Hitachi, Ltd.

Hokkaido University

Fujifilm Healthcare Corporation

Taisuke Takayanagi

Shinichiro Fujitaka

Taeko Matsuura

Yusuke Vincent Fujii

Kikuo Umegaki

Koji Matsuda

Masahiro Tadokoro

Chihiro Nakashima

Hiroyuki Takeuchi

Naoki Miyamoto

Masahiro Yoshida

Toru Umekawa

Yukinobu Imamura

Manabu Aoki

Hiroki Shirato

Shinichi Shimizu

Seishin Takao

Hideaki Nihongi

Arao Nishimura

Ryosuke Shinagawa

Yuichi Hirata

Hiroshi Akiyama

Masumi Umezawa

Hideaki Nishiuchi

Takuya Nomura

Rintaro Fujimoto

Shusuke Hirayama

Rintarou Fujimoto

Takao Kidani

Tomoki Murata

Yusuke Fujii

Takuto Miyoshi

Kengo Goto

Shin Hoshino

Takeshi Nakayama

Shinichirou Fujitaka

Sodai Tanaka

Rikiya Onimaru

Takeji Sakae

Toshiyuki Terunuma

A correlation between a CT value and a water equivalent thickness ratio distribution for each patient can be corrected without increasing a treatment time, and more accurate treatment can be realized. A treatment planning systemwhich generates a treatment plan for irradiating an irradiation target with a particle beam calculates a correction amount of a water equivalent thickness ratio of a first treatment plan created in advance, calculates a water equivalent thickness ratio distribution based on the correction amount and the first treatment plan, and creates a second treatment plan from the water equivalent thickness distribution.

Treatment planning system, treatment plan creation method, and computer program

A treatment planning system that generates treatment planning for irradiating a target with a particle beam, includes an arithmetic processing device that sets at least two or more irradiation patterns for one treatment planning, calculates a plurality of predicted dose distributions for each irradiation pattern based on a target dose set for each region for at least one region including a region of the target, and calculates an index for evaluating validity of the irradiation pattern based on the plurality of predicted dose distributions.

Treatment planning system, treatment planning generation method, and recording medium

An MRI apparatus equipped with a magnetic shield structure to reduce flux leakage. The MRI apparatus includes: a pair of static magnetic magnets that are disposed on opposite sides of an imaging space; and a pair of gradient coils that are disposed on opposite sides of the imaging space. Each static magnetic magnet has a disk-shaped magnetic material poleand a ring-shaped magnetic material pole. Each gradient coil has a first coilthat applies a magnetic field gradient in a Z axis direction in an imaging region, and a laminatethat shields the disk-shaped magnetic material pole from magnetic flux produced in the first coil. The laminate has a smaller thickness in the Z axis direction on the ring-shaped magnetic material pole side than that in a center portion of the imaging space. A vertical lowest portion of a laminate end portion on the ring-shaped magnetic material pole side of the laminate is in a higher position than a position of a lowest portion of a laminate central portion on the imaging region side of the laminate.

Magnetic resonance imaging apparatus

An open-type MRI apparatus includes a pair of static magnetic field magnets and a pair of gradient magnetic field coils. Each static magnetic field magnet includes a discoid magnetic pole configured to generate a static magnetic field in a Z axis direction in which the pair of static magnetic field magnets are opposed each other, and an annular magnetic pole configured to generate a static magnetic field on an X-Y plane perpendicular to the Z axis direction. Each gradient magnetic field coil includes a Z coil configured to provide a magnetic field being gradient in the Z axis direction in the imaging region, a magnetic material block configured to shield the discoid magnetic pole from a magnetic flux generated from the Z coil, and a correction coil configured to shield the annular magnetic pole from the magnetic flux generated from the Z coil.

Open-type magnetic resonance imaging apparatus

There is provided a treatment planning system and a particle therapy system. In the related art, it is unable to determine optimum beam intensity in irradiation for which discrete spot irradiation and continuous beam irradiation coexist. There is provided a treatment planning system that includes a spot determination unit that divides an irradiation region to be irradiated with a charged particle beam into a plurality of layers in an advancing direction of the charged particle beam and disposes a plurality of irradiation spots, which becomes irradiation points of the charged particle beam, in the layers and a beam intensity determination unit that determines beam intensity for each of the layers by evaluating the irradiation time by changing the beam intensity in a range of a condition of change in dose distribution which is set in advance.

Treatment planning system and particle therapy system

Provided are a radiation treatment planning system and a radiation treatment system that are capable of achieving time shortening and labor saving of treatment planning making when a radiation treatment is planned. A predicted DVH calculation portionof an arithmetic processing devicein a radiation treatment planning systemanisotropically enlarges a target regionin an irradiated body image which is input to the radiation treatment planning system, and calculates an overlap volume OV with an organ-at-risk regionper the number of times of enlargement. A DVH (Dose Volume Histogram) is predicted from a volume of the calculated OV, and a dose histogram in the OV per the number of times of enlargement which is calculated from a past treatment planning data group, and is displayed on a display device

Radiation treatment planning system and radiation treatment system

The invention provides a particle therapy system in which whether to perform any one irradiation method of a raster scanning method and a discrete spot scanning method can also be selected based on previous selection depending on a target volumeof a patientto be irradiated, and either of the irradiation methods of the raster scanning method and the discrete spot scanning method is configured to be capable of being performed by one irradiation apparatus. Therefore, a small particle therapy system capable of achieving both higher accuracy irradiation and high dose rate improvement is provided.

Particle therapy system

A radiation therapy planning apparatus performs dose calculation at high speed and with high accuracy for radiation therapy in a scanning irradiation method. The apparatus includes a display, an arithmetic processing apparatus, a memory, and a data server, which is connected to a particle beam irradiation apparatus. A dose calculation unit of the arithmetic processing apparatus calculates dose distribution by a simplified Monte Carlo algorithm, and corrects the dose distribution by a decreasing rate stored in a particle number decreasing rate table of the memory, and stores the corrected dose distribution in an integrated dose distribution table. By using the simplified Monte Carlo algorithm and the particle number decreasing rate that corrects the simplified Monte Carlo algorithm, the dose distribution is calculated, and thereby, it is possible to realize a radiation therapy planning apparatus that performs dose calculation at a high speed with high accuracy.

Radiation therapy planning system, radiation therapy planning method, and radiation therapy system

The particle therapy system includes a particle beam generator for generating a particle beam; an irradiation nozzle arranged in a treatment room and irradiating a target with the particle beam; a particle beam transport system communicating the particle beam generator with the irradiation nozzle; an X-ray imaging device arranged in the treatment room and imaging the position of the target through irradiation with X-rays; a dosimeter arranged at a position passed by the particle beam in the irradiation nozzle; and a control apparatus performing control to exclude the measurement result of the X-rays from the measurement result obtained using the dosimeter when the X-rays are emitted during treatment.

A structure configuring a ridge filter has line symmetry about a line vertical to a depth direction passing the center of the structure. A small structure obtained in such a way that the structure is divided by this line has a bilaterally asymmetric shape about a center line in an iterative direction, and has a point symmetric shape about an intersection between the center line in the iterative direction and the center line in the depth direction. Thicknesses in the iterative direction of an uppermost stream surface and a lowermost stream surface in the depth direction are equal to each other. The structure is configured so that a thick portion in the iterative direction of the uppermost stream surface and the lowermost stream surface is not present in the depth direction.

Particle beam therapy system, ridge filter, and method of making ridge filter

The present invention provides a particle therapy system including an irradiation compensating device made up of an energy absorber, a first collimator, and a second collimator for use in a short-range region. The irradiation compensating device is characterized by a mechanism for attaching and detaching the first energy absorber, first collimator, and second collimator. The first collimator is located upstream where the beam diameter is small with a view to suppressing the width of the compensating device, thereby contributing to making the compensating device small and lightweight. The second collimator is located downstream to improve penumbrae.

A stacked type of radiation detector and a calibration method that enables the radiation detector to correct variations in sensor-specific output easily and within a short time, without using a water-phantom dose detector. The radiation detector is equipped with a sensor section including a plurality of sensors arranged in layers in a traveling direction of a particle beam. A dummy absorber has water-equivalent thickness equal to an average water-equivalent thickness of the sensors. A signal-processing unit calculates sensor-specific calibration coefficients using a measurement result obtained during irradiation of the radiation detector with the radiation when electrical signals developed in each sensor are measured, and a measurement result obtained during irradiation of the radiation detector with the radiation when the sensor section is moved in the traveling direction of the radiation, then the dummy absorber is set in place, and electrical signals developed in each sensor are measured.

Calibration method for radiation detector, and particle therapy system

A radiation measuring device having a plurality of sensors configured to generate charges in response to the radiation includes a signal processing device. The signal processing device uses an signal generated by a proton beam irradiation device upon changing of beam energy and causes accumulation values of charges output from the sensors to be separately stored in a main control device for each value of the energy. The main control device calculates depth dose profiles for values of the beam energy from the accumulation values stored in the main control device and representing the charges. The main control device calculates a range of the beam for each of the values of the beam energy from the depth dose profiles, corrects the depth dose profiles for the values of the beam energy using a correction coefficient that depends on the range and sums the corrected depth dose profiles.

Radiation measuring device, particle beam therapy device provided with radiation measuring device, and method for calculating dose profile of particle beam

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.

Growing community of inventors

Tokyo, Japan

Taisuke Takayanagi