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Purpose: The norepinephrine transporter (NET) is a critical regulator of catecholamine uptake in normal physiology and is expressed in neuroendocrine tumors like neuroblastoma. Although the norepinephrine analog, meta-iodobenzylguanidine (MIBG), is an established substrate for NET, 123I/131I-MIBG has several clinical limitations for diagnostic imaging. In the current studies, we evaluated meta-[18F]-fluorobenzylguanidine ([18F]-MFBG) and compared it with 123I-MIBG for imaging NET-expressing neuroblastomas. Experimental Design: NET expression levels in neuroblastoma cell lines were determined by Western blot and 123I-MIBG uptake assays. Five neuroblastoma cell lines and two xenografts (SK-N-BE(2)C and LAN1) expressing different levels of NET were used for comparative in vitro and in vivo uptake studies. Results: The uptake of [18F]-MFBG in cells was specific and proportional to the expression level of NET. Although [18F]-MFBG had a 3-fold lower affinity for NET and an approximately 2-fold lower cell uptake in vitro compared with that of 123I-MIBG, the in vivo imaging and tissue radioactivity concentration measurements demonstrated higher [18F]-MFBG xenograft uptake and tumor-to-normal organ ratios at 1 and 4 hours after injection. A comparison of 4 hours [18F]-MFBG PET (positron emission tomography) imaging with 24 hours 123I-MIBG SPECT (single-photon emission computed tomography) imaging showed an approximately 3-fold higher tumor uptake of [18F]-MFBG, but slightly lower tumor-to-background ratios in mice. Conclusions: [18F]-MFBG is a promising radiopharmaceutical for specifically imaging NET-expressing neuroblastomas, with fast pharmacokinetics and whole-body clearance. [18F]-MFBG PET imaging shows higher sensitivity, better detection of small lesions with low NET expression, allows same day scintigraphy with a shorter image acquisition time, and has the potential for lower patient radiation exposure compared with 131I/123I-MIBG. Clin Cancer Res; 20(8); 2182–91. ©2014 AACR.

How to integrate heterogeneous data is the key problem of IETM. The paper designs the IETM integration framework structure based on XML technology, and then discusses three primary problems: data description, data storage and data parsing. After these research works, heterogeneous data is retrieved more quickly, maintain cost of equipment is reduced, efficiency of equipment is enhanced and the security of information is assured. And at the same time, the most important things are data integration and sharing problems have been effectively solved.

In the last grant period we have focused on multi-step targeting methodologies (MST), as a method for delivery of high dose to the tumor, with low dose to the bone marrow. We have explored uptake in colorectal, pancreatic and prostate cancer, using an special preparation, developed in collaboration with NeoRex A high tumor/bone marrow ratio is clearly achieved with MST, but with a cost, namely the higher dose to normal kidney. For this reason, we have in particular, (a) looked dosimetry for both tumor and normal organ, and especially renal dosimetry, which appears to be the target organ, for Y-90. (b) In parallel with this we have explored the dosimetry of very high dose rate radionuclides, including Holmium-166. (c) In addition, with NaiKong Cheung, we have developed a new MST construct based on the anti-GD2 targeting 5F11; (d) we have successfully completed development of s-factor tables for mice. In summary, renal dosimetry is dominated by about 4-5% of the injected dose being held long-term in the renal cortex, probably in the proximal tubule, due to the universal uptake of small proteins. This appears to be a function of a biotynlated protein binding of the strept-avidin construct, to HSP70. This corticalmore » uptake has caused us to reconsider renal dosimetry as a whole, with the smaller mass of the cortex, rather than the whole kidney, as the target organ. These insights into dosimetry will be of great importance as MST, becomes more common in clinical practice.« less