Neutron Capture Therapy Beams at the MIT Research Reactor
Several neutron beams that could be used for neutron capture therapy at MITR-II are dosimetrically characterized and their suitability for the treatment of glioblastoma multiforme and other types of tumors are described. The types of neutron beams studied are: 1) those filtered by various thicknesses of cadmium, D2O, 6Li, and bismuth; and 2) epithermal beams achieved by filtration with aluminum, sulfur, cadmium, 6Li, and bismuth. Measured dose vs. depth data are presented in polyethylene phantom with references to what can be expected in brain. The results indicate that both types of neutron beams are useful for neutron capture therapy. The first type of neutron beams have good therapeutic advantage depths (approximately 5 cm) and excellent in-phantom ratios of therapeutic dose to background dose. Such beams would be useful for treating tumors located at relatively shallow depths in the brain. On the other hand, the second type of neutron beams have superior therapeutic advantage depths (greater than 6 cm) and good in-phantom therapeutic advantage ratios. Such beams, when used along with bilateral irradiation schemes, would be able to treat tumors at any depth in the brain. Numerical examples of what could be achieved with these beams, using RBEs, fractionated-dose delivery, unilateral, and bilateral irradiation are presented in the paper. Finally, additional plans for further neutron beam development at MITR-II are discussed.
KeywordsNeutron Beam Thermal Neutron Flux Cadmium Ratio Background Dose Bilateral Irradiation
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- 1.S. D. Clement, J. R. Choi, R. G. Zamenhof, J. C. Yanch, and O. K. Harling, “Monte Carlo Methods of Neutron Beam Design for Neutron Capture Therapy at the MIT Research Reactor (MI’l’R-II).” (These Proceedings.)Google Scholar
- 2.F. H. Affix, Introduction to Radiological Physics and Radiation Dosimetry John Wiley and Sons, Inc., New York, p. 479 (1986).Google Scholar
- 4.ASTM E262–77, Standard Method for Measuring Thermal Neutron Flux by Radioactivation Techniques.Google Scholar
- 5.W. Zobel, “Experimental Determination of Corrections to the Neutron Activation of Gold Foils Exposed in Water,” ORNL-3407, Topical Report (1963).Google Scholar
- 6.M. Ashtari, Biological and Physical Studies of Boron Neutron Capture Therapy, Ph.D. Thesis, Massachusetts Institute of Technology, pp. 211–235 (1982).Google Scholar
- 7.Auix, op. cit., pp. 477–500.Google Scholar
- 8.Ashtari, op. cit., p. 240.Google Scholar
- 9.S. F. Mughabghab, M. Divadeenam, and N. E. Holden, Neutron Cross Sections: Vol. 1. Neutron Resonance Parameters and Thermal Cross Sections. Part A: Z = 1–60, Academic Press, Orlando, FL (1981).Google Scholar
- 10.R. G. Zamenhof, S. D. Clement, J. C. Yanch, O. K. Harling, J. F. Brenner, H. Madoc-Jones, and J. C. Yanch, “Monte Carlo Based Dosimetry and Treatment Planning for Neutron Capture Therapy of Brain Tumors.” (These Proceedings.)Google Scholar