No abstract

18F-FDG PET/CT is a safe imaging method that can be used in the determination of CRC recurrence in patients with elevated CEA levels, regardless of the CEA level.

Objective: The aim of this study is to explore the role of 18F-FDG PET/CT in the primary staging of gastric cancer in the comparison of ceCT as routine staging method and evaluate influencing parameters of 18F-FDG uptake. Methods: Thirty-one patients (mean age: 58.9±12.6) who underwent 18F-FDG PET/CT for primary staging of gastric cancer between June 2011 and June 2012 were included to the study. 18F-FDG PET/CT findings were compared with pathological reports in patients who underwent surgery following PET/CT. 18F-FDG PET/CT findings of primary lesions, lymph nodes and adjacent organs were compared with ceCT findings and pathological reports. Since 6 patients were accepted as inoperable according to 18F-FDG PET/CT and/or ceCT and/or laparotomy and/or laparoscopy findings, pathological confirmation could not be possible. Results: In the postoperative TNM staging of patients, while 1 (4%), 1 (4%), 4 (16%), 2 (8%), 12 (48%) and 5 (20%) patients were staged as T0, Tis, T1, T2, T3 and T4, respectively, 8 (32%), 6 (24%), 6 (24%) and 5 (20%) patients were N0, N1, N2 and N3 respectively. 18F-FDG PET/CT was totally normal in 2 patients. While primary tumors were FDG avid in 27 patients, in 17 and 6 patients FDG uptake was observed in perigastric lymph nodes and distant organs, respectively. Mean SUVmax of FDG avid tumors was calculated as 13.49±9.29 (3.00-44.60). However, SUVmax of lymph nodes was computed as 9.28±6.92 (2.80-29.10). According to sub-analysis of histopathological subtypes of primary tumors, SUVmax of adenocarsinomas was calculated as 15.16 (3.00-44.60), of signet ring cells as 9.90 (5.50-17.70), of adenocarcinomas with signet ring cell component as 11.27 (6.20-13.90) (p=0.721). In the comparison with histopathological examination while ceCT was TP, TN, FN in 23, 1 and 1 patients, 18F-FDG PET/CT was TP, FP, FN in 20, 1 and 4 patients, respectively. Sensitivity, specificity, accuracy, PPD and NPV of ceCT in the detection of lymph node metastasis was calculated as 83.3%, 75%, 80%, 87.5% and 66.6%, respectively. These parameters for 18F-FDG PET/CT were 64.7%, 100%, 76%, 100% and 57.1%.Conclusion: Despite lower sensitivity than ceCT, diagnostic power of 18F-FDG PET/CT in the preoperative staging of gastric cancer is acceptable. Because of its high PPV, it might be beneficial in the evaluation of patients with suspected lymph nodes. The role of 18F-FDG PET/CT seems to be limited in the early stage and signet ring cell carcinomas due to lower 18F-FDG uptake.

The loss of muscle mass and cachexia is commonly seen in hemodialysis (HD) patients and contribute to morbidity and mortality. The exact mechanism of this fact is multifactorial and still unclear. Myostatin, a transforming growth factor-ß family ligand, is released from the skeletal and heart muscle and may be responsible for muscle degradation and atrophy. The aim of this study is evaluation of the relationship between muscle mass and serum myostatin level in chronic HD patients. One hundred and forty HD patients (79 males, 28 diabetic, mean age; 53.96 ± 13.6) were included in this cross-sectional study. Muscle mass measurement was made with dual energy-X ray absorptiometry. Appendicular skeletal muscle index (ASMI) was used as a muscle mass indicator. The anthropometric and biochemistry data were obtained. Serum myostatin levels were determined by an ELISA kit. Serum myostatin levels were elevated when compared to controls (P <0.001), but no significant correlation with ASMI was observed (P = 0.624). ASMI significantly correlated with serum creatinine (P <0.001), creatine phosphokinase (P <0.001), prealbumin (P <0.012), albumin (P <0.039), transferrin (P <0.001), phosphorus (P <0.001), Ca×P (P <0.012), inversely with Kt/V (P <0.001); not with BUN (P = 0.739), parathyroid hormone (P = 0.698), 25-hydroxyvitamin D (P = 0.603), bicarbonate (P = 0.062); such that these parameters also have influence on muscle mass regulation. Our study indicated that myostatin levels were high in HD patients but had no relation with ASMI. Myostatin is a well-known regulator of muscle mass so further studies are needed to demonstrate possible relationship.

Background/aim: To describe the role of baseline gallium (Ga)-68 DOTATATE positron emission tomography (PET)/computed tomography (CT) in the prediction of the response to peptide receptor radionuclide therapy (PRRT) using lutetium (Lu)-177 DOTATATE.Materials and methods: Analysis was made of baseline Ga-68 DOTATATE PET/CT images of 29 patients (17 females and 12 males; mean age: 50.7 ± 14.6 years) with metastatic neuroendocrine tumors who received PRRT with Lu-177 DOTATATE. Maximum standardized uptake values (SUVmax) of reference lesions and their ratios to physiological uptake organs were calculated. The relationship between these values and the radiological response was analyzed.Results: Partial response was observed in 8 (28%) patients, stable disease in 18 (62%) patients, and progressive disease in 3 (10%) patients. Mean SUVmax of reference lesions was calculated as 23.8 ± 20.5 (min-max: 5.1-87.3). There was no significant correlation between radiological responses and SUVmax of reference lesions and their ratios to other organs. Conclusion:Baseline Ga-68 DOTATATE PET/CT helps to show somatostatin receptor expression status and disease stage in patients who are candidates for PRRT. However, SUVs do not have a role in the prediction of treatment response.