Abstract: The present disclosure provides a neutron capture therapy system, including a neutron generator to generate neutrons after irradiation by charged particles, and a beam shaping assembly includes a moderator and a reflector surrounding the moderator. A vacuum tube connected to the accelerator is provided at an accommodating portion. The vacuum tube transmits the charged particles accelerated by the accelerator to the neutron generator to generate neutrons. The neutron generator moves between a first position and a second position, at the first position, the neutron generator react with the charged particle beam to generate neutrons, at the second position, the neutron generator falls off the beam shaping assembly. The vacuum tube is detached to make the neutron generator fall off the beam shaping assembly, to reduce direct contact of a worker with the neutron generator after nuclear reactions, thereby reducing radioactive hazards for workers.

Abstract: Provided is a radiation detection system for improving the accuracy of a neutron beam irradiation dose for a neutron capture therapy system. The neutron capture therapy system includes a charged particle beam, a charged particle beam inlet for passing the charged particle beam, a neutron generating unit for generating the neutron beam by means of a nuclear reaction with the charged particle beam, a beam shaping assembly for adjusting flux and quality of the neutron beam, and a beam outlet adjoining to the beam shaping assembly, the radiation detection system includes a radiation detection device arranged within the beam shaper or outside the beam shaping assembly, the radiation detection device is used for real-time detection of the overflowing neutron beam by the neutron generating unit or the generated ?-ray after the nuclear reaction of the charged particle beam with the neutron generating unit.

Abstract: A method for preparing 18F-BPA and an intermediate, by which high-purity 18F-BPA is obtained. The method simplifies the synthesis steps after 18F labeling, and is easy to operate and efficient.

Abstract: A process for analyzing elements and mass ratios of elements of a tissue includes approximating the tissue having unknown elements and mass ratios of the unknown elements thereof using the data of the medical image corresponding to a tissue having known elements and mass ratios of the known elements thereof. A method for establishing a geometric model based on a medical image includes: reading data of the medical image; defining a type of a tissue according to a conversion relationship between the data of the medical image and tissue types or according to the process; determining a quantity of tissue clusters of the tissue; defining a tissue density of the tissue by a conversion relationship between the data of the medical image and density values; establishing a 3D coding matrix with information about the tissue and the density; and generating the geometric model.

Abstract: A neutron capture therapy system includes an accelerator for accelerating charged particles to generate a charged particle beam, a beam transmitting device, and a neutron beam generating device. The neutron beam generating device further includes a first, a second and a third neutron beam generating device. The beam transmitting device further includes a first transmitting device connected to the accelerator, a beam direction conversion device configured to switch a traveling direction of the charged particle beam, and a second, a third and a fourth transmitting device that respectively transmit the charged particle beam from the beam direction conversion device to the first, the second and the third neutron beam generating device, wherein two of the first, the third and the fourth transmitting device define a first plane, a first and a second transmitting device define a second plane, and the first plane is different from the second plane.

Abstract: A neutron capture therapy system includes a neutron beam generating unit, an irradiation room configured to irradiate an irradiated body with a neutron beam, a preparation room configured to implement preparation work required to irradiate the irradiated body with the neutron beam, and an auxiliary positioner disposed in the irradiation room and/or the preparation room. The irradiation room includes a first shielding wall, a collimator is disposed on the first shielding wall for emitting the neutron beam, and the neutron beam is emitted from the collimator and defines a neutron beam axis. The auxiliary positioner includes a laser emitter that emits a laser beam to position the irradiated body, wherein the position of the laser emitter is selectable. Therefore, the irradiated body can be positioned in any case to implement precise irradiation.

Abstract: A method for measuring radiation intensity includes measuring the radiation intensity received by the protein in a radiation field based on degree of protein degradation in the radiation field, wherein the degree of degradation is a ratio of the molecular weight of the protein before and after irradiation. The measuring method is simple in operation, small in number of steps, small in error, and capable of measuring radiation doses of various radiation fields or even mixed radiation fields. Use of a biological dosimeter for measuring the radiation intensity by the method in a neutron capture therapy system can not only assess radiation contamination in the irradiation chamber, but also evaluate the neutron dose.

Abstract: A beam shaping assembly (10) used in a neutron capture system and capable of changing an irradiation range of a neutron beam. The beam shaping assembly includes: a beam inlet (11), a target (12), a moderator (13) adjoining the target (12), a reflector (14) surrounding the moderator (13), a thermal neutron absorber (15) adjoining the moderator (13), a radiation shield (16) arranged inside the beam shaping assembly (10), and a beam outlet (17). The beam shaping assembly (10) further includes replacement components (21, 22) that can be attached to and detached from the beam shaping assembly (10) to change the irradiation range of the neutron beam.

Abstract: A neutron capture therapy system includes an accelerator for generating a charged particle beam, a neutron generator for generating a neutron beam having neutrons after irradiation by the charged particle beam, and a beam shaping assembly for shaping the neutron beam. The beam shaping assembly includes a moderator and a reflecting assembly surrounding the moderator. The neutron generator generates the neutrons after irradiation by the charged particle beam. The moderator moderates the neutrons generated by the neutron generator to a preset energy spectrum. The reflecting assembly includes a plurality of reflectors configured to guide deflected neutrons back to the neutron beam and a supporting member to support the plurality of reflectors. A lead-antimony alloy is for the reflecting assembly to mitigate a creep effect that occurs when only a lead material is for the plurality of reflectors, thereby improving the structural strength of a beam shaping assembly.

Abstract: Disclosed is a moderator for moderating neutrons, including a substrate and a surface treatment layer or a dry inert gas layer or a vacuum layer coated on the surface of the substrate, wherein the substrate is prepared from a moderating material by a powder sintering device through a powder sintering process from powders or by compacting powders into a block, and the moderating material includes 40% to 100% by weight of aluminum fluoride; wherein the surface treatment layer is a hydrophobic material; and the surface treatment layer or the dry inert gas layer or the vacuum layer is used for isolating the substrate from the water in the environment in which the substrate is placed. The surface treated moderator can avoid the hygroscopic or deliquescence of the moderating material during use, improve the quality of the neutron source and prolong the service life.

Abstract: A boron neutron capture therapy system includes a neutron capture therapy device, a photon emission detection device and a treatment bed. The photon emission detection device includes a detecting portion surrounding the periphery of the treatment bed and detecting gamma rays generated after irradiating a boron-containing drug with neutrons; the detecting portion includes a first detecting portion and a second detecting portion moving away from or close to the first detecting portion so that the detecting portion forms a ring with the radius being increased or decreased; and the ring surrounds the treatment bed. The photon emission detection device for use in the boron neutron capture therapy system can change the radius of the ring, surrounding an irradiated object, of the detecting portion according to the actual condition in the boron neutron capture therapy so as to improve the detection precision of the photon emission detection device.

Abstract: The present disclosure provides a positioning assembly for a radiation irradiation system. The positioning assembly includes a shielding body made of polymer and radiation shielding material capable of shielding the radiation and a sealing bag for accommodating the shielding body, when the target to be irradiated is placed on the positioning assembly, the positioning assembly is recessed with a shape of the target at the position where the target is placed and forms a contour corresponding to the target to position the target to be irradiated.

Abstract: A neutron capture therapy system, including a beam shaping assembly and a vacuum tube. The beam shaping assembly includes a beam entrance, an accommodating cavity accommodating the vacuum tube, a moderator adjacent to an end of the accommodating cavity, a reflector surrounding the moderator, a radiation shield disposed in the beam shaping assembly, and a beam exit. A target is disposed at an end of the vacuum tube, nuclear reactions occur between the target and a charged particle beam entering through the beam entrance to generate neutrons. The moderator moderates the neutrons, the reflector guides deflected neutrons back to the moderator. The moderator at least includes two cylindrical moderating members with different outer diameters respectively, the moderator has a first end close to the beam entrance and a second end close to the beam exit, and the target is accommodated between the first end and the second end.

Abstract: A neutron capture therapy system and a target for a particle beam generating device, which may improve the heat dissipation performance of the target, reduce blistering and extend the service life of the target. The neutron capture therapy system includes a neutron generating device and a beam shaping assembly. The neutron generating device includes an accelerator and a target, and a charged particle beam generated by acceleration of the accelerator interacts with the target to generate a neutron beam. The target includes an acting layer, a backing layer and a heat dissipating layer, the acting layer interacts with the charged particle beam to generate the neutron beam, the base layer supports the action layer, and the heat dissipating layer includes a tubular member composed of tubes arranged side by side.

Abstract: A neutron capture therapy system, including a beam shaping assembly, and a vacuum tube and at least one cooling device. The beam shaping assembly includes a beam inlet, an accommodating cavity accommodating the vacuum tube, a moderator adjacent to an end portion of the accommodation cavity, a reflector surrounding the moderator, and a radiation shield and a beam outlet arranged in the beam shaping assembly. An end portion of the vacuum tube is provided with a target. The cooling device undergoes a nuclear reaction with a charged particle beam incident from the beam inlet to produce neutrons. The moderator decelerates the neutrons produced by the target to an epithermal neutron energy region. The reflector leads deviating neutrons back to the moderator. At least one accommodating pipeline accommodating the cooling device is arranged in the beam shaping assembly. A filler is filled between the cooling device and the accommodating pipeline.

Abstract: In one aspect, a method for establishing a smooth geometric model based on data of a medical image includes: inputting or reading the data of the medical image; establishing a three-dimensional medical image voxel model based on the data of the medical image; smoothing the three-dimensional medical image voxel model; and establishing a three-dimensional voxel phantom tissue model based on the smoothed three-dimensional medical image voxel model. In another aspect, a method for establishing a smooth geometric model based on data of a medical image includes: inputting or reading the data of the medical image; establishing a three-dimensional voxel phantom tissue model based on the data of the medical image; and smoothing the three-dimensional voxel phantom tissue model.

Abstract: A neutron capture therapy system includes an accelerator for accelerating charged particles to generate a charged particle beam, a beam transmitting device, and a neutron beam generating device. The neutron beam generating device further includes a first, a second and a third neutron beam generating device. The beam transmitting device further includes a first transmitting device connected to the accelerator, a beam direction conversion device configured to switch a traveling direction of the charged particle beam, and a second, a third and a fourth transmitting device that respectively transmit the charged particle beam from the beam direction conversion device to the first, the second and the third neutron beam generating device, wherein two of the first, the third and the fourth transmitting device define a first plane, a first and a second transmitting device define a second plane, and the first plane is different from the second plane.

Abstract: A medical image-based radiation shielding device and method thereof, which may form a targeted and highly accurate radiation shielding according to individual differences in patients, such as tumor location and size, thereby reduce or avoid radiation from a irradiation apparatus to normal tissues of patients. The shielding device includes a medical image scanning means for scanning an irradiated site of an irradiated subject and outputting medical image voxel data, a data processing and three-dimensional modeling means for establishing a three-dimensional phantom tissue model according to the medical image voxel data and establishing a three-dimensional shield model according to the three-dimensional phantom tissue model; a shield located between the irradiation apparatus and the irradiated site, wherein the shield is formed by printing the three-dimensional shield model data input to a 3D printer.

Abstract: Provided is a beam diagnostic system for a neutron capture therapy system. The neutron capture therapy system includes a charged particle beam, a charged particle beam inlet for passing the charged particle beam, a neutron generating unit generating a neutron beam by a nuclear reaction with the charged particle beam, and a beam shaping assembly for adjusting flux and quality of the neutron beam generated by the neutron generating unit and a beam outlet adjoining to the beam shaping assembly. The charged particle beam inlet is accommodated into the beam shaping assembly and the neutron generating unit is accommodated in the beam shaping assembly. The beam diagnostic system includes a charged particle beam diagnostic device and a neutron beam diagnostic device, and the beam diagnostic system is used to simultaneously diagnose whether the neutron capture therapy system and/or the beam diagnostic system is malfunctioning.

Abstract: The present disclosure provides a beam shaping assembly for neutron capture therapy, wherein the beam shaping assembly includes a neutron generating device, a moderator, a disturbing unit and a beam outlet. The neutron generating device is used to generate neutrons that form a neutron beam in a direction from the neutron generating device to the beam outlet, the moderator adjacent to the neutron generating device for adjusting fast neutrons in the neutron beam to epithermal neutrons. The disturbing unit is located between the moderator and the beam outlet for passing through the neutron beam and reducing the gamma ray content in the neutron beam passing through the beam outlet. The technical solution provided by the present disclosure can effectively reduce the gamma ray content in the neutron beam under the premise that the quality of the neutron beam is not significantly adversely affected.