Prognostic significance of novel ¹⁸F-FDG PET/CT defined tumour variables in patients with oesophageal cancer

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

PURPOSE

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

The usefulness of the total metabolic tumor volume for predicting the postoperative recurrence of thoracic esophageal squamous cell carcinoma

Background

Induction or adjuvant therapies are not always beneficial for thoracic esophageal squamous cell carcinoma (ESCC) patients, and it is thus important to identify patients at high risk for postoperative ESCC recurrence. We investigated the usefulness of the total metabolic tumor volume (TMTV) for predicting the postoperative recurrence of thoracic ESCC.

Methods

We retrospectively analyzed the cases of 163 thoracic ESCC patients (135 men, 28 women; median age of 66 [range 34–82] years) treated at our hospital in 2007–2012. The TMTV was calculated from the fluorine-18 fluorodeoxyglucose (18F-FDG) uptake in the primary lesion and lymph node metastases. The optimal cut-off values for relapse and non-relapse were obtained by the time-dependent receiver operating curve analyses. Relapse-free survival (RFS) was evaluated by the Kaplan-Meier method, and between-subgroup differences in survival were analyzed by log-rank test. The prognostic significance of metabolic parameters and clinicopathological variables was assessed by a Cox proportional hazard regression analysis. The difference in the failure patterns after surgical resection was evaluated using the χ2-test.

Results

The optimal cut-off value of TMTV for discriminating relapse from non-relapse was 3.82. The patients with a TMTV ≥3.82 showed significantly worse prognoses than those with low values (p < 0.001). The TMTV was significantly related to RFS (model 1 for preoperative risk factors: TMTV: hazard ratio [HR] =2.574, p = 0.004; model 2 for preoperative and postoperative risk factors: HR = 1.989, p = 0.044). The combination of the TMTV and cN0–1 or pN0–1 stage significantly stratified the patients into low-and high-risk recurrence groups (TMTV cN0–1, p < 0.001; TMTV pN0–1, p = 0.004). The rates of hematogenous and regional lymph node metastasis were significantly higher in the patients with TMTV ≥3.82 than those with low values (hematogenous metastasis, p < 0.001, regional lymph node metastasis, p = 0.011).

Conclusions

The TMTV was a more significantly independent prognostic factor for RFS than any other PET parameter in patients with resectable thoracic ESCC. The TMTV may be useful for the identifying thoracic ESCC patients at high risk for postoperative recurrence and for deciding the patient management.

Prediction of lymph node metastases using pre-treatment PET radiomics of the primary tumour in esophageal adenocarcinoma: an external validation study

OBJECTIVES

To improve clinical lymph node staging (cN-stage) in oesophageal adenocarcinoma by developing and externally validating three prediction models; one with clinical variables only, one with positron emission tomography (PET) radiomics only, and a combined clinical and radiomics model.

METHODS

Consecutive patients with fluorodeoxyglucose (FDG) avid tumours treated with neoadjuvant therapy between 2010 and 2016 in two international centres (n = 130 and n = 60, respectively) were included. Four clinical variables (age, gender, clinical T-stage and tumour regression grade) and PET radiomics from the primary tumour were used for model development. Diagnostic accuracy, area under curve (AUC), discrimination and calibration were calculated for each model. The prognostic significance was also assessed.

RESULTS

The incidence of lymph node metastases was 58% in both cohorts. The areas under the curve of the clinical, radiomics and combined models were 0.79, 0.69 and 0.82 in the developmental cohort, and 0.65, 0.63 and 0.69 in the external validation cohort, with good calibration demonstrated. The area under the curve of current cN-stage in development and validation cohorts was 0.60 and 0.66, respectively. For overall survival, the combined clinical and radiomics model achieved the best discrimination performance in the external validation cohort (X² = 6.08, df = 1, p = 0.01).

CONCLUSION

Accurate diagnosis of lymph node metastases is crucial for prognosis and guiding treatment decisions. Despite finding improved predictive performance in the development cohort, the models using PET radiomics derived from the primary tumour were not fully replicated in an external validation cohort.

ADVANCES IN KNOWLEDGE

This international study attempted to externally validate a new prediction model for lymph node metastases using PET radiomics. A model combining clinical variables and PET radiomics improved discrimination of lymph node metastases, but these results were not externally replicated.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Pre- and postoperative prognostic factors for resectable esophageal adenocarcinoma

BACKGROUND

Prognostication for esophageal cancer has traditionally relied on postoperative tissue specimens. This study aimed to use a histologically homogenous cohort to investigate the relationship between clinical, pathological or radiological variables and overall survival in patients undergoing esophagectomy for adenocarcinoma.

METHODS

A single-centre study of patients who underwent esophagectomy for adenocarcinoma over 10 years in a tertiary centre was performed. By regression analysis, variables available preoperatively and postoperatively were studied for prognostication. The primary outcome was overall survival.

RESULTS

254 cases were analyzed. Over a median follow-up period of 31.8 months (IQR = 42.5), overall survival was 51.5 months (95% confidence interval: 33.0-69.9). According to hazard ratios (HR) for all-cause death, adverse prognostic factors included: a higher postoperative N-stage (HR ≥ 1.29; p ≤ 0.024), histopathological tumor length ≥25 mm (HR = 2.04; p = 0.03), poorer tumor differentiation (HR ≥ 2.86; p ≤ 0.042), and R1 status (HR = 2.33; p = 0.02). A lymph node yield ≥35 was a favorable prognostic factor (HR = 0.022; p < 0.001). Demographic and radiological variables, preoperative TNM stages, postoperative T-stage, and neoadjuvant/adjuvant treatment were not associated with overall survival.

CONCLUSIONS

This study identifies several postoperatively factors which are available for the prognostication and identifies factors that should not be used to exclude patients from curative surgery.

Prognostic value of 18F-FDG PET /CT metabolic parameters in patients with locally advanced pancreatic Cancer treated with stereotactic body radiation therapy

Background

¹⁸F-FDG PET/CT metabolic parameters have been applied as prognostic factors in multi-malignancies. However, the role in locally advanced pancreatic cancer (LAPC) was not confirmed. In this study, we investigated the prognostic value of ¹⁸F-FDG PET/CT metabolic parameters in LAPC patients treated with stereotactic body radiation therapy (SBRT).

Methods

Seventy three LAPC patients who received SBRT therapy and pre-treatment ¹⁸F-FDG PET/CT imaging from January 2012 to January 2016 were included in this retrospective study. The study aim was to evaluate the relationship between metabolic parameters with clinical factors, and the value of metabolic parameters in the prognosis of LAPC. The median of parameters was set as the cut-off value for statistical analysis. Univariate survival analysis was performed by the Kaplan Meier method and log-rank test, and multivariate analysis was carried out by a Cox proportional hazards model.

Results

Patients with lymph node metastasis or longer tumor diameters were associated with higher TLG (P < 0.05). Univariate analysis showed MTV, TLG, radiotherapy dose and chemotherapy were significantly associated with disease progression-free survival (PFS) and overall survival (OS) (P < 0.05). Lymph node metastasis and tumor longest diameter were associated with OS. Multivariate analysis demonstrated TLG, radiotherapy dose, and chemotherapy were independent factors of PFS and OS (HR: 2.307, 0.591, 0.572 and 2.145, 0.480, 0.471, P < 0.05).

Conclusions

TLG was found to be the independent prognostic factor of OS and PFS. Among clinical factors, radiotherapy dose and chemotherapy were independent prognostic factors of OS and PFS.

Cyclo-oxygenase-2 expression is associated with mean standardised uptake value on 18F-Fluorodeoxyglucose positron emission tomography in oesophageal adenocarcinoma

OBJECTIVES

This pilot study investigated the association of four PET image features and cyclo-oxygenase-2 (COX-2) expression in patients with oesophageal adenocarcinoma. The prognostic significance of these biomarkers was also assessed.

METHODS

50 consecutive patients [median age = 68 (range 47 - 84), males = 45) with oesophageal adenocarcinoma had PET/CT staging between January 2011 and July 2015. The maximum and mean standardised uptake values (SUV_max and SUV_mean), metabolic tumour volume (MTV) and tumour lesion glycolysis (TLG) were calculated from the primary tumour. Their association with COX-2 status was assessed using Mann-Whitney U tests. Kaplan-Meier and Cox regression analysis tested their prognostic significance. A p-value < 0.05 was considered statistically significant.

RESULTS

32 tumours (64.0%) were COX-2 positive. There was a significant association between SUV_mean and COX-2 status (p = 0.019). TLG (hazard ratio (HR) 1.001, 95 % confidence intervals (CI) 1.000 - 1.002, p = 0.018) was significantly associated with overall survival on multivariable analysis.

CONCLUSIONS

This study investigated the association between PET image features and COX-2 expression in oesophageal adenocarcinoma. The preliminary results signal that a combination of TLG (calculated as product of MTV and SUV_mean) and COX-2 status may be a strong and clinically important prognostic biomarker. Our research group are planning a prospective, multi-centre study to validate these findings.

ADVANCES IN KNOWLEDGE

Mean standardised uptake value (SUV_mean) on PET imaging is associated with COX-2 expression in oesophageal adenocarcinoma.

Glucose Drives Growth Factor-Independent Esophageal Cancer Proliferation via Phosphohistidine-Focal Adhesion Kinase Signaling

BACKGROUND & AIMS

Most targeted therapies against cancer are designed to block growth factor-stimulated oncogenic growth. However, response rates are low, and resistance to therapy is high. One mechanism might relate to the ability of tumor cells to induce growth factor-independent proliferation (GFIP). This project aims to understand how (1) cancer cells preferentially derive a major growth advantage by using critical metabolic products of glucose, such as phosphoenolpyruvate (PEP), to drive proliferation and (2) esophageal squamous cell carcinoma (ESCC) cells, but not esophageal adenocarcinoma cells, can induce GFIP by using glycolysis to activate phosphohistidine (poHis)-mediated signaling through focal adhesion kinase (FAK).

METHODS

The hypothesis to be tested is that ESCC GFIP induced by glucose is facilitated by PEP-mediated histidine phosphorylation (poHis) of FAK, leading to the possibility that ESCC progression can be targeted by blocking poHis signaling. Biochemical, molecular biological, and in vivo experiments including bromodeoxyuridine/5-ethynyl-2'-deoxyuridine labeling, radioisotope tracing, CRISPR gene editing, and analysis of signaling gene sets in human cancer tissues and xenograft models were performed to define the mechanisms underlying ESCC GFIP.

RESULTS

Glucose promotes growth factor-independent DNA replication and accumulation of PEP in ESCC cells. PEP is the direct phospho-donor to poHis58-FAK within a known "HG" motif for histidine phosphorylation. Glucose-induced poHis58 promotes growth factor-independent FAK-mediated proliferation. Furthermore, glucose activates phosphatidylinositol-3'-kinase/AKT via poHis58-FAK signaling. Non-phosphorylatable His58A-FAK reduces xenograft growth.

CONCLUSIONS

Glucose induces ESCC, but not esophageal adenocarcinoma GFIP via PEP-His58-FAK-AKT signaling. ESCC progression is controlled by actionable growth factor-independent, glucose-induced pathways that regulate proliferation through novel histidine phosphorylation of FAK.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Radiomics in Nuclear Medicine Applied to Radiation Therapy: Methods, Pitfalls, and Challenges

Radiomics is a recent area of research in precision medicine and is based on the extraction of a large variety of features from medical images. In the field of radiation oncology, comprehensive image analysis is crucial to personalization of treatments. A better characterization of local heterogeneity and the shape of the tumor, depicting individual cancer aggressiveness, could guide dose planning and suggest volumes in which a higher dose is needed for better tumor control. In addition, noninvasive imaging features that could predict treatment outcome from baseline scans could help the radiation oncologist to determine the best treatment strategies and to stratify patients as at low risk or high risk of recurrence. Nuclear medicine molecular imaging reflects information regarding biological processes in the tumor thanks to a wide range of radiotracers. Many studies involving ¹⁸F-fluorodeoxyglucose positron emission tomography suggest an added value of radiomics compared with the use of conventional PET metrics such as standardized uptake value for both tumor diagnosis and prediction of recurrence or treatment outcome. However, these promising results should not hide technical difficulties that still currently prevent the approach from being widely studied or clinically used. These difficulties mostly pertain to the variability of the imaging features as a function of the acquisition device and protocol, the robustness of the models with respect to that variability, and the interpretation of the radiomic models. Addressing the impact of the variability in acquisition and reconstruction protocols is needed, as is harmonizing the radiomic feature calculation methods, to ensure the reproducibility of studies in a multicenter context and their implementation in a clinical workflow. In this review, we explain the potential impact of positron emission tomography radiomics for radiation therapy and underline the various aspects that need to be carefully addressed to make the most of this promising approach.

Present and future roles of FDG-PET/CT imaging in the management of gastrointestinal cancer: an update

Positron emission tomography/computed tomography (PET/CT) integrated with 2-[18F]fluoro-2-deoxy-D-glucose (FDG) is a useful tool for acquisition of both glucose metabolism and anatomic imaging data, as only a single device and one diagnostic session is required, thus opening a new field in clinical oncologic imaging. FDG-PET/CT has been successfully used for initial staging, restaging, assessment of early treatment response, evaluation of metastatic disease response, and prognostication of intestinal cancer as well as various malignant tumors. We reviewed the current status and role of FDG-PET/CT for management of patients with esophageal cancer, gastric cancer, and colorectal cancer, with focus on both its usefulness and limitations.

Accuracy of contemporary oesophageal cancer lymph node staging with radiological-pathological correlation

AIM

To evaluate the accuracy of contemporary N-staging and provide radiological-pathological correlation in patients with lymph node metastases (LNMs) that were radiologically staged N0.

MATERIALS AND METHODS

One hundred and twelve patients were included who underwent surgery alone (n=41) or neoadjuvant therapy (n=71) between October 2010 and December 2015. Contrast-enhanced computed tomography (CECT), endoscopic ultrasound (EUS), and combined positron-emission tomography (PET) and CT N-stage were compared to pathological N-stage [node-negative (N0) versus node-positive (N+) groups]. Fifty LNMs from 15 patients preoperatively staged as N0 were measured and the maximum size recorded.

RESULTS

Accuracy, sensitivity, and specificity of N0 versus N+ disease with CECT, EUS, and PET/CT was 54.5%, 39.7% and 77.3%, 55.4%, 42.6% and 75%, and 57.1% 35.3%, and 90.9%, respectively. All techniques were more likely to under-stage nodal disease; CECT (X² 32.890, df=1, p<0.001), EUS (X² 28.471, df=1, p<0.001), and PET/CT (X² 50.790, df=1, p<0.001). PET/CT was more likely to under-stage nodal disease than EUS (p=0.031). Median LNM size was 3 mm, with 41 (82%) of LNMs measuring <6 mm and 22 (44%) classified as micro-metastases (≤2 mm).

CONCLUSION

This study has demonstrated poor N-staging accuracy in the modern era of radiological staging. Eighty-two percent of LNMs measured <6 mm, making direct identification extremely challenging on medical imaging. Future research should focus on investigating and developing alternative surrogate markers to predict the likelihood of LNMs.

Risk Stratification of Pediatric Patients With Neuroblastoma Using Volumetric Parameters of 18F-FDG and 18F-DOPA PET/CT

PURPOSE

This study determined the prognostic value of volumetric parameters derived from pretreatment F-FDG and F-DOPA PET/CT of neuroblastoma and their correlation with clinical and histopathologic features.

PATIENTS AND METHODS

A total of 25 children with neuroblastoma underwent pretreatment F-FDG and F-DOPA PET/CT within 4 weeks. The SUVmax of primary tumors on F-FDG and F-DOPA PET were recorded as SUVFDG and SUVDOPA, respectively. For volumetric parameters of primary tumors, 40% of SUVmax was used to generate volume of interest. If the 40% of SUVmax was below 2.5, an SUV threshold of 2.5 was used instead. Metabolic tumor volume (MTV), total lesion glycolysis (TLG), dopaminergic tumor volume (DTV), and total lesion F-DOPA activity (TLDA) were recorded as F-FDG and F-DOPA volumetric parameters. All indices were compared between groups distinguished by survival status and clinical features, including bone marrow involvement, lymph node metastasis, amplification of the MYCN oncogene, invasive features on anatomic images, and risk categories. The Kaplan-Meier method and log-rank test were used to compare the survival curves between groups.

RESULTS

The median follow-up period was 28.2 months. Nonsurvivors (20%) tended to have lower SUVDOPA, DTV, and TLDA (P ≤ 0.05), and higher SUVFDG, MTV, and TLG (all P < 0.05). Lower F-DOPA uptake is associated with bone marrow and lymph node metastases (all P < 0.05). Higher F-FDG uptake is associated with MYCN amplification (all P < 0.05) and anatomic invasive features of tumors such as vascular encasement or adjacent organ invasion (TLG, P = 0.05). Only volumetric indices (DTV, TLDA, MTV, and TLG) significantly differed among risk groups (all P < 0.05).

CONCLUSIONS

Pretherapeutic F-DOPA and F-FDG PET provided complementary information, and both can be served for risk stratification. Volumetric indices of F-DOPA and F-FDG PET correlate more highly with risk grouping.

Molecular biological correlation of fluorine-18 fluorodeoxyglucose uptake in esophageal squamous cell carcinoma

OBJECTIVE

The aim of this study was to assess the relationship between fluorine-18 fluorodeoxyglucose (F-FDG) uptake and molecular biological markers in esophageal squamous cell carcinoma (ESCC) patients.

METHODS

Our patient population included 51 patients who underwent F-FDG PET/computed tomography before surgery. Excised tumor tissue was analyzed immunohistochemically using monoclonal antibodies for glucose transporter-1 (GLUT-1), GLUT-3, CD34 [microvessel density (MVD) marker], CD68 (macrophage marker), and CD163 (tumor-associated macrophage marker). The relationships among pathological factors [pathological T stage (p-T stage), pathological lymph node status (p-N status), pathological stage (p-stage), and pathological tumor length], the maximum standardized uptake value (SUVmax), and these molecular biological markers were evaluated using Spearman's rank test and the Kruskal-Wallis test.

RESULTS

GLUT-1, GLUT-3, CD34, and CD163 significantly correlated with SUVmax (r=0.547, P<0.001 for GLUT-1; r=0.569, P<0.001 for GLUT-3; r=0.463, P=0.001 for CD34, r=0.455, P=0.001 for CD163), whereas SUVmax, GLUT-1, GLUT-3, CD34, and CD163 significantly correlated with p-T stage (r=0.552, P<0.001 for SUVmax, r=0.307, P=0.03 for GLUT-1, r=0.349, P=0.013 for GLUT-3, r=0.313, P=0.027 for CD34, r=0.526 for CD163, P<0.001), but not with p-N status. CD68 levels showed no significant correlation with SUVmax, p-T stage, p-stage, or p-N status.

CONCLUSION

SUVmax, GLUT-1 expression, GLUT-3 expression, MVD, and TAMs show a relationship with the tumor stage and extent of ESCC. GLUT-1, GLUT-3, MVD, and TAMs are associated with the mechanism of F-FDG uptake in ESCC.

Application of PET/CT in gastrointestinal cancers

Fluorine-18 fluoro-2-deoxy-D-glucose positron emission tomography (¹⁸F-FDG PET) is an imaging tool which reflects tumor metabolism. The integration of PET with computed tomography (CT) can provide precise anatomical information along with metabolic data. Here, we review the application and potential role of ¹⁸F-FDG PET/CT imaging in staging, evaluation of chemoradiation therapy, and detection of recurrence in gastrointestinal cancers.

The prognostic value of total lesion glycolysis via 18F-fluorodeoxyglucose PET-CT in surgically treated esophageal squamous cell carcinoma

OBJECTIVE

In addition to staging, the identification of prognostic factors is important for predicting survival in patients with esophageal cancer after esophagectomy. The present study was performed to document the prognostic role of total lesion glycolysis (TLG) in postoperative patients.

METHODS

We retrospectively reviewed the records of 50 patients with esophageal squamous cell carcinoma who underwent surgical resection and complete lymph node dissection after positron emission tomography-computed tomography (PET-CT). A volume of interest was drawn on the primary lesion and suspected metastatic lymph nodes, and the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), TLG of the primary lesion (TLGp), and whole-body TLG (TLGwb) were measured using an SUV cutoff of 2.5.

RESULTS

The study population included 50 patients with a mean age of 63.14 ± 8.18 years: 12 (24%) were reported as stage I, 13 (26%) as stage II, and 25 (50%) as stage III. The median follow-up period was 20.46 months, and recurrences occurred in 17 patients. The mean SUVmax, MTV, TLGp, and TLGwb were 11.11 ± 6.40, 20.47 ± 22.88, 122.54 ± 180.98, and 129.37 ± 193.66, respectively. On the multivariate analysis, TLGp was a risk factor for disease-free survival (DFS) [hazard ratio (HR) = 1.002, p = 0.026], and TLGwb was a risk factor for DFS (HR = 1.002, p = 0.021) and overall survival (OS) (HR = 1.002, p = 0.044). The 3-year OS rates were 66.1% in patients with low TLGwb (≤ 41.45) and 33.3% in those with high TLGwb (>41.45; p = 0.004). The concordance index of the TLGwb was 0.752 (95% CI 0.659-0.845).

CONCLUSION

TLGwb is a significant prognostic factor for OS and DFS in patients with surgically treated esophageal squamous cell carcinoma.

Prognostic Significance of 2-Deoxy-2-[18F]-Fluoro-D-Glucose PET/CT in Patients With Locally Advanced Esophageal Cancer Undergoing Neoadjuvant Chemoradiotherapy Before Surgery: A Nonparametric Approach

To investigate the prognostic value of tumor metabolism measurements on serial 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography and computed tomography scans in patients with locally advanced esophageal cancer undergoing neoadjuvant chemoradiotherapy. Forty-five patients (63 ± 7 years, 6 female) treated with concomitant chemoradiotherapy before surgery were followed up for 24 ± 18 months (range 4-71). Positron emission tomography and computed tomography scans were obtained within 1 week before the start (PET1) and 1 month after the completion of the treatment (PET2). Total body tumor metabolic activity was measured as the sum of the parameters: SUVmax, SUV corrected for lean body mass, and total lesion glycolysis (TLG40/50/70%). Then, delta values for the parameters between PET1 and PET2 were calculated and expressed as percentage of PET1 results. At the time of the analysis, 27 patients were dead and 18 were alive. There was no difference between the 2 groups in terms of age, sex, site of the disease, histology, and the presence/absence of linfonodal metastases (P = NS). Survival random forest analysis (20,000 trees) resulted in an estimate of error rate of 36%. The nonparametric approach identified ΔTLG40 as the most predictive factor of survival (relative importance 100%). Moreover, T (17%), N (5%), and M (5%) stage of the disease, cancer histology (11%), TLG70 (5%) at the end of chemioradioterapy, and ΔTLG(50-70) (17%-5%) were positively associated with patient outcome. The nonparametric analysis confirmed the prognostic importance of some clinical parameters, such as TNM stage and cancer histology. Moreover, ΔTLG resulted to be the most important factor in predicting outcome and should be considered in risk stratification of patients treated with neoadjuvant chemoradiotherapy.

[Prognostic value of the metabolically active tumour volume]

PURPOSE

The purpose of this study was to assess the prognostic value of different parameters on pretreatment fluorodeoxyglucose [((18)F)-FDG] positron emission tomography-computed tomography (PET-CT) in patients with localized oesophageal cancer.

PATIENTS AND METHOD

We retrospectively reviewed 83 cases of localised oesophageal cancer treated in our institution. Patients were treated with curative intent and have received chemoradiotherapy alone or followed by surgery. Different prognostic parameters were correlated to survival: cancer-related factors, patient-related factors and parameters derived from PET-CT (maximum standardized uptake value [SUV max], metabolically active tumor volume either measured with an automatic segmentation software ["fuzzy locally adaptive bayesian": MATVFLAB] or with an adaptive threshold method [MATVseuil] and total lesion glycolysis [TLGFLAB and TLGseuil]).

RESULTS

The median follow-up was 21.8 months (range: 0.16-104). The median overall survival was 22 months (95% confidence interval [95%CI]: 15.2-28.9). There were 67 deaths: 49 associated with cancer and 18 from intercurrent causes. None of the tested factors was significant on overall survival. In univariate analysis, the following three factors affected the specific survival: MATVFLAB (P=0.025), TLGFLAB (P=0.04) and TLGseuil (P=0.04). In multivariate analysis, only MATVFLAB had a significant impact on specific survival (P=0.049): MATVFLAB<18 cm(3): 31.2 months (95%CI: 21.7-not reached) and MATVFLAB>18 cm(3): 20 months (95%CI: 11.1-228.9).

CONCLUSION

The metabolically active tumour volume measured with the automatic segmentation software FLAB on baseline PET-CT was a significant prognostic factor, which should be tested on a larger cohort.

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

INTRODUCTION

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Prognostic utility of diffusion-weighted MRI in oesophageal cancer: is apparent diffusion coefficient a potential marker of tumour aggressiveness?

PURPOSE

To investigate the role of the apparent diffusion coefficient (ADC) as a potential prognostic biomarker in the evaluation of the aggressiveness of oesophageal cancer.

MATERIALS AND METHODS

Between November 2009 and December 2013, 43 patients with evidence of oesophageal or oesophago-gastric junction cancer were referred to our institution and prospectively entered in our database. The final study population consisted of 23 patients (18 men; 5 women; mean age, 64.62 ± 10.91 years) who underwent diffusion-weighted Magnetic Resonance before surgical intervention. Specifically, 14 were directly treated with surgery and 9 were addressed to chemo/radiotherapy beforehand. Two radiologists independently measured mean tumour ADC and inter-observer agreement (Spearman's and intraclass correlation coefficient [ICC]) was assessed. In the univariate analysis, overall survival curves related to pathological ADC, pT, pN, tumour location and histotype were fitted using the Kaplan-Meier method. Survival curves were then compared using the log-rank test.

RESULTS

Inter-observer reproducibility was very good (Spearman's rho = 0.95; ICC = 0.94). At a total median follow-up of 19 months (2-49 months), 4 patients had died. The median follow-up was 18.50 months (5-49 months) for the surgery-only group (1/4 events, 25 %) and 24 months (2-34 months) for the chemo/radiotherapy group (3/4 events, 75 %). Survival time at 48 months for the overall population was 59 % (±0.11), while for the surgery-only group and the chemo/radiotherapy group was 90 % (±0.09) and 61 % (±0.34), respectively. In the univariate analysis, ADC values below or equal to 1.4 × 10(-3) mm(2)/s were associated with a negative prognosis both in the total population (P = 0.016) and in the surgery-only group (P < 0.001).

CONCLUSION

Despite the biggest limitation of our study (i.e. the small study population), we were able to show that pathological ADC could be considered a prognostic factor for oesophageal cancer. DWI might be introduced into clinical practice as a promising and reliable technique in the diagnostic pathway of this tumour.

Change in volume parameters induced by neoadjuvant chemotherapy provide accurate prediction of overall survival after resection in patients with oesophageal cancer

OBJECTIVES

To assess the prognostic value of volumetric parameters measured with CT and PET/CT in patients with neoadjuvant chemotherapy (NACT) and resection for oesophageal cancer (EC).

METHODS

Patients with locally advanced EC, who were treated with NACT and resection, were retrospectively analysed. Data from CT volumetry and (18) F-FDG PET/CT (maximum standardized uptake [SUVmax], metabolic tumour volume [MTV], and total lesion glycolysis [TLG]) were recorded before and after NACT. The impact of volumetric parameter changes induced by NACT (MTVRATIO, TLGRATIO, etc.) on overall survival (OS) was assessed using a Cox proportional hazards model.

RESULTS

Eighty-four patients were assessed using CT volumetry; of those, 50 also had PET/CT before and after NACT. Low post-treatment CT volume and thickness, MTV, TLG, and SUVmax were all associated with longer OS (p < 0.05), as were CTthicknessRATIO, MTVRATIO, TLGRATIO, and SUVmaxRATIO (p < 0.05). In the multivariate analysis, only MTVRATIO (Hazard ratio, HR 2.52 [95% Confidence interval, CI 1.33-4.78], p = 0.005), TLGRATIO (HR 3.89 [95%CI 1.46-10.34], p = 0.006), and surgical margin status (p < 0.05), were independent predictors of OS.

CONCLUSIONS

MTVRATIO and TLGRATIO are independent prognostic factors for survival in patients after NACT and resection for EC.

KEY POINTS

• Change in PET parameters shows close correlation to survival in oesophageal cancer. • Association with OS is independent of changes in SUVmax and CT volume. • Metabolic parameters after NACT correlate with pathologic response and nodal status. • Metabolic parameters may be better suited than SUVmax for response assessment.