Evaluation of the effect of gadolinium on dose enhancement factor of x-ray and gamma ray from linear electron accelerator

Authors

Abstract

The aim of radiation therapy is to maximize the dose applied to the tumor while minimizing the dose in adjacent healthy tissues. A new approach to meet this requirement is using high atomic number materials to label the tumor site. In this study, gadolinium was used for this purpose. In the practical part of the research, the 6 MV gamma source of linear electron accelerator located in Milad Hospital of Isfahan and a cubic phantom containing water were used. The detector area, which houses gafchromic films, is a rectangular cube, which is the hypothetical location of the tumor and healthy tissues on either side of it and is located inside the phantom. Different concentrations of gadolinium were injected into the tumor area and the dose enhancement factor (DEF) was investigated in different areas of the detector. The phantom and detector were simulated using the Geant4 software package. The dose enhancement factors were calculated in different regions of the detector and for different concentrations of gadolinium irradiated with low energy X-rays, 2 MeV gamma rays (mean energy of linear electron accelerator) and the photon energy spectra of 6 MV linear. Study shows that the dose enhancement factor increases with increasing gadolinium concentration. The optimum energy for DEF at all concentrations of gadolinium is about 70 keV, and its effect decreases as the energy of the photon increases. In the energy spectrum of 6 MV we see fluctuations in the amount of DEF for different concentrations of gadolinium due to the presence of low and high energy spectra of photons.

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[1] G. Delaney, S. Jacob, C. Featherstone and M. Barton. The role of radiotherapy in cancer treatment: estimating optimal utilization from a review of evidence-based clinical guidelines. Cancer, 104(6) (2005) 1129-1137. [2] M. Babaei and M. Ganjalikhani. The potential effectiveness of anoparticles as radio sensitizers for radiotherapy, Biolmpacts, 4(1) (2014) 15-20. [3] D. Kwatra, A. Venugopal and Sh. Anant. Nanoparticles in radiation therapy: a summary of various approaches to enhance radiosensitization in cancer, Translation Cancer Reaserch, 2(4) (2013) 330-342. [4] W.N. Rahman, N. Bishara, T. Ackerly, C.F. He and P. Jackson. Enhancement of radiation effects by gold nanoparticles for superficial radiation therapy, Nanomedicine, 5(2) (2009) 136-142. [5] L. Sancey, F. Lux, S. Kotb and S. Roux. The Use of Theranostic Gadolinium-Based Nanoprobes to Improve Radiotherapy Efficacy, Br J Radiol, 87(1041) (2014) 20140134. [6] J.C. G. Jeynes, M.J. Merchant, A. Spindler, A-C. Wera and K.J. Kirkby. Investigation of gold nanoparticles radiosensitization mechanisms using a free radical scavenger and protons of different energies, Physics in Medicine & Biology, 59(21) (2014) 6431-6443. [7] L. Stefancikova, E. Porcel, P. Eustache, Sh. Li, D. Salado and S. Marco. Cell localisation of gadolinium-based nanoparticles and related radiosensitising efficacy in glioblastoma cells, Cancer Nanotechnol; 5(1) (2014):6. [8] Y. Prezado, G. Fois, G.L. Duc and A. Bravin. Gadolinium dose enhancement studies in microbeam radiation therapy, Med phys. 36(8) (2009) 3568-3574. [9] F. Taupin, M. Flander, R. Delorme, T. Btochard, J.F. Mayol, P. Perriat, L. Sancey, F. Lux, R.F. Barth, M. Carriere, L. Ravanat and H. Elleaume. Gadolinium nanoparticles and Nanotechnol contrast agent as radiation sensitizers, Phys. Med. Biol. 60(11) (2015) 4449-4464. [10] A. Detappe, S. Kunjachan, P. Drane, S. Kotb, M. Myronakis, D. E. Biancur, T. Ireland, M. Wagar, F. Lux, O. Tillement and R. Berbeco. Key clinical beam parameters for nano-particle-contrast agent as radiation sensitizers, Scientific reports, 6(1)(2016). [11] D.G. Zhang, V. Feygelman, E.G. Moros, K. Latifi and G.G. Zhang. Monte Carlo Study of Radiation Dose Enhancement by Gadolinium in Megavoltage and High Dose Rate Radiotherapy, Plos one, 9(10) (2014). [12] l. Martinez-Rovira and Y. Prezadoa. Monte Carlo dose enhancement studies in microbeam radiation therapy, Med Phys, 38(7) (2011) 4430-4439. [13] R. Delorme, F. Taupin, M. Flaender, J. Ravanant, Ch. Champion, M. Agelou and H. Elleaume. Comparison of Gadolinium Nanoparticles and Molecular Contrast Agents for Radiation Therapy Enhancement, Med. Phys, 44(11) (2017) 5949-5960. [14] J.L. Robar, S. Ricca and M.A. Martin. Tumor dose enhancement using modified megavoltage photon beams and contrast media. Phys Med Biol, 47(14) (2014) 2433–2449. [15] M. Santibanez, M. Fuentealbe, F.A. Torres-Ruiz and A. Vargas. Experimental determination of the gadolinium dose enhancement in phantom irradiated with low energy X-ray sources by a spectrophotometer-Gafchromic-EBT3 dosimetry system, Applied Radiation and Isotopes, 154(2019) 108857. [16] M. Luchette, H. Korideck, M. Makrigiorgos, O. Tillement and R. Berbeco. Radiation dose enhancement of gadolinium-based AGuIX nanoparticles on HeLa cells, Nanomedicine, 10(8) (2014) 1751-5. [17] N.R. Paudel, Nanoparticle-aided radiation therapy: micro-dosimetry and evaluation of the mediators producing biological damage, Univercity of Toledo, August 2014. [20] H. Ranjbar, M. Shamsaei and M.R. Ghasemi. Investigation of dose enhancement factor of high intensity low mono-energetic X-ray radiation with labeled tissues by gold nanoparticles, Nukleonica, 55(3) (2010) 307-312.