Abstract：
BACKGROUND: As radiotherapy techniques advance, so do planning methods for multi-target intracranial SRS cases. Multi-target-single-isocenter (MTSI) planning offers high-precision beam delivery with shortened duration. However, accommodating all targets in a single Patient-Specific-Quality-Assurance (PSQA) with QA devices like SRS MapCHECK (SRS MC) is generally impractical.
OBJECTIVE: Consequently, we conducted PSQA, using a custom script, by relocating each Target or Neighboring-Target-Group (T-NTG) relative to the beam isocenter on the PSQA device, ensuring each target\'s dose coverage at high precision.
METHODS: SRS treatment plans use 6MV-FFF beams, consisting of four Volumetric Modulated ARC Therapy (VMAT) arcs, including one full-arc and three half arcs with couch-kicks. A custom script calculated T-NTG coordinates relative to the beam isocenter. QA verification plans were created for each T-NTG, redefining the beam isocenter for precise alignment with the center of the SRS MC. CBCT images were acquired during PSQA for SRS MC alignment, and gamma-index analysis (GIA) was performed. A single-tail paired t-test assessed the passing rate (PR) for 75 QA verification plans.
RESULTS: GIA with l.0 mm/2.0% criteria for each QA plan yielded a PR > 95.5%, with an average of 98.9%. Plans achieving PR > 99.0% and > 97.0% constituted 63% and 92% of studied plans, respectively. Statistical significance was observed in a t-test with an ideal PR value of 100%, while insignificance was found with a PR value of 99%, suggesting that PSQA for individual targets consistently approaches 99% PR. In MTSI cases using 6MV-FFF beams, targets within the lateral dose-fall-off region require careful verification for acceptability. Our clinical study on individual T-NTG relocation demonstrates that the presented PSQA methods are generally acceptable, supported by a statistically insignificant PR against a 99% PR value.
CONCLUSIONS: Presented statistical analysis results indicate that the proposed PSQA approach can serve as a reliable tool in clinical settings.
OBJECTIVE: Consequently, we conducted PSQA, using a custom script, by relocating each Target or Neighboring-Target-Group (T-NTG) relative to the beam isocenter on the PSQA device, ensuring each target\'s dose coverage at high precision.
METHODS: SRS treatment plans use 6MV-FFF beams, consisting of four Volumetric Modulated ARC Therapy (VMAT) arcs, including one full-arc and three half arcs with couch-kicks. A custom script calculated T-NTG coordinates relative to the beam isocenter. QA verification plans were created for each T-NTG, redefining the beam isocenter for precise alignment with the center of the SRS MC. CBCT images were acquired during PSQA for SRS MC alignment, and gamma-index analysis (GIA) was performed. A single-tail paired t-test assessed the passing rate (PR) for 75 QA verification plans.
RESULTS: GIA with l.0 mm/2.0% criteria for each QA plan yielded a PR > 95.5%, with an average of 98.9%. Plans achieving PR > 99.0% and > 97.0% constituted 63% and 92% of studied plans, respectively. Statistical significance was observed in a t-test with an ideal PR value of 100%, while insignificance was found with a PR value of 99%, suggesting that PSQA for individual targets consistently approaches 99% PR. In MTSI cases using 6MV-FFF beams, targets within the lateral dose-fall-off region require careful verification for acceptability. Our clinical study on individual T-NTG relocation demonstrates that the presented PSQA methods are generally acceptable, supported by a statistically insignificant PR against a 99% PR value.
CONCLUSIONS: Presented statistical analysis results indicate that the proposed PSQA approach can serve as a reliable tool in clinical settings.
摘要：
背景：随着放射治疗技术的进步，多目标颅内SRS病例的规划方法也是如此。多目标单等中心（MTSI）规划提供了高精度的波束传输，缩短了持续时间。然而,使用像SRSMapCHECK（SRSMC）这样的QA设备在单个患者特定质量保证（PSQA）中适应所有目标通常是不切实际的。
目标：因此，我们进行了PSQA,使用自定义脚本，通过相对于PSQA设备上的波束等中心点重新定位每个目标或相邻目标组(T-NTG)，确保每个目标的剂量覆盖高精度。
方法：SRS治疗计划使用6MV-FFF波束，由四个体积调制ARC治疗(VMAT)弧组成，包括一个全弧形和三个带沙发踢的半弧形。自定义脚本计算T-NTG相对于光束等中心点的坐标。为每个T-NTG创建了QA验证计划，重新定义波束等中心点，以便与SRSMC的中心精确对准。在PSQA期间获取CBCT图像，用于SRSMC对齐，并进行了伽马指数分析(GIA)。单尾配对t检验评估了75个QA验证计划的通过率（PR）。
结果：每个质量保证计划的1.0mm/2.0％标准的GIA产生的PR>95.5％，平均为98.9%。实现PR>99.0%和>97.0%的计划占研究计划的63%和92%，分别。在t检验中观察到统计学显著性,理想PR值为100%,虽然发现PR值为99%时微不足道，这表明单个目标的PSQA始终接近99%PR。在使用6MV-FFF梁的MTSI情况下，横向剂量下降区域内的目标需要仔细验证是否可接受性。我们对个体T-NTG重新定位的临床研究表明，提出的PSQA方法通常是可以接受的，由一个统计上不显著的PR支持，而PR值为99%。
结论：所提供的统计分析结果表明，拟议的PSQA方法可以作为临床环境中的可靠工具。
目标：因此，我们进行了PSQA,使用自定义脚本，通过相对于PSQA设备上的波束等中心点重新定位每个目标或相邻目标组(T-NTG)，确保每个目标的剂量覆盖高精度。
方法：SRS治疗计划使用6MV-FFF波束，由四个体积调制ARC治疗(VMAT)弧组成，包括一个全弧形和三个带沙发踢的半弧形。自定义脚本计算T-NTG相对于光束等中心点的坐标。为每个T-NTG创建了QA验证计划，重新定义波束等中心点，以便与SRSMC的中心精确对准。在PSQA期间获取CBCT图像，用于SRSMC对齐，并进行了伽马指数分析(GIA)。单尾配对t检验评估了75个QA验证计划的通过率（PR）。
结果：每个质量保证计划的1.0mm/2.0％标准的GIA产生的PR>95.5％，平均为98.9%。实现PR>99.0%和>97.0%的计划占研究计划的63%和92%，分别。在t检验中观察到统计学显著性,理想PR值为100%,虽然发现PR值为99%时微不足道，这表明单个目标的PSQA始终接近99%PR。在使用6MV-FFF梁的MTSI情况下，横向剂量下降区域内的目标需要仔细验证是否可接受性。我们对个体T-NTG重新定位的临床研究表明，提出的PSQA方法通常是可以接受的，由一个统计上不显著的PR支持，而PR值为99%。
结论：所提供的统计分析结果表明，拟议的PSQA方法可以作为临床环境中的可靠工具。
