A Dual-radiolabel Marker Quantifies Decrease in HT29 Xenograft Hypoxia Induced by Mild Temperature Hyperthermia

• 作者: C. Clifton Ling David Gagne Gloria Li John L. Humm John Pizzonia Makiko Suehiro Mutian Zhang Xiao-Feng Li Zhigang Zhang Zhihong Zhao
• 来源期刊: 医学物理学、临床工程、放射肿瘤学(英文)
• 学科: 医学
• 关键词: Digital AUTORADIOGRAPHY IAZGP Imaging Plate MILD TEMPERATURE HYPERTHERMIA Tumor Hypoxi
• 年，卷（期）: 2012,（2）
• 页码范围: 32-39
• 页数: 8页
• 分类号: R73

摘要

Purpose: In this project, we developed novel methods to quantify changes in tumor hypoxia following a mild tempera-ture hyperthermia (MTH) treatment in rat HT29 human colon adenocarcinoma xenograft. Materials and Methods: An exogenous hypoxia marker (IAZGP) was labeled with two radioisotopes of iodine (131I and 123I, respectively) to form two distinct tracers. The two tracers were injected into HT29-bearing nude rats 4-hour before and immediately following 41.5℃, 45-minute mild hyperthermia treatment. The distributions of the two hypoxia tracers were obtained by performing digital autoradiography on tumor sections, and image processing resulted in quantitative information at 50 μm pixel size. Results: Following the hyperthermia treatment, there was a remarkable decrease in hypoxia tracer binding. The average whole tumor hypoxia tracer targeted fraction in five animals changed from 30.3% ± 9.7% to 13.0% ± 5.3% after the hyperthermia treatment (P = 0.001). Detailed pixelby-pixel analysis of the image data revealed a decline in hypoxia tracer uptake after hyperthermia in most regions. However, there was concomitant emergence of some new regions of hypoxia identified by increased tracer uptake. In the control group, the overall hypoxia tracer targeted fraction remained almost constant, with some hypoxic tracer redistribution (putative acute hypoxia) observed. Conclusion: Reoxygenation occurred in the rat HT29 xenograft following MTH treatment. This was evident with preponderance of decreased hypoxia specific tracer uptake on tumor sections. Our methodology might be a useful tool in hypoxia study.