Dose-rate scaling factor estimation of THOR BNCT test beam

• Published in: Applied radiation and isotopes 2004-11, Vol.61 (5), p.881-885
• Main Authors: Hsu, F.Y., Tung, C.J., Chen, J.C., Wang, Y.L., Huang, H.C., Zamenhof, R.G.
• Format: Article
• Language: English
• Subjects: BNCT; Boron Neutron Capture Therapy - instrumentation; Boron Neutron Capture Therapy - statistics & numerical data; Brain Neoplasms - radiotherapy; DRSF; Humans; Monte Carlo Method; NCTPlan; Phantoms, Imaging; Radiometry - instrumentation; Radiotherapy Planning, Computer-Assisted - statistics & numerical data; Taiwan
• ISSN: 0969-8043; 1872-9800
• DOI: 10.1016/j.apradiso.2004.05.048

In 1998, an epithermal neutron test beam was designed and constructed at the Tsing Hua Open-Pool Reactor (THOR) for the purpose of preliminary dosimetric experiments in boron neutron capture therapy (BNCT). A new epithermal neutron beam was designed at this facility, and is currently under construction, with clinical trials targeted in late 2004. Depth dose-rate distributions for the THOR BNCT test beam have been measured by means of activation foil and dual ion chamber techniques. Neutron and structure-induced gamma spectra measured at the test beam exit were configured into a source function for the Monte Carlo-based treatment planning code NCTPlan. Dose-rate scaling factors (DRSFs) were determined to normalize computationally derived dose-rate distributions with experimental measurements in corresponding mathematical and physical phantoms, and to thus enable accurate treatment planning using the NCTPlan code. A similar approach will be implemented in characterizing the new THOR epithermal beam in preparation for clinical studies. This paper reports the in-phantom calculated and experimental dosimetry comparisons and derived DRSFs obtained with the THOR test beam.