摘要目的:探讨个体化三维（3D）打印胸部模体（简称模体）在调强放疗剂量验证中的临床应用价值。方法:选取2023年10月徐州市肿瘤医院收治的1例食管癌患者（女性，78岁）的定位CT扫描医学数字成像和通信格式图像进行回顾性研究。基于患者胸部CT图像与模体CT图像，分别设计调强放疗计划，比较靶区（椎体）、危及器官（脊髓、双肺、心脏）及参考点（右肺内的一个测量点）的剂量学参数差异。通过模体预设的电离室通道，在靶区和参考点分别插入指形电离室，将模体固定于医用直线加速器治疗床上，执行放疗计划并采集剂量数据。计量资料的组间比较采用单样本 t检验。 结果:剂量体积直方图分析结果显示，模体与患者放疗计划的靶区及危及器官剂量分布曲线基本重合。剂量测量实验结果显示，靶区5次剂量测量值分别为210.5、211.1、210.8、210.7、211.9 cGy。靶区测量剂量平均值为（211.0±0.5）cGy，计算剂量平均值为210.4 cGy，其绝对剂量偏差为0.60 cGy (95% CI：?0.08~1.28），相对剂量偏差为0.29%（95% CI：?0.04%~0.61%）。单样本 t检验结果显示，靶区5次测量剂量和计算剂量的差异有统计学意义（ t=2.449， P=0.035）。参考点5次剂量测量值分别为49.2、49.8、49.5、49.4、50.8 cGy。参考点测量剂量平均值为（49.7±0.6）cGy，计算剂量平均值为49.1 cGy，其绝对剂量偏差为0.60 cGy (95% CI：?0.14~1.42），相对剂量偏差为1.22% （95% CI：?0.29%~2.91%）。单样本 t检验结果显示，参考点5次测量剂量和计算剂量的差异有统计学意义（ t=2.268， P=0.043）。靶区和参考点的相对剂量偏差绝对值均<3%，符合《WS 674—2020医用电子直线加速器质量控制检测规范》的要求。 结论:该模体为临床放疗质量保证提供了可靠的新方法。

abstractsObjective:To evaluate the clinical application value of individualized three dimensional (3D) printed thoracic phantoms (referred to as phantoms) in dose verification for intensity-modulated radiation therapy.Methods:A retrospective study was conducted using the CT localization images in digital imaging and communications in medicine format obtained from a patient (female, 78 years old) with esophageal cancer treated at the Xuzhou Cancer Hospital in October 2023. Intensity-modulated radiation therapy plans were designed on the basis of the patient and phantom CT images. Dosimetric parameters were compared for the target volume (vertebral body), organs at risk (spinal cord, bilateral lungs and heart) and a reference point (a measurement point within the right lung). A thimble ionization chamber was inserted into the target volume and the reference point through predesigned channels in the phantom. The phantom was fastened to the treatment couch of a medical linear accelerator, and the radiation plan was executed to collect dose data. Intergroup comparisons of measurement data were performed using one sample t-test. Results:Dose-volume histogram analysis demonstrated that the dose distribution curves for the target volume and organs at risk nearly overlapped in the phantom and patient intensity-modulated radiation therapy plans. Dose measurement experimental results showed five dose measurements for the target volume: 210.5, 211.1, 210.8, 210.7, 211.9 cGy. The average measured and calculated doses for the target volume were (211.0±0.5) cGy and 210.4 cGy, respectively, with absolute and relative dose deviations of 0.6 cGy (95% CI: ?0.08 to 1.28) and 0.29% (95% CI: ?0.04% to 0.61%), respectively. One sample t-test revealed a statistically significant difference between the five times measured and calculated doses for the target volume ( t=2.449, P=0.035). For the reference point, the five dose measurements were 49.2, 49.8, 49.5, 49.4, 50.8 cGy. The average measured and calculated doses were (49.7±0.6) cGy and 49.1 cGy, respectively, with absolute and related dose deviations of 0.6 cGy (95% CI: ?0.14 to 1.42) and 1.22% (95% CI: ?0.29% to 2.91%), respectively. One sample t-test showed a statistically significant difference between the dose measured five times and the calculated dose for the reference point ( t=2.268, P=0.043). The absolute values of relative dose deviations at both sites were <3%, meeting the requirements of the WS 674—2020 Specification for Testing of Quality Control in Medical Linear Accelerator. Conclusion:The phantom provides a dose verification method for clinical radiotherapy quality assurance.