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.

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

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 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.