PURPOSE: The purpose of this paper is to compare the uptake of two clinically promising positron emission tomography (PET) hypoxia targeting agents, (124)I-iodoazomycin galactopyranoside ((124)I-IAZG) and (18)F-fluoromisonidazole ((18)F-FMISO), by dynamic microPET imaging, in the same rats bearing liver tumors and peritoneal metastasis. METHODS: Morris hepatoma (RH7777) fragments were surgically implanted into the livers of four nude rats. Tumors formed in the liver and disseminated into the peritoneal cavity. Each rat had a total of two to three liver tumors and peritoneal metastasis measuring 10-15 mm in size. Animals were injected with (18)F-FMISO, followed on the next day (upon complete (18)F decay) by (124)I-IAZG. The animals were imaged in list mode on the microPET system from the time of injection of each tracer for 3 h and then again at 6 h and 24 h for the long-lived (124)I-IAZG tracer (4.2-day half-life). Micro computed tomography (CT) scans of each rat were performed for co-registration with the microPET scans acquired with a liver contrast agent, allowing tumor identification. Regions of interest (ROIs) were drawn over the heart, liver, muscle, and the hottest areas of the tumors. Time-activity curves (TACs) were drawn for each tissue ROI. RESULTS: The (18)F-FMISO signal increased in tumors over the 3-h time course of observation. In contrast, after the initial injection, the (124)I-IAZG signal slowly and continuously declined in the tumors. Nevertheless, the tumor-to-normal-tissue ratios of (124)I-IAZG increased, but more slowly than those of (18)F-FMISO and as a result of the differentially faster clearance from the surrounding normal tissues. These pharmacokinetic patterns were seen in all 11 tumors of the four animals. CONCLUSIONS: (18)F-FMISO localizes in the same intra-tumor regions as (124)I-IAZG. The contrast ratios (tumor/background) reach similar values for the two hypoxia tracers, but at later times for (124)I-IAZG than for (18)F-FMISO and, therefore, with poorer count statistics. As a consequence, the (18)F-FMISO images are of superior diagnostic image quality to the (124)I-IAZG images in the Morris hepatoma McA-R-7777 tumor model.
PURPOSE: The purpose of this paper is to compare the uptake of two clinically promising positron emission tomography (PET) hypoxia targeting agents, (124)I-iodoazomycin galactopyranoside ((124)I-IAZG) and (18)F-fluoromisonidazole ((18)F-FMISO), by dynamic microPET imaging, in the same rats bearing liver tumors and peritoneal metastasis. METHODS:Morris hepatoma (RH7777) fragments were surgically implanted into the livers of four nude rats. Tumors formed in the liver and disseminated into the peritoneal cavity. Each rat had a total of two to three liver tumors and peritoneal metastasis measuring 10-15 mm in size. Animals were injected with (18)F-FMISO, followed on the next day (upon complete (18)F decay) by (124)I-IAZG. The animals were imaged in list mode on the microPET system from the time of injection of each tracer for 3 h and then again at 6 h and 24 h for the long-lived (124)I-IAZG tracer (4.2-day half-life). Micro computed tomography (CT) scans of each rat were performed for co-registration with the microPET scans acquired with a liver contrast agent, allowing tumor identification. Regions of interest (ROIs) were drawn over the heart, liver, muscle, and the hottest areas of the tumors. Time-activity curves (TACs) were drawn for each tissue ROI. RESULTS: The (18)F-FMISO signal increased in tumors over the 3-h time course of observation. In contrast, after the initial injection, the (124)I-IAZG signal slowly and continuously declined in the tumors. Nevertheless, the tumor-to-normal-tissue ratios of (124)I-IAZG increased, but more slowly than those of (18)F-FMISO and as a result of the differentially faster clearance from the surrounding normal tissues. These pharmacokinetic patterns were seen in all 11 tumors of the four animals. CONCLUSIONS: (18)F-FMISO localizes in the same intra-tumor regions as (124)I-IAZG. The contrast ratios (tumor/background) reach similar values for the two hypoxia tracers, but at later times for (124)I-IAZG than for (18)F-FMISO and, therefore, with poorer count statistics. As a consequence, the (18)F-FMISO images are of superior diagnostic image quality to the (124)I-IAZG images in the Morris hepatoma McA-R-7777 tumor model.
Authors: S Hunjan; D Zhao; A Constantinescu; E W Hahn; P P Antich; R P Mason Journal: Int J Radiat Oncol Biol Phys Date: 2001-03-15 Impact factor: 7.038
Authors: J S Rasey; W J Koh; M L Evans; L M Peterson; T K Lewellen; M M Graham; K A Krohn Journal: Int J Radiat Oncol Biol Phys Date: 1996-09-01 Impact factor: 7.038
Authors: J G Rajendran; K R G Hendrickson; A M Spence; M Muzi; K A Krohn; D A Mankoff Journal: Eur J Nucl Med Mol Imaging Date: 2006-07 Impact factor: 9.236
Authors: Joseph G Rajendran; David L Schwartz; Janet O'Sullivan; Lanell M Peterson; Patrick Ng; Jeffrey Scharnhorst; John R Grierson; Kenneth A Krohn Journal: Clin Cancer Res Date: 2006-09-15 Impact factor: 12.531
Authors: R P Mason; D Zhao; J Pacheco-Torres; W Cui; V D Kodibagkar; P K Gulaka; G Hao; P Thorpe; E W Hahn; P Peschke Journal: Q J Nucl Med Mol Imaging Date: 2010-06 Impact factor: 2.346
Authors: P Mahy; X Geets; M Lonneux; P Levêque; N Christian; M De Bast; J Gillart; D Labar; J Lee; V Grégoire Journal: Eur J Nucl Med Mol Imaging Date: 2008-03-04 Impact factor: 9.236
Authors: Christopher C Riedl; Peter Brader; Pat B Zanzonico; Yun Shin Chun; Yanghee Woo; Paramjeet Singh; Sean Carlin; Bixiu Wen; C Clifton Ling; Hedvig Hricak; Yuman Fong Journal: Radiology Date: 2008-08 Impact factor: 11.105
Authors: Andrew C Gordon; Sarah B White; Vanessa L Gates; Daniel Procissi; Kathleen R Harris; Yihe Yang; Zhuoli Zhang; Weiguo Li; Tianchu Lyu; Xiaoke Huang; Reed A Omary; Riad Salem; Robert J Lewandowski; Andrew C Larson Journal: Acad Radiol Date: 2020-06-07 Impact factor: 5.482