目的:研究使用OCTAVIUS 4D验证设备对全中枢容积旋转调强放疗计划进行接野部位剂量验证的可行性和准确性,为全中枢容积旋转调强放疗计划接野部位剂量验证提供参考方法。方法:选取12例接受全中枢容积旋转调强接野放疗的患者,在治疗计划...目的:研究使用OCTAVIUS 4D验证设备对全中枢容积旋转调强放疗计划进行接野部位剂量验证的可行性和准确性,为全中枢容积旋转调强放疗计划接野部位剂量验证提供参考方法。方法:选取12例接受全中枢容积旋转调强接野放疗的患者,在治疗计划系统中分别建立头部中心、胸部中心、腹部中心验证计划和头胸射野衔接处、胸腹射野衔接处验证计划,通过OCTAVIUS 4D验证设备采集真实剂量。通过前后移床验证相邻中心射野衔接处的剂量分布。使用Verisoft 7.1软件分析全中枢容积旋转调强放疗单中心验证计划和射野衔接处验证计划的γ通过率。结果:阈值为10%时,头部、胸部和腹部中心计划在3 mm/3%标准下的γ通过率分别为(99.68±0.60)%、(99.63±0.52)%和(99.53±0.86)%,高于美国医学物理学家协会(American Association of Physicists in Medicine,AAPM)报告的关于治疗前患者计划剂量验证通过率的建议。相同条件下不同相邻中心射野衔接处的剂量分布略有差异,头胸接野部位的γ通过率略低于胸腹接野部位的γ通过率,且差异具有统计学意义(P<0.05)。阈值为10%时,横断面、冠状面、矢状面3 mm/3%标准下的γ通过率超过92%,5 mm/5%标准下的γ通过率则超过97%,均符合放疗计划治疗前的要求。结论:OCTAVIUS 4D验证设备可以用于全中枢容积旋转调强放疗计划剂量验证和接野部位的剂量验证,且接野部位的剂量验证通过率符合相关质控要求。展开更多
Introduction: Radiotherapy (RT) is a vital cancer treatment modality for both curative and palliative purposes. Nepal is a developing country with a population of around 30 million people. Cancer affects 100 - 120 peo...Introduction: Radiotherapy (RT) is a vital cancer treatment modality for both curative and palliative purposes. Nepal is a developing country with a population of around 30 million people. Cancer affects 100 - 120 people out of every 100,000, and the figure is increasing. The number of radiation facility machines in the country is still countable in fingers. Purbanchal Cancer Hospital, Nepal is the first comprehensive cancer facility capable of performing stereotactic radiosurgery (SRS). Our facility has cutting-edge Varian Truebeam Linear Accelerators with millennium MLC, which makes SRS and SRT’S for intracranial lesions such as small benign and malignant tumors much easier. In addition to SRS, we are the pioneers of SBRT for lung using 4DCT, interstitial & intraluminal brachytherapy, RPM Gated & DIBH modalities in Nepal. Methods & Materials: The purpose of this study is to share our experience in establishing an SRS facility in the country, which includes training the RT team on the importance of process accuracy, patient selection, patient assessment, mould preparation, and describing image data acquisition, target, and organ at risk delineation on CT and MRI images, treatment planning process, and quality assurance. Results & Discussion: The plans for all SRS and SRT cases are based on target coverage, OAR sparing, hotspot inside the target, conformity index, heterogeneity index, and dose fall off. To select the final plan, we used strict passing criteria such as a conformity index Paddick (CIPaddick) more than 0.85, a falloff between 100% and 50% of less than 5.5 mm (maximum 6 mm in irregular targets), and a hotspot inside the target between 115 to 140 percent, as per clinical standards. In addition, we determined the CILomax and CIRTOG for each case. Passing criteria for verification plans are set as minimum of 95% for a 2% percentage dose difference (% DD) and a 2-mm distance to an agreement (DTA). We also gathered demographic data from patients treated in the first year, such as diagnosis, lesion size, dose fraction, heterogeneity index (HI), conformity index (CI) and gamma index. SRS/SRT treatment was successfully implemented, and over 40 patients were treated with positive clinical outcomes. Conclusion: SRS now has a wider range of alternatives, thanks to technology advancements in recent years. SRS’s dosimetric advantages have steadily been extended to extracranial locations. Purbanchal Cancer Hospital, Birtamode, Nepal established a comprehensive cancer facility with qualified workforce with the goal of providing high-quality treatment to the people of Nepal.展开更多
文摘目的:研究使用OCTAVIUS 4D验证设备对全中枢容积旋转调强放疗计划进行接野部位剂量验证的可行性和准确性,为全中枢容积旋转调强放疗计划接野部位剂量验证提供参考方法。方法:选取12例接受全中枢容积旋转调强接野放疗的患者,在治疗计划系统中分别建立头部中心、胸部中心、腹部中心验证计划和头胸射野衔接处、胸腹射野衔接处验证计划,通过OCTAVIUS 4D验证设备采集真实剂量。通过前后移床验证相邻中心射野衔接处的剂量分布。使用Verisoft 7.1软件分析全中枢容积旋转调强放疗单中心验证计划和射野衔接处验证计划的γ通过率。结果:阈值为10%时,头部、胸部和腹部中心计划在3 mm/3%标准下的γ通过率分别为(99.68±0.60)%、(99.63±0.52)%和(99.53±0.86)%,高于美国医学物理学家协会(American Association of Physicists in Medicine,AAPM)报告的关于治疗前患者计划剂量验证通过率的建议。相同条件下不同相邻中心射野衔接处的剂量分布略有差异,头胸接野部位的γ通过率略低于胸腹接野部位的γ通过率,且差异具有统计学意义(P<0.05)。阈值为10%时,横断面、冠状面、矢状面3 mm/3%标准下的γ通过率超过92%,5 mm/5%标准下的γ通过率则超过97%,均符合放疗计划治疗前的要求。结论:OCTAVIUS 4D验证设备可以用于全中枢容积旋转调强放疗计划剂量验证和接野部位的剂量验证,且接野部位的剂量验证通过率符合相关质控要求。
文摘Introduction: Radiotherapy (RT) is a vital cancer treatment modality for both curative and palliative purposes. Nepal is a developing country with a population of around 30 million people. Cancer affects 100 - 120 people out of every 100,000, and the figure is increasing. The number of radiation facility machines in the country is still countable in fingers. Purbanchal Cancer Hospital, Nepal is the first comprehensive cancer facility capable of performing stereotactic radiosurgery (SRS). Our facility has cutting-edge Varian Truebeam Linear Accelerators with millennium MLC, which makes SRS and SRT’S for intracranial lesions such as small benign and malignant tumors much easier. In addition to SRS, we are the pioneers of SBRT for lung using 4DCT, interstitial & intraluminal brachytherapy, RPM Gated & DIBH modalities in Nepal. Methods & Materials: The purpose of this study is to share our experience in establishing an SRS facility in the country, which includes training the RT team on the importance of process accuracy, patient selection, patient assessment, mould preparation, and describing image data acquisition, target, and organ at risk delineation on CT and MRI images, treatment planning process, and quality assurance. Results & Discussion: The plans for all SRS and SRT cases are based on target coverage, OAR sparing, hotspot inside the target, conformity index, heterogeneity index, and dose fall off. To select the final plan, we used strict passing criteria such as a conformity index Paddick (CIPaddick) more than 0.85, a falloff between 100% and 50% of less than 5.5 mm (maximum 6 mm in irregular targets), and a hotspot inside the target between 115 to 140 percent, as per clinical standards. In addition, we determined the CILomax and CIRTOG for each case. Passing criteria for verification plans are set as minimum of 95% for a 2% percentage dose difference (% DD) and a 2-mm distance to an agreement (DTA). We also gathered demographic data from patients treated in the first year, such as diagnosis, lesion size, dose fraction, heterogeneity index (HI), conformity index (CI) and gamma index. SRS/SRT treatment was successfully implemented, and over 40 patients were treated with positive clinical outcomes. Conclusion: SRS now has a wider range of alternatives, thanks to technology advancements in recent years. SRS’s dosimetric advantages have steadily been extended to extracranial locations. Purbanchal Cancer Hospital, Birtamode, Nepal established a comprehensive cancer facility with qualified workforce with the goal of providing high-quality treatment to the people of Nepal.
