Palmans H, Seuntjens J, Verhaegen F, Denis J M, Vynckier S, Thierens H
Department of Biomedical Physics, University of Ghent, Belgium.
Bull Cancer Radiother. 1996;83 Suppl:176s-8s. doi: 10.1016/0924-4212(96)84907-3.
The importance of water calorimetry in clinical proton beam dosimetry has increased for various reasons: there has been an increasing interest in proton therapy from the radiotherapy world; existing dosimetry protocols for clinical proton beams recommend calorimetry as the primary dosimetry method (ie, AAPM and ECHED); water has recently become the reference material for dose specification. For the water calorimetric dose evaluation, the water calorimeter developed in Ghent was used. Ionometry was performed following the ECHED protocol. The study resulted in a calorimetric to ionometric dose ratio of 0.974 +/- 0.009. The discrepancy should in our opinion be attributed to the (Wle)p,air value of 35.2 J/C implemented in the protocol, possibly next to ion chamber dependent effects for which indications are found in the ionometry measurements.
由于多种原因，水热剂量法在临床质子束剂量测定中的重要性日益增加：放射治疗界对质子治疗的兴趣不断上升；现有的临床质子束剂量测定协议推荐热剂量法作为主要剂量测定方法（即美国医学物理学家协会和欧洲临床质子治疗剂量测定合作组织）；水最近已成为剂量规范的参考材料。对于水热剂量评估，使用了根特开发的水热量计。按照欧洲临床质子治疗剂量测定合作组织的协议进行了电离测量。该研究得出热剂量与电离剂量的比值为0.974±0.009。我们认为，这种差异应归因于协议中采用的35.2 J/C的（Wle）p,空气值，可能还与电离室相关效应有关，在电离测量中发现了相关迹象。
