Dose escalated neoadjuvant chemoradiotherapy with dose-painting intensity-modulated radiation therapy and improved pathologic complete response in locally advanced esophageal cancer

Nuclear medicine radiomics in digestive system tumors: Concept, applications, challenges, and future perspectives

Radiomics aims to develop novel biomarkers and provide relevant deeper subvisual information about pathology, immunophenotype, and tumor microenvironment. It uses automated or semiautomated quantitative analysis of high-dimensional images to improve characterization, diagnosis, and prognosis. Recent years have seen a rapid increase in radiomics applications in nuclear medicine, leading to some promising research results in digestive system oncology, which have been driven by big data analysis and the development of artificial intelligence. Although radiomics advances one step further toward the non-invasive precision medical analysis, it is still a step away from clinical application and faces many challenges. This review article summarizes the available literature on digestive system tumors regarding radiomics in nuclear medicine. First, we describe the workflow and steps involved in radiomics analysis. Subsequently, we discuss the progress in clinical application regarding the utilization of radiomics for distinguishing between various diseases and evaluating their prognosis, and demonstrate how radiomics advances this field. Finally, we offer our viewpoint on how the field can progress by addressing the challenges facing clinical implementation.

Induction Fluorouracil-Based Chemotherapy and PET-Adapted Consolidation Chemoradiation with Esophagectomy for High-Risk Gastroesophageal Adenocarcinoma

Background: Neoadjuvant chemoradiation with esophagectomy is standard management for locally advanced esophageal adenocarcinoma. Induction chemotherapy with a tailored approach to chemoradiation based on metabolic response to therapy on PET was explored as an alternative strategy in the CALGB 80803 trial. We sought to describe real-world institutional experience implementing this approach outside of a clinical trial. Methods: Patients who were treated with induction fluorouracil-leucovorin-oxaliplatin (FOLFOX) or fluorouracil-leucovorin-oxaliplatin-docetaxel (FLOT) with tailored chemoradiation based on PET response and subsequent esophagectomy were identified from a prospectively maintained database. Primary outcomes were pathologic complete response (pCR) and overall survival (OS) following completion of all therapy. Results: There were 35 patients who completed induction chemotherapy, chemoradiation, and esophagectomy. Thirty-three completed restaging PET following induction chemotherapy with metabolic response seen in 76% (n = 25/33). The pCR rate was 31% (n = 11/35) and the ypN0 rate was 71% (n = 25/35). Among the patients who demonstrated metabolic response to induction FOLFOX/FLOT and subsequently continued fluorouracil-based chemoradiation, the pCR rate was 39% (n = 9/23). The rate of pathologically negative lymph nodes in this group was high (n = 19/23, 83%) with 100% R0 resection rate (n = 23/23). With the median follow-up of 43 months, the median OS was not reached for this group and was significantly longer than the OS for the remainder of the cohort (p = 0.027, p = 0.046 adjusted for clinical stage). Conclusions: Induction FOLFOX/FLOT chemotherapy with evaluation of sensitivity via metabolic response and tailored chemoradiation seems to lead to high pCR and ypN0 rates in high-risk patients with adenocarcinoma of the esophagus and GE junction. This approach in clinical practice seems to recapitulate encouraging results in clinical trials.

The effect of histologic grade on neoadjuvant treatment outcomes in esophageal cancer

BACKGROUND AND OBJECTIVES

The gold standard for locoregional esophageal cancer (LEC) treatment includes preoperative chemoradiation and surgical resection, with possible perioperative or adjuvant systemic therapy. With few data associating histologic grade and prognosis in LEC patients receiving neoadjuvant chemoradiation followed by resection, we seek to evaluate this association.

METHODS

Our institutional esophagectomy database between 1999 and 2019 was queried, selecting esophageal adenocarcinoma patients who completed neoadjuvant therapy (NAT), followed by esophagectomy. Propensity-score matching of low- and high-histologic grade groups was performed to assess survival metrics using initial clinical grade (cG) and final pathologic grade (pG). We performed a multivariable logistic regression to study predictors of pathologic complete response as a secondary objective.

RESULTS

A total of 518 patients met the inclusion criteria. Kaplan-Meier analysis of the matched dataset showed no difference in initial or 5-year recurrence-free survival or overall survival (OS) between cG1 and cG2 versus cG3 based on original grade. When matched according to pG, cG1-2 had improved median survival parameters compared to cG3, with 5-year OS for cG1-2 of 45% versus 27% (p = 0.001). Higher pG, pathologic N stage, and poor response to NAT are predictors of poor survival.

CONCLUSION

Patients with post-NAT pG1-2 demonstrated improved survival. Integrating histologic grade into postneoadjuvant staging may be warranted.

Prognostic Effect of the Dose of Radiation Therapy and Extent of Lymphadenectomy in Patients Receiving Neoadjuvant Chemoradiotherapy for Esophageal Squamous Carcinoma

Neoadjuvant chemoradiotherapy has been used for patients with locally advanced esophageal squamous cell carcinoma (ESCC). However, the optimal dose of radiation therapy and the effect of lymphadenectomy after neoadjuvant therapy on patient outcomes are uncertain. We retrospectively reviewed the data of patients who received neoadjuvant therapy followed by surgery for ESCC. Overall survival (OS), disease-free survival (DFS), and perioperative outcomes were compared between patients who received radiation doses of 45.0 Gy (PF4500) and 50.4 Gy (PF5040). Subgroup analysis was performed based on the number of lymph nodes removed through lymph node dissection (LND). Data from a total of 126 patients were analyzed. No significant differences were found in 3-year OS and DFS between the PF4500 and PF5040 groups (OS: 45% versus 54%, p = 0.218; DFS: 34% versus 37%, p = 0.506). In both groups, no significant differences were found in 3-year locoregional-specific DFS between patients with a total LND number ≤17 and >17 (PF4500, 35% versus 50%, p = 0.291; PF5040 group, 45% versus 46%, p = 0.866). The PF5040 and PF4500 groups were comparable in terms of survival outcomes and local control. Although no additional survival benefits were identified, the extent of LND should not be altered according to the radiation dose.

Impact of histology classification on pathologic treatment response and overall survival in distal esophageal cancer patients: a propensity matched analysis

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) has been linked to superior pathologic treatment response compared to esophageal adenocarcinoma (EAC) after neoadjuvant chemoradiation. However, the impact of histology on survival remains unclear. It has been suggested, based on epidemiologic similarities, that distal EAC should be grouped with gastric cancers as an entity distinct from distal ESCC, but there is little data to support this recommendation. We therefore aim to compare pathologic treatment response (PTR) and overall survival (OS) in patients with distal EAC versus distal ESCC.

METHODS

This retrospective cohort study included patients who underwent esophagectomy for distal esophageal malignancy. Histologic sub-groups were matched (1:1) using a propensity-score matching approach. Pre-operative clinical parameters, oncologic outcomes and survival were compared between groups.

RESULTS

1031 distal EC patients, with a median age of 64.4 years and a male preponderance (86.5%), underwent esophagectomy at our institution between 1999 and 2019. 939 (91.1%) patients had a diagnosis of EAC and 92 (8.9%) had ESCC. A higher proportion of ESCC patients were female (26.1% vs. 12.1%; P < 0.01) and non-white (12.0% vs. 3.8%; P < 0.01). Propensity-score sub-analysis identified 75 matched pairs. Rates of pathologic complete response (58.0% vs. 48.9%; P = 0.67) and OS (43.0 vs. 52.0 months; P = 0.808) were not significantly different between matched groups.

CONCLUSIONS

Although traditionally known to have a better overall PTR compared to EAC, ESCC patients in our large series did not show any improvement in PTR or OS. Treatment recommendations for patients with EAC and ESCC should consider tumor location in addition to histology.

Pretreatment CT and 18 F-FDG PET-based radiomic model predicting pathological complete response and loco-regional control following neoadjuvant chemoradiation in oesophageal cancer

INTRODUCTION

To develop a radiomic-based model to predict pathological complete response (pCR) and outcome following neoadjuvant chemoradiotherapy (NACRT) in oesophageal cancer.

METHODS

We analysed 68 patients with oesophageal cancer treated with NACRT followed by esophagectomy, who had staging 18F-fluorodeoxyglucose (¹⁸ F-FDG) positron emission tomography (PET) and computed tomography (CT) scans performed at our institution. An in-house data-chjmirocterization algorithm was used to extract 3D-radiomic features from the segmented primary disease. Prediction models were constructed and internally validated. Composite feature, F_c  = α * F_PET  + (1 - α) * F_CT , 0 ≤ α ≤ 1, was constructed for each corresponding CT and PET feature. Loco-regional control (LRC), recurrence-free survival (RFS), metastasis-free survival (MFS) and overall survival (OS) were estimated by Kaplan-Meier analysis, and compared using log-rank test.

RESULTS

Median follow-up was 59 months. pCR was achieved in 34 (50%) patients. Five-year RFS, LRC, MFS and OS were 67.1%, 88.5%, 75.6% and 57.6%, respectively. Tumour Regression Grade (TRG) 0-1 indicative of complete response or minimal residual disease was significantly associated with improved 5-year LRC [93.7% vs 71.8%; P = 0.020; HR 0.19, 95% CI 0.04-0.85]. Four sepjmirote pCR predictive models were built for CT alone, PET alone, CT+PET and composite. CT, PET and CT+PET models had AUC 0.73 ± 0.08, 0.66 ± 0.08 and 0.77 ± 0.07, respectively. The composite model resulted in an improvement of pCR predicting power with AUC 0.87 ± 0.06. Stratifying patients with a low versus high radiomic score showed clinically relevant improvement in 5-year LRC favouring low-score group (91.1% vs. 80%, 95% CI 0.09-1.77, P = 0.2).

CONCLUSION

The composite CT/PET radiomics model was highly predictive of pCR following NACRT. Validation in larger data sets is warranted to determine whether the model can predict clinical outcomes.

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.

A FDG-PET radiomics signature detects esophageal squamous cell carcinoma patients who do not benefit from chemoradiation

Detection of patients with esophageal squamous cell carcinoma (ESCC) who do not benefit from standard chemoradiation (CRT) is an important medical need. Radiomics using 18-fluorodeoxyglucose (FDG) positron emission tomography (PET) is a promising approach. In this retrospective study of 184 patients with locally advanced ESCC. 152 patients from one center were grouped into a training cohort (n = 100) and an internal validation cohort (n = 52). External validation was performed with 32 patients treated at a second center. Primary endpoint was disease-free survival (DFS), secondary endpoints were overall survival (OS) and local control (LC). FDG-PET radiomics features were selected by Lasso-Cox regression analyses and a separate radiomics signature was calculated for each endpoint. In the training cohort radiomics signatures containing up to four PET derived features were able to identify non-responders in regard of all endpoints (DFS p < 0.001, LC p = 0.003, OS p = 0.001). After successful internal validation of the cutoff values generated by the training cohort for DFS (p = 0.025) and OS (p = 0.002), external validation using these cutoffs was successful for DFS (p = 0.002) but not for the other investigated endpoints. These results suggest that pre-treatment FDG-PET features may be useful to detect patients who do not respond to CRT and could benefit from alternative treatment.

Refusal of Local Therapy in Esophageal Cancer and Impact on Overall Survival

OBJECTIVE

The aim of this study was to understand factors associated with refusal of local therapy in esophageal cancer and compare the overall survival (OS) of patients who refuse therapies with those who undergo recommended treatment.

METHODS

National Cancer Database data for patients with non-metastatic esophageal cancer from 2006 to 2013 were pooled. T1N0M0 tumors were excluded. Pearson's Chi-square test and multivariate logistic regression analyses were used to assess demographic, clinical, and treatment factors. After propensity-score matching with inverse probability of treatment weighting, OS was compared between patients who refused therapies and those who underwent recommended therapy, using Kaplan-Meier analyses and doubly robust estimation with multivariate Cox proportional hazards modeling.

RESULTS

In total, 37,618 patients were recommended radiation therapy (RT) and/or esophagectomy; we found 1403 (3.7%) refused local therapies. Specifically, 890 of 18,942 (4.6%) patients refused surgery and 667 of 31,937 (2.1%) refused RT. Older patients, females, those with unknown lymphovascular space invasion, and those uninsured or on Medicare were more likely to refuse. Those with squamous cell carcinoma, N1 disease, higher incomes, living farther from care, and those who received chemotherapy were less likely to refuse. Five-year OS was decreased in patients who refused (18.1% vs. 27.6%). The survival decrement was present in adenocarcinoma but not squamous cell carcinoma. In patients who received surgery or ≥ 50.4 Gy RT, there was no OS decrement to refusing the other therapy.

CONCLUSIONS

We identified characteristics that correlate with refusal of local therapy. Refusal of therapy was associated with decreased OS. Patients who received either surgery or ≥ 50.4 Gy RT had no survival decrement from refusing the opposite modality.

Neoadjuvant and Definitive Radiochemotherapeutic Approaches in Esophageal Cancer: A Retrospective Evaluation of 122 Cases in Daily Clinical Routine

INTRODUCTION

Esophageal cancer (EC) is a common malignant tumor entity with increasing occurrence. The incidence of esophageal adenocarcinoma (AC), particularly, is constantly rising in the Western world. The mainstays of therapy with curative intent for EC in advanced stages are neoadjuvant radiochemotherapy (neoRCT) with surgery and definitive radiochemotherapy (defRCT).

METHODS

We examined our internal files to identify patients suffering from EC. Palliative cases were excluded. Statistical testing was performed by χ2 test, Student's t test, Kaplan-Meier analyses, and the Mann-Whitney U test.

RESULTS

One hundred and twenty-two cases were included. Histology revealed squamous cell carcinoma in 92 cases and AC in 23 cases. Ninety-five patients underwent defRCT, 27 underwent neoRCT, and 114 (in both therapy regimes) received simultaneous chemotherapy. There was no difference in the overall survival (OS) (p = 0.654; HR 1.145; 95% CI 0.629-2.086) or and progression-free survival (PFS) (p = 0.912) of patients who underwent neoRCT or defRCT. Median OS was 13.5 (2-197) months for defRCT patients and 19.5 (2-134) months for neoRCT patients (p = 0.751). Karnofsky index (KI) with a cut-off of 70% was strongest, but not a significant parameter for OS (p = 0.608) or PFS (p = 0.137).

CONCLUSION

defRCT is a valid and an equal alternative to neoRCT for patients suffering from EC. Selection of patients for therapy is of crucial relevance. Further studies and improvements in follow-up are needed when neoRCT has been completed before surgery, in order to spare the patient undergoing operative treatment if there is complete remission. The identification of valid markers urgently needed to limit treatment side effects.

Clinical factors associated with the development of postoperative atrial fibrillation in esophageal cancer patients receiving multimodality therapy before surgery

Background

The incidence of esophageal cancer (EC) is increasing in the USA. Neoadjuvant therapy for locally advanced cancers followed by surgical resection is the standard of care. The most common post-esophagectomy cardiac complication is atrial fibrillation (AF). New-onset postoperative AF can require a prolonged hospital stay and may confer an overall poorer prognosis. In this study, we seek to identify clinical factors associated with postoperative AF.

Methods

Query of an IRB approved database of 1,039 esophagectomies at our institution revealed 677 patients with EC from 1999 to 2017 who underwent esophagectomy after neoadjuvant treatment. Age, treatment location (primary vs. other), gender, neoadjuvant radiation type [2D vs. 3D vs. intensity modulated radiation therapy (IMRT)], radiation dose, surgery type (transthoracic vs. transhiatal vs. three field), smoking history, coronary artery disease (CAD), chronic obstructive pulmonary disease (COPD), operative time, blood transfusions, fluid management, and length of stay (LOS) were analyzed in relationship to the development of AF. Statistical analysis was performed with SPSS 24.

Results

The mean age of the entire cohort was 64.3 (range, 28-86 years), with a Caucasian and male preponderance (White: 94.5%; male: 83.6%). Of the 677 patients, 14.9% (n=101) developed postoperative AF. Increasing age (P<0.001), increased radiation dose (P=0.034), operative time (P=0.001), and blood transfusions (P=0.027) were associated with AF. LOS was longer in patients with AF than those without AF (10.5 vs. 10.0 days, P=0.001). On multivariate analysis, increasing age (95% CI: 1.023-1.080, P<0.001) and radiation dose (95% CI: 1.000-1.001, P=0.034) remained significant. None of the other parameters assessed were associated with the development of AF.

Conclusions

Increasing age and radiation dose were associated with the development of postoperative AF in this cohort. This study suggests that older patients or patients receiving higher radiation dose should be monitored more closely in the postoperative setting and potentially referred earlier preoperatively for cardio-oncology assessment. Future study is required to determine if modification of current radiation techniques and cardiac dose constraints in this patient population may be warranted.

Cardiotoxicity of radiation therapy in esophageal cancer

With a development of radiotherapeutic techniques, availability of radiotherapy data on cardiotoxicity, and slowly improving esophageal cancer outcomes, an increasing emphasis is placed on the heart protection in radiation treated esophageal cancer patients. Radiation induced heart complications encompass mainly pericardial disease, cardiomyopathy, coronary artery atherosclerosis, valvular heart disease, and arrhythmias. The most frequent toxicity is pericardial effusion which is usually asymptomatic in the majority of patients. The use of modern radiotherapy techniques is expected to reduce the risk of cardiotoxicity, although this expectation has to be confirmed by clinical data.

Radiation-induced hepatitis masquerading as metastatic disease: the importance of correlating diagnostic imaging with treatment planning

We are presenting a 63-year-old Caucasian male who complained of 2 months of progressive dysphagia. Upper endoscopy discovered a mass in the distal esophagus near the gastroesophageal junction. Biopsy was consistent with adenocarcinoma. Endoscopic ultrasound (EUS) showed extension beyond the muscularis propria, with an enlarged paraesophageal lymph node (T3N1). Initial positron emission tomography (PET)/computed tomography (CT) showed hypermetabolic portocaval lymphadenopathy presumed to be metastatic, but otherwise without distant disease extension. Neoadjuvant treatment included induction FOLFOX followed by 5,600 cGy over 28 fractions in combination with 5-FU and oxaliplatin. Approximately 3.5 weeks after completion, a repeat PET/CT revealed reduced uptake in both the primary esophageal mass and regional lymph nodes. Of note there were several new mass-like foci of hypermetabolism in the liver, specifically the left lobe, concerning for metastatic disease. Image-guided biopsy did not show any identifiable lesions, but sampling was performed based on anatomical landmarks. Pathology revealed benign parenchyma with minimal inflammation and mild reactive regeneration. In light of this, the patient proceeded to undergo definitive resection via robotic Ivor-Lewis esophagectomy with only 1 positive lymph node. Given pleural involvement by the tumor, staging was revised to pT4aN1 with final histology characterized as adenosquamous carcinoma. Postoperative course was fairly uneventful, with a mild exacerbation of his chronic heart failure. The patient was discharged on post-operative day 7, with his feeding tube removed at his 2-week post-operative clinic visit. This scenario is of particular educational value from the standpoint that when the post-treatment PET/CT images are registered to the radiotherapy treatment planning CT and dose, the areas of abnormal uptake in the liver fall within the higher dose regions. Given this and the liver biopsy findings, caution should be exercised before declaring progressive disease following radiotherapy without first reviewing the treatment plan.

Radiation dose and pathological response in oesophageal cancer patients treated with neoadjuvant chemoradiotherapy followed by surgery: a multi-institutional analysis

Purpose: To explore whether a higher neoadjuvant radiation dose increases the probability of a pathological complete response (pCR) or pathological major response (pMR) response in oesophageal cancer patients. Material and methods: Between 2000 and 2017, 1048 patients from four institutions were stratified according to prescribed neoadjuvant radiation doses of 36.0 Gy (13.3%), 40.0 Gy (7.4%), 41.4 Gy (20.1%), 45.0 Gy (25.5%) or 50.4 Gy (33.7%) in 1.8-2.0 Gy fractions. Endpoints were pCR (tumour regression grade (TRG) 1) and pMR (TRG 1 + 2). Multivariable binary (TRG 1 + 2 vs. TRG > 2) and ordinal (TRG 1 vs. TRG 2 vs. TRG > 2) logistic regression analyses were performed, with subgroup analyses according to histology (squamous cell carcinoma (SCC) vs. adenocarcinoma (AC)). Variables entered in the regression model along with neoadjuvant radiation dose were clinical tumour stage (cT), histology, chemotherapy regimen, induction chemotherapy and time from neoadjuvant chemoradiation to surgery. Results: A pCR was observed in 312 patients (29.8%); in 22.7% patients with AC and in 49.6% patients with SCC. No radiation dose-response relation was observed for pCR (OR = 1.01, 95% CI: 0.98-1.05 for AC and OR = 1.03, 95% CI: 0.96-1.10 for SCC). A pMR was observed in 597 patients (57.0%); in 53.4% patients with AC and in 67.2% patients with SCC. A higher radiation dose increased the probability of achieving pMR (OR = 1.04, 95% CI: 1.02-1.05). Factors reducing this probability were advanced cT stage (reference = cT1-2; cT3: OR = 0.54, 95% CI: 0.37-0.80; cT4: OR = 0.45, 95% CI: 0.24-0.84), AC histology (reference = SCC; OR = 0.62, 95% CI: 0.44-0.88), the use of non-platinum based chemotherapy in SCC patients (OR = 0.30, 95% CI: 0.10-0.91) and platinum based chemotherapy without induction chemotherapy in patients with AC (OR = 0.56, 95% CI: 0.42-0.76). The radiation dose-response relation was confirmed in a subgroup analysis of histologic subtypes (OR = 1.02, 95% CI: 1.01-1.04 for AC and OR = 1.05, 95% CI: 1.02-1.08 for SCC). Conclusions: Neoadjuvant radiation dose impacts pathological response in terms of pMR in oesophageal cancer patients. No radiation dose-response effect was observed for pCR. Further prospective trials are needed to investigate the dose-response relation in terms of pCR.

Higher Doses of Neoadjuvant Radiation for Esophageal Cancer Do Not Affect the Pathologic Complete Response Rate or Survival: A Propensity-Matched Analysis

BACKGROUND

Traditional neoadjuvant therapy for esophageal cancer has used chemoradiation doses greater than 45 Gy. This study aimed to examine the dose of preoperative radiation in relation to the pathologic complete response (pCR) rate and overall survival (OS) for patients with resectable esophageal cancer.

METHODS

The National Cancer Database was queried for all patients with esophageal or gastroesophageal junction cancer who received neoadjuvant chemoradiation (CRT) followed by esophagectomy between 2006 and 2015. The radiation doses were divided into four ranges based on Grays (Gy) received: less than 39.6 Gy, 39.60-44.99 Gy, 45-49.99 Gy, and 50 Gy or more.

RESULTS

The inclusion criteria were met by 10,293 patients. All patients received neoadjuvant CRT, with 689 patients (6.7%) receiving less than 39.6 Gy, 973 patients (9.5%) receiving 39.6-44.9 Gy, 3837 patients (37.3%) receiving 45-49.9 Gy, and 4794 patients (46.6%) receiving 50 Gy or more. The overall pCR rate was 17.2% (1769/10,293) and was significantly lower for those who received less than 39.6 Gy of radiation than for those who received 39.6 Gy or more (13.9% [96/689] vs. 17.4% [1673/9604]; p = 0.017). The median OS of 37.2 months was significantly better for those who received 39.6 Gy or more than for those who received less than 39.6 Gy (38 vs. 29.6 months (p < 0.0001). The pCR and OS did not differ between the three higher radiation doses (39.6-44.9 vs. 45-49.9 Gy vs. ≥ 50 Gy; pCR [p = 0.1] vs. OS [p = 0.097]). The patients who received 39.6-44.9 Gy were propensity matched with those who received 45 Gy or more of radiation. There remained no difference in pCR (p = 0.375) or OS (p = 0.957).

CONCLUSIONS

In the United States, the heterogeneity in neoadjuvant CRT dosing is significant, with 84% of patients receiving more than 45 Gy. The benefit of neoadjuvant CRT in terms of pCR and overall  survival is seen with doses of 39.6 Gy or more, but not with doses higher than 45 Gy.

Analyzing the impact of neoadjuvant radiation dose on pathologic response and survival outcomes in esophageal and gastroesophageal cancers

Background

The optimal neoadjuvant radiation therapy (RT) dose prior to esophagectomy is unknown. We compared patients receiving lower-dose RT (LD-RT) of 41.4-45 Gy versus those receiving higher-dose RT (HD-RT) of 50-54 Gy.

Methods

Patients with non-metastatic esophageal or gastroesophageal cancer diagnosed from 2004 to 2015 who underwent neoadjuvant chemoradiation (CRT) followed by esophagectomy were identified using the National Cancer Database (NCDB) and divided into LD-RT and HD-RT groups. Logistic regression was used to evaluate predictors of HD-RT utilization and propensity score matching. Overall survival (OS) was compared between HD-RT and LD-RT groups using Cox regression. Logistic regression was performed with respect to pathologic complete response (pCR), positive surgical margins, postoperative mortality, and readmission rates.

Results

We identified 7,996 patients meeting inclusion criteria, of which 5,732 (71.7%) received HD-RT. At median follow-up of 3.3 years, 3-year OS was 48.7% for HD-RT versus 48.4% for LD-RT (P=0.734). pCR rates were 20.3% with HD-RT versus 16.3% with LD-RT [odds ratio (OR) 1.24; 95% CI: 1.06-1.44; P=0.006]. There were no statistically significant differences between HD-RT and LD-RT with respect to positive margins, 90-day postoperative mortality, or readmission rates. In a separate analysis of patients treated with CRT alone and no subsequent esophagectomy, HD-RT was associated with improved OS (HR 0.83; 95% CI: 0.78-0.88; P<0.001).

Conclusions

Our analysis suggests that 41.4-45 and 50-54 Gy dose regimens are similar in survival and postoperative outcomes. However, in cases of equivocal resectability, a higher RT dose of 50-54 Gy may be preferred.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Meta-analysis of risk factors and complications associated with atrial fibrillation after oesophagectomy

Background

Oesophagectomy is associated with high morbidity and mortality rates. New-onset atrial fibrillation (AF) is a frequent complication following oesophagectomy. Several studies have explored whether new-onset AF is associated with adverse events after oesophagectomy.

Methods

This review was performed according to PRISMA guidelines. Eligible studies were identified through a search of PubMed, Scopus and Cochrane CENTRAL databases up to 25 November 2018. A meta-analysis was conducted with the use of random-effects modelling. The I2 statistic was used to assess for heterogeneity.

Results

In total, 53 studies including 9087 patients were eligible for analysis. The overall incidence of postoperative AF was 16·5 per cent. Coronary artery disease and hypertension were associated with AF, whereas diabetes, smoking and chronic obstructive pulmonary disease were not. Patients with AF had a significantly higher risk of overall postoperative adverse events than those without fibrillation (odds ratio (OR) 5·50, 95 per cent c.i. 3·51 to 8·30), including 30-day mortality (OR 2·49, 1·70 to 3·64), anastomotic leak (OR 2·65, 1·53 to 4·59) and pneumonia (OR 3·42, 2·39 to 4·90).

Conclusion

Postoperative AF is frequently observed in patients undergoing oesophagectomy for cancer. It is associated with an increased risk of death and postoperative complications.