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Photon and photon–neutron experimental dosimetry in Grid therapy with 18 MV photon beams

Published online by Cambridge University Press:  15 September 2020

Sareh Tajiki ,
Somayeh Gholami Open the ORCID record for Somayeh Gholami [Opens in a new window] ,
Mahbod Esfahani ,
Ali Rastjoo ,
Amir Hakimi ,
Amir K. Beheshti  and
Ali Meigooni
Sareh Tajiki
Affiliation:
Radiation Oncology Department, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran
Somayeh Gholami*
Affiliation:
Radiation Oncology Department, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran
Mahbod Esfahani
Affiliation:
Radiation Oncology Department, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran
Ali Rastjoo
Affiliation:
Radiation Oncology Department, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran
Amir Hakimi
Affiliation:
Health Physics and Dosimetry Research Laboratory, Department of Energy Engineering and Physics, Amirkabir University of Technology, Tehran, Iran
Amir K. Beheshti
Affiliation:
Department of Nuclear Engineering, University of Isfahan, Isfahan, Iran
Ali Meigooni
Affiliation:
Comprehensive Cancer Centers of Nevada, Las Vegas, NV, USA
*
Author for correspondence: Somayeh Gholami, Tehran University of Medical Sciences, Keshavarz St., Tehran, Tehran, Iran. E-mail: s-gholami@sina.tums.ac.ir
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Abstract

Propose:

Spatially fractionated Grid radiation therapy (SFGRT) in an effective technique for bulky and radio-sensitive tumours. SFGRT using a constructed block has been used to evaluate the photon and photo-neutron (PN) dose measurement in 18-MV photon beam energy.

Methods and materials:

A mounted Grid block on to a Varian Clinac 2100c linear accelerator was used to perform photon dosimetry. The percentage depth dose, in-plane and cross-plane beam profile and output factor was measured by ionization chamber in water. The PN contamination was measured after photon dosimetry using the combination of thermoluminescence dosimetry types 600 and 700, and Polycarbonate Film dosimeters on the surface and in the maximum depth dose (dmax) of solid water™ slabs.

Results:

The valley-to-peak ration for 6 and 18 MV photon beams obtained from the beam profiles was ~35 and 72%, respectively. Fast and thermal PN equivalent dose decreased in the Grid field compared to an open field (without Grid).

Conclusion:

The Grid therapy dosimetry compared to the conventional radiotherapy (without the grid) the production of fast and thermal neutrons were reduced. Using of a Grid block in high-energy photon beams for a long period of the treatment continuously might be a new source of contamination due to the interaction of photon beam resulting the activation of the Grid block

Keywords

grid therapyneutron contaminationPolycarbonate FilmSpatially fractionated radiation therapyTLD
Type
Original Article
Information
Journal of Radiotherapy in Practice , Volume 20 , Issue 4 , December 2021 , pp. 466 - 472
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Copyright
© The Author(s), 2020. Published by Cambridge University Press

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References

Nedaie, H A, Darestani, H, Banaee, N et al. Neutron dose measurements of Varian and Elekta linacs by TLD600 and TLD700 dosimeters and comparison with MCNP calculations. J Med Phys 2014; 39: 10.CrossRefGoogle ScholarPubMed
Zwicker, R D, Meigooni, A, Mohiuddin, M. Therapeutic advantage of grid irradiation for large single fractions. Int J Radiat Oncol Biol Phys 2004; 58: 1309–1315.CrossRefGoogle ScholarPubMed
Ayyangar, K, Lakshmanan, A, Chandra, B et al. A comparison of thermal neutron and gamma ray sensitivities of common TLD materials. Phys Med Biol 1974; 19: 665.CrossRefGoogle ScholarPubMed
Sohrabi, M, Hakimi, A. Novel 6 MV X-ray photoneutron detection and dosimetry of medical accelerators. Phys Med 2017; 36: 103–109.CrossRefGoogle Scholar
Chegeni, N and Karimi, A H. Photoneutron dose estimation in GRID therapy using an anthropomorphic phantom: a Monte Carlo study. J Med Signals Sens 2018; 8: 175–183.CrossRefGoogle Scholar
Wang, X, Charlton, M A, Esquivel, C et al. Measurement of neutron dose equivalent outside and inside of the treatment vault of GRID therapy. Med Phys 2013; 40: 8.CrossRefGoogle ScholarPubMed
Sohrabi, M, Hakimi, A, Mahdavi, S R. A novel position-sensitive mega-size dosimeter for photoneutrons in high-energy X-ray medical accelerators. Phys Med 2016; 32: 778–786.CrossRefGoogle ScholarPubMed
Meigooni, A S, Dou, K, Meigooni, N J et al. Dosimetric characteristics of a newly designed grid block for megavoltage photon radiation and its therapeutic advantage using a linear quadratic model. Med Phys 2006; 33: 3165–3173.CrossRefGoogle ScholarPubMed
Klett, A, Leuschner, A. Pulsed Neutron Dose Monitoring-A New Approach. 2006 IEEE Nuclear Science Symposium Conference Record. IEEE, 2006: 806–808.Google Scholar
Mitev, G, Suntharalingam, N. Semiempirical calculation of dose distributions for high-energy photon-beam grid therapy. Medical Physics. Amer inst physics circulation fulfillment div, 500 sunnyside blvd, woodbury … 1986: 592–592.Google Scholar
Neuner, G, Mohiuddin, M M, Vander Walde, N et al. High-dose spatially fractionated Grid radiation therapy (SFGRT): a comparison of treatment outcomes with Cerrobend vs. MLC SFGRT. Int J Radiat Oncol Biol Phys 2012; 82: 1642–1649.CrossRefGoogle ScholarPubMed
Sohrabi, M, Hakimi, A. Novel ‘photoneutron volume dose equivalent’ hypothesis and methodology for second primary cancer risk estimation in high-energy X-Ray medical accelerators. Radiat Protect Dosimet 2020; 188: 432–443.CrossRefGoogle Scholar
Gholami, S, Nedaie, H, Meigooni, A et al. Grid therapy: impact of radiobiological models on calculation of therapeutic ratio. World Congress on Medical Physics and Biomedical Engineering, June 7-12, 2015, Toronto, Canada: Springer, 2015: 487–489.Google Scholar
Marks, H. Clinical experience with irradiation through a GRID. Radiology 1952; 58: 338–342.CrossRefGoogle ScholarPubMed
Reiff, J E, Huq, M S, Mohiuddin, M et al. Dosimetric properties of megavoltage grid therapy. Int J Radiat Oncol Biol Phys 1995; 33: 937–942.CrossRefGoogle ScholarPubMed
Sohrabi, M, Morgan, K. Neutron dosimetry in high energy X-ray beams of medical accelerators. Phys Med Biol 1979; 24: 756.CrossRefGoogle ScholarPubMed
Zhang, H, Johnson, E L, Zwicker, R D. Dosimetric validation of the MCNPX Monte Carlo simulation for radiobiologic studies of megavoltage grid radiotherapy. Int J Radiat Oncol Biol Phys 2006; 66: 1576–1583.CrossRefGoogle ScholarPubMed
Zhang, H, Wang, J Z, Mayr, N et al. Fractionated grid therapy in treating cervical cancers: Conventional fractionation or hypofractionation? Int J Radiat Oncol Biol Phys 2008; 70: 280–288.CrossRefGoogle ScholarPubMed
Sohrabi, M, Morgan, K. A new polycarbonate fast neutron personnel dosimeter. Am Ind Hyg Assoc J 1978; 39: 438–447.CrossRefGoogle ScholarPubMed
Triolo, A, Marrale, M, Brai, M. Neutron–gamma mixed field measurements by means of MCP–TLD600 dosimeter pair. Nucl Instrum Methods Phys Res Sect B 2007; 264: 183–188.CrossRefGoogle Scholar
Sohrabi, M, Katouzi, M. Design characteristics of a three-component AEOI Neutriran albedo neutron personnel dosimeter. Int J Radiat Appl Instrum D 1991; 19: 537–540.Google Scholar
Sohrabi, M. The amplification of recoil particle tracks in polymers and its application in fast neutron personnel dosimetry. Health Phys 1974; 27: 598.Google ScholarPubMed
Sohrabi, M, Hakimi, A. Novel air-to-tissue conversion factors for fast, epithermal and thermal photoneutrons in a Siemens ONCOR dual energy 18 MV X-ray medical linear accelerator. Radiat Meas 2019; 126: 106138.CrossRefGoogle Scholar
Mukherjee, B. Glow curve analysis of TLD-700 dosimeters exposed to fast neutrons and gamma rays from isotopic sources. Nucl Instrum Meth A 1997; 385: 179–182.CrossRefGoogle Scholar
Gholami, S, Nedaie, H A, Longo, F et al. Grid block design based on monte carlo simulated dosimetry, the linear quadratic and Hug–Kellerer radiobiological models. J Med Phys 2017; 42: 213.Google ScholarPubMed
Gholami, S, Nedaie, H A, Longo, F et al. Is grid therapy useful for all tumors and every grid block design? J Appl Clin Med Phys 2016; 17: 206–219.CrossRefGoogle ScholarPubMed
Hakimi, A, Sohrabi, M, Rabie Mahdavi, S. Effects of field size and depth on photoneutron dose equivalent distributions in an 18 MV X-ray medical accelerator. Radiat Prot Dosim 2017; 176: 354–364.CrossRefGoogle Scholar