Irazola L, Terrón J A, Bedogni R, Pola A, Lorenzoli M, Sánchez-Nieto B, Gómez F, Sánchez-Doblado F
Departamento de Fisiología Médica y Biofísica, Universidad de Sevilla, Spain; Servicio de Radiofísica, Hospital Universitario Virgen Macarena, Sevilla, Spain.
Politecnico di Milano, Dipartimento di Ingegneria Nuclear, Milano, Italy.
Appl Radiat Isot. 2016 Sep;115:49-54. doi: 10.1016/j.apradiso.2016.06.009. Epub 2016 Jun 9.
The increasing interest of the medical community to radioinduced second malignancies due to photoneutrons in patients undergoing high-energy radiotherapy, has stimulated in recent years the study of peripheral doses, including the development of some dedicated active detectors. Although these devices are designed to respond to neutrons only, their parasitic photon response is usually not identically zero and anisotropic. The impact of these facts on measurement accuracy can be important, especially in points close to the photon field-edge. A simple method to estimate the photon contribution to detector readings is to cover it with a thermal neutron absorber with reduced secondary photon emission, such as a borated rubber. This technique was applied to the TNRD (Thermal Neutron Rate Detector), recently validated for thermal neutron measurements in high-energy photon radiotherapy. The positive results, together with the accessibility of the method, encourage its application to other detectors and different clinical scenarios.
近年来，医学界对接受高能放疗患者因光中子导致的放射性继发恶性肿瘤越来越感兴趣，这刺激了对周边剂量的研究，包括一些专用有源探测器的开发。尽管这些装置设计为仅对中子作出响应，但其寄生光子响应通常并非完全为零且具有各向异性。这些因素对测量精度的影响可能很大，尤其是在靠近光子场边缘的点处。一种估计光子对探测器读数贡献的简单方法是用具有减少二次光子发射的热中子吸收体覆盖探测器，例如硼酸橡胶。该技术已应用于TNRD（热中子率探测器），该探测器最近已在高能光子放疗的热中子测量中得到验证。这些积极结果以及该方法的可操作性，鼓励将其应用于其他探测器和不同的临床场景。
