Bagheri Hamed, Rabie Mahdavi Seyed, Shekarchi Babak, Manouchehri Farhad, Farhood Bagher
Radiation and Wave Research Center, Aja University of Medical Science, Tehran, Iran.
Department of Medical Physics, Iran University of Medical Sciences, Tehran, Iran.
Radiat Prot Dosimetry. 2018 Jan 1;178(1):73-81. doi: 10.1093/rpd/ncx076.
This research aimed to measure the received photon and thermal neutron doses to contralateral breast (CB) in breast cancer radiotherapy for various field sizes in presence of physical and dynamic wedges. The measurement of photon and thermal neutron doses was carried out on right breast region of RANDO phantom (as CB) for 18 MV photon beams. The dose measurements were performed by thermoluminescent dosimeter chips. These measurements obtained for various field sizes in presence of physical and dynamic wedges. The findings of this study showed that the received doses (both of the photon and thermal neutron) to CB in presence of physical wedge for 11 × 13, 11 × 17 and 11 × 21 cm2 field sizes were 5.92, 6.36 and 6.77% of the prescribed dose, respectively as well as for dynamic wedge were 2.92, 4.63 and 5.60% of the prescribed dose, respectively. The results showed that the received photon and thermal neutron doses to CB increase with increment of field sizes. The received photon and thermal neutron doses to CB in presence of physical wedge were more than dynamic wedge. According to obtained findings, it is suggested that using a dynamic wedge is preferable than physical wedge, especially for medial tangential field.
本研究旨在测量在存在物理楔形板和动态楔形板的情况下，乳腺癌放疗中不同射野大小对侧乳腺（CB）所接受的光子和热中子剂量。在RANDO体模的右乳腺区域（作为CB）对18 MV光子束进行光子和热中子剂量测量。剂量测量通过热释光剂量计芯片进行。这些测量是在存在物理楔形板和动态楔形板的情况下针对不同射野大小进行的。本研究结果表明，在存在物理楔形板时，对于11×13、11×17和11×21 cm²射野大小，CB所接受的剂量（光子和热中子剂量）分别为处方剂量的5.92%、6.36%和6.77%，而在存在动态楔形板时分别为处方剂量的2.92%、4.63%和5.60%。结果表明，CB所接受的光子和热中子剂量随射野大小的增加而增加。存在物理楔形板时CB所接受的光子和热中子剂量高于动态楔形板。根据所得结果，建议使用动态楔形板优于物理楔形板，尤其是对于内侧切线野。
