Application of invasion mathematical model in dosimetry for boron neutron capture therapy for malignant glioma

Yamamoto, Kazuyoshi; Kumada, Hiroaki; Nakai, Kei*; Endo, Kiyoshi*; Yamamoto, Tetsuya*; Matsumura, Akira*

Proceedings of 11th World Congress on Neutron Capture Therapy (ISNCT-11) (CD-ROM), 14 Pages, 2004/10

A dose distribution considered the tumor cell density distribution is required on the radiation therapy. We propose a novel method of determining target region considering the tumor cell concentration as a new function for the next generation Boron Neutron Capture Therapy (BNCT) dosimetry system. It has not been able to sufficiently define the degree of microscopic diffuse invasion of the tumor cells peripheral to a tumor bulk in malignant glioma using current medical imaging. Referring to treatment protocol of BNCT, the target region surrounding the tumor bulk has been set as the region which expands at the optional distance with usual 2cm margin from the region enhanced on T1 weighted gadolinium Magnetic Resonance Imaging (MRI). In this research, the cell concentration of the region boundary of the target was discussed by using tumor cell diffusion model in the sphere spatio-temporal system. The survival tumor cell density distribution after the BNCT irradiation was predicted by the two regions diffusion model for a virtual brain phantom.

User's manual of a supporting system for treatment planning in boron neutron capture therapy; JAERI computational dosimetry system

Kumada, Hiroaki; Torii, Yoshiya

JAERI-Data/Code 2002-018, 158 Pages, 2002/09

JAERI-Data-Code-2002-018.pdf:30.28MB

A boron neutron capture therapy (BNCT) with epithermal neutron beam is expected to treat effectively for malignant tumor that is located deeply in the brain. It is indispensable to estimate preliminarily the irradiation dose in the brain of a patient in order to perform the epithermal neutron beam BNCT. Thus, the JAERI Computational Dosimetry System (JCDS), which can calculate the dose distributions in the brain, has been developed. JCDS is a software that creates a 3-dimentional head model of a patient by using CT and MRI images and that generates a input data file automaticly for calculation neutron flux and gamma-ray dose distribution in the brain by the Monte Carlo code: MCNP, and that displays the dose distribution on the head model for dosimetry by using the MCNP calculation results. JCDS has any advantages as follows; By treating CT data and MRI data which are medical images, a detail three-dimensional model of patinet's head is able to be made easily. The three-dimensional head image is editable to simulate the state of a head after its surgical processes such as skin flap opening and bone removal for the BNCT with craniotomy that are being performed in Japan. JCDS can provide information for the Patient Setting System to set the patient in an actual irradiation position swiftly and accurately. This report describes basic design and procedure of dosimetry, operation manual, data and library structure for JCDS (ver.1.0)

Comparison of dosimetry by the realistic patient head phantom and by the patient's brain, and the JCDS calculation; A Clinical dosimetry study

Endo, Kiyoshi*; Matsumura, Akira*; Yamamoto, Tetsuya*; Nose, Tadao*; Yamamoto, Kazuyoshi; Kumada, Hiroaki; Kishi, Toshiaki; Torii, Yoshiya; Kashimura, Takanori*; Otake, Shinichi*

Research and Development in Neutron Capture Therapy, p.425 - 430, 2002/09

Using the Rapid Prototyping Technique, we produced a realistic phantom as a formative model of a patient head. This realistic phantom will contribute to verification of our planning system. However, cross-correlation among the calculations using the JAERI Computational Dosimetry System (JCDS), the realistic phantom, and the in vivo measurements were not fully completed because of the difficulty involved in modeling a post-surgical brain and a thermal neutron shield. The experimental simulation technique using the realistic phantom is a useful tool for more reliable dose planning for the intraoperative BNCT.

A Combination use of boron and gadolinium compounds in NCT trial

Zhang, T.*; Matsumura, Akira*; Yamamoto, Tetsuya*; Yoshida, Fumiyo*; Sakurai, Yoshinori*; Kumada, Hiroaki; Yamamoto, Kazuyoshi; Nose, Tadao*

Research and Development in Neutron Capture Therapy, p.819 - 824, 2002/09

From present study, the irradiation effect by using combination of Boron and Gd, showed various irradiation effects (additive effect, less than additive effect, non additive effect), which depend on Gd concentration. The additive effect will be occurred when using a combination of Gd and Boron with low concentration, however, adding Gd to high concentration will reduce additive effect resulting in less than additive to finally non-additive effect. This result indicate that achieving suitable concentrations of Gd and Boron together in tumors may increase the therapy effect, but achieving excess concentration of Gd with Boron together in tumor may cause negative therapeuitic effect.