Role of ultrasonography in the staging of gastrointestinal neoplasms

Double Contrast-Enhanced Ultrasonography in Preoperative T Staging of Gastric Cancer: A Comparison With Endoscopic Ultrasonography

Objective: To compare the precision of double contrast-enhanced ultrasonography (DCEUS) to endoscopic ultrasonography (EUS) in preoperative T staging of gastric cancers.

Methods: This retrospective study consisted of 158 pathologically confirmed gastric cancer patients. All patients underwent DCEUS (intravenous contrast-enhanced ultrasonography combined with oral contrast-enhanced ultrasonography) and endoscopic ultrasonography (EUS) preoperatively. The histopathological findings of resected specimens were compared with the results of DCEUS and EUS retrospectively.

Results: The accuracy of DCEUS and EUS in evaluating the T staging of gastric cancer were 82.3% (T1 62.5%,T2 84.4%,T3 87.9%,T4 91.3%) and 76.6% (T1 84.4%,T2 82.2%,T3 72.4%,T4 65.2%), respectively. There were no significant differences between the methods for the overall T staging accuracy (χ² = 1.569, P = 0.210). But EUS was superior to DCEUS for T1 stage (χ² = 3.925, P = 0.048) and DCEUS was superior to EUS for T3 stage (χ² = 4.393, P = 0.036) and T4 stage (χ² = 4.600, P = 0.032).

Conclusion: DCEUS is a convenient and noninvasive method with high precision, which can be used as the primary imaging technique for advanced gastric cancer T staging. In early gastric cancer, we should prefer EUS. Two methods are complementary for assessing tumor invasion depth of gastric cancer.

Double contrast-enhanced ultrasonography for the preoperative evaluation of gastric cancer: a comparison to endoscopic ultrasonography with respect to histopathology. Am J Surg. 2011;202:605-611. [PMID: 21824594 DOI: 10.1016/j.amjsurg.2010.09.033]

BACKGROUND

This study was designed to compare the accuracy of endoscopic ultrasound (EUS) with double contrast-enhanced ultrasound (DCUS) in the staging of gastric malignancies. DCUS is a transabdominal ultrasound technique using both intravenous and intraluminal contrast to enhance sonographic visualization.

METHODS

This retrospective study included 162 patients with biopsy-proven gastric cancer who underwent DCUS and EUS preoperatively with the ultrasound results compared with the pathologic findings of the resected specimens.

RESULTS

The overall accuracy of DCUS and EUS for tumor (T) staging was 77.2% and 74.7%, respectively. Comparison of ultrasound techniques for T staging revealed that DCUS was superior to EUS only for a tumor depth of T3 (chi-square, P = .025). Lymph nodes were staged correctly with DCUS and EUS in 78.4% and 57.4% of cases, respectively (chi-square, P = .001).

CONCLUSIONS

DCUS offers a noninvasive approach for the staging of gastric cancer. DCUS was comparable to EUS in tumor depth evaluation but offered an advantage in lymph node detection.

Predicting lymph node status in patients with early gastric carcinoma using double contrast-enhanced ultrasonography

INTRODUCTION

Double contrast-enhanced ultrasonography (DCUS) is a new method we used in predicting lymph node metastasis (LNM) in patients with early gastric cancer.

MATERIAL AND METHODS

Seventy-six patients with early gastric cancer diagnosed by gastroscope and confirmed by pathology after operation were examined using DCUS preoperatively. Group N1 included 15 patients with LNM and group N0 61 patients without LNM.

RESULTS

In group N1, 13 patients (87%) had marked hyperenhancement during early arterial phase using DCUS, and 2 patients (13%) were unmarked as hyperenhancement. In group N0, 24 patients (39%) had marked hyperenhancement during early arterial phase using DCUS, and 37 patients (61%) had unmarked hyperenhancement. The sensitivity and specificity of marked hyperenhancement in predicting LNM in patients with early gastric cancer was 86.7% and 60.7% respectively, and the Youden's index was 0.474. The κ value of this method was 0.89.

CONCLUSIONS

Double contrast-enhanced ultrasonography is a new valuable method to evaluate LNM at an early stage of gastric cancer and prognosis of early gastric cancer preoperatively.

Detection of focal liver lesions: from the subjectivity of conventional ultrasound to the objectivity of volume ultrasound

PURPOSE

This study was undertaken to establish the reliability of automated volumetric liver scans in detecting focal liver lesions by evaluating the degree of agreement between conventional and volume ultrasound (US) examinations.

MATERIALS AND METHODS

Over a period of 3 months, we prospectively studied 100 consecutive patients (36 men and 64 women; age range 15-87 years; mean age 63 years) referred to our institute for US imaging of the liver. Volumetric acquisition of the liver was achieved with a 3D transducer (2.0-5.0 MHz) and a Logiq 9 US scanner. All patients underwent both 2- and 3D US studies performed by two expert radiologists. Volumetric acquisitions were subsequently reviewed by the second radiologist, who was blinded to the first radiologist's report. Three categories were established: 1=presence of focal liver lesions; 2=doubtful finding; 3=absence of focal liver lesions. Concordance between volume US and conventional US was calculated by using the k statistic.

RESULTS

Out of 100 patients examined, 39 were found to be affected by focal liver lesions. All volume US examinations were technically adequate, allowing exploration of all hepatic sectors, except for five cases that were marred by major respiratory motion artefacts. Conventional and volume US identified the same number of focal liver lesions, with the exception of four cases of doubtful findings at volume US. Concordance between automated volume US and conventional US of the liver was high (k=0.92).

CONCLUSIONS

The identification of focal liver lesions on automated volume US is possible, and the examination shows a high level of concordance with conventional US.

Lymphoscintigraphy in detection of the regional lymph node involvement in gastric cancer

INTRODUCTION

Involvement of regional lymph node is a critical sign in prognosis of gastric cancer. Radiological techniques are commonly used to evaluate the extension of gastric cancer. But their sensitivity and specificity are low especially in the early stage. Our aim was to assess the value of gastric lymphoscintigraphy in identifying regional lymph node involvement in patients with gastric cancer, as compared to the abdominal ultrasonography, computed tomography and postoperative histopathological evaluation.

PATIENTS AND METHODS

50 patients (12 females) with a median age of 61 years (range, 35-73 years) were included in the study. Pre-operative staging in all cases included upper gastrointestinal endoscopy and biopsy, followed by ultrasound, computed tomography and lymphoscintigraphy. 148 MBq Technetium-99m lymphoscint was injected around the tumour during endoscopy and immediately after injection, anterior, lateral and posterior images were taken in 5-min intervals using a gamma camera. Findings were compared to the findings of other tests. The sensitivity, specificity, positive predictive value, and negative predictive value of each test were calculated and compared.

RESULTS

Histologically, 68% of cases (34/50) had metastasis in regional lymph nodes and all cases were accurately diagnosed by lymphoscintigraphy. Lymphoscintigraphy was significantly more sensitive for detecting lymph node involvement (P < 0.01). Both abdominal ultrasonography and CT had very low sensitivity in identifying lymph nodes.

CONCLUSIONS

Lymphoscintigraphy is a promising test in the identification of regional lymph nodes pre-operatively in patients with gastric cancer. It might help the surgeon to plan the extent of dissection before surgery which may decrease postoperative complications related to unnecessary extensive lymph node dissection.

Imagerie en coupes de l’estomac et du duodénum

Imaging of the stomach and duodenum provides an abundant semiology, which allows precise diagnosis. In this chapter we will review specific considerations related to CT, MRI and US imaging of the stomach and duodenum. Normal imaging features as well as the main gastric and duodenal diseases will be described and illustrated.

N/A

N/A

Staging laparoscopy for gastric cancer

Surgical resection remains the only potentially curative treatment of patients with gastric cancer. Evaluation of surgery and other treatments depends on accurate staging of the disease. The objective of the study was to compare staging laparoscopy with ultrasonography, endoscopic ultrasound, computed tomography, and histology for serosal infiltration, lymph node metastasis, peritoneal seeding, and hepatic metastasis. Diagnostic laparoscopy was carried out in 48 patients. Prelaparoscopic staging in all cases included upper gastrointestinal endoscopy and biopsies followed by endosonography, ultrasound, and computed tomography. Preoperative combined examination using CT and laparoscopy was superior when compared with each modality alone or the combinations of the other tests. The present study showed that preoperative evaluation of patients with laparoscopy is superior to all other diagnostic tests. We also found that laparoscopy and computed tomography were better in accurately assessing the serosal infiltration, peritoneal seeding, and hepatic metastases, which thus allows the surgeon to choose more effective treatment modality.