Correction Factors of Medical Electron Beams for Various Water-equivalent Materials
YAO Jintao1,2,LI Yihua1,WANG Kun2,WANG Zhipeng2,JIN Sujun2,WU Han1,2
1. School of Mechanical Engineering, Anhui University of Science and Technology, Huainan, Anhui 232001, China
2. National Institute of Metrology, Beijing 100029, China
Abstract:In view of the measurement and application of the correction factor for water equivalent materials in medical electron beam dose measurement, the experimental values of depth scaling factor (cpl), fluence scaling factor (hpl) and total correction factor (kpl) are obtained by scanning the percentage depth dose (PDD) curve of medical electron beam in water and water-equivalent materials. The results show that the measurement results of water equivalent materials can be converted into absorbed dose to water by the combination of cpl and hpl or only using kpl. Comparing the PDD curves shows that the maximum deviation of R50 of three water-equivalent materials after cpl-hpl correction are 0.19%, 0.28% and 0.22% compared with that measured in water at the electron energy of 10~20MeV. The maximum deviation of R50 obtained by kpl correction are 0.23%, 0.29% and 0.18%, respectively. Conclusion: the experimental data of cpl-hpl and kpl are provided, which is convenient for users to quickly measure the absorbed dose to water of electron beam, and it is simpler and more efficient to use kpl than cpl-hpl.
姚金涛,李毅华,王坤,王志鹏,金孙均,吴晗. 多种水等效材料的医用电子束修正因子研究[J]. 计量学报, 2024, 45(5): 747-754.
YAO Jintao,LI Yihua,WANG Kun,WANG Zhipeng,JIN Sujun,WU Han. Correction Factors of Medical Electron Beams for Various Water-equivalent Materials. Acta Metrologica Sinica, 2024, 45(5): 747-754.
ANDREO P, BURNS D T, HOHLFELD K, et al. Absorbed Dose Determination in External Beam Radiotherapy: An International Code of Practice for Dosimetry Based on Standards of Absorbed Dose to Water: IAEA TRS-398[S]. 2004.
[8]
BAGHANI R H, ROBATJAZI M. Scaling factors measurement for intraoperative electron beam calibration inside PMMA plastic phantom [J]. Measurement, 2020, 165: 108096.
[12]
AL-SULAITI L, SHIPLEY D, THOMAS R, et al. Water equivalence of some plastic-water phantom materials for clinical proton beam dosimetry [J]. Applied Radiation and Isotopes, 2012, 70(7): 1052-1057.
[14]
BAGHANI H R, ANDEROLI S, ROBATJAZI M. On the measurement of scaling factors in the RW3 plastic phantom during high energy electron beam dosimetry [J]. Physical and engineering sciences in medicine, 2023, 46(1): 185-195.
[16]
MCEWEN R M, NIVEN D. Characterization of the phantom material Virtual WaterTM in high-energy photon and electron beams [J]. Medical Physics, 2006, 33(4): 876-887.
HIRAKU F, KOICHI H, TATSYYA F, et al. Determination of scaling factors for a new plastic phantom at 6-15MeV electron beams [J]. Radiation Physics and Chemistry, 2022, 193: 109994.
[18]
ANEREO P, BRAHME A, NAHUM A, et al. Influence of energy and angular spread on stopping-power ratios for electron beams [J]. Physics in Medicine and Biology, 1989, 34(6): 751-768.
WANG Z P, XING S M, WANG K, et al. Study on the Equivalence of Water Equivalent Materials to Water under High-energy X-ray [J]. Acta Metrologica Sinica, 2020, 41(2): 257-262.
[13]
ADE N, EEDEN V D, PLESSIS D F. Characterization of Nylon-12 as a water-equivalent solid phantom material for dosimetric measurements in therapeutic photon and electron beams [J]. Applied Radiation and Isotopes, 2020, 155: 108919.
[1]
ROEDER F, MORILLO V, SALEH-EBRAHIMI L, et al. Intraoperative radiation therapy (IORT) for soft tissue sarcoma-ESTRO IORT Task Force/ACROP recommendations [J]. Radiotherapy and Oncology, 2020, 150: 293-302.
WANG Z P, WANG K, JIN S J, et al. Measurements of Absorbed Dose to Water in Medical Electron Beams and Discussion of lts Uncertainty [J]. Acta Metrologica Sinica, 2023, 44(12): 1897-1903.
HU J Y, ZOU L, XIE Z,et al. Study on the Influencing Factors and Long-term Stability of the CT Number of Siemens Large Aperture CT Simulator[J]. Acta Metrologica Sinica, 2023, 44(5): 783-789.
WANG J, WU J J, GUO S M, et al. The International Key Comparison in Mammoraphy X-rays Air-kerma[J]. Acta Metrologica Sinica, 2023, 44(5): 790-795.
[7]
JAN S, MARINA O, MICHAEL E, et al. Absorbed dose to water reference dosimetry using solid phantoms in the context of absorbed-dose protocols [J]. Medical physics, 2005, 32(9): 2945-2953.
[9]
DANIEL J O, GABRIEL O S. Monte Carlo study of the chamber-phantom air gap effect in a magnetic field [J]. Medical physics, 2017, 44(7): 3830-3838.
[11]
HILL R, KUNCIC Z, BALDOCK C. The water equivalence of solid phantoms for low energy photon beams [J]. Medical physics, 2010, 37(8): 4355-4363.
[15]
TELLO V M, TAILOR R C, HANSON W F. How water equivalent are water-equivalent solid materials for output calibration of photon and electron beams [J]. Medical Physics, 1995, 22(7): 1177-1189.
[17]
SCHOENFELD A A, HARDER D, POPPE B, et al. Water equivalent phantom materials for 192Ir brachytherapy [J]. Physics in Medicine and Biology, 2015, 60(24): 9403-9420.
[19]
DINA G X, ROGERS D W O, MACKIE T R. Calculation of stopping-power ratios using realistic clinical electron beams [J]. Medical Physics, 1995, 22(5): 489-501.