F-18 FDG PET/CT contributes to more accurate detection of lymph nodal metastasis from actively proliferating esophageal squamous cell carcinoma

Value of Computed Tomography Scan for Detecting Lymph Node Metastasis in Early Esophageal Squamous Cell Carcinoma

BACKGROUND

The necessity of computed tomography (CT) scan for detecting potential lymph node metastasis (LNM) in early esophageal squamous cell carcinoma (ESCC) before endoscopic and surgical treatments is under debate.

METHODS

Patients with histologically proven ESCC limited to the mucosa or submucosa were examined retrospectively. Diagnostic performance of CT for detecting LNM was analyzed by comparing original CT reports with pathology reports. The sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were calculated.

RESULTS

A total of 625 patients from three tertiary referral hospitals were included. The rate of pathologically confirmed LNM was 12.5%. Based on original CT reports, the sensitivity, specificity, accuracy, PPV, and NPV of CT to determine LNM in T1 ESCC were 41.0%, 83.2%, 77.9%, 25.8%, and 90.8% respectively. For mucosal cancers (T1a), these parameters were 50.0%, 81.7%, 80.9%, 6.8%, and 98.4%, respectively. For submucosal cancers (T1b), they were 40.0%, 85.0%, 75.0%, 43.0%, and 83.3%, respectively. Additionally, the diagnostic performance of CT for LNM was relatively better for ESCC in the lower esophagus. Pathologically, 69.2% of patients with LNM did not exhibit lymphovascular invasion (LVI), and the sensitivity of CT for recognizing LNM in these patients (33.3%) was lower than those with LVI (58.3%).

CONCLUSIONS

Computed tomography can detect nearly half of the LNM cases in early ESCC with high specificity. The performance of CT further improved in LNM cases with LVI. Therefore, we conclude that routine preoperative CT for the assessment of potential LNM risk in patients with early ESCC is necessary.

Validation of the cutoff values for the number of metastatic lymph nodes for esophageal cancer staging: a multi-institutional analysis of 655 patients in Japan

BACKGROUND

The number of metastatic lymph nodes (LNs) is an important prognostic factor for esophageal cancer, and N staging is important for prognostic stratification. The optimal cutoff values for clinical (cN) and pathologic N (pN) staging should be reconsidered following advances in neoadjuvant therapy.

METHODS

The study included 655 patients who underwent esophagectomy between January 2014 and December 2016 in four high-volume centers in Japan. Optimal cutoff values for the number of metastatic LNs in cN and pN staging were examined using X-tile, and their prognostic performance was validated using the Kaplan-Meier method.

RESULTS

The cutoff values were 1, 2, and 3 for cN staging and 1, 3, and 7 for pN staging. Prognosis was significantly better in patients with cN0 than in those with modified (m)-cN1 (p = 0.0211). However, prognosis was not significantly different among the patients with m-cN1, m-cN2, and m-cN3 disease. Prognosis was significantly different among the patients with pN0, pN1, pN2, and pN3 disease (pN0 vs pN1, p < 0.0001; pN1 vs pN2, p < 0.0001; pN2 vs pN3, p < 0.0001). In patients who received preoperative neoadjuvant therapy, prognosis, which was not significantly different among the patients with cN0, m-cN1, m-cN2, and m-cN3 disease (cN0 vs m-cN1, p = 0.5675; m-cN1 vs m-cN2, p = 0.4425; m-cN2 vs m-cN3, p = 0.7111), was significantly different among the patients with pN0, pN1, pN2, and pN3 disease (pN0 vs pN1, p = 0.0025; pN1 vs pN2, p = 0.0046; pN2 vs pN3, p = 0.0104).

CONCLUSIONS

cN has no prognostic impact in patients who underwent preoperative treatment followed by esophagectomy, despite the optimization of cN classification. The conventional TNM8th pN classification is useful for predicting prognosis even for patients who have undergone preoperative treatment. The conventional cutoffs for metastatic LNs in the International Union against Cancer tumor node metastasis staging system are valid and can be effectively used in clinical practice.

False-Positive Cases of Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomographic Scans in Metastasis of Esophageal Cancer

Of 129 esophagectomies at our institute from June 2010 to March 2015, we experienced three preoperative positron emission tomography-computed tomographic (PET/CT) false positives. Bone metastasis was originally suspected in 2 cases, but they were later found to be bone metastasis negative after a preoperative bone biopsy and clinical course observation. The other cases suspected of mediastinal lymph node metastasis were diagnosed as inflammatory lymphadenopathy by a pathological examination of the removed lymph nodes. Conducting a PET/CT is useful when diagnosing esophageal cancer metastasis, but we need to be aware of the possibility of false positives. Therapeutic decisions should be made based on appropriate and accurate diagnoses, with pathological diagnosis actively introduced if necessary.

Consensus and controversies on dose and target volume of three-dimensional conformal radiotherapy for esophageal carcinoma

Radiotherpay is the mainstay treatment for esophageal cancer. Three-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiotherapy have been widely applied in routine clinical work, because they can raise the target dose and reduce the injury to normal tissue, and therefore raise the five-year survival rate to > 20%. In recent years, a number of studies on 3DCRT have been carried out with regard to radiation dose, target volume contour, and preventive lymph node irradiation, and this article will summarize these issues.

FDG Positron Emission Tomography and Computed Tomography Demonstration of Carcinoma Arising in an Epiphrenic Diverticulum

Esophageal carcinoma arising within an epiphrenic diverticulum is rare. We describe a case of a carcinoma in a long-standing epiphrenic diverticulum in a 62-year-old patient. Fluorine-18-2-Fluoro-2-Deoxy-D-Glucose Positron Emission Tomography and Computed Tomography, and endoscopic ultrasound revealed a hypermetabolic mass within the diverticulum. A preoperative diagnosis was made via endoscopic biopsy. The patient underwent Ivor-Lewis esophagectomy. He remains well and free of recurrence 18 months after surgery.

Diagnostic value of ¹⁸F-FDG PET/CT for lymph node metastasis of esophageal squamous cell carcinoma

PURPOSE

This study investigated the diagnostic accuracy of hybrid positron-emission tomography/computed tomography (PET/CT) for lymph node (LN) metastasis of esophageal cancer. We also investigated the correlation between the size of metastatic nests and the detection by PET/CT.

METHODS

Two hundred and fifty-eight patients with esophageal squamous cell carcinoma who underwent esophagectomy with two- or three-field radical lymphadenectomy were analyzed retrospectively. We compared the diagnosis of preoperative PET/CT to the postoperative histopathological examination by each anatomical field (n = 1,231) in all 258 patients. The metastatic LNs resected from PET/CT positive fields were classified as belonging to the PET/CT-N-positive group (n = 229) and those from negative fields as belonging to the PET/CT-N-negative group (n = 352). The cross-sectional areas of metastatic nests were measured in each metastatic LN.

RESULTS

Of the 1,231 fields, 275 (22 %) were positive for metastasis, including 581 LNs from 408 regional LN stations. The sensitivity and specificity of PET/CT examined by each anatomical field were 25.8 and 97.8 %, respectively. The median area of metastatic nests was 17.7 mm2 in the PET/CT-N-positive group, and 7.7 mm2 in the PET/CT-N-negative group (p < 0.001).

CONCLUSIONS

A significant correlation was suggested between the nest size and detection by PET/CT. Because of its low sensitivity, PET/CT alone is insufficient to determine the surgical procedures, especially when considering reduction surgery.

Hypoxia, blood flow and metabolism in squamous-cell carcinoma of the head and neck: correlations between multiple immunohistochemical parameters and PET

Background

The relationship between the uptake of [¹⁸F]fluoroerythronitroimidazole ([¹⁸F]FETNIM), blood flow ([¹⁵O]H₂O) and 2-[¹⁸F]fluoro-2-deoxyglucose ([¹⁸F]FDG) and immunohistochemically determined biomarkers was evaluated in squamous-cell carcinomas of the head and neck (HNSCC).

Methods

[¹⁸F]FETNIM and [¹⁸F]FDG PET were performed on separate days on 15 untreated patients with HNSCC. Hypoxia imaging with [¹⁸F]FETNIM was coupled with measurement of tumor blood flow using [¹⁵O]H₂O. Uptake of [¹⁸F]FETNIM was measured as tumor-to-plasma ratio (T/P) and fractional hypoxic volume (FHV), and that of [¹⁸F]FDG as standardized uptake value (SUV) and the metabolically active tumor volume (TV). Tumor biopsies were cut and stained for GLUT-1, Ki-67, p53, CD68, HIF-1α, VEGF_sc-152, CD31 and apoptosis. The expression of biomarkers was correlated to PET findings and patient outcome.

Results

None of the PET parameters depicting hypoxia and metabolism correlated with the expression of the biomarkers on a continuous scale. When PET parameters were divided into two groups according to median values, a significant association was detected between [¹⁸F]FDG SUV and p53 expression (p =0.029) using median SUV as the cut-off. There was a significant association between tumor volume and the amount of apoptotic cells (p =0.029). The intensity of VEGF stained cells was associated with [¹⁸F]FDG SUV (p =0.036). Patient outcome was associated with tumor macrophage content (p =0.050), but not with the other biomarkers. HIF-1α correlated with GLUT-1 (r_s =0.553, p =0.040) and Ki-67 with HIF-1α (r_s =506, p =0.065). p53 correlated inversely with GLUT-1 (r_s = −618, p =0.019) and apoptosis with Ki-67 (r_s = −638, p =0.014).

Conclusions

A high uptake of [¹⁸F]FDG expressed as SUV is linked to an aggressive HNSCC phenotype: the rate of apoptosis is low and the expressions of p53 and VEGF are high. None of the studied biomarkers correlated with perfusion and hypoxia as evaluated with [¹⁵O]H₂O-PET and [¹⁸F]FETNIM-PET. Increased tumor metabolism evaluated with PET may thus signify an aggressive phenotype, which should be taken into account in the management of HNSCC.

The overall prevalence of metastasis in T1 esophageal squamous cell carcinoma: a retrospective analysis of 295 patients

OBJECTIVES

T1 esophageal squamous cell carcinoma (ESCC) has a low, but still present, risk of lymph node (LN) metastasis. Endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) is often applied for T1 ESCC. To achieve successful treatment by EMR/ESD, the risk of LN metastases, LN recurrence, and hematological recurrence need to be better understood. The aim of this study was to determine the precise risk for metastasis in T1 ESCC.

METHODS

We divided 295 patients with T1 ESCC who underwent surgery and/or ESD/EMR into 6 categories (m1, m2, m3, sm1, sm2, and sm3). Their risks of LN metastasis, LN recurrence, hematological recurrence, and the outcome were determined.

RESULTS

The rates of LN metastasis and LN recurrence were 0% in m1 and m2, 9% in m3, 16% in sm1, 35% in sm2, and 62% in sm3 cases. The incidence of hematological recurrence was 0% in m1, m2, m3, and sm1 cases; 9% in sm2 cases; and 13% in sm3 cases. The overall risk of metastasis was 9% in m3, 16% in sm1, 38% in sm2, and 64% in sm3 patients. The 5-year disease-specific survival rates were 100% in m1, m2, and m3; 90.9% in sm1; 78.8% in sm2; and 68.6% in sm3 patients. Statistically, both lymphatic and venous invasion were selected as predictive markers for metastasis. In m3 patients, positivity for either of these had an odds ratio for metastasis of 7.333 (P = 0.093).

CONCLUSIONS

Our study provides a precise assessment of the comprehensive risk of metastasis and feasible predictive markers for T1 ESCC.