Hitachi, Ltd.

Rintaro Fujimoto

Yusuke Vincent Fujii

Hiroshi Akiyama

Yoshihiko Nagamine

Masumi Umezawa

Toru Umekawa

Shusuke Hirayama

Kazuo Hiramoto

Masahiro Tadokoro

Taisuke Takayanagi

Shinichiro Fujitaka

Hideaki Nihongi

Yusuke Fujii

Yusuke Fuji

There is disclosed a radiation treatment planning system for preparing treatment planning information for carrying out radiation treatment. The apparatus includes an input unit with which an operator inputs a prescription dose and an irradiation angle; an arithmetic unit which prepares the treatment planning information by determining irradiation conditions in such a manner as to bring a dose distribution calculated based on the result of the input from the input unit closer to the prescription dose, and a display unit which displays the treatment planning information. The arithmetic unit sets, per point for radiation irradiation, an index representing the degree of demand for irradiation amount suppression, the degree of demand determined by the radiation irradiation point, and the arithmetic unit further determines the irradiation conditions using the index.

Radiation treatment planning system and method of radiation treatment planning

A treatment planning system is provided which, with irradiation parameters varied over time, performs highly accurate dose distribution calculations based on information about tumor movements included in 4D CT images. The system is characterized by the ability to read CT images furnished with timing information and associate the status of the irradiation target corresponding to an elapsed time from the beginning of irradiation with positions being irradiated at corresponding elapsed time points so as to calculate the dose distribution.

Treatment planning system

In a particle therapy treatment planning system for creating treatment plan data, the movement of a target (patient's affected area) is extracted from plural tomography images of the target, and the direction of scanning is determined by projecting the extracted movement on a scanning plane scanned by scanning magnets. Irradiation positions are arranged on straight lines parallel with the scanning direction making it possible to calculate a scanning path for causing scanning to be made mainly along the direction of movement of the target. The treatment planning system can thereby realize dose distribution with improved uniformity.

Treatment planning system, device for calculating a scanning path and particle therapy system

The present invention provides, at low cost, a multilayer radiation detector whose position relative to a beam axis can be verified. The radiation detector includes a plurality of sensors that react to radiation and are stacked in parallel inlayers in a traveling direction of the radiation. The sensors are each sectioned into a central region including the center of the sensor and another region surrounding the central region. The radiation detector independently measures signals measured by the central regions and signals measured by the other regions. Thus, the position of the radiation detector can be verified.

Radiation detector and verification technique of positioning accuracy for radiation detector

A charged particle beam reduces treatment time in the uniform scanning or in the conformal layer stacking irradiation. In the uniform scanning, an optimum charged particle beam scan path for uniformly irradiating a collimator aperture area is calculated. In the conformal layer stacking irradiation, an optimum charged particle beam scan path for uniformly irradiating a multi-leaf collimator aperture area of each layer for each of the layers obtained by partitioning the target volume is calculated. Alternatively, a minimum irradiation field size that covers the multi-leaf collimator aperture area of each layer is calculated, and a scan path corresponding to the irradiation field size, prestored in a memory of a particle therapy control apparatus, is selected. The charged particle beam scan path is optimally changed in the lateral directions in conformity with the collimator aperture area in the uniform scanning or in each layer in the conformal layer stacking irradiation.

Treatment planning apparatus and particle therapy system

Optimal irradiation conditions determined by iterative calculation are based upon an operator-defined irradiating direction, prescription dose, and other conditions. Dose matrixes A and B relating doses to calculation points from a beam delivered to irradiating positions are divided into a dose matrix Aor Bfor the calculation points in a target region that are present at distances equal to or less than a distance L from the beam axis of the beam delivered to each spot, and a dose matrix Aor Bfor the calculation points that are present at distances greater than L. When the iterative calculation is conducted following completion of the division, dose values and {right arrow over (d)}and {right arrow over (d)}that include the dose matrixes Aand Bare regarded as constants, and if updating conditions are satisfied, an objective function is recalculated using the values of the dose matrixes A, B and the spot irradiation dose {right arrow over (x)}.

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Hitachinaka, Japan

Rintaro Fujimoto