[Comparison of (18)F-FDG PET/CT and enhancement CT in diagnosing regional lymph node metastasis of colorectal cancer].

OBJECTIVE: The aim of this study was to compare the diagnostic value of (18)F-FDG PET/CT with contrast CT for regional lymph node metastasis of colorectal cancer. METHODS: Imaging results of 40 patients with colorectal cancer were retrospectively reviewed, and all the patients underwent both abdomen contrast CT and (18)F-FDG PET/CT imaging. Final diagnosis was made by histopathology. RESULTS: 20 colorectal cancer patients were verified with lymph node metastasis while the other 20 patients were absent. Finally, (18)F-FDG PET/CT produced 4 false-positive patients and 3 false-negative patients. (18)F-FDG PET/CT displayed sensitivity 85.0% (17/20), specificity 80.0% (16/20), positive predictive value 81.0% (17/21), negative predictive value 84.2% (16/19) and accuracy 82.5% (33/40) in the diagnosis of lymph node metastasis. Contrast CT produced 5 false-positive patients and 8 false-negative patients. Contrast CT had the sensitivity 60.0% (12/20), specificity 75.0% (15/20) , positive predictive value 70.6% (12/17), negative predictive value 65.2% (15/23) and accuracy 67.5% (27/40). Sensitivity and specificity of PET/CT was better than of contrast CT, but no statistically significant difference between PET/CT and contrast CT (P = 0.478, P = 0.893; P = 0.344. Fisher's exact test and McNemar test). CONCLUSION: Sensitivity and specificity of PET/CT was better than of contrast CT, but no statistically significant difference. Clinical works also need to select the appropriate inspection methods based on the patient's situation.

[Diagnostic value of (18)F-labeled NaF positron emission tomography-computed tomography imaging in the detection of bone metastases in patients with lung cancer before treatment].

OBJECTIVE: To evaluate the diagnostic values of (18)F-sodium fluoride ((18)F-NaF) positron emission tomography/computed tomography (PET/CT) imaging in the detection of bone metastases of lung cancer. METHODS: A total of 107 lung cancer patients were diagnosed by histopathology and undergone (18)F-NaF PET-CT imaging. RESULTS: Among them, the histopathologically diagnosed tumors included adenocarcinoma (n = 47), squamous cell carcinoma (n = 19), small cell lung cancer (n = 4) and other malignant types (n = 34). Bone metastases occurred in adenocarcinoma (n = 19) and squamous cell carcinoma (n = 4).(18)F-NaF PET/CT imaging had a high sensitivity of 100% in the diagnosis of bone metastases with malignant lung tumors. And its specificity was 98.7%, accuracy 99% and positive predictive value 97.0%. CONCLUSION: (18)F-NaF PET-CT imaging can detect the bone metastases of lung cancer preoperatively with a high level of sensitivity and accuracy.

Clinical Value of 18F-FDG PET/CT in Prediction of Visceral Pleural Invasion of Subsolid Nodule Stage I Lung Adenocarcinoma.

RATIONALE AND OBJECTIVES: This study investigated the utility of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for predicting visceral pleural invasion (VPI) of subsolid nodule (SSN) stage I lung adenocarcinoma. MATERIALS AND METHODS: A retrospective analysis of 18F-FDG PET/CT data from 65 postsurgical cases with surgical pathology-confirmed SSN lung adenocarcinoma identified significant VPI predictors using multivariate logistic regression. RESULTS: Nodule and solid component sizes, solid component-to-tumor ratios, pleural indentations, distances between nodules and pleura, and maximum standardized uptake values (SUVmax) differed significantly between VPI-positive (n = 30) and VPI-negative (n = 35) cases on univariate analysis. The distance between the nodule and pleura and SUVmax were significant independent VPI predictors on multivariate analysis. Areas under the curve of the distance between the nodule and pleura and SUVmax on receiver operating characteristic curves were 0.76 and 0.79, respectively; both factors were 0.90. The area under the curve of combined predictors was significantly superior to the distance between the nodule and pleura only but not SUVmax alone. The threshold of the distance between the nodule and pleura, to predict VPI was 4.50 mm, with 96.67% sensitivity, and 57.14% specificity. The threshold of SUVmax to predict VPI was 1.05, with 100% sensitivity and 60% specificity. The sensitivity and specificity of model 2 using the independent predictive factors were 96.67%, and 71.43%, respectively. CONCLUSION: Distance between the nodule and pleura and SUVmax are independent predictors of VPI in SSN stage I lung adenocarcinoma. Further, combining these factors improves their predictive ability.

PET-CT for Evaluation of Spleen and Liver 18F-FDG Diffuse Uptake Without Lymph Node Enlargement in Lymphoma.

The aim of the study was to compare differences between lymphoma and inflammation as indicated by high diffuse uptake of F-fluorodeoxyglucose (F-FDG) in the spleen, liver, and bone marrow without increased F-FDG uptake in the lymph nodes and without enlarged peripheral lymph nodes.Eighteen lymphoma patients and 14 inflammation patients were examined with F-FDG positron emission tomography-computer tomography (PET-CT). All patients displayed high diffuse uptake of F-FDG in the spleen, liver, and bone marrow without increased F-FDG uptake in the lymph nodes and without enlarged peripheral lymph nodes. Our analyses compared the maximum standardized uptake values (SUVmax) of F-FDG uptake ratios between the spleen/liver, the spleen/bone marrow, and the liver/bone marrow and further compared spleen sizes between lymphoma and inflammation patients.Using Student t test, no significant differences were found in the SUVmax ratios of spleen/liver and liver/bone marrow between the lymphoma and inflammation patients (t = 0.853, P = 0.401 > 0.05; t = 1.622, P = 0.115 > 0.05). However, the SUVmax ratio of the spleen/bone marrow of the lymphoma patients was significantly different from that of the inflammation patients (t = 2.426, P = 0.021 < 0.05). The spleen size between the lymphoma and inflammation patients was also significantly different (t = 2.911, P = 0.007 < 0.05).As indicated by F-FDG PET-CT, our study demonstrated that lymphoma and inflammation patients displayed a few differences despite both having high diffuse uptake of F-FDG in the spleen, liver, and bone marrow without enlarged peripheral lymph nodes and without increased F-FDG uptake in lymph nodes.

18F-Labeled NaF PET-CT in Detection of Bone Metastases in Patients With Preoperative Lung Cancer.

We compared the diagnostic accuracy of F-labeled sodium fluoride (F-NaF) PET-CT with 99m-technetium methylene diphosphonate (Tc-MDP) single photon emission computed tomography (SPECT) to detect bone metastases (BMs) in patients with preoperative lung cancer. Patients with lung cancer (n = 181) were examined with F-NaF PET-CT, and another 167 patients with lung cancer were examined with Tc-MDP SPECT. F-NaF PET-CT and Tc-MDP SPECT were evaluated by 2 experienced readers. Lesions were graded on a scale of 0 (degenerative lesion) to 4 (definite BM), and equivocal lesions were determined as indifferent (grade 3). Based on patient-based analysis, there were only 4 equivocal patients in F-NaF PET-CT detection. However, in Tc-MDP SPECT detection, there were 19 equivocal patients, which indicated a significant difference in terms of occurrence ratio (χ = 9.005, P = 0.03). Sensitivity and specificity of PET-CT was significantly better than that of SPECT when equivocal reading was categorized as malignant or benign (P < 0.05). Based on lesions-based analysis, SPECT produced 26 equivocal lesions of 333 lesions, but PET-CT produced only 5 equivocal lesions of 991 lesions. PET-CT was significantly better than SPECT in the aspect of producing equivocal patients (χ = 58.141, P < 0.001). Sensitivity and specificity of PET-CT was significantly better than that of SPECT when equivocal reading was categorized as malignant or benign (P < 0.05). F-NaF PET-CT is a highly sensitive and specific modality for the detection of BM in patients with preoperative lung cancer. It is better than conventional Tc-MDP SPECT in detecting BM in patients with preoperative lung cancer.

Musashi2 as a novel predictive biomarker for liver metastasis and poor prognosis in colorectal cancer.

Aberrant expression of musashi2 (MSI-2) has been detected in several malignancies. However, its role in the progression of colorectal cancer (CRC) remains unknown. Our study was designed to investigate the expression and prognostic significance of MSI-2 protein in patients with colorectal cancer. The expression of MSI-2 was detected in 164 patients' colorectal cancer and control specimens by the tissue microarray technique and immunohistochemical staining. The correlations between MSI-2 expression and clinicopathological variables including overall survival were analyzed. The prognostic value of liver metastasis is evaluated by logistic regression and receiver operating characteristic (ROC) analysis. MSI-2 was highly expressed in 32.9% (54/164) of the colorectal cancer. Overexpression of MSI-2 was associated with depth of invasion, lymph node metastasis, distant metastasis, liver metastasis, Tumor Node Metastasis (TNM) clinical stage, and Carcinoembryonicantigen (CEA) level (P = 0.040, 0.014, <0.001, <0.001, 0.003, and 0.002, respectively). In the Cox multivariate test, MSI-2 overexpression, lymph node metastasis, and distant metastasis were found to be the independent prognostic factors (P = 0.027, 0.010, and 0.001, respectively). Further logistic regression suggested that TNM stage and MSI-2 high expression were related to liver metastasis in colorectal cancer patients. Conclusively, our study indicates that MSI-2 overexpression is associated with an unfavorable prognosis and may be a potential biomarker for liver metastasis in colorectal cancer patients.

Imaging findings of inflammatory pseudotumor-like follicular dendritic cell tumor of spleen.

Inflammatory pseudotumor-like follicular dendritic cell tumor (IPT-like FDCT) histology is similar to that of the classical follicular dendritic cell (FDC) tumor, but, in addition, the inflammatory component is quite prominent. We report a case of IPT-like FDCT of the spleen by abdominal CT and 18F-FDG PET/CT. Abdominal CT showed a low-density, round, well-circumscribed defined mass in spleen, and the mass showed a high metabolism rate on 18F-FDG PET/CT.

[Value of (18)F-FDG PET/CT and CECT in detecting postoperative recurrence and extrahepatic metastasis of hepatocellular carcinoma in patients with elevated serum alpha-fetoprotein].

OBJECTIVE: To assess the clinical value of (18)F-FDG PET/CT and contrast-enhanced computed tomography (CECT) in detecting residual tumor or tumor recurrence and metastasis in patients with hepatocellular carcinoma (HCC) who show an elevated serum alpha-fetoprotein (AFP) level after surgical intervention. METHODS: The data of (18)F-FDG PET/CT and CECT, which were performed at an interval within 2 weeks, were reviewed in 54 HCC patients showing elevated AFP levels after surgical interventions of the tumor. The patients were followed up for at least 6 months and the imaging findings were confirmed by pathological examination, follow-up imaging examination, or serum AFP level monitoring. RESULTS: Forty-five patients were found to have focal intrahepatic HCC recurrence after surgical interventions, and 9 patients were free of HCC recurrence. Twenty-three patients developed extrahepatic metastasis, among whom 19 also had intrahepatic tumor recurrence and 4 had extrahepatic metastasis only. The sensitivity, specificity, and accuracy of (18)F-FDG PET/CT in the detection of HCC recurrence were 88.9% (40/45), 77.8% (7/9), and 87.0% (47/54), respectively, as compared with those of 57.8% (26/45), 100% (9/9), and 64.8% (35/54) by CECT detection. CONCLUSION: Compared with CECT, (18)F-PET/CT shows a high sensitivity and accuracy in detecting postoperative tumor residual or recurrence in the liver, and can also be an effective modality for detecting extrahepatic lesions in HCC patients.

[Comparison of (18)F-FDG PET-CT and abdomen enhancement CT in diagnosing peritoneal metastases].

OBJECTIVE: To compare the diagnostic value of (18)F-FDG PET-CT with abdomen contrast CT in the diagnosis of peritoneal metastases. METHODS: Between January 2008 and May 2011, imaging results of 97 patients with suspicious peritoneal metastases were retrospectively reviewed, and all the patients underwent both abdomen contrast CT and (18)F-FDG PET-CT imaging. Final diagnosis was made by histopathology or follow up. RESULTS: Seventy-seven patients were verified as peritoneal metastases after pathological examination(n=88) or follow up(n=9), while the other 20 patients were absent. The sensitivity of (18)F-FDG PET-CT was 90.9%(70/77), the specificity 85.0%(17/20), and the accuracy 89.7%(87/97). There were 3 false positive and 7 false negative. The sensitivity of contrast CT was 66.2%(51/77), the specificity 80.0%(16/20), and the accuracy 69.1%(67/97). There were 4 false positive and 26 false negative. The difference in diagnostic accuracy was statistically significantly between these two methods(P<0.05). CONCLUSION: The diagnostic value of (18)F-FDG PET-CT is significantly higher than that of abdominal enhanced CT for peritoneal metastases.