OAC were studied. Following nCRT, PET2 identified M1 disease in 2·0 per cent of patients. There were no significant associations between PET2 SUVmax or %ΔSUVmax with respect to primary tumour stage (ypT) (P = 0.216 and P = 0·975 respectively), tumour regression grade (P = 0·109 and P = 0·232), pCR (P = 0·633 and P = 0·870) or complete resection (R0) (P = 0·440 and P = 0·235). The sensitivity of PET2 for ypN was 10 per cent. %ΔSUVmax was not associated with disease-free or overall survival (P = 0·162 and P = 0·154 respectively). Of 46 patients with a cMR on PET2, 37 (80 per cent) had histological evidence of residual tumour in the resected specimen, and cMR was not associated with overall survival benefit (P = 0·478).

Conclusion

CT–PET following nCRT for OAC has poor prognostic and discriminatory value for clinical application.

The application of functional imaging techniques to personalise chemoradiotherapy in upper gastrointestinal malignancies

Functional imaging gives information about physiological heterogeneity in tumours. The utility of functional imaging tests in providing predictive and prognostic information after chemoradiotherapy for both oesophageal cancer and pancreatic cancer will be reviewed. The benefit of incorporating functional imaging into radiotherapy planning is also evaluated. In cancers of the upper gastrointestinal tract, the vast majority of functional imaging studies have used (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET). Few studies in locally advanced pancreatic cancer have investigated the utility of functional imaging in risk-stratifying patients or aiding target volume definition. Certain themes from the oesophageal data emerge, including the need for a multiparametric assessment of functional images and the added value of response assessment rather than relying on single time point measures. The sensitivity and specificity of FDG-PET to predict treatment response and survival are not currently high enough to inform treatment decisions. This suggests that a multimodal, multiparametric approach may be required. FDG-PET improves target volume definition in oesophageal cancer by improving the accuracy of tumour length definition and by improving the nodal staging of patients. The ideal functional imaging test would accurately identify patients who are unlikely to achieve a pathological complete response after chemoradiotherapy and would aid the delineation of a biological target volume that could be used for treatment intensification. The current limitations of published studies prevent integrating imaging-derived parameters into decision making on an individual patient basis. These limitations should inform future trial design in oesophageal and pancreatic cancers.

PET/CT planning during chemoradiotherapy for esophageal cancer

PURPOSE

To evaluate the usefulness of positron emission tomography/computed tomography (PET/CT) for field modification during radiotherapy in esophageal cancer.

MATERIALS AND METHODS

We conducted a retrospective study on 33 patients that underwent chemoradiotherapy (CRT). Pathologic findings were squamous cell carcinoma in 32 patients and adenocarcinoma in 1 patient. All patients underwent PET/CT scans before and during CRT (after receiving 40 Gy and before a 20 Gy boost dose). Response evaluation was determined by PET/CT using metabolic tumor volume (MTV), total glycolytic activity (TGA), MTV ratio (rMTV) and TGA ratio (rTGA), or determined by CT. rMTV and rTGA were reduction ratio of MTV and TGA between before and during CRT, respectively.

RESULTS

Significant decreases in MTV (MTV2.5: mean 70.09%, p < 0.001) and TGA (TGA2.5: mean 79.08%, p<0.001) were found between before and during CRT. Median rMTV2.5 was 0.299 (range, 0 to 0.98) and median rTGA2.5 was 0.209 (range, 0 to 0.92). During CRT, PET/CT detected newly developed distant metastasis in 1 patient, and this resulted in a treatment strategy change. At a median 4 months (range, 0 to 12 months) after completion of CRT, 8 patients (24.2%) achieved clinically complete response, 11 (33.3%) partial response, 5 (15.2%) stable disease, and 9 (27.3%) disease progression. SUVmax (p = 0.029), rMTV50% (p = 0.016), rMTV75% (p = 0.023) on intra-treatment PET were found to correlate with complete clinical response.

CONCLUSION

PET/CT during CRT can provide additional information useful for radiotherapy planning and offer the potential for tumor response evaluation during CRT. rMTV50% during CRT was found to be a useful predictor of clinical response.

Current concepts in clinical radiation oncology

Based on its potent capacity to induce tumor cell death and to abrogate clonogenic survival, radiotherapy is a key part of multimodal cancer treatment approaches. Numerous clinical trials have documented the clear correlation between improved local control and increased overall survival. However, despite all progress, the efficacy of radiation-based treatment approaches is still limited by different technological, biological, and clinical constraints. In principle, the following major issues can be distinguished: (1) The intrinsic radiation resistance of several tumors is higher than that of the surrounding normal tissue, (2) the true patho-anatomical borders of tumors or areas at risk are not perfectly identifiable, (3) the treatment volume cannot be adjusted properly during a given treatment series, and (4) the individual heterogeneity in terms of tumor and normal tissue responses toward irradiation is immense. At present, research efforts in radiation oncology follow three major tracks, in order to address these limitations: (1) implementation of molecularly targeted agents and 'omics'-based screening and stratification procedures, (2) improvement of treatment planning, imaging, and accuracy of dose application, and (3) clinical implementation of other types of radiation, including protons and heavy ions. Several of these strategies have already revealed promising improvements with regard to clinical outcome. Nevertheless, many open questions remain with individualization of treatment approaches being a key problem. In the present review, the current status of radiation-based cancer treatment with particular focus on novel aspects and developments that will influence the field of radiation oncology in the near future is summarized and discussed.

Timing and intensity of changes in FDG uptake with symptomatic esophagitis during radiotherapy or chemo-radiotherapy

Purpose

To study whether esophageal FDG activity changes by time of mid-course of fractionated radiotherapy (RT), and whether these changes are associated with radiation esophagitis in patients with non-small cell lung cancer (NSCLC).

Methods

Fifty patients with stage I-III NSCLC were enrolled prospectively and, all received ≥60 Gy RT. FDG-PET/CT scans were acquired prior to, and during-RT after delivery of 45 Gy. Normalized standardized uptake values (NSUV), defined by the esophageal maximum SUV relative to intravascular background level in the aortic arch, were sampled in the esophagus at the level of the primary tumor, sternal notch, aortic arch, carina, and gastro-esophageal junction. Symptomatic radiation esophagitis was defined as an event.

Results

Compared to baseline, esophageal NSUV increased significantly during-RT at the level of the primary tumor (1.09 ± 0.05 vs.1.28 ± 0.06, p = 0.001), but did not change at other levels in the esophagus. 16 patients had radiation esophagitis events and these patients had significantly higher during-RT to baseline NSUV ratios than those without esophagitis (1.46 ± 0.12, 95% CI 1.20-1.71; vs. 1.11 ± 0.05, 95% CI 1.01-1.21, p = 0.002). Maximum esophageal dose (p = 0.029), concurrent chemotherapy (p = 0.022) and esophageal FDG PET NSUV ratio (during-RT to baseline, p = 0.007), were independent factors associated with esophagitis and area under curves (AUC) were 0.76, 0.70 and 0.78, respectively. Combining esophageal maximum dose and FDG PET NSUV Ratio at the tumor level increased AUC to 0.85 (p = 0.016).

Conclusion

FDG uptake increased in esophagus during-RT and this increase may predict radiation esphagitis during later course of treatment.

Role of surgical resection in complete responders on FDG-PET after chemoradiotherapy for locally advanced esophageal squamous cell carcinoma

BACKGROUND AND OBJECTIVES

To determine the role of surgery in complete responders on FDG-PET after CRT and the prognostic significance of metabolic response in locally advanced esophageal squamous cell carcinoma.

METHODS

We retrospectively reviewed 154 patients with locally advanced esophageal cancer with increased uptake on FDG-PET. Eighty-one patients received definitive CRT and 73 received trimodality therapy. We defined metabolic complete remission (PET-CR) when FDG uptake of the primary tumor and lymph nodes were decreased and was indistinguishable from surrounding normal tissue. Oncologic outcomes were compared between trimodality group, definitive CRT group, and PET-CR subgroup of definitive CRT.

RESULTS

Thirty-one (38.3%) of the definitive CRT patients and 39 (53.4%) of the trimodality therapy patients achieved PET-CR after CRT. The 2-year OS of the trimodality group was higher than that of the definitive CRT group, but equivalent to that of the PET-CR subgroup of definitive CRT. The 2-year LRFS and DFS of the trimodality group were higher than that of the PET-CR subgroup or the entire of definitive CRT group.

CONCLUSION

The addition of surgery showed higher DFS and LRFS rates than those of the PET-CR subgroup of definitive CRT. Despite achieving PET-CR, surgery still seems to improve local tumor control.

Prediction of outcome with FDG-PET in definitive chemoradiotherapy for esophageal cancer

The purpose of this study was to assess the efficacy of ¹⁸F-fluoro-2-deoxy-glucose uptake positron emission tomography (FDG-PET) for the prediction of outcome in definitive chemoradiotherapy (CRT) for esophageal cancer. We enrolled 56 patients with esophageal cancer treated with definitive CRT and examined by FDG-PET before treatment. We examined the correlation of the maximum standardized uptake value (SUVmax) in FDG-PET of the primary tumor with overall survival (OS), progression-free survival (PFS), local control (LC) and response of the primary tumor. After definitive CRT, 30 patients had a clinical complete response (CR), making the CR rate 54%. For all 56 patients, the 2-year OS rate, PFS rate and LC rates were 64%, 38% and 51%, respectively. We divided the patients into two groups according to SUVmax: SUVmax < 10 (low-SUV) and ≥10 (high-SUV). The 2-year OS rates in the low- and high-SUV groups were 100% and 41%, the PFS rates were 73% and 19%, the LC rates were 71% and 39%, and the CR rates were 100% and 32%, respectively. A univariate analysis revealed significant differences between the low- and high-SUV group in OS, PFS, LC and response (P = 0.0005, 0.0002, 0.048, and <0.0001, respectively). SUVmax and T stage were significantly associated with OS, PFS, LC and response. A multivariate analysis showed significant differences between the SUVmax <10 and ≥10 groups in overall survival and response (P < 0.05). Our result suggests that the SUVmax in FDG-PET of the primary tumor before treatment may have prognostic value for esophageal cancer.

Complete metabolic response is not uniformly predictive of complete pathologic response after induction therapy for esophageal cancer

BACKGROUND

Positron emission tomography scanning is used to assess response to induction therapy after treatment of esophageal cancer. A decrease in standardized uptake value has been correlated with response to therapy, with a standardized uptake value of zero often assumed to indicate complete absence of disease. We hypothesize that a significant number of patients may have residual esophageal cancer despite complete metabolic response (CMR).

METHODS

A prospective database was reviewed for esophageal cancer patients receiving induction therapy followed by esophagectomy on whom both preinduction and postinduction positron emission tomography scans were obtained. Patients with a postinduction SUV of 0 (or "no uptake") were categorized as complete metabolic responders. Survival was calculated by the Kaplan-Meier statistic.

RESULTS

Among 120 patients, 32 (27%) had postinduction CMR after chemotherapy (21 of 81, 26%) or chemoradiation (11 of 39, 28%). At surgery, 19 patients (59%) with CMR had residual disease, including 12 (38%) with nodal metastases. Even among patients with a negative postinduction biopsy, 4 of 10 (40%) had residual disease. Final pathologic stages of patients with CMR were yp0 (complete pathologic response) in 13 (41%), ypI in 4 (12%), ypII in 9 (28%), and ypIII in 6 (19%). Three-year survival was 83% in the CMR group versus 41% in the remainder of the cohort (p = 0.02).

CONCLUSIONS

A CMR on postinduction positron emission tomography scan predicts but should not be assumed to be synonymous with complete pathologic response in esophageal cancer patients. The presence of residual disease should be strongly considered despite CMR and negative biopsy in patients receiving induction therapy.

Automated biological target volume delineation for radiotherapy treatment planning using FDG-PET/CT

BACKGROUND

This study compared manually delineated gross tumour volume (GTV) and automatically generated biological tumour volume (BTV) based on fluoro-deoxy-glucose (FDG) positron emission tomography (PET)/CT to assess the robustness of predefined PET algorithms for radiotherapy (RT) planning in routine clinical practice.

METHODS

RT-planning data from 20 consecutive patients (lung- (40%), oesophageal- (25%), gynaecological- (25%) and colorectal (10%) cancer) who had undergone FDG-PET/CT planning between 08/2010 and 09/2011 were retrospectively analysed, five of them underwent neoadjuvant chemotherapy before radiotherapy. In addition to manual GTV contouring, automated segmentation algorithms were applied-among these 38%, 42%, 47% and 50% SUVmax as well as the PERCIST total lesion glycolysis (TLG) algorithm. Different ratios were calculated to assess the overlap of GTV and BTV including the conformity index and the ratio GTV included within the BTV.

RESULTS

Median age of the patients was 66 years and median tumour SUVmax 9.2. Median size of the GTVs defined by the radiation oncologist was 43.7 ml. Median conformity indices were between 30.0-37.8%. The highest amount of BTV within GTV was seen with the 38% SUVmax algorithm (49.0%), the lowest with 50% SUVmax (36.0%). Best agreement was obtained for oesophageal cancer patients with a conformity index of 56.4% and BTV within GTV ratio of 71.1%.

CONCLUSIONS

At present there is only low concordance between manually derived GTVs and automatically segmented FDG-PET/CT based BTVs indicating the need for further research in order to achieve higher volumetric conformity and therefore to get access to the full potential of FDG-PET/CT for optimization of radiotherapy planning.

The predictive value of treatment response using FDG PET performed on day 21 of chemoradiotherapy in patients with oesophageal squamous cell carcinoma. A prospective, multicentre study (RTEP3)

PURPOSE

FDG PET has been suggested to have predictive value in the prognosis of oesophageal carcinoma. However, the retrospective studies reported in the literature have shown discordant results. Additionally, only four studies have evaluated FDG PET during chemoradiotherapy (CRT) in patients with different histological lesions. The purpose of this study was to investigate the predictive value of FDG PET performed early during CRT (on day 21) in a population of patients with oesophageal squamous cell carcinoma.

METHODS

Included in this prospective study were 57 patients with a histological diagnosis of squamous cell carcinoma of the oesophagus. Of these 57 patients, 48 (84%) were evaluated (aged 63 ± 11 years; 44 men, 4 women). Each patient underwent FDG PET (4.5 MBq/kg) before CRT, according to the Herskovic protocol (t0; PET₁) and on day 21 ± 3 from the start of CRT (d21; PET₂). The response assessment included a clinical examination, CT scan or FDG PET and histological analysis 3 months and 1 year after PET₁. The patients were classified as showing a complete response (CR) or a noncomplete response. A quantitative analysis was carried out for PET₁ and PET₂ using the following parameters: SUVmax, SUVmean (with SUVmean40 as the 3-D volume at an SUVmax threshold of 40% and SUVmeanp as that defined by a physician), tumour volume (TV, with TV40 defined as the TV at 40% of SUVmax, and TVp as that defined by a physician); and the total lesion glycolysis (TLG, SUVmean × TV, with TLG₄₀ defined as the TLG at 40% of SUVmax, and TLGp as that defined by a physician). The differences in responses at 3 months and 1 year between PET₁ (t0) and PET₂ (d21) were assessed in terms of variations in SUV, TV and TLG using a repeated measures of variance (ANOVA).

RESULTS

SUVmax, SUVmean and TLG decreased significantly between PET₁ (t0) and PET₂ (d21; p < 0.0001). The TV significantly decreased only when assessed as TVp (p = 0.02); TV₄₀ did not decrease significantly. With respect to the predictive value of PET₁, only TV40_1 and TVp_1 values, and therefore TLG40_1 and TLGp_1, but not the SUV values, were significantly lower in patients with CR at 3 months. SUVmax1, TVp_1 and TLGp_1 were significantly lower in patients with CR at 1 year. With respect to the predictive value of PET₂, only TV40_2 and TVp_2 values, and therefore TLG40_2 and TLGp_2, but not the SUV values, were significantly lower in patients with CR at 3 months. None of the PET₂ parameters had significant value in predicting patient outcome at 1 year. The changes in SUVmax, TV₄₀, TVp, TLG₄₀ and TLGp between PET₁ and PET₂ had no relationship to patient outcome at 3 months or 1 year.

CONCLUSION

This prospective, multicentre study performed in a selected population of patients with oesophageal squamous cell cancer demonstrates that the parameters derived from baseline PET₁ are good predictors of response to CRT. Specifically, a high TV and TLG are associated with a poor response to CRT at 3 months and 1 year, and a high SUVmax is associated with a poor response to CRT at 1 year. FDG PET performed during CRT on day 21 appears to have less clinical relevance. However, patients with a large functional TV on day 21 of CRT have a poor clinical outcome (ClinicalTrials.gov NCT 00934505).

Multidisciplinary management of esophageal cancer

This article reviews the current management of esophageal cancer, including staging and treatment options, as well as providing support for using multidisciplinary teams to better manage esophageal cancer patients.

18F-fluorodeoxyglucose positron emission tomography after definitive chemoradiotherapy in patients with oesophageal carcinoma

BACKGROUND

The purpose of the study was to investigate the value of 18F-fluorodeoxyglucose-positron emission tomography performed after definitive chemoradiotherapy in patients with locally advanced oesophageal carcinoma.

METHODS

Forty consecutive patients underwent 18F-fluorodeoxyglucose-positron emission tomography at baseline and after chemoradiotherapy completion. Assessment of the clinical complete response to chemoradiotherapy included oesophagoscopy plus biopsies and computed tomography scan. Cox regression analysis was used to develop the univariate and multivariate models describing the association of the independent variables with survival and local control.

RESULTS

A clinical complete response and 18F-fluorodeoxyglucose-positron emission tomography response were present in 29 patients (72.5%) and 13 patients (32.5%), respectively. A combined response was observed in 11 patients (27.5%). During follow-up, a local failure was detected in 27.2% of patients with 18F-fluorodeoxyglucose-positron emission tomography response versus 33.3% in non-responders (p=.9). In multivariate analysis, clinical complete response (HR 5.77, p=.009) and 18F-fluorodeoxyglucose-positron emission tomography response (HR 6.27, p=.031) were identified as independent prognostic factors of overall survival.

CONCLUSION

In patients treated for an esophageal cancer, the present study suggested that 18F-fluorodeoxyglucose-positron emission tomography after chemoradiotherapy completion was an independent prognostic factor of overall survival without significant impact on local recurrence prediction.