碘125在临床应用中的相对生物效应（RBE）是多少？

Which RBE for iodine 125 in clinical applications?

作者信息

Scalliet P, Wambersie A

出版信息

Radiother Oncol. 1987 Jul;9(3):221-30. doi: 10.1016/s0167-8140(87)80234-7.

Abstract

The problem of the selection of a RBE value for 125I is discussed for clinical applications in interstitial therapy. Microdosimetric studies indicate that the emission of the 125I has a y spectra similar to X-rays of 12-140 keV (conventional X-rays), but differs from 60Co, 137Cs gamma-rays and high energy X-rays. The radiobiological data available show RBE values ranging from 1 to 2.4 for 125I (reference beam 60Co). Although obtained with different biological systems and endpoints, RBE values of 1.15-1.20 are in general observed for high doses and high dose rates. On the other hand, higher RBE values (up to 2) are observed at low doses or low dose rates, which is consistent with theoretical and microdosimetric data.

摘要

讨论了在间质治疗临床应用中为¹²⁵I选择相对生物效应（RBE）值的问题。微剂量学研究表明，¹²⁵I的发射具有与12 - 140 keV的X射线（传统X射线）相似的γ能谱，但与⁶⁰Co、¹³⁷Csγ射线和高能X射线不同。现有的放射生物学数据显示，¹²⁵I的RBE值范围为1至2.4（参考射线为⁶⁰Co）。尽管是在不同的生物系统和终点条件下获得的，但在高剂量和高剂量率时，通常观察到的RBE值为1.15 - 1.20。另一方面，在低剂量或低剂量率时观察到较高的RBE值（高达2），这与理论和微剂量学数据一致。