title: A comprehensive system for dosimetric commissioning and Monte Carlo validation for the small animal radiation research platform.
abstract: Our group has constructed the small animal radiation research platform (SARRP) for delivering focal, kilo-voltage radiation to targets in small animals under robotic control using cone-beam CT guidance. The present work was undertaken to support the SARRP's treatment planning capabilities. We have devised a comprehensive system for characterizing the radiation dosimetry in water for the SARRP and have developed a Monte Carlo dose engine with the intent of reproducing these measured results. We find that the SARRP provides sufficient therapeutic dose rates ranging from 102 to 228 cGy min(-1) at 1 cm depth for the available set of high-precision beams ranging from 0.5 to 5 mm in size. In terms of depth-dose, the mean of the absolute percentage differences between the Monte Carlo calculations and measurement is 3.4% over the full range of sampled depths spanning 0.5-7.2 cm for the 3 and 5 mm beams. The measured and computed profiles for these beams agree well overall; of note, good agreement is observed in the profile tails. Especially for the smallest 0.5 and 1 mm beams, including a more realistic description of the effective x-ray source into the Monte Carlo model may be important.
authors.affiliation: Deptartment of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: E
authors.initials: E
authors.lastname: Tryggestad
authors.forename: M
authors.initials: M
authors.lastname: Armour
authors.forename: I
authors.initials: I
authors.lastname: Iordachita
authors.forename: F
authors.initials: F
authors.lastname: Verhaegen
authors.forename: J W
authors.initials: JW
authors.lastname: Wong
mesh_terms: D000818:Animals; D019985:Benchmarking; D002138:Calibration; D054893:Cone-Beam Computed Tomography; D009010:Monte Carlo Method; D019047:Phantoms, Imaging; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods; D011880:Radiotherapy Planning, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D014867:Water
chemical_list: D014867:Water
references.citation: Phys Med Biol. 2009 Feb 21;54(4):891-905
references.pmid: 19141881
references.citation: Int J Radiat Oncol Biol Phys. 2008 Aug 1;71(5):1591-9
references.pmid: 18640502
references.citation: Med Phys. 1983 Nov-Dec;10(6):741-71
references.pmid: 6419029
references.citation: Med Phys. 2005 Jul;32(7Part1):2245-2253
references.pmid: 28493574
references.citation: Phys Med Biol. 2003 Nov 7;48(21):R107-64
references.pmid: 14653555
references.citation: Med Phys. 2007 Nov;34(11):4359-67
references.pmid: 18072501
references.citation: Med Phys. 2007 Dec;34(12):4706-16
references.pmid: 18196798
references.citation: Phys Med Biol. 1999 Jul;44(7):1767-89
references.pmid: 10442712
references.citation: Med Phys. 1995 May;22(5):503-24
references.pmid: 7643786