Objective

To determine if heparin labeled with ^99mTechnetium (^99mTc) could be an imaging probe to detect eosinophil-related inflammation in eosinophilic esophagitis and to determine the biodistribution and radiation dosimetry of ^99mTc-heparin oral administration using image-based dosimetry models with esophageal modeling.

Methods

Freshly prepared ^99mTc-heparin was administered orally to 5 research subjects. Radioactivity was measured by whole-body scintigraphy and single-photon emission computed tomography during the 24 hours postadministration. Following imaging, endoscopic examination was performed. The biodistribution of esophageal radioactivity was compared with endoscopic findings, eosinophil counts in biopsy tissues, and immunostaining for eosinophil granule major basic protein-1 (eMBP1). These studies were conducted from July 1, 2013, until April 22, 2017.

Results

Oral administration of ^99mTc-heparin was well tolerated in all 5 subjects. The entire esophagus could be visualized dynamically during oral administration. Bound esophageal radioactivity marked areas of inflammation as judged by endoscopy scores, by eosinophils per high power field and by localization of eMBP1 using immunostaining. Ninety percent of the radioactivity did not bind to the esophagus and passed through the gastrointestinal tract.

Conclusion

The biodistribution of ingested ^99mTc-heparin is almost exclusively localized to the gastrointestinal tract. Radiation exposure was highest in the lower gastrointestinal tract and was comparable with other orally administered diagnostic radiopharmaceuticals. The use of swallowed ^99mTc-heparin may aid in assessing eosinophil-related inflammation in the esophagus.

中文翻译：

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在嗜酸性粒细胞性食管炎中口服 99m 锝标记的肝素。

客观的

确定用^99m锝 ( ^99m Tc)标记的肝素是否可以作为成像探针来检测嗜酸性粒细胞性食管炎中的嗜酸性粒细胞相关炎症，并使用基于图像的剂量测定模型和食管建模确定口服^99m Tc-肝素的生物分布和辐射剂量学.

方法

将新鲜制备的^99m Tc-肝素口服给药至 5 个研究对象。在给药后 24 小时内通过全身闪烁扫描和单光子发射计算机断层扫描测量放射性。影像学检查后，进行内窥镜检查。将食管放射性的生物分布与内窥镜检查结果、活检组织中的嗜酸性粒细胞计数和嗜酸性粒细胞颗粒主要碱性蛋白 1 (eMBP1) 的免疫染色进行比较。这些研究是在 2013 年 7 月 1 日至 2017 年 4 月 22 日期间进行的。

结果

所有 5 名受试者对^99m Tc-肝素的口服给药均耐受良好。在口服给药期间可以动态地观察整个食道。通过内窥镜评分、每个高倍视野的嗜酸性粒细胞和使用免疫染色对 eMBP1 的定位，结合的食道放射性标记炎症区域。百分之九十的放射性物质没有与食道结合并通过胃肠道。

结论

摄入的^99m Tc-肝素的生物分布几乎完全局限于胃肠道。下胃肠道的辐射暴露最高，与其他口服诊断放射性药物相当。使用吞咽的^99m Tc-肝素可能有助于评估食管中嗜酸性粒细胞相关的炎症。