α核素肿瘤靶向治疗药物研究的进展与挑战

与目前常用于肿瘤内放射治疗研究的β核素相比,α核素具有射线能量高、射程短、放射生物学效应和细胞毒性作用强等特点,对散在性癌和微转移癌的内放射治疗具有良好的应用前景。本文介绍了近年来211 At、213Bi、212Bi、225Ac和223 Ra等α核素肿瘤靶向治疗研究的最新进展,并结合本课题组的工作对211 At肿瘤靶向治疗药物的研究现状进行重点评述。同时,对目前α核素肿瘤靶向治疗药物研究中面临的问题及临床应用前景进行分析与展望。

Evaluation of decay data of ^(213)Bi

213Bi disintegrates (97.91±0.03) % by β-emission to the levels in 213Po, and (2.09±0.03) % through α decay to 209Tl. The evaluation of the complete decay scheme and data of 213Bi including the recent new measurements are presented in this report. The Limitation of Relative Statistical Weight Method (LWM) was applied to average numbers throughout the evaluation. The uncertainty assigned to the average value was always greater than or equal to the smallest uncertainty of the values used to calculate the average. The half-life is determined to be 45.59±0.06 minutes. All known measured gamma-ray relative emission probabilities have been examined. And the gamma-ray emission probability of the reference γ line of 440.44keV is recommended to be (26.1±0.3) %. The calculated internal conversion coefficients and their uncertainties have been used to obtain the complete decay intensity balance. The other decay characteristics are calculated using the ENSDF analysis program. Finally the new 213Bi decay scheme was re-built.

α放射性金属药物的研究现状与展望

靶向α治疗(TAT)是一种很有前景的肿瘤治疗方法。在TAT中,把含有α发射体核素的放射性药物的辐射选择性地传送到癌症细胞,而尽可能将全身的毒副作用最小化。与β粒子相比,α粒子具有更高的能量、更高的线性能量传递(LET)和更短的组织穿透距离。因此,TAT在靶向治疗中具有明显的优势。本文概述了用于TAT的一些锕系元素和它们的放射性金属衰变子体。这些放射性金属核素包括225 Ac、212/213 Bi、212 Pb、227 Th以及223 Ra。首先比较了α粒子和β粒子的物理和辐射生物学性质。然后,描述了这些放射性金属核素的化学性质和来源。接着,展示了TAT中常用的一些双功能螯合剂。其后,介绍了TAT放射性药物的研究现状。最后,给出了TAT放射性药物研发中的挑战性问题和前景展望。