การศึกษาเปรียบเทียบรังสีคณิตเทคนิครังสีรักษาสามมิติโดยใช้จุดร่วมเดียวของลำรังสีในผู้ป่วยมะเร็งเต้านมข้างซ้ายที่ได้รับการผ่าตัดทั้งเต้า

Abstract

Introduction: A numerous patients of breast cancer is recently increasing. The sophisticated techniques benefit the treatment qualities, but the limitations are raised in term of the treatment preparation steps and time. The three-dimensional radiation therapy is necessarily used to serve these population, but the limitation is the method of the field junction. Various method was proposed to solve this problem, but the limitations are remained. This research aims to propose a new matching method and compare various methods in three-dimensional radiotherapy (3DRT) for left breast post mastectomy radiotherapy (PMRT). Method: The twenty-two CT data sets of left breast PMRT patient were used. Three single isocenter techniques (SIT), with off-axis supraclavicular field (SIToaSPC) method SIT with coplanar field border (SITCFB) method and SIT with half beam block (SITHBB) method, were created. The dosimetric parameters of organ at risk (OARs), lymph node level I-III and region of interest at gap junction (ROIg) were analyze and used to compare plans. The HBB was benchmarked to grant the score of the decision. Result: The results show the SIToaSPC method gave a low dose on the organs at risk (OAR) but ROlg was lower than prescribed dose. The SITCFB and SITHBB methods were shown the same dosimetric results of OARs but the SITHBB method was shown higher volume of the ipsilateral lung that receive 20 Gy than n SIToaSPC method. The decision score of The SITCFB method was higher than the SIToaSPC method and also slightly better than the SITHBB method. Conclusion: The SITCFB method shows benefit of OAR sparing and dose at matching field. The decision score ensures a performance of SITCFB is comparable to the SITHBB method. Furthermore, field size limitation of the SITHBB method was solved.