Investigations of different kilovoltage X-ray energy for three-dimensional converging stereotactic radiotherapy system; Monte Carlo simulations with CT data

Deloar, H. M.*; Kunieda, Etsuo*; Kawase, Takatsugu*; Tsunoo, Takanori*; Saito, Hidetoshi*; Ozaki, Masahiro*; Saito, Kimiaki; Takagi, Shunji*; Sato, Osamu*; Fujisaki, Tatsuya*; et al.

Medical Physics, 33(12), p.4635 - 4642, 2006/12

https://doi.org/10.1118/1.2361080

We are investigating three-dimensional converging stereotactic radiotherapy for small lung tumors with better dose homogeneity at the target. A computed tomography radiotherapy was simulated with BEAMnrc X-ray energy of 147.5, 200, 300, and 500 kilovoltage system was validated by comparing calculated and measured percentage of depth dose in a water phantom for the energy of 120 and 147.5 kVp. A thorax phantom and CT data from lung tumors compare dose homogeneities of kVp energies with MV energies of 4, 6, and 10 MV. Three non-coplanar arcs of the target were employed. The Monte Carlo dose data format was converted to the XiO RTP format to compare dose homogeneity, differential, and integral dose volume histograms of kVp and MV energies. In terms of dose homogeneity and DVHs, dose distributions at the target of all kVp energies with the thorax phantom were better than MV energies, with mean dose absorption at the ribs of 100%, 85%, 50%, 30% for 147.5, 200, 300, and 500 kVp, respectively. Considering dose distributions and reduction of the enhanced dose absorption at the ribs, a minimum of 500 kVp is suitable for the lung kVp 3DCSRT system.

Verification of the dose calculation system IMAGINE for providing benchmark X-ray therapy doses through computer networks

Saito, Kimiaki; Kunieda, Etsuo*; Narita, Yuichiro*; Myojoyama, Atsushi*; Saito, Hidetoshi*

no journal, , 

Evaluation of radiation shielding ability of lead glass

Tsuda, Keisuke; Fukushi, Masahiro*; Myojoyama, Atsushi*; Kitamura, Hideaki*; Inoue, Kazumasa*; Nakaya, Giichiro*; Kimura, Junichi*; Sawaguchi, Masato*; Kinase, Sakae; Saito, Kimiaki

no journal, , 

Positron emission tomography (PET) is very effective in the diagnosis and management of patients with various types of cancers. PET scanning with the tracer FDG is widely used in clinical PET. However, the effective dose constant of the positron emitter is about eight times of nuclide Tc used in a nuclear medicine diagnosis widely. Severe radiation protection is necessary for development of the examination with a positron emitter. Radiation protection in the PET institution therefore and safe security are problems. Hence, lead glass has attracted considerable attention as the radiation shielding materials of the PET institution. In the present study, we received a request of the radiation shielding ability evaluation of two kinds of lead glass made in Pilkington plc. The aim of the present work is the radiation shielding ability evaluation for positron emitter such as F(511 keV) of the lead glass. The shielding ability evaluation has been studied in the experimental and the Monte Carlo simulation evaluation. Consequently, effective dose transmission factor with experimental and the Monte Carlo simulation value was calculated. There were enough protection effects to evaluated lead glass. Furthermore, radiation shielding ability evaluation for Cs(662 keV), Co(1.17, 1.33 MeV) was performed, and it was shown that there was a similar protection effect.