Menzel H G, Pihet P, Wambersie A
Fachrichtung Biophysik, Universität des Saarlandes, Homburg (Saar), Federal Republic of Germany.
Int J Radiat Biol. 1990 Apr;57(4):865-83. doi: 10.1080/09553009014550991.
The neutron beams used by various radiotherapy centres are of widely differing energies, and differences of up to 50 per cent in the relative biological effectiveness (RBE) between different beams have been found in radiobiological experiments. Moreover, at some facilities RBE variations have been observed with increasing depth in a phantom. In spite of this evidence, there is no quantitative and uniquely accepted specification of radiation quality used in practice. The urgency of an adequate solution of this problem is illustrated by the fact that in radiation therapy the usual accuracy requirement for the quantity of radiation, i.e. the absorbed dose to be delivered to the tumour, is 3.5 per cent (1 SD). In this paper a pragmatic solution for the specification of radiation quality for fast neutron therapy is proposed. It is based on empirical RBE versus lineal energy response or weighting functions. These were established by using existing radiobiological data and microdosimetric spectra measured under identical irradiation conditions at several European neutron irradiation units.
各个放射治疗中心所使用的中子束能量差异很大，并且在放射生物学实验中发现，不同束之间的相对生物效应（RBE）相差高达50%。此外，在一些设施中，已观察到在模体中随着深度增加RBE会发生变化。尽管有这些证据，但在实际应用中，对于辐射质量并没有定量且唯一被认可的规范。在放射治疗中，对辐射量（即要传递到肿瘤的吸收剂量）的通常精度要求为3.5%（1标准差），这一事实说明了充分解决该问题的紧迫性。本文提出了一种用于快速中子治疗辐射质量规范的实用解决方案。它基于经验性的RBE与线能量响应或权重函数的关系。这些关系是通过使用现有的放射生物学数据以及在几个欧洲中子辐照装置相同照射条件下测量的微剂量谱建立起来的。
