Oesophageal squamous cell carcinoma: relationship between fluorine-18 fludeoxyglucose positron emission tomography CT maximum standardised uptake value, metabolic tumour volume, and tumour, node and metastasis classification

FDG PET/CT and Endoscopic Ultrasound for Preoperative T-Staging of Esophageal Squamous Cell Carcinoma

This study aimed to compare the diagnostic performances of endoscopic ultrasound (EUS) and FDG PET/CT in the preoperative T-staging of esophageal squamous cell carcinoma (ESCC) and determine whether their innovative coordination achieves better prediction. In total, 100 patients diagnosed with ESCC, 57 without (CRT[-]sub) and 43 with (CRT[+]sub) neoadjuvant chemoradiotherapy, undergoing EUS and FDG PET/CT, followed by surgical resection of the tumor, were included in this analysis. EUS classified T-stages based on the depth of primary tumor invasion, and FDG PET/CT used thresholded maximal standardized uptake value (SUVmax) classifications. By employing pathology results as the reference standard, we assessed the accuracy of EUS and FDG PET/CT, evaluated their concordance using the κ statistic, and conducted a comparative analysis between the two modalities through McNemar's chi-square test. FDG PET/CT had higher overall accuracy than EUS (for CRT[-]sub: 71.9%, κ = 0.56 vs. 56.1%, κ = 0.31, p = 0.06; for CRT[+]sub: 65.1%, κ = 0.50 vs. 18.6%, κ = 0.05, p < 0.01) in predicting pT- and ypT-stage. Our proposed method of incorporating both FDG PET/CT and EUS information could achieve higher accuracies in differentiating between early and locally advanced disease in the CRT[-]sub group (82.5%) and determining residual viable tumor in the CRT[+]sub group (83.7%) than FDG PET/CT or EUS alone. FDG PET/CT had a better diagnostic ability than EUS to predict the (y)pT-stage of ESCC. Our complementary method, which combines the advantages of both imaging modalities, can deliver higher accuracy for clinical applications of ESCC.

Intratumoral Metabolic Heterogeneity and Other Quantitative 18F-FDG PET/CT Parameters for Prognosis Prediction in Esophageal Cancer

PURPOSE

To evaluate the impact of intratumoral metabolic heterogeneity (IMH) and other quantitative fluorine 18 (¹⁸F) fluorodeoxyglucose (FDG) PET/CT parameters for predicting progression-free survival (PFS) and overall survival (OS) in patients with esophageal cancer.

MATERIALS AND METHODS

In this retrospective study, an automated gradient-based segmentation method was used to assess the maximum standardized uptake value, mean standardized uptake value, metabolic tumor volume (MTV), and IMH index of the primary tumor in patients with biopsy-proven adenocarcinoma or squamous cell carcinoma of the esophagus with an initial staging ¹⁸F-FDG PET/CT. Data were collected between July 2006 and February 2016. OS and PFS were calculated using multivariable Cox proportional hazards regression with the adjustment (as covariates) of age, sex, weight, stage, tumor type, tumor grade, and treatment. All PET parameters were standardized before analysis. Log-rank tests were performed, and corresponding Kaplan-Meier survival plots were generated.

RESULTS

A total of 71 patients (mean age, 64 years ± 10 [standard deviation], 62:9 men:women) were included. Median follow-up time was 28.2 months (range, 4-38 months), and median survival was 16.1 months (range, 0.1-60.3 months). Higher MTV was associated with reduced PFS for every standard deviation increase (hazard ratio [HR], 0.193; 95% CI: 0.052, 0.711; P = .01). Higher IMH was associated with reduced PFS for every standard deviation decrease in the area under the curve (HR, 10.78; 95% CI: 1.31, 88.96; P = .03).

CONCLUSION

PFS for patients with esophageal cancer was associated with MTV and with IMH.Keywords: Esophagus, Neoplasms-Primary, PET/CT, Tumor Response © RSNA, 2020.

Queuine Micronutrient Deficiency Promotes Warburg Metabolism and Reversal of the Mitochondrial ATP Synthase in Hela Cells

Queuine is a eukaryotic micronutrient, derived exclusively from eubacteria. It is incorporated into both cytosolic and mitochondrial transfer RNA to generate a queuosine nucleotide at position 34 of the anticodon loop. The transfer RNA of primary tumors has been shown to be hypomodified with respect to queuosine, with decreased levels correlating with disease progression and poor patient survival. Here, we assess the impact of queuine deficiency on mitochondrial bioenergetics and substrate metabolism in HeLa cells. Queuine depletion is shown to promote a Warburg type metabolism, characterized by increased aerobic glycolysis and glutaminolysis, concomitant with increased ammonia and lactate production and elevated levels of lactate dehydrogenase activity but in the absence of significant changes to proliferation. In intact cells, queuine deficiency caused an increased rate of mitochondrial proton leak and a decreased rate of ATP synthesis, correlating with an observed reduction in cellular ATP levels. Data from permeabilized cells demonstrated that the activity of individual complexes of the mitochondrial electron transport chain were not affected by the micronutrient. Notably, in queuine free cells that had been adapted to grow in galactose medium, the re-introduction of glucose permitted the mitochondrial F₁F_O-ATP synthase to operate in the reverse direction, acting to hyperpolarize the mitochondrial membrane potential; a commonly observed but poorly understood cancer trait. Together, our data suggest that queuosine hypomodification is a deliberate and advantageous adaptation of cancer cells to facilitate the metabolic switch between oxidative phosphorylation and aerobic glycolysis.

Prognostic value of metabolic tumor volume and total lesion glycolysis in esophageal carcinoma patients treated with definitive chemoradiotherapy

PURPOSE

The aim of this study was to evaluate the prognostic importance metabolic tumor volume (MTV), total lesion glycolysis (TLG), and standardized uptake value (SUV) in patients with esophageal cancer treated with definitive chemoradiotherapy.

PATIENTS AND METHODS

Seventy-two esophageal cancer patients treated with definitive chemoradiotherapy [57 (79%) patients] or definitive radiotherapy [15 (21%) patients] were retrospectively analyzed. The regions equal to or greater than SUV of 2.5 were selected to delineate MTV and TLG was calculated by multiplying the mean SUV by the MTV of the primary lesions. The overall survival (OS) and disease-free survival (DFS) were evaluated for all patients and also patients with squamous cell carcinoma.

RESULTS

The median survival time was 13.4 months (range: 1.8-119.3 months) for all patients. Maximum SUV, mean SUV, MTV, and TLG values were significantly higher in patients with extensive T-stage (T3-T4) compared with patients with T1-T2 disease. Patients with regional lymph node metastasis had significantly higher MTV and TLG values compared with patients with no lymph node metastasis. On multivariate analysis, MTV, TLG, presence of lymph node metastasis, and lack of concurrent chemotherapy were negative significant prognostic factors for OS and DFS for the entire cohort and for patients with squamous cell carcinoma esophageal cancer.

CONCLUSION

Metabolic volumes (MTV and TLG), regional lymph node metastasis, and concurrent chemotherapy are major prognostic factors for DFS and OS in patients with esophageal carcinoma. In addition, MTV and TLG are important in predicting nodal metastasis, and together with metabolic volumes, SUV are associated significantly with local tumor invasion.

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.

Pre-Chemoradiotherapy FDG PET/CT cannot Identify Residual Metabolically-Active Volumes within Individual Esophageal Tumors

Objective

To study whether subvolumes with a high pre-chemoradiotherapy (CRT) FDG uptake could identify residual metabolically-active volumes (MAVs) post-CRT within individual esophageal tumors. Accurate identification will allow simultaneous integrated boost to these subvolumes at higher risk to improve clinical outcomes.

Methods

Twenty patients with esophageal cancer were treated with CRT plus surgery and underwent FDG PET/CT scans before and after CRT. The two scans were rigidly registered. Seven MAVs pre-CRT and four MAVs post-CRT within a tumor were defined with various SUV thresholds. The similarity and proximity between the MAVs pre-CRT and post-CRT were quantified with three metrics: fraction of post-CRT MAV included in pre-CRT MAV, volume overlap and centroid distance.

Results

Eight patients had no residual MAV. Six patients had local residual MAV (SUV ≥2.5 post-CRT) within or adjoining the original MAV (SUV ≥2.5 pre-CRT). On average, less than 65% of any post-CRT MAVs was included in any pre-CRT MAVs, with a low volume overlap <45%, and large centroid distance >8.6 mm. In general, subvolumes with higher FDG-uptake pre-CRT or post-CRT had lower volume overlap and larger centroid distance. Six patients had new distant MAVs that were determined to be inflammation from radiation therapy.

Conclusions

Pre-CRT PET/CT cannot reliably identify the residual MAVs within individual esophageal tumors. Simultaneous integrated boost to subvolumes with high FDG uptake pre-CRT may not be feasible.

Prediction of occult lymph node metastasis by metabolic parameters in patients with clinically N0 esophageal squamous cell carcinoma

The aim of this study was to investigate the value of (18)F-FDG parameters of the primary tumor in predicting occult lymph node metastasis in patients with clinically N0 esophageal squamous cell carcinoma.

METHODS

The study comprised 143 consecutive patients (mean age ± SD, 63.9 ± 8.6 y; range, 31.8-81.2 y) from May 2003 to January 2010 who had clinically N0 esophageal squamous cell carcinoma based on preoperative imaging studies including chest CT, (18)F-FDG PET/CT, and endoscopic ultrasound. We measured maximum standardized uptake value (SUV max), mean SUV (SUV mean), total lesion glycolysis (TLG), and metabolic tumor volume (MTV) of the primary tumor and analyzed the relationship between clinicopathologic variables including PET parameters and occult lymph node metastasis using a logistic regression model.

RESULTS

Univariate analysis indicated that clinical T classification, SUV max, SUV mean, MTV, TLG, and longitudinal diameter of tumor were significant risk factors associated with occult lymph node metastasis. Optimal thresholds were cT2-4, SUV max ≥ 4.8, SUV mean ≥ 3.2, MTV ≥ 5.5 cm(3), TLG ≥ 220, and diameter ≥ 3.8 cm. After multivariate analysis, the logistic regression model revealed that clinical T classification (hazard ratio [HR], 4.6; 95% confidence interval [CI], 1.7-12.4; P = 0.003) and SUV max (HR, 3.5; 95% CI, 1.3-9.2; P = 0.012) were independent risk factors. The combination of SUV max and clinical T classification (HR, 13.2; 95% CI, 5.4-31.9; P < 0.001) was a significantly better powerful risk factor for occult lymph node metastasis than SUV max or clinical T classification alone. Sensitivity, specificity, positive predictive value, and negative predictive value of the combination of clinical T classification and SUV max were 73.0%, 81.5%, 60.0%, and 89.7%, respectively.

CONCLUSION

SUV max, combined with clinical T classification, may be useful for predicting occult lymph node metastasis in patients with clinically N0 squamous cell carcinoma of the esophagus.