Introduction: Radiation therapy after breast surgery is an integral part of the treatment of early breast cancer. The goal of radiation therapy is to achieve the best possible coverage of the planning target volume (P...Introduction: Radiation therapy after breast surgery is an integral part of the treatment of early breast cancer. The goal of radiation therapy is to achieve the best possible coverage of the planning target volume (PTV), while reducing the dose to organs at risk (OARs) which are normal tissues whose sensitivity to irradiation could cause damage that can lead to modification of the treatment plan. In the last decade, radiation oncologist started to use the Intensity Modulated Radiotherapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) for irradiating the breast, in order to achieve better dose distribution and target dose to the PTV and OAR. The aim of this study is to compare 2 external radiotherapy techniques (VMAT vs 3D) for patients with node-positive left breast cancer. Patients and Methods: We randomly selected 10 cases of postoperative radiotherapy for breast cancer in our hospital. The patients are all female, the average age was 45.4 years old, and the primary lesions are left breast. The ANOVA test was used to compare the mean difference between subgroups, and the p value Results: Dose volume histogram (DVH) was used to analyze each evaluation dose of clinical target volume (CTV) and organs at risk (OARs). Compared to 3DCRT plans, VMAT provided more uniform coverage to the breast and regional lymph nodes. The max point dose for tVMAT was lower on average (106.4% for VMAT versus 109% for 3DCRT). OAR sparing was improved with tVMAT, with a lower average V17Gy for the left lung (27.91% for VMAT versus 30.04% for 3DCRT, p and lower for V28Gy (13.75% for VMAT versus 22.34% for 3DCRT, p = 0.01). We also found a lower V35Gy for the heart on VMAT plan (p = 0.02). On the contrary, dose of contralateral breast was lower in 3DCRT than VMAT (0.59 Gy vs 3.65 Gy, p = 0.00). Conclusion: The both types of plans can meet the clinical dosimetry demands of postoperative radiotherapy for left breast cancer. The VMAT plan has a better conformity, but 3CDRT can provide a lower dose to the contralateral organs (breast and lung) to avoid the risk of secondary cancers.展开更多
Modern radiation treatments have become fairly complex and involve in utilizing a variety of medical devices to achieve the goal of providing conformal radiation dose coverage to the tumor target(s)while maximizing th...Modern radiation treatments have become fairly complex and involve in utilizing a variety of medical devices to achieve the goal of providing conformal radiation dose coverage to the tumor target(s)while maximizing the sparing of normal organ structures.Recently,different forms of linear accelerators/radioactive source based machines have been invented and developed with the aim of providing improved treatments and more treatment options.Besides linear accelerators(Linac)that have been undergoing constant improvement and advancement and can deliver fairly complicated dose distribution patterns,imaging systems,computer information and calculation systems have been more and more integrated into radiotherapy processes.To bring radiotherapy to a potentially higher level,many institutions have either acquired or started to consider particle therapy,especially proton therapy.The complexity of modern radiotherapy demands in-depth understanding of radiation physics and machine engineering as well as computer information systems.This paper is intended to provide an introductory description of radiation oncology and related procedures,and to provide an overview of the current status of medical devices in radiotherapy in the United States of America.This paper covers the radiation delivery systems,imaging systems,treatment planning systems,record and verify systems,and QA systems.展开更多
Radiation oncology is one of the three major treatment modalities to manage cancer patient cares,and is a discipline mainly driven by technology and medical devices.Modern radiation treatments have become fairly compl...Radiation oncology is one of the three major treatment modalities to manage cancer patient cares,and is a discipline mainly driven by technology and medical devices.Modern radiation treatments have become fairly complex and involve in utilizing a variety of medical devices to achieve the goal of providing conformal radiation dose coverage to the tumor target(s)while maximizing the sparing of normal organ structures.Recently,different forms of linear accelerators/radioactive source based machines have been invented and developed with the aim of providing improved treatments and more treatment options.Besides linear accelerators(Linac)that have been undergoing constant improvement and advancement and can deliver fairly complicated dose distribution patterns,imaging systems,computer information and calculation systems have been more and more integrated into radiotherapy processes.To bring radiotherapy to a potentially higher level,many institutions have either acquired or started to consider particle therapy,especially proton therapy.The complexity of modern radiotherapy demands in-depth understanding of radiation physics and machine engineering as well as computer information systems.This paper is intended to provide an introductory description of radiation oncology and related procedures,and to provide an overview of the current status of medical devices in radiotherapy in the United States of America.This paper covers the radiation delivery systems,imaging systems,treatment planning systems,record and verify systems,and QA systems.展开更多
文摘Introduction: Radiation therapy after breast surgery is an integral part of the treatment of early breast cancer. The goal of radiation therapy is to achieve the best possible coverage of the planning target volume (PTV), while reducing the dose to organs at risk (OARs) which are normal tissues whose sensitivity to irradiation could cause damage that can lead to modification of the treatment plan. In the last decade, radiation oncologist started to use the Intensity Modulated Radiotherapy (IMRT) and Volumetric Modulated Arc Therapy (VMAT) for irradiating the breast, in order to achieve better dose distribution and target dose to the PTV and OAR. The aim of this study is to compare 2 external radiotherapy techniques (VMAT vs 3D) for patients with node-positive left breast cancer. Patients and Methods: We randomly selected 10 cases of postoperative radiotherapy for breast cancer in our hospital. The patients are all female, the average age was 45.4 years old, and the primary lesions are left breast. The ANOVA test was used to compare the mean difference between subgroups, and the p value Results: Dose volume histogram (DVH) was used to analyze each evaluation dose of clinical target volume (CTV) and organs at risk (OARs). Compared to 3DCRT plans, VMAT provided more uniform coverage to the breast and regional lymph nodes. The max point dose for tVMAT was lower on average (106.4% for VMAT versus 109% for 3DCRT). OAR sparing was improved with tVMAT, with a lower average V17Gy for the left lung (27.91% for VMAT versus 30.04% for 3DCRT, p and lower for V28Gy (13.75% for VMAT versus 22.34% for 3DCRT, p = 0.01). We also found a lower V35Gy for the heart on VMAT plan (p = 0.02). On the contrary, dose of contralateral breast was lower in 3DCRT than VMAT (0.59 Gy vs 3.65 Gy, p = 0.00). Conclusion: The both types of plans can meet the clinical dosimetry demands of postoperative radiotherapy for left breast cancer. The VMAT plan has a better conformity, but 3CDRT can provide a lower dose to the contralateral organs (breast and lung) to avoid the risk of secondary cancers.
文摘Modern radiation treatments have become fairly complex and involve in utilizing a variety of medical devices to achieve the goal of providing conformal radiation dose coverage to the tumor target(s)while maximizing the sparing of normal organ structures.Recently,different forms of linear accelerators/radioactive source based machines have been invented and developed with the aim of providing improved treatments and more treatment options.Besides linear accelerators(Linac)that have been undergoing constant improvement and advancement and can deliver fairly complicated dose distribution patterns,imaging systems,computer information and calculation systems have been more and more integrated into radiotherapy processes.To bring radiotherapy to a potentially higher level,many institutions have either acquired or started to consider particle therapy,especially proton therapy.The complexity of modern radiotherapy demands in-depth understanding of radiation physics and machine engineering as well as computer information systems.This paper is intended to provide an introductory description of radiation oncology and related procedures,and to provide an overview of the current status of medical devices in radiotherapy in the United States of America.This paper covers the radiation delivery systems,imaging systems,treatment planning systems,record and verify systems,and QA systems.
文摘Radiation oncology is one of the three major treatment modalities to manage cancer patient cares,and is a discipline mainly driven by technology and medical devices.Modern radiation treatments have become fairly complex and involve in utilizing a variety of medical devices to achieve the goal of providing conformal radiation dose coverage to the tumor target(s)while maximizing the sparing of normal organ structures.Recently,different forms of linear accelerators/radioactive source based machines have been invented and developed with the aim of providing improved treatments and more treatment options.Besides linear accelerators(Linac)that have been undergoing constant improvement and advancement and can deliver fairly complicated dose distribution patterns,imaging systems,computer information and calculation systems have been more and more integrated into radiotherapy processes.To bring radiotherapy to a potentially higher level,many institutions have either acquired or started to consider particle therapy,especially proton therapy.The complexity of modern radiotherapy demands in-depth understanding of radiation physics and machine engineering as well as computer information systems.This paper is intended to provide an introductory description of radiation oncology and related procedures,and to provide an overview of the current status of medical devices in radiotherapy in the United States of America.This paper covers the radiation delivery systems,imaging systems,treatment planning systems,record and verify systems,and QA systems.
