Output factor determination based on Monte Carlo simulation for small cone field in 10-MV photon beam

被引：4

作者：

Fukata K. ^{[1
]}

Sugimoto S. ^{[2
]}

Kurokawa C. ^{[2
]}

Saito A. ^{[3
]}

Inoue T. ^{[4
]}

Sasai K. ^{[2
]}

机构：

[1] Cancer Center, Keio University School of Medicine, 35 Shinano-machi, Shinjuku, Tokyo

[2] Graduate School of Medicine, Juntendo University, 2-1-1, Hongo, Bunkyo-ku, Tokyo

[3] Department of Radiation Oncology, Hiroshima University Hospital, 1-2-3, Kasumi, Minami-ku, Hiroshima, 734-8551, Hiroshima

[4] Department of Radiology, Juntendo University Urayasu Hospital, Tomioka 2-1-1, Urayasu-shi, Chiba

来源：

Radiological Physics and Technology | 2018年 / 11卷 / 2期

关键词：

Dosimetry; Monte Carlo; Small field; SRS;

D O I：

10.1007/s12194-018-0455-4

中图分类号：

学科分类号：

摘要：

The difficulty of measuring output factor (OPF) in a small field has been frequently discussed in recent publications. This study is aimed to determine the OPF in a small field using 10-MV photon beam and stereotactic conical collimator (cone). The OPF was measured by two diode detectors (SFD, EDGE detector) and one micro-ion chamber (PinPoint 3D chamber) in a water phantom. A Monte Carlo simulation using simplified detector model was performed to obtain the correction factor for the detector measurements. About 12% OPF difference was observed in the measurement at the smallest field (7.5 mm diameter) for EDGE detector and PinPoint 3D chamber. By applying the Monte Carlo-based correction factor to the measurement, the maximum discrepancy among the three detectors was reduced to within 3%. The results indicate that determination of OPF in a small field should be carefully performed. Especially, detector choice and appropriate correction factor application are very important in this regard. © 2018, Japanese Society of Radiological Technology and Japan Society of Medical Physics.

引用

页码：192 / 201

页数：9

共 39 条

[11]

Underwood T.S.A., Winter H.C., Hill M.A., Fenwick J.D., Mass-density compensation can improve the performance of a range of different detectors under non-equilibrium conditions, Phys Med Biol, 58, pp. 8295-8310, (2013)

[12]

Czarnecki D., Zink K., Monte Carlo calculated correction factors for diodes and ion chambers in small photon fields, Phys Med Biol, 58, pp. 2431-2444, (2013)

[13]

Fenwick J.D., Kumar S., Scott A.J.D., Nahum A.E., Using cavity theory to describe the dependence on detector density of dosimeter response in non-equilibrium small fields, Phys Med Biol, 58, pp. 2901-2923, (2013)

[14]

Francescon P., Kilby W., Satariano N., Monte Carlo simulated correction factors for output factor measurement with the CyberKnife system—results for new detectors and correction factor dependence on measurement distance and detector orientation, Phys Med Biol, 59, pp. N11-N17, (2014)

[15]

Benmakhlouf H., Sempau J., Andreo P., Output correction factors for nine small field detectors in 6 MV radiation therapy photon beams: a PENELOPE Monte Carlo study, Med Phys, 41, (2014)

[16]

Kamio Y., Bouchard H., Correction-less dosimetry of nonstandard photon fields: a new criterion to determine the usability of radiation detectors, Phys Med Biol, 59, pp. 4973-5002, (2014)

[17]

Dieterich S., Sherouse G.W., Experimental comparison of seven commercial dosimetry diodes for measurement of stereotactic radiosurgery cone factors, Med Phys, 38, (2011)

[18]

Araki F., Moribe N., Shimonobou T., Yamashita Y., Dosimetric properties of radiophotoluminescent glass rod detector in high-energy photon beams from a linear accelerator and Cyber-Knife, Med Phys, 31, pp. 1980-1986, (2004)

[19]

Sham E., Seuntjens J.P., Devic S., Podgorsak E.B., Influence of focal spot on characteristics of very small diameter radiosurgical beams, Med Phys, 35, pp. 3317-3330, (2008)

[20]

Cranmer-Sargison G., Weston S., Evans J.A., Sidhu N.P., Thwaites D.I., Implementing a newly proposed Monte Carlo based small field dosimetry formalism for a comprehensive set of diode detectors, Med Phys, 38, (2011)

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