In vivo dosimetry of the patients treated by I-131 is important from patient dosimetry and radiation protection points of view. Knowledge of delivered dose to the target volume and adjacent normal tissues can improve the effectiveness of radioiodine treatment. Herein, design, fabrication, and assessment processes of an iodine radionuclide dosimeter (IRD) are explained. Two CsI(Tl) scintillator crystals coupled to photodiodes were used in IRD fabrication with specifications derived from Monte Carlo (MC) simulation. Linearity, sensitivity, and long-term performance of the system were tested. Delivered dose due to a known administered activity of I-131 was calculated by MC simulation which was validated based on the Medical Internal Radiation Dose (MIRD) Committee formalism, and the calibration factor was provided. Using the current mode signal acquisition method, the system showed a linear response up to 8.2 GBq radioiodine activity to prohibit the pile-up error without a need for correction factor. On the other hand, IRD was sensitive down to the rarely detectable activity of 7.4 MBq. A prototype version of the IRD system has been developed to guide the hospital staff for the safe release of iodine - administered patients and to provide an insight for physicians about the delivered dose to the thyroid and nearby organs. Graphical abstract IRD attached to MIHAN.

中文翻译：

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碘放射性核素剂量计（IRD）的体外评估，用于持续的患者监测。

从患者剂量测定法和放射防护的观点来看，I-131治疗的患者的体内剂量测定法很重要。了解向目标体积和邻近正常组织的给药剂量可以提高放射性碘治疗的有效性。在此，说明碘放射性核素剂量计（IRD）的设计，制造和评估过程。IRD制造中使用了两个与光电二极管耦合的CsI（Tl）闪烁体晶体，其规格源自蒙特卡罗（MC）模拟。测试了系统的线性，灵敏度和长期性能。通过MC模拟计算出由于I-131已知的给药活性而产生的剂量，该模拟基于医学内部辐射剂量（MIRD）委员会的形式验证，并提供了校准因子。使用电流模式信号采集方法，该系统显示出高达8.2 GBq放射性碘活度的线性响应，从而无需校正因子即可抑制堆积误差。另一方面，IRD对7.4 MBq很少检测到的活性敏感。已开发出IRD系统的原型版本，以指导医院工作人员安全释放碘治疗的患者，并向医生提供有关向甲状腺和附近器官输送剂量的见解。MIHAN附带的图形抽象IRD。已开发出IRD系统的原型版本，以指导医院工作人员安全释放碘治疗的患者，并向医生提供有关向甲状腺和附近器官输送剂量的见解。MIHAN附带的图形抽象IRD。已开发出IRD系统的原型版本，以指导医院工作人员安全释放碘管理的患者，并向医生提供有关向甲状腺和附近器官输送剂量的见解。MIHAN附带的图形抽象IRD。