Neutron Scattering, Linear Accelerator (LINAC), Nuclear Track Methodology
||August 07, 2017
||The Author(s) 2017. This article is published with open access at www.chitkara.edu. in/publications
In several theoretical and experimental studies, the topic of the undesirable generation of photoneutrons in rooms where a linear accelerator (LINAC) operates has been discussed. When energies above 10 MeV are used to produce X-rays and give radiotherapy treatment to patients resulting in additional radiation to patients. Accordingly, an analysis and characterization of the neutron scattering distribution on different zones in a treatment room contributes to evaluate the radiological health risk to patients, technical and other workers involved in treatment. For the evaluation, a device developed at the PAD-IFUNAM formed by a CR-39 detector enclosed by two 3mm thick acrylic plates was employed. To avoid environmental contamination, the CR-39 and the acrylics plates are enclosed in a round plastic box. Sixteen of these devices were settled in different places inside the treatment room, where a linear accelerator is used. The results show a significant concentration of neutron scattering in areas near the head of irradiation. The recommendation will be to evaluate the neutron scattering concentration in all rooms that’s operates a LINAC in order to verify the radiological health risk and to mitigate the neutron scattering when concentration levels are to high like those in our case, in order to avoid unnecessary exposition to patients and personnel in general.
- A. Ma et at. (2008) Monte Carlo study of photoneutron production in the Varian Clinac 2100C linac. Journal of Radioanalytical and Nuclear Chemistry. 276, 119–123.
- A. Szydlowski et al. (2013) Application of nuclear track detectors as sensors for photoneutrons generated by medical accelerators. Radiation Measurements. 50, 74–77.
- D. T. Barile, J. Booz, & K. G. Harrison. (1987). Etched Track Neutron Dosimetry. Ashford: Nuclear Technology Publishing.
- Espinosa, G. (1994). Trazas Nucleares en Sólidos. Distrito Federal: Universidad Nacional Autónoma de México.
- Espinosa G. et al. (2015) Neutron detection of the Triga Mark III reactor, using Nuclear Track Methodology, doi: 10.1063/1.4927182
- F. Castillo et al. (2013) Fast neutron dosimetry using CR-39 track detectors with polyethylene as radiator. Radiation Measurements. 50, 71–73.
- F. Sanchez-Doblado et al. (2012) Estimation of neutron-equivalent dose in organs of patients undergoing radiotherapy by the use of a novel online digital detector, doi: 10.1088/0031-9155/57/19/6167.
- Fieischer, R.L., Price, P.B. & Walker, R.M. Nuclear tracks in solids, principles and applications. Berkeley: University of California Press (1975).
- Fivozinsky, Sherman P. & Padikal, Thomas N. (1982). Medical physics data book. Washington, D.C.: U.S. Dept. of Commerce, National Bureau of Standards.
- Followill, D.S., Nusslin, F., Orton, C.G. (2007) IMRT should not be administered at photon energies greater than 10 MV, doi: 10.1118/1.2734751
- Gammage, R.B. & Espinosa, G. (1997) Digital Imaging System for Track Measurements. Radiation Measurements. 28, 835.
- Glenn F. Knoll. (1999). Radiation Detection Measurements. (pp. 103-128). New York: John Wiley & Sons, Inc.
- Hall, E.J., & Wu, C.S. (2003) Radiation-induced second cancer: the impact of 3D-CRT and IMRT. International Journal of Radiation Oncology*Biology*Physics. 56, 83–88.
- Hall, E.J., Phil, D. (2006) Intensity-modulated radiation therapy, protons, and the risk of second cancers. International Journal of Radiation Oncology*Biology*Physics. 65, 1–7.
- H., Al-Ghamdi, Fazal-ur-Rehman, M.I., Al-Jarallah, & N., Maalej. (2008) Photoneutron intensity variation with field size around radiotherapy linear accelerator 18-MeV X-ray beam. Radiation Measurements. 43, S495–S499.
- H.R. Vega-Carrillo et al. (2008) Neutron room return effect. Revista Mexicana de Física S. 54 (1), 63–66.
- IAEA. (1979). Radiological safety aspects of the operation of electron linear accelerators. Vienna: International Atomic Energy Agency.
- Khan, A., Hameed, & Khan, A. Naemm. (1980) A new plastic track detector for fast neutron dosimetry. Applied Radiation and Isotopes. 31, 775–779.
- Khan, F. M. (2003). The Physics of Radiation Therapy. Philadelphia: Lippincott Williams and Wilkins.
- N.E. Ipe et al. (1992) A Comparison of the Neutron Response of CR-39 Made by Different Manufacturers. Radiation Protection Dosimetry. 44 (1-4), 317–321.
- Podgorsak, E. B. (2003). Review of Radiation Oncology: A Handbook for Teachers and Students. Vienna: International Atomic Energy Agency.
- R. Barquero et al. (2005) Neutron Spectra and Dosimetric Features Around an 18 mv Linac Accelerator, doi: 10.1097/01.HP.0000142500.32040.ac
- R. Bedogni et al. (2013) Calibration of PADC-based neutron area dosemeters in the neutron field produced in the treatment room of a medical LINAC. Radiation Measurements. 50, 78–81.
- W. Gonzales et al. (2014) PADC Detected External Neutron Field by Nuclear Tracks at RFX-mod, doi: 10.15415/jnp.2014.21006