Brachytherapy is a radiotherapy procedure performed with radioactive sources implanted into the patient's body, close to the area affected by cancer. This is a reference procedure for the treatment of prostate and gynecologic cancer due to the reduction of the dose released close to organs at risk (e.g., rectum, bladder, colon). For this reason, real-time dose verification and source localisation are essential for an optimal treatment plan. The ORIGIN collaboration aims to achieve this goal through a 16-fibre sensor system, designed to house a small volume of scintillating material in a transparent fibre tip to enable point-like measurements. The selected scintillating materials feature a decay time of about 500 μs and the signal associated with the primary γ-ray interaction results in the emission of a sequence of single photons distributed over time. Therefore, the dosimeter requires a detector with single-photon sensitivity and a system designed to provide dose measurements by photon counting. Uniformity of fibre response, system stability and reproducibility of measurements are key features of the dosimeter. The characterisation of the 16-channel dosimeter system equipped with thermo-electrically cooled Silicon Photomultipliers, carried out in the laboratory using an X-ray cabinet, is discussed and the results are compared with an earlier version equipped with SiPMs operated at room temperature.

中文翻译：

---

用于低剂量率 (LDR) 肿瘤近距离放射治疗的硅光电倍增剂量计的设计和调试

近距离放射治疗是一种放射治疗程序，将放射源植入患者体内靠近癌症影响的区域。由于减少了靠近危险器官（例如直肠、膀胱、结肠）释放的剂量，因此这是治疗前列腺癌和妇科癌症的参考程序。因此，实时剂量验证和源定位对于最佳治疗计划至关重要。 ORIGIN 合作旨在通过 16 光纤传感器系统实现这一目标，该系统旨在将少量闪烁材料容纳在透明光纤尖端中，以实现点状测量。所选闪烁材料的衰减时间约为 500 μs，并且与初级相关的信号γ射线相互作用导致随时间分布的一系列单光子的发射。因此，剂量计需要具有单光子灵敏度的探测器和旨在通过光子计数提供剂量测量的系统。光纤响应的均匀性、系统稳定性和测量的再现性是剂量计的关键特性。讨论了在实验室中使用 X 射线柜进行的配备热电冷却硅光电倍增管的 16 通道剂量计系统的表征，并将结果与​​配备在室温下运行的 SiPM 的早期版本进行了比较。