Prognostic value of initial fluorodeoxyglucose-PET in esophageal cancer: a prospective study

Maximum standardised uptake value of positron emission tomography as a predictor of oesophageal cancer outcomes

OBJECTIVES

This study aimed to analyse the value of pre-operative 18F-fluorodeoxyglucose positron emission tomography (PET)-computed tomography that can predict tumour pathological complete response, tumour histology grade, overall survival, and recurrence-free survival in patients with locally advanced oesophageal squamous cell carcinoma who underwent neoadjuvant chemoradiotherapy (NCRT) followed by surgery.

METHODS

We retrospectively reviewed the cases of patients with locally advanced oesophageal squamous cell carcinoma undergoing NCRT followed by surgery. Patients who did not undergo PET within 3 months of surgery were excluded. We set a pre-operative PET maximum standardised uptake value (SUVmax) of > 5 as the threshold and classified the patients into two groups. We analysed the tumour response and histology grade, and compared the overall survival and recurrence-free survival between the two groups.

RESULTS

This cohort included 92 patients with oesophageal squamous cell carcinoma who underwent NCRT followed by surgery; 49 patients had a pre-operative PET SUVmax < 5, and 43 patients had a pre-operative PET SUVmax > 5. The patients' pre-operative PET SUVmax correlated with tumour histology, ypT stage, and tumour response. Patients with a pre-operative SUVmax < 5 had better 2-year-overall survival (78% vs. 62%, P < 0.05) and 2-year recurrence-free survival (62% vs. 34%, P < 0.05) than those with a pre-operative SUV > 5.

CONCLUSIONS

Pre-operative SUVmax may be useful to predict tumour response, survival, and recurrence in patients with locally advanced oesophageal squamous cell carcinoma who undergo NCRT followed by surgery.

18F-Fluorodeoxyglucose Positron Emission Tomography Parameters can Predict Long-Term Outcome Following Trimodality Treatment for Oesophageal Cancer

AIMS

¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸FDG-PET/CT) is routinely used for the pre-treatment staging of oesophageal or gastro-oesophageal junction cancers (EGEJC). The aim of this study was to identify objective ¹⁸FDG-PET/CT-derived parameters that can aid in predicting the patterns of recurrence and prognostication in patients with EGEJC.

PATIENTS AND METHODS

EGEJC patients referred for consideration of preoperative chemoradiation therapy were identified and clinicopathological data were collected. ¹⁸FDG-PET/CT imaging data were reviewed and correlated with treatment outcomes. Maximum standardised uptake value (SUV_max), metabolic tumour volume (MTV) and total lesion glycolysis were assessed and association with recurrence-free survival (RFS), locoregional recurrence-free survival (LR-RFS), oesophageal cancer-specific survival (ECSS) and overall survival were evaluated using receiver operating characteristic curves, as well as Cox regression and Kaplan-Meier models.

RESULTS

In total, 191 EGEJC patients completed trimodality treatment and 164 with ¹⁸FDG-PET/CT data were included in this analysis. At the time of analysis, 15 (9.1%), 70 (42.7%) and two (1.2%) patients were noted to have locoregional, distant and both locoregional and distant metastases, respectively. The median RFS was 30 months (9.6-50.4) and the 5-year RFS was 31.1%. The 5-year overall survival and ECSS were both noted to be 34.8%. Pre-treatment MTV₂₅ > 28.5 cm³ (P = 0.029), MTV₄₀ > 12.4 cm³ (P = 0.018) and MTV₅₀ > 10.2 cm³ (P = 0.005) predicted for worse LR-RFS, ECSS and overall survival for MTV definition of voxels ≥25%, 40% and 50% of SUV_max.

CONCLUSION

¹⁸FDG-PET/CT parameters MTV and total lesion glycolysis are useful prognostic tools to predict for LR-RFS, ECSS and overall survival in EGEJC. MTV had the highest accuracy in predicting clinical outcomes. The volume cut-off points we identified for different MTV thresholds predicted outcomes with significant accuracy and may potentially be used for decision making in clinical practice.

Prognostic Significance of FDG PET/CT in Esophageal Squamous Cell Carcinoma in the Era of the 8th AJCC/UICC Staging System

Introduction

Recently, the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) staging system was updated for its 8th edition. F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) is a useful imaging tool to diagnose and predict prognoses for esophageal cancer. However, there was no previous study to explore the role of FDG PET/CT in the staging system based on the 8th edition. The prognostic value of FDG PET/CT was investigated in patients with esophageal squamous cell carcinoma (SqCC) considering the new 8th AJCC/UICC staging system.

Methods

Subjects were 721 patients with esophageal SqCC undergoing pretherapeutic FDG PET/CT. Clinico-pathological variables and the maximum standardized uptake value (SUVmax) of the primary tumor were included in survival analysis. Subgroup analysis was performed to compare hazard ratios according to pathological stage and SUVmax. A new staging classification including FDG uptake was proposed.

Results

In multivariate survival analysis, pathological stage and SUVmax of the primary tumor were selected as independent prognostic factors for overall survival in both the 7th and 8th editions. The proposed new staging system showed better discrimination for overall survival between stage I and II than did the conventional staging system (hazard ratios: 2.250 vs. 1.341).

Conclusions

The FDG uptake of the primary tumor was found to be an independent prognostic factor along with pathological stage based on both 7th and 8th AJCC/UICC staging systems in patients with esophageal SqCC. The suggested new staging system including SUVmax was better for predicting prognoses than the conventional staging system.

Prognostic Significance of FDG PET/CT in Esophageal Squamous Cell Carcinoma in the Era of the 8th AJCC/UICC Staging System

INTRODUCTION

Recently, the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) staging system was updated for its 8th edition. F-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) is a useful imaging tool to diagnose and predict prognoses for esophageal cancer. However, there was no previous study to explore the role of FDG PET/CT in the staging system based on the 8th edition. The prognostic value of FDG PET/CT was investigated in patients with esophageal squamous cell carcinoma (SqCC) considering the new 8th AJCC/UICC staging system.

METHODS

Subjects were 721 patients with esophageal SqCC undergoing pretherapeutic FDG PET/CT. Clinico-pathological variables and the maximum standardized uptake value (SUVmax) of the primary tumor were included in survival analysis. Subgroup analysis was performed to compare hazard ratios according to pathological stage and SUVmax. A new staging classification including FDG uptake was proposed.

RESULTS

In multivariate survival analysis, pathological stage and SUVmax of the primary tumor were selected as independent prognostic factors for overall survival in both the 7th and 8th editions. The proposed new staging system showed better discrimination for overall survival between stage I and II than did the conventional staging system (hazard ratios: 2.250 vs. 1.341).

CONCLUSIONS

The FDG uptake of the primary tumor was found to be an independent prognostic factor along with pathological stage based on both 7th and 8th AJCC/UICC staging systems in patients with esophageal SqCC. The suggested new staging system including SUVmax was better for predicting prognoses than the conventional staging system.

Glucosamine Conjugated Gadolinium (III) Oxide Nanoparticles as a Novel Targeted Contrast Agent for Cancer Diagnosis in MRI

BACKGROUND

Glucose transporter (Glut), a cellular transmembrane receptor, has a key role in the metabolism of cell glucose and is also associated with various human carcinomas.

OBJECTIVE

In this study, we evaluated a magnetic resonance (MR) imaging contrast agent for tumor detection based on paramagnetic gadolinium oxide (Gd₂O₃) coated polycyclodextrin (PCD) and modified with glucose (Gd₂O₃@PCD-Glu) for the targeting of overexpressed glucose receptors.

MATERIAL AND METHODS

In this experimental study, 3T magnetic resonance imaging (MRI) scanner was used to assess the specific interactions between Glut1-overexpressing tumor cells (MDA-MB-231) and Gd₂O₃@PCD-Glu NPs. Furthermore, the capacity of transporting Gd₂O₃@PCD-Glu NPs to tumor cells was evaluated.

RESULTS

It was found that the acquired MRI T₁ signal intensity of MDA-MB-231 cells that were treated with the Gd₂O₃@PCD-Glu NPs increased significantly. Based on the results obtained, Gd₂O₃@PCD-Glu NPs can be applied in targeting Glut1-overexpressing tumor cells in vivo, as well as an MRI-targeted tumor agent to enhance tumor diagnosis.

CONCLUSION

Results have shown that glucose-shell of magnetic nanoparticles has a key role in diagnosing cancer cells of high metabolic activity.

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

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

Metabolic tumor volume provides complementary prognostic information to EUS staging in esophageal and junctional cancer

To determine the correlation between 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) derived esophageal tumor parameters [maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV)] and endoscopic ultrasound (EUS) derived tumor parameters (T stage, N stage) and their prognostic implications. 150 consecutive patients with cancer of the esophagus or esophagogastric junction underwent staging PET-CT and staging EUS. PET-CT derived SUVmax and MTV of the primary tumor was recorded. EUS evaluated T and N stage. Relationships between parameters were investigated using the Mann-Whitney U tests, survival analysis performed using Kaplan-Meier and independent prognostic factors determined using Cox regression multivariate analysis. A significant difference in MTV was noted between EUS T1/T2 tumors (median 6.7 cm3) and EUS T3/T4 tumors (median 35.7 cm3; P < 0.0001). An MTV of <23.4 cm3 (P = 0.0001), SUVmax < 4.1 (P = 0014), EUS T stage (P < 0.0001), EUS N stage (P < 0.0001), and clinical stage (P < 0.0001) were all significantly associated with survival, with MTV <23.4 cm3 (P = 0.004), EUS T stage (P = 0.01), and EUS N stage (P = 0.01) significant in multivariate analysis. MTV, a volumetric parameter of PET-CT, has more prognostic importance than SUVmax and provides valuable prognostic information in esophageal and junctional cancer, along with EUS T and N stage. MTV provides complementary information to EUS and should be included in the staging of esophageal and junctional cancer.

Does Metastatic Lymph Node SUVmax Predict Survival in Patients with Esophageal Cancer?

Objective:

We aimed to investigate the SUVmax of primary tumor and metastatic lymph node in predicting survival in patients with esophageal cancer.

Methods:

We retrospectively analyzed patients with esophageal cancer between 2009 and 2011 who had FDG positron-emission tomography (PET)/computed tomography (CT). All patients were followed-up to 2013. Clinical staging, SUVmax of primary tumor and metastatic lymph node were evaluated.

Results:

One hundred seven patients were included in the study. All patients were followed-up between 2 and 49 months. The mean SUVmax of primary tumor and metastatic lymph node were 19.3±8.8 and 10.4±9.1, respectively. Metastatic lymph node SUVmax had an effect in predicting survival whereas primary tumor SUVmax did not have an effect (p=0.014 and p=0.262, respectively). Multivariate Cox regression analysis showed that clinical stage of the disease was the only independent factor predicting survival (p=0.001).

Conclusion:

Among patients with esophageal cancer, the value of primary tumor SUVmax did not have an effect on survival. Clinical stage assessed with FDG PET/CT imaging was found to predict survival in esophageal carcinoma. Additionally, lymph node SUVmax was identified as a new parameter in predicting survival in the present study.

Role of Pre-therapeutic (18)F-FDG PET/CT in Guiding the Treatment Strategy and Predicting Prognosis in Patients with Esophageal Carcinoma

OBJECTIVES

The present study aimed to evaluate the role of pre-therapeutic (18)fluorine-fluorodeoxyglucose positron emission tomography-computed tomography ((18)F-FDG PET-CT) and maximum standardized uptake value (SUVmax) in guiding the treatment strategy and predicting the prognosis of esophageal carcinoma, using the survival data of the patients.

METHODS

The present retrospective, cohort study was performed on 40 consecutive patients with esophageal carcinoma (confirmed by endoscopic biopsy), who underwent pre-operative (18)F-FDG PET-CT staging between January 2009 and June 2014. All the patients underwent contrast-enhanced CT and non-contrasted (18)F-FDG PET-CT evaluations. The patients were followed-up over 12 months to assess the changes in therapeutic strategies. Survival analysis was done considering the primary tumor SUVmax, using the Kaplan-Meier product-limit method.

RESULTS

In a total of 40 patients, (18)F-FDG PET-CT scan led to changes in disease stage in 26 (65.0%) cases, with upstaging and downstaging reported in 10 (25.0%) and 16 (40.0%) patients, respectively. The management strategy changed from palliative to curative in 10 out of 24 patients and from curative to palliative in 7 out of 16 cases. Based on the (18)F-FDG PET-CT scan alone, the median survival of patients in the palliative group was 4.0 (95% CI 3.0-5.0) months, whereas the median survival in the curative group has not been reached, based on the 12-month follow-up. Selection of treatment strategy on the basis of (18)F-FDG PET/CT alone was significantly associated with the survival outcomes at nine months (P=0.03) and marginally significant at 12 months (P=0.03). On the basis of SUVmax, the relation between survival and SUVmax was not statistically significant.

CONCLUSION

(18)F-FDG PET/CT scan had a significant impact on stage stratification and subsequently, selection of a stage-specific treatment approach and the overall survival outcome in patients with esophageal carcinoma. However, pre-treatment SUVmax failed to stablish its usefulness in the assessment of patient prognosis and survival outcome.

Diagnostic accuracy of ¹⁸F-FDG PET/CT for detection of suspected recurrence in patients with oesophageal carcinoma

PURPOSE

To evaluate the role of (18)F-FDG PET/CT in the detection of recurrence in patients with oesophageal carcinoma, suspected clinically or following conventional investigations.

METHODS

This was a retrospective study. Data from 180 patients (age 56.3 ± 10.4 years; 126 men, 54 women) with histopathologically proven oesophageal carcinoma (squamous cell 115, adenocarcinoma 59, neuroendocrine carcinoma 4, small cell 1, poorly differentiated 1) who had undergone 227 (18)F-FDG PET/CT studies for suspected recurrence were analysed. Recurrence was suspected clinically or following conventional investigations. PET/CT images were revaluated by two nuclear medicine physicians in consensus. Findings were grouped into local, nodal and distant recurrence. Results were compared to those from contrast-enhanced (CE) CT when available (109 patients). Clinical/imaging follow-up (minimum 6 months) with histopathology (when available) was taken as the reference standard.

RESULTS

Of the 227 (18)F-FDG PET/CT studies,166 were positive and 61 were negative for recurrent disease. PET/CT showed local recurrence in 134, nodal recurrence in 115 and distant recurrence in 47, with more than one site of recurrence in 34. The PET/CT findings were true-positive in 153 studies, true-negative in 54, false-positive in 13 and false-negative in 7. The sensitivity of (18)F-FDG PET/CT was 96%, the specificity was 81%, the positive and negative predictive values were 92% and 89%, respectively, and the accuracy was 91%. PET/CT showed similar accuracy in patients with squamous cell carcinoma and in those with adenocarcinoma (P = 0.181).(18)F-FDG PET/CT was more specific than CECT (67% vs. 21%; P < 0.0001). PET/CT was superior to CECT for the detection of nodal recurrence (P < 0.0001), but not local recurrence (P = 0.093) or distant metastases (P = 0.441).

CONCLUSION

(18)F-FDG PET/CT shows high accuracy in the detection of suspected recurrence in patients with oesophageal carcinoma. It is more specific than and is superior to CECT in the detection of nodal recurrence.

Prognostic value of baseline FDG uptake on PET-CT in esophageal carcinoma

AIM: To evaluate the influence of baseline maximum standardized uptake value (SUV_max) on survival in a cohort of patients, undergoing positron emission tomography-computed tomography (PET-CT) scan for esophageal carcinoma.

METHODS: The pre-treatment SUV_max numeric reading was determined in patients with confirmed esophageal or junctional cancer having PET-CT scan during the time period 1^st January 2007 until 31^st July 2012. A minimum follow up of 12 mo was required. Patients were subdivided into quartiles according to SUV_max value and the influence of SUV_max on survival was assessed using univariate and multivariate analysis. The following pre-treatment factors were investigated: patient characteristics, tumor characteristics and planned treatment.

RESULTS: The study population was 271 patients (191 male) with esophageal or junctional carcinoma. The median age was 65 years (range 40-85) and histologic subtype was adenocarcinoma in 197 patients and squamous carcinoma in 74 patients. The treatment intent was radical in 182 and palliative in 89 patients. SUV_max was linked to histologic subtype (P = 0.008), tumor site (P = 0.01) and Union for International Cancer Control (UICC) stage (P < 0.001). On univariate analysis, prognosis was significantly associated with SUV_max (P = 0.001), T-stage (P < 0.001) and UICC stage (P < 0.001). On multivariate analysis, only T-stage and UICC stage remained significant.

CONCLUSION: Pretreatment SUV_max was not a useful marker in isolation for determining prognosis of patients with esophageal carcinoma.

Diethylentriaminepenta acetic acid glucose conjugates as a cell permeable iron chelator

Objective:

To find out whether DTPA-DG complex can enhance clearance of intracellular free iron.

Materials and Methods:

Diethylenetriaminepentaacetic acid-D-deoxy-glucosamine (DTPA-DG) was synthesized and examined for its activity as a cell-permeable iron chelator in human hepatocellular carcinoma (HEPG2) cell line exposed to high concentration of iron sulfate and compared with deferoxamine (DFO), a prototype iron chelator. The effect of DTPA-DG on cell viability was monitored using the 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide MTT assay as well.

Results:

There was a significant increase of iron level after iron overload induction in HEPG2 cell culture. DTPA-DG presented a remarkable capacity to iron burden reducing with estimated 50% inhibitory concentration value of 65.77 nM. In fact, glycosyl moiety was gained access of DTPA to intracellular iron deposits through glucose transporter systems.

Conclusion:

DTPA-DG, more potent than DFO to sequester deposits of free iron with no profound toxic effect. The results suggest the potential of DTPA-DG in chelating iron and permitting its excretion from primary organ storage.

Maximum standardized uptake value in 18F-fluoro-2-deoxyglucose positron emission tomography is associated with advanced tumor factors in esophageal cancer

Positron emission tomography/computed tomography (PET/CT) with ¹⁸F-fluoro-2-deoxyglucose (FDG-PET/CT) has become established in cancer imaging, and derived maximum standardized uptake values (SUVmax) add functional information regarding cancer, including esophageal squamous cell carcinoma (ESCC). The aim of the present study was to determine the clinical significance and association of tumor progression using SUVmax derived from PET/CT images in patients with ESCC. In total, 101 patients with ESCC were assessed using FDG-PET/CT and the SUVmax was then compared with the clinical backgrounds and prognoses of the patients. Endoscopic ESCC biopsy specimens were obtained in order to analyze mRNA expression relative to tumor progression. The results showed that values for SUVmax were significantly higher in patients with tumor progression factors, particularly those with lymph node metastasis. Analysis of receiver operating characteristics curves revealed an optimum SUVmax cut-off value of 10.26 for node-positive disease. Patients with SUVmax ≥10.26 had gene alterations with epithelial-mesenchymal transition (EMT) and significantly worse overall survival (P=0.0012). A higher SUVmax in patients with ESCC was associated with lymph node metastasis and a poorer prognosis. Thus, the SUVmax may reflect the potential of EMT in patients with ESCC.

Introduction to the analysis of PET data in oncology

Several reviews on specific topics related to positron emission tomography (PET) ranging in complexity from introductory to highly technical have already been published. This introduction to the analysis of PET data was written as a simple guide of the different phases of analysis of a given PET dataset, from acquisition to preprocessing, to the final data analysis. Although sometimes issues specific to PET in neuroimaging will be mentioned for comparison, most of the examples and applications provided will refer to oncology. Due to the limitations of space we couldn't address each issue comprehensively but, rather, we provided a general overview of each topic together with the references that the interested reader should consult. We will assume a familiarity with the basic principles of PET imaging.

18F-FDG PET/CT has a high impact on patient management and provides powerful prognostic stratification in the primary staging of esophageal cancer: a prospective study with mature survival data

The aim of this study is to evaluate the incremental staging information, management impact, and prognostic stratification of PET/CT in the primary staging of esophageal cancer in a cohort of patients with mature survival data.

METHODS

Between July 2002 and June 2005, 139 consecutive patients with newly diagnosed esophageal cancer underwent conventional staging investigations (CSI), followed by PET/CT. Disease stage was classified according to the American Joint Committee on Cancer staging system (6th edition) and grouped as stage I-IIA, stage IIB-III, and stage IV reflecting broad groupings that determine therapeutic choice. Validation of results was performed when PET/CT and CSI stage groups were discordant and in those patients where PET/CT changed management. Management impact was determined by comparing prospectively recorded pre-PET/CT management plans with post-PET/CT management plans. Survival after follow-up of at least 5 y in patients was analyzed using the Kaplan-Meier product limit method and the Cox proportional hazards regression model.

RESULTS

PET/CT changed the stage group in 56 of 139 (40%) patients and changed management in 47 of 139 (34%) patients. In 22 patients, therapy was changed from curative to palliative and in 3 from palliative to curative; in 11, treatment modality was changed without a change in treatment intent, and in 11 the delivery of therapy or diagnostic procedure was changed. Of the 47 patients with management change, imaging results could be validated in 31 patients, and PET/CT correctly changed management in 26 (84%) of these. Of the remaining 5 patients, CSI stage was also incorrect in 4 and correct in 1. Median survival was 23 mo. PET/CT stages I-IIA, IIB-III, and IV had a 5-y survival of 40%, 38%, and 6%, respectively. Post-PET/CT stage group and treatment intent were both strongly associated with survival (P < 0.001).

CONCLUSION

PET/CT provides incremental staging information compared with CSI, changes management in one third of patients, and has powerful prognostic stratification in the primary staging of esophageal cancer.

Accuracy of PET-CT in predicting survival in patients with esophageal cancer

BACKGROUND

Positron emission tomography (PET) is an integral part of tumor staging for patients with esophageal cancer. Recent studies suggest a role for PET scan in predicting survival in these patients, but this relationship is unclear in the setting of neoadjuvant therapy. We examined pretreatment maximum standard uptake value (SUV(max)) of the primary tumor in patients treated with and without neoadjuvant therapy.

METHODS

All patients undergoing esophagectomy with a preoperative PET scan over a nine-year period (2001-2010) were identified from a prospectively maintained database. Positron emission tomography data were obtained from computers housing the original PET scans. Overall survival was correlated with SUV(max) of the primary tumor.

RESULTS

A total of 191 patients were identified, and 103 patients met inclusion criteria. Eighty-two had an adenocarcinoma (80%), and 21 (20%) had a squamous cell carcinoma. Fifty-seven (55%) patients received neoadjuvant therapy. In the surgery alone group, a SUV(max) of > 5.0 in the primary tumor was associated with poor prognosis [Hazard Ratio (HR) 0.32; p = 0.007], but this factor did not retain its significance on multivariate analysis (HR 0.65; p = 0.43). Pretreatment SUV(max) in patients who underwent neoadjuvant therapy was not significant in predicting overall survival (p = 0.10).

CONCLUSIONS

This study does not support the use of SUV(max) on pretreatment PET scans as a prognostic tool for patients with esophageal cancer, especially in those who have received neoadjuvant therapy. Lymph node status is a more accurate predictor of outcome, and efforts to improve pretreatment staging should focus on this factor.

The value of [18F]fluorodeoxyglucose-PET/CT in oesophageal cancer

[¹⁸F]Fluorodeoxyglucose-positron emission tomography/computed tomography (CT) is recognized as a useful adjunct to conventional imaging with CT and endoscopic ultrasonography for the staging of oesophageal cancer, for response assessment and identification of recurrent disease and it may provide prognostic information.

Preoperative positron emission tomography/computed tomography predicts advanced lymph node metastasis in esophageal squamous cell carcinoma patients

BACKGROUND

We aimed to study whether positron emission tomography/computed tomography (PET/CT) findings are associated with lymph node staging, as outlined by the 7th edition American Joint Committee on Cancer (AJCC) TNM staging system in patients with esophageal squamous cell carcinoma (ESCC).

METHODS

A series of 76 ESCC patients undergoing esophagectomy were included in this study. The relation between PET/CT findings [maximum standardized uptake value (SUVmax)] and pathologic lymph node status (N stage) was studied.

RESULTS

The SUVmax of extra-tumor uptake, but not that of the main tumor, was significantly associated with the N classification. N2/N3 disease was observed in 61.1% of patients with an SUVmax for extra-tumor uptake of >4.9, whereas only 17.2% of patients with an SUVmax of extra-tumor uptake of <4.9 were classified as N2/N3 The number of PET abnormalities (NPAs) was also significantly associated with the N classification. Patients with three or more NPAs had a 65% chance of being classified as N2/N3, whereas patients with one or two NPAs had less than a 20% chance of being classified as N2/N3.

CONCLUSIONS

The SUVmax of extra-tumor uptake and the NPAs were significantly associated with the N classification outlined by the 7th edition of the AJCC TNM staging system. PET/CT does help identify patients with advanced lymph node metastasis (N2/N3 stage) instead of simply indicating nodal involvement.

FDG-PET parameters as prognostic factor in esophageal cancer patients: a review

BACKGROUND

(18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) has been used extensively to explore whether FDG Uptake can be used to provide prognostic information for esophageal cancer patients. The aim of the present review is to evaluate the literature available to date concerning the potential prognostic value of FDG uptake in esophageal cancer patients, in terms of absolute pretreatment values and of decrease in FDG uptake during or after neoadjuvant therapy.

METHODS

A computer-aided search of the English language literature concerning esophageal cancer and standardized uptake values was performed. This search focused on clinical studies evaluating the prognostic value of FDG uptake as an absolute value or the decrease in FDG uptake and using overall mortality and/or disease-related mortality as an end point.

RESULTS

In total, 31 studies met the predefined criteria. Two main groups were identified based on the tested prognostic parameter: (1) FDG uptake and (2) decrease in FDG uptake. Most studies showed that pretreatment FDG uptake and postneoadjuvant treatment FDG uptake, as absolute values, are predictors for survival in univariate analysis. Moreover, early decrease in FDG uptake during neoadjuvant therapy is predictive for response and survival in most studies described. However, late decrease in FDG uptake after completion of neoadjuvant therapy was predictive for pathological response and survival in only 2 of 6 studies.

CONCLUSIONS

Measuring decrease in FDG uptake early during neoadjuvant therapy is most appealing, moreover because the observed range of values expressed as relative decrease to discriminate responding from nonresponding patients is very small. At present inter-institutional comparison of results is difficult because several different normalization factors for FDG uptake are in use. Therefore, more research focusing on standardization of protocols and inter-institutional differences should be performed, before a PET-guided algorithm can be universally advocated.

Gd(3+)-DTPA-DG: novel nanosized dual anticancer and molecular imaging agent

Background:

Difficulties in the use, preparation, and cost of radioactively-labeled glycosylated compounds led to this research and development study of a new gadolinium-labeled glucose compound that does not have a radioactive half-life or difficulties in its synthesis and utilization.

Methods:

Based on the structure of the 2-fluoro-2-deoxy-D-glucose molecule (¹⁸FDG), a new compound consisting of D-glucose (1.1 nm) conjugated to a well-known chelator, diethylenetriamine penta-acetic acid (DTPA), was synthesized, labeled with Gd³⁺, and examined in vitro and in vivo.

Results:

This novel compound not only demonstrated excellent and less costly imaging capability, but also showed anticancer effects on treated cells. Our results demonstrated that the new Gd³⁺-DTPA-DG compound (GDD, with GDD conjugate aggregation of about 8 nm at 0.02 mg/mL concentration) significantly decreased HT1080 and HT29 tumor cell numbers. Application of GDD to cancer cells also increased levels of tumor necrosis factor alpha, but did not alter blood glucose levels. Interestingly, no toxicological findings were seen in normal human kidney cells.

Conclusion:

Dual application of GDD for both imaging and treatment of tumor cells could be remarkably advantageous in both the diagnosis and treatment of cancer.

Prognostic significance of the endoscopic ultrasound defined lymph node metastasis count in esophageal cancer

The key prognostic factor which predicts outcome after esophagectomy for cancer is the number of malignant lymph node metastases, but data regarding the accuracy of endoscopic ultrasound (EUS) in determining and predicting the metastatic lymph node count preoperatively are limited. The aim of this study was to assess the prognostic significance of EUS defined lymph node metastasis count (eLNMC) in patients diagnosed with esophageal cancer. Two hundred and sixty-seven consecutive patients (median age 63 years, 187 months) underwent specialist EUS followed by stage directed multidisciplinary treatment (183 esophagectomy [64 neoadjuvant chemotherapy, 19 neoadjuvant chemoradiotherapy], 79 definitive chemoradiotherapy, and 5 palliative therapy). The eLNMC was subdivided into four groups (0, 1, 2 to 4, >4) and the primary measure of outcome was survival. Survival was related to EUS tumor (T) stage (P < 0.0001), EUS node (N) stage (P < 0.0001), EUS tumor length (p < 0.0001), and eLNMC (P < 0.0001). Multivariable analysis revealed EUS tumor length (hazard ratio [HR] 1.071, 95% CI 1.008-1.138, P= 0.027) and eLNMC (HR 1.302, 95% CI 1.133-1.496, P= 0.0001) to be significantly and independently associated with survival. Median and 2-year survival for patients with 0, 1, 2-4, and >4 lymph node metastases were: 44 months and 71%, 36 months and 59%, 24 months and 50%, and 17 months and 32%, respectively. The total number of EUS defined lymph node metastases was an important and significant prognostic indicator.

The clinical application of (18)F-fluorodeoxyglucose positron emission tomography to predict survival in patients with operable esophageal cancer

BACKGROUND

Metabolic tumor activity using (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) was believed to have a predictive value for patient outcome in malignancies. The objective of the current study was to assess the prognostic effectiveness of the highest standardized uptake value (SUV) in the primary or regional area (peak SUV) and the number of PET-positive lymph nodes in esophageal cancer.

METHODS

The authors retrospectively reviewed their experience with 184 consecutive esophageal cancer patients imaged preoperatively using FDG-PET scanning.

RESULTS

The median peak SUV was 4.5 (range, 1.4-21.9). The survival curve was analyzed using the median peak SUV as the cutoff value. Comparison of each group and clinicopathologic characteristics revealed significant associations between peak SUV and each of the following factors: tumor status (P < .001), lymph node status (P < .001), metastatic status (P < .05), stage of disease (P < .001), number of PET-positive lymph nodes (P < .001), and the number of histologically positive lymph nodes (P < .001). The 5-year overall survival (OS) rate for patients having FDG uptake with a peak SUV > or =4.5 was 47% and that for patients with a peak SUV <4.5 was 76% (P < .0001). On multivariate survival analysis using the Cox proportional hazards model, peak SUV and the number of PET-positive lymph nodes were found to be independent predictive factors for OS. The number of PET-positive lymph nodes was a single prognostic factor predicting both disease-free survival and OS.

CONCLUSIONS

Pretreatment PET cannot only potentially diagnose the extent of disease, but also may be predictive of patient survival after esophageal cancer resection.

Gastrointestinal 18F-FDG accumulation on PET without a corresponding CT abnormality is not an early indicator of cancer development

Focal gastrointestinal 2-deoxy-2-[(18)F]-fluoro-D: -glucose (FDG) uptake can frequently be found on FDG-PET/CT even in patients without known gastrointestinal malignancy. The aim of this study was to evaluate whether increased gastrointestinal FDG uptake without CT correlate is an early indicator of patients developing gastrointestinal malignancies. A total of 1,006 patients without esophagogastric or anorectal malignancies underwent FDG-PET/CT. The esophagogastric junction, the stomach and the anorectum were evaluated for increased FDG uptake. Patients without elevated uptake were assigned to group A, patients with elevated uptake were allocated to group B. The SUVmax values of both groups were tested for significant differences using the U test. A follow-up of longer than 1 year (mean 853 +/- 414 days) served as gold standard. A total of 460 patients had to be excluded based on insufficient follow-up data. For the remaining 546 patients the mean SUVmax was as follows: (a) esophagogastric junction, group A 3.1 +/- 0.66, group B 4.0 +/- 1.11, p < 0.01; (b) stomach, group A 2.8 +/- 0.77, group B 4.1 +/- 1.33, p < 0.01; (c) rectal ampulla, group A 2.8 +/- 0.83, group B 3.9 +/- 1.49, p < 0.01; (d) anal canal, group A 2.7 +/- 0.55, group B 3.9 +/- 1.59, p < 0.01. Only one patient developed gastric cancer. In the case of an unremarkable CT, elevated esophagogastric or anorectal FDG uptake does not predict cancer development and does not have to be investigated further.

Use of positron emission tomography in surgery follow-up of esophageal cancer

INTRODUCTION

Although the prognosis of patients with esophageal cancer has been improved by extended dissection, the incidence of recurrence still remains high. In esophageal cancer, positron emission tomography (PET) using (18)F-fluorodeoxyglucose (FDG) already demonstrated to be useful for initial staging and monitoring response to therapy. This prospective study compared the ability of FDG-PET and conventional imaging to detect early recurrence of esophageal cancer after initial surgery in asymptomatic patients.

MATERIALS AND METHODS

Between October 2003 and September 2006, 41 patients with esophageal cancer were included in a prospective study after initial radical esophagectomy. FDG-PET, thoracoabdominal computed tomography (CT), abdominal ultrasonography, and endoscopy were performed every 6 months after initial treatment.

RESULTS AND DISCUSSION

Twenty-three patients had recurrent disease (56%), mostly within the first 6 months after surgery (70%). Despite two false-positive scans due to postoperative changes, FDG-PET was more accurate than CT (91% vs. 81%, p = 0.02) for the detection of recurrence with a sensitivity of 100% (vs. 65%), a specificity of 85% (vs. 91%), and a negative predictive value of 100% on a patient-by-patient-based analysis. For the detection of locoregional recurrence, FDG-PET was more accurate than CT (96.2% vs. 88.9%). FDG-PET was also more accurate than CT for the detection of distant metastases (92.5% vs. 84.9%), especially when involving either bones (100%) or liver (98.1%). A lower sensitivity of FDG-PET (57%) for the early detection of small lung metastases did not affect patient management (accuracy = 92.5%).

CONCLUSION

FDG-PET appears to be very useful for the systematic follow-up of asymptomatic patients after esophagectomy with an initial scan performed 6 months after surgery.

Positron emission tomography changes management and prognostic stratification in patients with oesophageal cancer: results of a multicentre prospective study

OBJECTIVES

The aims of this study were (1) to determine the incremental information provided by (18)F-FDG positron emission tomography (PET) in staging patients with oesophageal cancer, and (2) to determine the impact of PET staging on post-PET clinical management of oesophageal cancer, and on prognosis.

METHODS

In a multicentre, single-arm open study, patients with proved oesophageal cancer without definite distant metastases and regarded as suitable for potentially curative treatment were examined by PET. Clinicians were requested to supply a management plan before and another plan after being supplied with the PET scan results. Patients were followed for at least 1 year for outcome analysis.

RESULTS

A total of 129 patients (104 men, mean age 67 y) were recruited. PET detected additional sites of disease in 53 patients (41%). Significant changes in management (high or medium impact) were observed in 38% of patients, primarily as a result of identifying additional sites of disease and/or confirming previously equivocal regional and distant metastases. Progression-free survival was significantly shorter in patients found to have additional lesions on PET (p < 0.05), but was not related to SUV(max).

CONCLUSION

These findings demonstrate the significant impact of PET on the clinical management of patients with newly diagnosed oesophageal carcinoma, and on prognostic stratification of these patients.