A Study of the TPS Based Beam-Matching Concept for Medical Linear Accelerators at a Tertiary Hospital  

作　　者：Ntombela N. Lethukuthula Rovetto J. Nicolas Nethwadzi C. Lutendo Mpumelelo Nyathi Ntombela N. Lethukuthula;Rovetto J. Nicolas;Nethwadzi C. Lutendo;Mpumelelo Nyathi(Department of Radiation Oncology, Steve Biko Academic Hospital, Pretoria, South Africa;Department of Medical Physics, University of Pretoria, Pretoria, South Africa;Department of Medical Physics, Sefako Makgatho Health Sciences University, Ga-Rankuwa, South Africa)

机构地区：[1]Department of Radiation Oncology, Steve Biko Academic Hospital, Pretoria, South Africa [2]Department of Medical Physics, University of Pretoria, Pretoria, South Africa [3]Department of Medical Physics, Sefako Makgatho Health Sciences University, Ga-Rankuwa, South Africa

出　　处：《International Journal of Medical Physics, Clinical Engineering and Radiation Oncology》2024年第1期16-25,共10页医学物理学、临床工程、放射肿瘤学（英文）

摘　　要：The flexibility in radiotherapy can be improved if patients can be moved between any one of the department’s medical linear accelerators (LINACs) without the need to change anything in the patient’s treatment plan. For this to be possible, the dosimetric characteristics of the various accelerators must be the same, or nearly the same. The purpose of this work is to describe further and compare measurements and parameters after the initial vendor-recommended beam matching of the five LINACs. Deviations related to dose calculations and to beam matched accelerators may compromise treatment accuracy. The safest and most practical way to ensure that all accelerators are within clinical acceptable accuracy is to include TPS calculations in the LINACs matching evaluation. Treatment planning system (TPS) was used to create three photons plans with different field sizes 3 × 3 cm, 10 × 10 cm and 25 × 25 cm at a depth of 4.5 cm in Perspex. Calculated TPS plans were sent to Mosaiq to be delivered by five LINACs. TPS plans were compared with five LINACs measurements data using Gamma analyses of 2% and 2 mm. The results suggest that for four out of the five LINACs, there was generally good agreement, less than a 2% deviation between the planned dose distribution and the measured dose distribution. However, one specific LINAC named “Asterix” exhibited a deviation of 2.121% from the planned dose. The results show that all of the LINACs’ performance were within the acceptable deviation and delivering radiation dose consistently and accurately.The flexibility in radiotherapy can be improved if patients can be moved between any one of the department’s medical linear accelerators (LINACs) without the need to change anything in the patient’s treatment plan. For this to be possible, the dosimetric characteristics of the various accelerators must be the same, or nearly the same. The purpose of this work is to describe further and compare measurements and parameters after the initial vendor-recommended beam matching of the five LINACs. Deviations related to dose calculations and to beam matched accelerators may compromise treatment accuracy. The safest and most practical way to ensure that all accelerators are within clinical acceptable accuracy is to include TPS calculations in the LINACs matching evaluation. Treatment planning system (TPS) was used to create three photons plans with different field sizes 3 × 3 cm, 10 × 10 cm and 25 × 25 cm at a depth of 4.5 cm in Perspex. Calculated TPS plans were sent to Mosaiq to be delivered by five LINACs. TPS plans were compared with five LINACs measurements data using Gamma analyses of 2% and 2 mm. The results suggest that for four out of the five LINACs, there was generally good agreement, less than a 2% deviation between the planned dose distribution and the measured dose distribution. However, one specific LINAC named “Asterix” exhibited a deviation of 2.121% from the planned dose. The results show that all of the LINACs’ performance were within the acceptable deviation and delivering radiation dose consistently and accurately.

关 键 词：RADIOTHERAPY Beam-Matching Linear Accelerator DOSIMETRY 

分 类 号：TL5[核科学技术—核技术及应用]