Dual-isotope imaging method for Actinium-225 and Bismuth-213 using alpha imaging detector.

Recently, Ac has received considerable attention for its use in targeted alpha therapy because it has a relatively long half-life and yields four more alpha-particles from the daughter nuclides. The performance evaluation should separately assess the distribution of Ac and Bi because daughter nuclides, including Bi, can cause renal toxicity, which may hinder the widespread use of Ac for targeted alpha therapy. In this study, we describe and validate a spectrum decomposition method for dual-isotope imaging of Ac and Bi using an alpha imaging detector.

Recurrent/metastatic thyroid carcinomas false negative for serum thyroglobulin but positive by posttherapy I-131 whole body scans.

Purpose: Serum Tg and I-131 WBS have been used to detect recurrent and metastatic thyroid cancers postoperatively. Tg is known to be more sensitive than I-131 WBS, and therefore, false-negative WBS cases with elevated Tg levels are frequently found. However, the clinical characteristics of false-negative Tg cases with positive WBS have not been clarified.