The 18F 2-fluoro-2-deoxyglucose (FDG) PET/CT scan is an imaging modality used in the management of patients with various types of malignancies. 18F-FDG PET/CT has demonstrated significant efficacy in the staging and detection of metastatic disease in malignancies of the gastrointestinal tract. The assessment of the metabolic response to chemotherapy and improvements of overall survivals in malignancies of esophagus and stomach has been demonstrated in several studies. This review focuses on the role of 18F-FDG PET/CT scan in staging, metastasis, predict of recurrence and assessment of metabolic response in malignancies of the upper gastrointestinal tract.
Esophageal Neoplasms/pathology/*radionuclide imaging ; Fluorodeoxyglucose F18/diagnostic use ; Humans ; Lymphatic Metastasis ; Neoplasm Metastasis ; Neoplasm Staging ; Positron-Emission Tomography ; Radiopharmaceuticals/diagnostic use ; Recurrence ; Stomach Neoplasms/pathology/*radionuclide imaging

Portal vein thrombus has been detected in patients with liver cirrhosis, pancreatitis, ulcerative colitis, septicemia, myeloproliferative disorder, and neoplasm. The formation of portal tumor thrombus by hepatocellular carcinoma is well recognized, because of its high incidence, and subsequent development of portal hypertension such as rupture of varices, ascites and liver failure indicates the poor prognosis. In gastric cancer, portal hypertension as an initial presentation is extremely rare. Herein we report a case presenting as portal hypertension caused by tumor thrombus without invasion of liver parenchyma. It is presumed to be intraluminal tumor thrombus originating from primary foci of gastric adenocarcinoma. Tumor thrombus in the portal vein is demonstrated on the PET-CT.
Adenocarcinoma/*diagnosis/pathology/radionuclide imaging ; Endoscopy, Gastrointestinal ; Fluorodeoxyglucose F18/diagnostic use ; Humans ; Hypertension, Portal/*diagnosis ; Male ; Middle Aged ; Positron-Emission Tomography and Computed Tomography ; Stomach Neoplasms/*diagnosis/pathology/radionuclide imaging

OBJECTIVETo evaluate the feasibility and clinical value of whole body diffusion weighted magnetic resonance imaging (WB-DWI) in detection of bone metastases.

METHODSTotally 38 patients with malignant tumors and suspected bone metastases were enrolled. All patients underwent WB-DWI and bone scintigraphy within 2 weeks. The skeletal system was divided into 13 regions: skull, sternum, clavicle, cervical spine, thoracic spine, lumbar spine, sacrum, ribs, pelvic bone, scapula, humerus, femur, and tibia/fibula. Bone metastases were assessed for both modalities in a separate consensus reading and apparent diffusion coefficient (ADC) values were calculated.

RESULTSWB-DWI identified 214 pathological lesions in 20 patients, while bone scintigraphy demonstrated 197 lesions in 20 patients. Concordance between WB-DWI and bone scintigraphy occurred in 34 of 38 patients. There was no statistical difference between these two modalities (P = 0.488). Compared with bone scintigraphy, the regions missed by WB-DWI were mainly located in skull, thoracic spine, humerus, and tibia/fibula. WB-DWI was more sensitive in the detection of metastases to the cervical spine, lumbar spine, sacrum, pelvis, ribs and femur. No statistical significance was found among the ADC values of bone metastases in different skeletal areas, and the mean ADC value was (0.75 +/- 0.10) x 10(-3) mm2/s. Furthermore, WB-DWI revealed more metastases to the lymph lodes and extraskeletal organs. Conclusion WB-DWI has high accordance with skeletal scintigraphy in detecting bone metastases, and the two modalities are complementary to each other.

Adult ; Aged ; Aged, 80 and over ; Bone Neoplasms ; diagnosis ; diagnostic imaging ; secondary ; Diffusion Magnetic Resonance Imaging ; methods ; Feasibility Studies ; Female ; Humans ; Lung Neoplasms ; pathology ; Male ; Middle Aged ; Radionuclide Imaging ; Stomach Neoplasms ; pathology ; Whole Body Imaging ; methods ; Young Adult

We report an unusual case of osteoblastic metastasis from gastric carcinoma. In this case, bone metastasis was the initial manifestation of the cancer. The laboratory findings revealed mild hypocalcemia and markedly elevated alkaline phosphatase levels. Plain X-ray showed mottled osteoblastic changes in the pelvis. Bone marrow and bone biopsy of the pelvis revealed metastatic adenocarcinoma with increased osteoblastic activity. An extensive search for the primary site revealed advanced gastric carcinoma, which was confirmed by endoscopic biopsy.
Adenocarcinoma/diagnosis/*secondary ; Adult ; Bone Neoplasms/*diagnosis/pathology/*secondary ; Case Report ; Female ; Human ; *Osteoblasts/radiography ; *Pelvis/radiography ; Radionuclide Imaging ; Stomach Neoplasms/*diagnosis ; Tomography, X-Ray Computed

We report an unusual case of osteoblastic metastasis from gastric carcinoma. In this case, bone metastasis was the initial manifestation of the cancer. The laboratory findings revealed mild hypocalcemia and markedly elevated alkaline phosphatase levels. Plain X-ray showed mottled osteoblastic changes in the pelvis. Bone marrow and bone biopsy of the pelvis revealed metastatic adenocarcinoma with increased osteoblastic activity. An extensive search for the primary site revealed advanced gastric carcinoma, which was confirmed by endoscopic biopsy.
Adenocarcinoma/diagnosis/*secondary ; Adult ; Bone Neoplasms/*diagnosis/pathology/*secondary ; Case Report ; Female ; Human ; *Osteoblasts/radiography ; *Pelvis/radiography ; Radionuclide Imaging ; Stomach Neoplasms/*diagnosis ; Tomography, X-Ray Computed

The purpose of this study was to evaluate the value of fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) for detecting the recurrence of gastric cancer. We performed a retrospective review of 139 consecutive patients who underwent PET/CT and contrast-enhanced abdominal CT (CECT) for surveillance of gastric cancer after curative resection. Recurrence of gastric cancer was validated by histopathologic examination for local recurrence or serial imaging study follow-up with at least 1 yr interval for recurrence of distant metastasis form. Twenty-eight patients (20.1%) were confirmed as recurrence. On the patient based analysis, there was no statistically significant difference in the sensitivity, specificity and accuracy of PET/CT (53.6%, 84.7%, and 78.4%, respectively) and those of CECT (64.3%, 86.5%, and 82.0%, respectively) for detecting tumor recurrence except in detection of peritoneal carcinomatosis. Among 36 recurrent lesions, 8 lesions (22.2%) were detected only on PET/CT, and 10 lesions (27.8%) only on CECT. PET/CT had detected secondary malignancy in 8 patients. PET/CT is as accurate as CECT in detection of gastric cancer recurrence after curative resection, excepting detection of peritoneal carcinomatosis. Moreover, additional PET/CT on CECT could improve detection rate of tumor recurrence and provide other critical information such as unexpected secondary malignancy.
Aged ; Female ; Fluorodeoxyglucose F18/*diagnostic use ; Humans ; Male ; Middle Aged ; Neoplasm Recurrence, Local/*diagnosis/radiography/radionuclide imaging ; Positron-Emission Tomography/*methods ; Radiopharmaceuticals/*diagnostic use ; Retrospective Studies ; Sensitivity and Specificity ; Stomach Neoplasms/*diagnosis/pathology/surgery ; Tomography, X-Ray Computed/*methods

BACKGROUND/AIMS: Accurate preoperative detection of regional lymph nodes and evaluation of tumor resectability is critical to determining the most adequate therapy for gastric cancer. The aim of this study is to identify a possible link between 18F-fluorodeoxyglucose (18F-FDG) uptake on PET scan combined with CT scan (PET/CT) and predictions of lymph node metastasis and non-curative surgery. METHODS: This study included 156 gastric cancer patients who underwent preoperative 18F-FDG PET/CT and surgery. In cases with perceptible FDG uptake in the primary tumor or lymph nodes, the maximum standardized uptake value (SUVmax) was calculated. RESULTS: In multivariate analysis, non-curative surgery (OR, 11.05; 95% CI, 1.10-111.08; p=0.041), tumor size (> or =3 cm) (OR, 7.39; 95% CI, 2.41-22.70; p<0.001), and lymph node metastasis (OR, 5.47; 95% CI, 2.05-14.64; p=0.001) were significant independent predictors for 18F-FDG uptake in the primary tumors. Tumor size (tumor size > or =3 cm) (OR, 3.15; 95% CI, 1.16-8.58; p=0.025) and lymph node metastasis (OR, 3.36; 95% CI, 1.23-9.14; p=0.018) showed significant association with 18F-FDG uptake in lymph node. When the SUVmax of the primary gastric tumor was greater than 3.75, the sensitivity and specificity of PET/CT with regard to the diagnosis of metastatic lymph node were 73.5% and 74.5%. When the SUVmax of the primary gastric tumor was greater than 4.35 and the FDG uptake of lymph nodes was positive, non-curative surgery was predicted with a sensitivity of 58.8% and specificity of 91.6%. CONCLUSIONS: A high FDG uptake of the gastric tumor was related to histologic positive lymph nodes and non-curative surgery.
Adult ; Aged ; Aged, 80 and over ; Area Under Curve ; Carcinoma/*diagnosis/pathology/surgery ; Female ; Fluorodeoxyglucose F18 ; Humans ; Lymph Nodes/surgery ; Lymphatic Metastasis/radionuclide imaging ; Male ; Middle Aged ; Neoplasm Staging ; Odds Ratio ; Peritoneal Neoplasms/diagnosis/secondary ; Positron-Emission Tomography ; ROC Curve ; Regression Analysis ; Stomach Neoplasms/*diagnosis/pathology/surgery ; Tomography, X-Ray Computed

OBJECTIVE: The aim of our study was to compare the accuracy of CT and 18F-FDG PET for detecting peritoneal metastasis in patients with gastric carcinoma. MATERIALS AND METHODS: One-hundred-twelve patients who underwent a histologic confirmative exam or treatment (laparotomy, n = 107; diagnostic laparoscopy, n = 4; peritoneal washing cytology, n = 1) were retrospectively enrolled. All the patients underwent CT and 18F-FDG PET scanning for their preoperative evaluation. The sensitivities, specificities and accuracies of CT and 18F-FDG PET imaging for the detection of peritoneal metastasis were calculated and then compared using Fisher's exact probability test (p < 0.05), on the basis of the original preoperative reports. In addition, two board-certified radiologists and two board-certified nuclear medicine physicians independently reviewed the CT and PET scans, respectively. A receiver-operating characteristic curve analysis was performed to compare the diagnostic performance of CT and 18F-FDG PET imaging for detecting peritoneal metastasis. RESULTS: Based on the original preoperative reports, CT and 18F-FDG PET showed sensitivities of 76.5% and 35.3% (p = 0.037), specificities of 91.6% and 98.9% (p = 0.035), respectively, and equal accuracies of 89.3% (p = 1.0). The receptor operating characteristics curve analysis showed a significantly higher diagnostic performance for CT (Az = 0.878) than for PET (Az = 0.686) (p = 0.004). The interobserver agreement for detecting peritoneal metastasis was good (κ value = 0.684) for CT and moderate (κ value = 0.460) for PET. CONCLUSION: For the detection of peritoneal metastasis, CT was more sensitive and showed a higher diagnostic performance than PET, although CT had a relatively lower specificity than did PET.
*Tomography, Emission-Computed ; Stomach Neoplasms/*pathology ; Sensitivity and Specificity ; Retrospective Studies ; Radiopharmaceuticals/diagnostic use ; ROC Curve ; *Positron-Emission Tomography ; Peritoneal Neoplasms/*radiography/*radionuclide imaging/*secondary ; Middle Aged ; Male ; Iohexol/analogs & derivatives/diagnostic use ; Humans ; Fluorodeoxyglucose F18/diagnostic use ; Female ; Contrast Media ; Aged, 80 and over ; Aged ; Adult ; Adolescent

OBJECTIVE: To quantify the cumulative effective dose (cED) of radiation due to repeated CT and PET/CT examinations after curative resection of gastric cancer and to assess the lifetime attributable risk (LAR) estimates based on Biological Effects of Ionizing Radiation VII models. SUBJECTS AND METHODS: Patients who underwent a curative resection for gastric cancer between January 2006 and December 2006 and were followed-up until May 2010 were included in this study. The cED was calculated by using the dose-length product values and conversion factors for quantitative risk assessment of radiation exposure. cED and LAR were compared between early and advanced gastric cancer patients and among American Joint Committee on Cancer TNM stage groups (stage I, II, and III). The nonparametric Mann-Whitney U and Kruskal-Wallis tests, followed by a post-hoc analysis with Bonferroni adjustment, were employed as part of the statistical analysis. RESULTS: The overall median cED was 57.8 mSv (interquartile range [IQR], 43.9-74.7). The cED was significantly higher in the advanced (median, 67.0; IQR, 49.1-102.3) than in the early gastric cancer group (median, 52.3; IQR, 41.5-67.9) (p < 0.001), and increased as the TNM stage increased. For radiation exposure, 62% of all patients received an estimated cED of over 50 mSv, while 11% of patients received over 100 mSv. The median LAR of cancer incidence was 0.28% (IQR, 0.20-0.40) and there were significant differences between the early gastric cancer and advanced gastric cancer group (p < 0.001) as well as among the three TNM stage groups (p = 0.015). The LAR of cancer incidence exceeded 1% in 2.4% of the patients. CONCLUSION: The cED increases proportionally along with tumor stage and, even in early gastric cancer or stage I patients, cED is much higher than that found among the general population. Considering the very good prognosis of early gastric cancer after curative surgery, the cED should be considered when designing a postoperative follow-up CT protocol.
Adult ; Aged ; Aged, 80 and over ; Female ; Follow-Up Studies ; Gastrectomy ; Humans ; Male ; Middle Aged ; Neoplasm Staging ; *Positron-Emission Tomography and Computed Tomography ; *Radiation Dosage ; Retrospective Studies ; Risk Assessment ; Statistics, Nonparametric ; Stomach Neoplasms/pathology/*radiography/*radionuclide imaging/surgery ; *Tomography, X-Ray Computed ; Treatment Outcome