Innovative utilization of compact disc for measuring fast neutron generated from a 10 MV medical linear accelerator

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Porama Thepsiri
Phiphat Phruksarojanakun
Natch Rattanarungruangchai
Thiti Rungseesumran
Tanapol Dachviriyakij
Chayanit Jumpee


Background: High-energy photons produced from a medical linear accelerator (LINAC) have long been used as one of the most effective ways for treating cancers. During the treatment process, some photo neutrons are unavoidably created by [γ,n] reactions, imposing additional and undesirable dose on a patient. This amount of unplanned dose from photo neutrons can potentially harm the patient as well as medical personnel during the treatment. This study is aimed to develop a methodology for measuring fast neutron dose generated from 10 MV LINAC by employing polycarbonate from base material of compact disk (CDs) and a fast neutron converter.

Materials and methods: The polycarbonate base layer of CDs has been applied to fast neutron dosimetry with nuclear track method by combining with polymethyl methacrylate (PMMA) converter for fast neutrons. A number of CDs badges were irradiated with high energy photon from 10 MV Elekta Synergy LINAC in the solid water phantom at depth of 0, 2.5, 5, 10, 15 and 20 cm then etched with potassium hydroxide ethanol water (PEW) solution that containing with potassium hydroxide, ethanol and water with ratio of 15:45:40. The optimal condition for the chemical etching were found at 60±2 °C, for 14 hr.

Results: Comparison of neutron equivalent doses from measurement of CD track detector and CR-39 track detector has shown that the maximum fast neutron dose equivalent was at depth of 5 cm of phantom. This agreement has confirmed that the CD track detector can be employed to measure fast neutron doses produced from LINAC in an accurate and affordable fashion.

Conclusion: It is confirmed that the CD track detector can be employed to measure fast neutron doses produced from LINAC in an accurate and affordable fashion.


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Thepsiri, P., Phruksarojanakun, P., Rattanarungruangchai, N., Rungseesumran, T., Dachviriyakij, T., & Jumpee, C. (2021). Innovative utilization of compact disc for measuring fast neutron generated from a 10 MV medical linear accelerator. Journal of Associated Medical Sciences, 55(1), 1-6. Retrieved from
Radiologic Technology


[1] Takam R, Bezak E, Marcu L, Yeoh E. Out-of-Field Neutron and Leakage Photon Exposures and the Associated Risk of Second Cancers in High-Energy Photon Radiotherapy: Current Status. Radiation research. 2011; 176: 508-20.

[2] Zacharatou Jarlskog C, Paganetti H. Risk of Developing Second Cancer From Neutron Dose in Proton Therapy as Function of Field Characteristics, Organ, and Patient Age. International Journal of Radiation Oncology, Biology, Physics. 2008; 72(1): 228-35.

[3] Expósito MR, Sánchez-Nieto B Fau - Terrón JA, Terrón Ja Fau - Domingo C, Domingo C Fau - Gómez F, Gómez F Fau - Sánchez-Doblado F, Sánchez-Doblado F. Neutron contamination in radiotherapy: estimation of second cancers based on measurements in 1377 patients. (1879-0887 (Electronic)).

[4] Park C-S, Cho J-H, Lee H-K, Lee S-Y, Jang H-C, Dong K-R, et al. A study on measurement of neutrons generated in radiation therapy – Measurement of neurons in CR-39 detection method. Annals of Nuclear Energy. 2013; 51: 196-202.

[5] Farhood B, Ghorbani M, Abdi Goushbolagh N, Najafi M, Geraily G. Different Methods of Measuring Neutron Dose/Fluence Generated During Radiation Therapy with Megavoltage Beams. (1538-5159 (Electronic)).

[6] Nedaie HA, Darestani H, Banaee N, Shagholi N, Mohammadi K, Shahvar A, 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(1): 10-7.

[7] Hendrick JS. NEW METHOD FOR NEUTRON RESPONSE CALCULATIONS WITH MCNP. Joint International Conference on Mathematical Method & Superconducting for Nuclear Application, Saratoga Springs, NY; 1997. Report No.: LA-UR-97-898.

[8] Madland REPaDG. LAHET Code System Modifications for LAHET 2.8. 1995. Report No.: LA-UR-95-3605.

[9] Durrani SA, Bull RK. CHAPTER 1 - Introduction to Nuclear Track Detectors. In: Durrani SA, Bull RK, editors. Solid State Nuclear Track Detection: Pergamon; 1987. p. 1-12.

[10] Hashemi S, Majdabadi A, Ghafoori M, Raisali MG, Taheri M. The effect of external wedge on the photoneutron dose equivalent at a high energy medic linac. Nukleonika. 2011; 56(1): 49-51.

[11] Hashemi SM, Hashemi-Malayeri B, Raisali G, Shokrani P, Sharafi AA, Torkzadeh F. Measurement of photoneutron dose produced by wedge filters of a high energy linac using polycarbonate films. J Radiat Res. 2008; 49(3): 279-83.

[12] Cesar MF, Franco MAR. Some studies on the registration of particles on Makrofol E. International Journal of Radiation Applications and Instrumentation Part D Nuclear Tracks and Radiation Measurements. 1986; 12(1): 193-6.

[13] Su C-S. Comparison of chemical etching with the alkali-alcohol mixture and the ultrasonic etchings of fission fragment and alpha particle tracks in lexan polycarbonates. Radiation Effects and Defects in Solids. 1990; 114(1-2): 157-66.

[14] Souto EB, Campos LL. Fast neutron dose response of a commercial polycarbonate. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 2007; 580(1): 335-7.

[15] Castillo F, Espinosa G, Golzarri JI, Osorio D, Rangel J, Reyes PG, et al. Fast neutron dosimetry using CR-39 track detectors with polyethylene as radiator. Radiation Measurements. 2013; 50: 71-3.

[16] Fujibuchi T, Kodaira S, Sawaguchi F, Abe Y, Obara S, Yamaguchi M, et al. Measurement of the secondary neutron dose distribution from the LET spectrum of recoils using the CR-39 plastic nuclear track detector in 10MV X-ray medical radiation fields. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 2015; 349: 239-45.

[17] Shahmohammadi Beni M, Hau TC, Krstic D, Nikezic D, Yu KN. Monte Carlo studies on neutron interactions in radiobiological experiments. PloS one. 2017; 12(7): e0181281-e.

[18] Shagholi N, Nedaie H, Sadeghi M, Shahvar A, Darestani H, Nooshin B, et al. Neutron dose evaluation of Elekta Linac at two energies (10 & 18 MV) by MCNP code and comparison with experimental measurements. JOURNAL OF ADVANCES IN PHYSICS. 2014; 6: 1006-15.