CT for local staging of esophageal cancer

The Diagnostic Utility of Prone Position Chest CT for the Evaluation of Esophageal Cancer

The aim of this study was to assess the potential of a prone chest CT for the evaluation of esophageal cancer, as compared with a routine supine chest CT. 69 patients (67±18 years old) with pathologically confirmed esophageal cancers underwent MDCT in the supine and prone positions. The supine CT was performed first, followed by the prone position. Localization and staging of individual esophageal lesions on both the prone and supine CTs were assessed by two thoracic radiologists, using a scoring system that consisted of three confidence scales, and the results were correlated with the endoscopic and surgical findings. The mean confidence score for the detection of esophageal cancer was higher in the prone position (2.58±0.74) than that in the supine position (2.42±0.83) with statistical significance (p=0.002). The mean confidence score for predicting local invasion in the selected patients (n=18) who underwent esophagectomy was also higher in the prone position (2.39±0.85) than that in the supine position (2.06±0.73) with statistical significance (p=0.01). In 10 of 11 cases that showed definitive determination for periesophageal infiltration or adjacent organ invasion on the prone CT (score 3), the corresponding findings were also observed in the post-operative evaluations. In conclusion, prone chest CT for evaluating esophageal cancer could have advantages in regards to the localization of esophageal cancer and predicting local invasion compared to that of routine supine CT and can improve the diagnostic accuracy of chest CTs.

Metastasis to regional lymph nodes in patients with esophageal squamous cell carcinoma: CT versus FDG PET for presurgical detection prospective study

PURPOSE

To prospectively compare the accuracy of fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) and computed tomography (CT) for detection of primary tumor and metastasis to individual lymph node groups and for nodal staging.

MATERIALS AND METHODS

From February 2000 to July 2001, 81 patients with squamous cell carcinoma of the esophagus (78 men and three women; age range, 31-90 years; mean age, 63 years) underwent CT and FDG PET before esophagectomy and lymph node dissection. During surgery, all visible and palpable lymph nodes in the surgical fields were removed. The accuracies of CT and FDG PET for depiction of metastasis to lymph nodes were compared.

RESULTS

For depiction of malignant nodal groups in each lymph node group, the sensitivity, specificity, and accuracy, respectively, of CT were 11% (11 of 96 nodal groups), 95% (553 of 581), and 83% (564 of 677), whereas those of FDG PET were 30% (29 of 96), 90% (525 of 581), and 82% (554 of 677) (P values: < .001, .009, and .382, respectively). Twenty-eight false-positive interpretations were rendered at CT in evaluations of 11 mediastinal, four hilar, and 13 abdominal nodal groups, and 56 false-positive interpretations were rendered at FDG PET in evaluations of 23 mediastinal, 32 hilar, and one abdominal nodal group.

CONCLUSION

FDG PET is more sensitive than CT for depicting nodal metastases in patients with squamous cell carcinoma of the esophagus. FDG PET is slightly less specific than CT for depicting metastases, but the difference in specificity between the two modalities is statistically significant. Both FDG PET and CT have low sensitivity for depicting nodal metastasis. The relatively low specificity of FDG PET for depiction of nodal metastasis compared with that of CT is caused mainly by a high rate of false-positive hilar node interpretations.

Helical CT versus EUS with fine needle aspiration for celiac nodal assessment in patients with esophageal cancer

BACKGROUND

Conventional CT is insensitive for detection of metastatic involvement of celiac lymph nodes in esophageal cancer. Helical CT has theoretical advantages over "slice" CT in this regard, but its performance has not yet been prospectively studied.

METHODS

Consecutive patients with untreated esophageal cancer were recruited after obtaining informed consent. Helical CT was performed on all patients and TNM staging was performed by a single radiologist. Subsequently, all patients underwent esophageal radial and, as needed, curvilinear array EUS with fine needle aspiration (FNA), for evaluation of celiac lymph nodes and TNM staging. Test performance characteristics with 95% confidence intervals were calculated, assuming EUS with FNA as the reference standard.

RESULTS

Forty-eight patients were recruited, of whom 37 (77%) were men. The mean (SD) age was 63.6 (10) years. Excluding 5 patients in whom a confirmatory FNA was not available (n = 43), helical CT identified celiac lymph nodes in 12 (28%) patients. The reference standard of EUS with FNA identified 15 (35%) patients with metastatic celiac lymph nodes, giving a sensitivity, specificity, and positive and negative predictive values for helical CT of 53% (95% CI [28%, 79%]), 86% (95% CI [73%, 99%]), 67% (95% CI [40%, 93%]), and 77% (95% CI [63%, 92%]), respectively, for assessing celiac lymph nodal involvement. The sensitivity and specificity of helical CT in detecting T4 disease were 25% (95% CI [3.8%, 46%]) and 94% (95% CI [85%, 100%]), respectively. There were 12 patients (25%; 95% CI [13%, 37%]) who were felt to have resectable disease by helical CT but had either metastatic involvement of celiac lymph nodes or T4 disease by EUS/FNA.

CONCLUSIONS

Despite technological advances, helical CT still appears unreliable, mainly because of insensitivity, for the identification of inoperable T4 or metastatic involvement of celiac lymph node disease in esophageal cancer.