The accelerator-based boron neutron capture reaction evaluation system for head and neck cancer.

The purpose of this study is to assess accelerator-based boron neutron capture reaction (BNCR) in human tumor cell lines by colony formation assay and modified high density survival assay (HDS assay). The results of post irradiation survival rate in human oral squamous cell carcinoma and osteosarcoma using both assays were similar. Therefore, HDS assay would be efficient to evaluate BNCR in not only tumor cells but also in normal cells as BNCT screening.

Determination of the thermal and epithermal neutron sensitivities of an LBO chamber.

An LBO (LiBO) walled ionization chamber was designed to monitor the epithermal neutron fluence in boron neutron capture therapy clinical irradiation. The thermal and epithermal neutron sensitivities of the device were evaluated using accelerator neutrons from the Be(d, n) reaction at a deuteron energy of 4 MeV (4 MeV d-Be neutrons). The response of the chamber in terms of the electric charge induced in the LBO chamber was compared with the thermal and epithermal neutron fluences measured using the gold-foil activation method.

L Band EPR Tooth Dosimetry for Heavy Ion Irradiation.

Electron Paramagnetic Resonance (EPR) tooth dosimetry is being developed as a device to rapidly assess large populations that were potentially exposed to radiation during a major radiation accident or terrorist event. While most exposures are likely to be due to fallout and therefore involve low linear energy transfer (LET) radiation, there is also a potential for exposures to high LET radiation, for which the effect on teeth has been less well characterized by EPR. Therefore, the aim of this paper is to acquire fundamental response curves for high LET radiation in tooth dosimetry using L band EPR.

Development of target system for intense neutron source of p-Li reaction.

A target cooling system was developed for an intense neutron source of p-Li reaction. The system consists of target cooling devices and protection devices for lithium evaporation. A pin-structure cooling device was developed to enhance cooling power.

[Experimental study on treatment planning verification using a positron emitting (10)C beam for heavy-ion radiotherapy.].

An advantage of heavy-ion therapy is its good dose concentration. A limit for full use of this desirable feature comes from range ambiguities in treatment planning. The treatment planning is based on X-ray CT measurements, and the range ambiguities are mainly due to an error in calibration of the CT number.

[The examination of optimal positron emitting nuclide in the estimation of attainment depth within the body of RI beams by positron camera].

The (10)C and (11)C beam stop position in a homogeneous phantom was measured using the range verification system in HIMAC. This system was developed to clear uncertainty of beam range within the patient body in heavy ion radiotherapy. In this system, a target is irradiated with RI beams ((11)C or (10)C) and the distribution of the beam end-points are measured by a positron camera.

Range verification system using positron emitting beams for heavy-ion radiotherapy.

It is desirable to reduce range ambiguities in treatment planning for making full use of the major advantage of heavy-ion radiotherapy, that is, good dose localization. A range verification system using positron emitting beams has been developed to verify the ranges in patients directly. The performance of the system was evaluated in beam experiments to confirm the designed properties.