Chekhonadskij V N, Merkle K
Institut für klinische Onkologie des Wissenschaftlichen Allunionszentrums für Onkologie der AdMW der UdSSR, Moskau.
Strahlenther Onkol. 1987 Nov;163(11):742-5.
In clinical practice, some dosimetric problems of contact therapy with CF-252 are not yet sufficiently clarified. One possibility to solve these problems is to apply the conception of total photon-equivalent energy doses. This conception serves to calculate clinical guidance values of the RBE of the Cf-252 neutron constituent for radiogenic late effects in dependence on the total dose rate of the mixed radiation. The correlations indicated are valid for dose rates of 0.05 to 4 Gy/h and 4 to 1.25.10(4) Gy/h. On the basis of these functional correlations and taking into consideration the critical normal tissues of rectum and urinary bladder, the minimum RBE values of the tumors are indicated which allow a therapeutic effect of more than 1 in case of application of Cf-252. The formulas for the RBE dependence of the Cf-252 neutron constituent on the total dose rate permit to take into account any modifications of this value caused by varying source distances in contact therapy. It is concluded from these investigations that in oncologic patients, better results are to be expected from a treatment with high-energy Cf-252 sources, if the other treatment conditions are identical.
在临床实践中，使用Cf - 252进行接触治疗的一些剂量学问题尚未得到充分阐明。解决这些问题的一种可能性是应用总光子等效能量剂量的概念。这一概念用于根据混合辐射的总剂量率计算Cf - 252中子成分对放射性晚期效应的相对生物效应（RBE）的临床指导值。所表明的相关性适用于0.05至4 Gy/h以及4至1.25×10⁴ Gy/h的剂量率。基于这些函数相关性并考虑到直肠和膀胱等关键正常组织，给出了肿瘤的最小RBE值，在使用Cf - 252时，这些值可实现大于1的治疗效果。Cf - 252中子成分的RBE对总剂量率的依赖公式允许考虑接触治疗中源距离变化引起的该值的任何改变。从这些研究得出的结论是，在其他治疗条件相同的情况下，对于肿瘤患者，使用高能Cf - 252源进行治疗有望获得更好的结果。
