体内剂量测定（IVD）成为高剂量率近距离放射治疗中治疗交付验证的热点。时间分辨方法，包括源追踪，具有实时检测治疗错误和减小实验不确定性的能力。多探针IVD体系可以同时测定目标肿瘤和周围健康组织的剂量，同时提高测量准确性。然而，目前大多数已开发的多探针剂量计要么存在体积紧凑的问题，要么依赖于复杂的治疗后数据处理。我们引入了一种新颖的小型多探针闪烁体探测器的概念，并展示其在高剂量率近距离放射治疗中的适用性。我们设计制造的七光纤探测系统足够细小，可以插入近距离治疗针或导管中。我们的多探针探测系统由一束七根光纤末端的六个微型无机Gd2 O2 S:Tb闪烁体探测器的平行实施组成，其中一根光纤保持裸露以评估支杆效应。所得系统窄于320微米，在水模体中使用MicroSelectron 9.14 Ci Ir-192高剂量率近距离放射治疗装置进行了测试。来自六个探针的检测信号同时使用sCMOS相机进行读取（速率为0.06秒）。相机与色散滤波器相结合，以消除光纤暴露时产生的Cerenkov信号。通过实现沿光纤束轴向的六个闪烁细胞的非周期排列，我们首先确定了导致最佳源追踪精度的探针间距的范围（第一追踪方法）。然后，我们测试和比较了涉及所有闪烁探针的三种不同源追踪算法。在这四种方法中，通过剂量测量评估了留置位置，并与治疗计划进行了比较。还确定了留置时间，并与治疗计划进行了比较。准确的源追踪所需的最佳探针间距范围为15至35毫米。最佳的检测算法是将所有探测器探针的读出信号相加。在这种情况下，与计划的留置位置相比的误差为0.01±0.14毫米，在源和探测器轴之间的距离为5.5至40毫米；使用该方法，与预期留置时间的平均偏差为-0.006±0.009秒和-0.008±0.058秒，在源和探针轴之间的距离为5.5至20毫米。我们的六探针Gd2 O2 S:Tb剂量计与sCMOS相机耦合，可在高剂量率近距离放射治疗中进行时间分辨治疗验证。这个具有高空间和时间分辨率（分别为0.25毫米和0.06秒）的检测系统通过留置时间和位置验证提供了治疗交付的准确信息，其准确性无可匹敌。© 2023 The Authors. Medical Physics，由Wiley Periodicals LLC代表美国医学物理师协会发布。

In vivo dosimetry (IVD) is gaining interest for treatment delivery verification in HDR-brachytherapy. Time resolved methods, including source tracking, have the ability both to detect treatment errors in real time and to minimize experimental uncertainties. Multiprobe IVD architectures holds promise for simultaneous dose determinations at the targeted tumor and surrounding healthy tissues while enhancing measurement accuracy. However, most of the multiprobe dosimeters developed so far either suffer from compactness issues or rely on complex data post-treatment.We introduce a novel concept of a compact multiprobe scintillator detector and demonstrate its applicability in HDR-brachytherapy. Our fabricated seven-fiber probing system is sufficiently narrow to be inserted in a brachytherapy needle or in a catheter.Our multiprobe detection system results from the parallel implementation of six miniaturized inorganic Gd2 O2 S:Tb scintillator detectors at the end of a bundle of seven fibers, one fiber is kept bare to assess the stem effect. The resulting system, which is narrower than 320 microns, is tested with a MicroSelectron 9.14 Ci Ir-192 HDR afterloader, in a water phantom. The detection signals from all six probes are simultaneously read with a sCMOS camera (at a rate of 0.06 s). The camera is coupled to a chromatic filter to cancel Cerenkov signal induced within the fibers upon exposure. By implementing an aperiodic array of six scintillating cells along the bundle axis, we first determine the range of inter-probe spacings leading to optimal source tracking accuracy (first tracking method). Then, three different source tracking algorithms involving all the scintillating probes are tested and compared. In each of these four methods, dwell positions are assessed from dose measurements and compared to the treatment plan. Dwell time is also determined and compared to the treatment plan.The optimum inter-probe spacing for an accurate source tracking ranges from 15 to 35 mm. The optimum detection algorithm consists of adding the readout signals from all detector probes. In that case, the error to the planned dwell positions is of 0.01 ± 0.14 mm and 0.02 ± 0.29 mm at spacings between the source and detector axes of 5.5 and 40 mm, respectively. Using this approach, the average deviations to the expected dwell time are of - 0.006 ± 0.009 $-0.006\,\pm \,0.009$ s and - 0.008 ± 0.058 $-0.008\, \pm 0.058$ s, at spacings between source and probe axes of 5.5 and 20 mm, respectively.Our six-probe Gd2 O2 S:Tb dosimeter coupled to a sCMOS camera can perform time-resolved treatment verification in HDR brachytherapy. This detection system of high spatial and temporal resolutions (0.25 mm and 0.06 s, respectively) provides a precise information on the treatment delivery via a dwell time and position verification of unmatched accuracy.© 2023 The Authors. Medical Physics published by Wiley Periodicals LLC on behalf of American Association of Physicists in Medicine.