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.

In evaluating cervical lymph node (LN) metastasis from papillary thyroid cancer (PTC), ultrasonography (US)-guided fine-needle aspiration biopsy (FNAB) is very important tool. There were limited number of studies about the diagnostic value of thyroglubion measurement in FNAB (FNAB-Tg) in non-thyroidectomized patients. Therefore, in this study, the authors evaluated the role of FNAB-Tg in diagnosing cervical LN metastases in patients with PTC before thyroidectomy. A total 91 suspicious LNs of 68 patients were undergone US-guided FNAB-Tg and cytology. Any FNAB-Tg concentration above 50 ng/ml considered as positive, irrespective of thyroid gland presence. Based on the final pathology, 49 LNs were positive, and the remaining 42 LNs were negative for metastasis. The sensitivity, specificity, and accuracy of FNAB-Tg in thyroidectomized patients were 80.0, 100.0, and 88.9%, respectively. The diagnostic performance of FNAB-Tg was not compromised by the presence of thyroid gland (sensitivity, specificity and accuracy = 95.0, 90.9 and 93.2%, respectively). FNAB-Tg is useful and simple method for the diagnosis of metastatic cervical LNs from PTC. The diagnostic performance of FNAB-Tg was not compromised by the presence of thyroid gland. Therefore, FNAB-Tg could be performed actively for the LN staging of PTC.

Asparagine‐glycine‐arginine (NGR)‐containing peptides targeting aminopeptidase N (APN)/CD13 can be an excellent candidate for targeting ligands in molecular tumor imaging. In this study, we developed two NGR‐containing hexapeptides, and evaluated the diagnostic performance of Tc‐99 m labeled hexapeptides as molecular imaging agents in an HT‐1080 fibrosarcoma‐bearing murine model. Peptides were synthesized using Fmoc solid‐phase peptide synthesis. Radiochemical purity of Tc‐99 m was evaluated using instant thin‐layer chromatography. The uptake of two NGR‐containing hexapeptides within HT‐1080 cells was evaluated in vitro. In HT‐1080 fibrosarcoma tumor‐bearing mice, gamma images were acquired. A biodistribution study was performed to calculate percentage of the injected dose per gram of tissue (%ID/g). Two hexapeptides, glutamic acid‐cysteine‐glycine (ECG)‐NGR and NGR‐ECG were successfully synthesized. After radiolabeling procedures with Tc‐99 m, the complexes Tc‐99 m hexapeptides were prepared in high yield. The uptake of Tc‐99 m ECG‐NGR within the tumor cells had been assured by in vitro studies. The gamma camera imaging in the murine model showed that Tc‐99 m ECG‐NGR was accumulated substantially in the subcutaneously engrafted tumor. However, Tc‐99 m NGR‐ECG was accumulated minimally in the tumor. Two NGR‐containing hexapeptides, ECG‐NGR and NGR‐ECG were developed as molecular imaging agents to target APN/CD13 in HT‐1080 fibrosarcoma. Tc‐99 m ECG‐NGR showed a significant uptake in the tumor, and it is a good candidate for tumor imaging.

Two ELR-containing 6-mer peptides, ELR-ECG and ECG-ELR, were developed as a molecular imaging agent to target CXCR2 of epidermoid carcinoma. Tc-99m ELR-ECG had showed significant uptake in tumor and it was good candidate for a tumor imaging.

Purpose Standardized uptake values (SUVs) normalized by lean body mass (LBM) determined by CT were compared with those normalized by LBM estimated using predictive equations (PEs) in normal liver, spleen, and aorta using 18 F-FDG PET/CT. Methods Fluorine-18 fluorodeoxyglucose (F-FDG) positron emission tomography/computed tomography (PET/CT) was conducted on 453 patients. LBM determined by CT was defined in 3 ways (LBM CT1-3 ). Five PEs were used for comparison (LBM PE1-5 ). Tissue SUV normalized by LBM (SUL) was calculated using LBM from each method (SUL CT1-3 , SUL

A 50-yr-old man presented with intermittent hemoptysis and was diagnosed small cell lung cancer. 18F-FDG PET/CT for staging demonstrated extensive hypermetabolic lesions throughout the skeleton and liver. Interestingly, skeletal muscles of limbs, mediastinum, bowel, and especially brain showed very low FDG uptake. Because of some characteristics in common with super scan on skeletal scintigraphy, this case could be considered as 'metabolic super scan'.

Purpose Dual-time-point (DTP) FDG PET/CT has been shown to be useful for lymph node (LN) staging in patients with non-small-cell lung cancer (NSCLC). The aim of this study was to evaluate the LN staging ability of DTP FDG PET/CT in the predominant area of pulmonary tuberculosis. Methods Sixty-nine NSCLC patients underwent DTP PET/ CT. Regions of interest were placed on each LN of each station, and the maximum SUVs were measured. Three variables were obtained: (1) the SUV on the early scan (SUV early ), (2) the SUV on the delayed scan (SUV delayed ), and (3) the retention index of the SUV (RI). Each patient had one final LN stage and three other LN stages according to the cutoff values of SUV early , SUV delayed , and RI. Results In the LN-based analysis, the area under the ROC curve of SUV delayed (0.884) was significantly larger (P< 0.01) than those of SUV early (0.868) and RI (0.717). Among the three variables, SUV delayed was more accurate (P<0.01) for detecting the mediastinal LN metastasis than SUV early and RI. In the patient-based analysis, SUV delayed had correctly determined LN stages in 55 of 69 patients (sensitivity, specificity, and accuracy088.7 %, 50.0 %, and 79.7 %), whereas SUV early and RI correctly determined LN stages in 53 and 52 patients, respectively. Conclusions In this study, comparing the diagnostic efficacy of SUV early , SUV delayed , and RI for LN staging in patients with NSCLC, SUV delayed was the most accurate variable for LN staging. DTP PET/CT could provide improved diagnostic accuracy for the LN staging of NSCLC.

We successfully developed Tc-99m ECG-RRL as a new tumor imaging candidate. Specific tumoral uptake of Tc-99m ECG-RRL was evaluated both in vitro and in vivo, and it was determined to be a good tumor imaging candidate. Additionally, Tc-99m ECG-RRL effectively distinguished between cancerous tissue and inflammatory lesions.