JP7092576B2 - 18F reaction vessel - Google Patents

Description

The present disclosure relates to an 18F reaction vessel.

In PET (positron emission tomography) examination, which is used as a method for diagnosing cancer, 18-fluorine isotope (18F) is incorporated into glucose that is easily absorbed by the affected area of cancer, and this is administered to cancer patients and released from 18F. The location of the affected area of cancer is identified by detecting gamma rays.

Here, in Patent Document 1, as a method for recovering 18F for PET from a solid containing 18F, the solid is an individual containing a sulfuric acid acidic salt containing 6Li and 16O or a sulfuric acid acidic water containing 18O. A method has been proposed in which the 18F is reacted with a gaseous gasifying agent to be gasified, and the gasified 18F is absorbed by an absorbing liquid and recovered.

Japanese Unexamined Patent Publication No. 2002-60394

In recent years, PET examinations have been widely used because medical technology has advanced to the point where cancer can be completely cured if it is detected at an early stage. Along with this, there has been a demand for a method for efficiently producing 18F.

Further, in the method proposed in Patent Document 1, the acid salt sulfate containing 6Li and 16O or the acidic sulfuric acid water containing 18O to be used is expensive, and the operator may be exposed to radiation when producing 18F. There was a problem that it was expensive.

Therefore, it has been desired to establish an 18F reaction vessel capable of efficiently producing 18F while having a low possibility of radiation exposure.

The present disclosure has been devised in view of such circumstances, and an object of the present invention is to provide an 18F reaction vessel capable of efficiently producing 18F while having a low possibility of radiation exposure.

The 18F reaction vessel of the present disclosure has an inlet and an outlet for γ-rays, and also has a first flow path whose inside is a flow path for neon gas. The first portion including the inlet and the second portion including the outlet are made of ceramics.

The 18F reaction vessel of the present disclosure has a low possibility of being exposed to radiation and can efficiently produce 18F.

It is a perspective view which shows an example of the 18F reaction vessel of this disclosure. It is a perspective view which shows the other example of the 18F reaction vessel of this disclosure. FIG. 2 is a cross-sectional view taken along the line i-i in FIG.

Hereinafter, the 18F reaction vessel of the present disclosure will be described in detail below.

From recent research, a method of irradiating neon gas with γ-rays to react is inexpensive and has a low possibility of radiation exposure. However, in the method for producing 18F by this method, the 18F reaction vessel through which γ-rays pass reacts with γ-rays, or the heat generated when neon gas and γ-rays react causes the neon gas to generate heat. The production efficiency of 18F was low.

As shown in FIG. 1, the 18F reaction vessel 10 of the present disclosure has an inlet 1 and an outlet 2 for γ-rays, and also has a first flow path 3 whose inside is a flow path for neon gas. Here, the γ-ray inlet 1 is a portion of the path through which the γ-ray passes through the 18F reaction vessel 10 from the time when the γ-ray is incident to the time when the γ-ray reaches the first flow path 3. On the other hand, the γ-ray outlet 2 is a portion of the path through which the γ-ray passes through the 18F reaction vessel 10 until the γ-ray is emitted from the first flow path 3.

In FIG. 1, the 18F reaction vessel 10a is discharged from the first inflow path 7 and the first flow path 3 which are connected to the first flow path 3 and are the flow paths for allowing the neon gas to flow into the first flow path 3. An example is shown in which a first discharge passage 8 is provided, which is a flow path through which neon gas flows.

Further, in the 18F reaction vessel 10 of the present disclosure, the first part 4 including the inlet 1 and the second part 5 including the outlet 2 are made of ceramics. Here, the first site 4 is a portion of 1/17 on the inlet 1 side when the 18F reaction vessel 10 is divided into 17 equal parts in total length. On the other hand, the second portion 5 is a portion of 1/17 on the outlet 2 side when the 18F reaction vessel 10 is divided into 17 equal parts in total length.

As described above, by satisfying the above configuration, when the 18F reaction vessel 10 is irradiated with γ-rays and the γ-rays pass from the inlet 1 to the outlet 2 through the first flow path 3, the first flow. The neon gas flowing through the path 3 reacts with γ-rays to generate 18F. After that, the generated neon gas containing 18F can be sent to a separation device (not shown), and 18F can be separated and recovered from the neon gas. Furthermore, the recovered neon gas can be reused. Since the first part 4 including the inlet 1 and the second part 5 including the outlet 2 are made of ceramics, the 18F reaction vessel 10 of the present disclosure efficiently manufactures 18F without reacting γ-rays with anything other than neon gas. can do.

The ceramics constituting the first portion 4 and the second portion 5 are, for example, aluminum oxide ceramics, zirconium oxide ceramics, composite ceramics of aluminum oxide and zirconium oxide, silicon nitride ceramics, aluminum nitride ceramics, and carbonized. Silicone ceramics, mulite ceramics, etc. In particular, if the first part 4 and the second part 5 in the 18F reaction vessel 10 of the present disclosure are made of silicon carbide ceramics, the neon gas reacts with γ-rays because of excellent heat resistance and high thermal conductivity. The heat generated during this process can be efficiently dissipated. The silicon carbide ceramics contain 70% by mass or more of silicon carbide in 100% by mass of all the components constituting the ceramics. The same applies to other ceramics.

The materials of the first part 4 and the second part 5 in the 18F reaction vessel 10 of the present disclosure can be confirmed by the following method. First, the first site 4 and the second site 5 are measured using an X-ray diffractometer (XRD), respectively, and from the obtained 2θ (2θ is a diffraction angle), a JCPDS card is used. Perform identification. Next, quantitative analysis of the components contained in each of the first site 4 and the second site 5 is performed using an ICP emission spectroscopic analyzer (ICP) or a fluorescent X-ray analyzer (XRF). Then, for example, if the presence of silicon carbide is confirmed by the above identification and the content converted from the silicon (Si) content measured by ICP or XRF into silicon carbide (SiC) is 70% by mass or more, it is carbonized. Silicone ceramics.

The 18F reaction vessel 10 disclosed in the present disclosure is not limited to the first site 4 and the second site 5, and may be entirely made of ceramics. If such a configuration is satisfied, the heat resistance will be further improved and it will be able to withstand long-term use.

Further, the first flow path 3 in the 18F reaction vessel 10 of the present disclosure may have any shape, but as shown in FIG. 1, it may have a shape extending from the inlet 1 side to the outlet 2 side. good. If such a configuration is satisfied, the length of the first flow path 3 through which the γ-rays pass can be increased in the path through which the γ-rays pass through the 18F reaction vessel 10, and the 18F can be manufactured more efficiently. be able to. Note that FIG. 1 shows an example in which the first flow path 3 is a columnar shape extending from the inlet 1 side to the outlet 2 side.

Further, as shown in FIG. 2, the 18F reaction vessel 10 of the present disclosure may include a second flow path 6 which is a flow path of the refrigerant located on the outer peripheral side of the first flow path 3. Here, the outer peripheral side of the first flow path 3 is outside the first flow path 3 in the direction orthogonal to the direction in which the neon gas of the first flow path 3 flows. Further, the outer peripheral side of the first flow path 3 is a cross section orthogonal to the direction in which the neon gas of the first flow path 3 flows, and the distance from the center of the first flow path 3 is from the inner surface of the first flow path 3. Is also a distant position. If such a configuration is satisfied, even if the neon gas generates heat due to the heat generated when the neon gas flowing through the first flow path 3 reacts with the γ-rays, it can be cooled by the refrigerant flowing through the second flow path 6. Therefore, the 18F reaction vessel 10 of the present disclosure can produce 18F more efficiently.

Further, the flow path direction of the second flow path 6 in the 18F reaction vessel 10 of the present disclosure may be along the flow path direction of the first flow path 3. The flow path direction of the first flow path 3 is from top to bottom in FIG. 2, and the flow path direction of the second flow path 6 is along the flow path direction of the first flow path 3. The flow path direction of No. 6 is also from top to bottom. If such a configuration is satisfied, the neon gas flowing through the first flow path 3 can be efficiently cooled by the refrigerant flowing through the second flow path 6, and the 18F reaction vessel 10 of the present disclosure can be made more than 18F. It can be manufactured efficiently.

Further, the second flow path 6 in the 18F reaction vessel 10 of the present disclosure may surround the first flow path 3 along the first flow path 3. Here, the fact that the second flow path 6 surrounds the first flow path 3 means that the second flow path 6 has a cylindrical shape and the first flow path 6 is inside the second flow path 6. It means that the flow path 3 is located. If such a configuration is satisfied, the neon gas flowing through the first flow path 3 can be cooled more efficiently by the refrigerant flowing through the second flow path 6, and the 18F reaction vessel 10 of the present disclosure has 18F. It can be manufactured more efficiently.

Note that FIGS. 2 and 3 show an example in which the second flow path 6 is an annular cylinder extending from the inlet 1 side to the outlet 2 side. Further, in FIG. 2, the 18F reaction vessel 10b is discharged from the second inflow path 9 and the second flow path 6 which are connected to the second flow path 6 and are the flow paths for allowing the refrigerant to flow into the second flow path 6. An example is shown in which the second discharge passage 11 which is a flow path through which the refrigerant flows is provided.

Further, the first flow path 3 in the 18F reaction vessel 10 of the present disclosure may have a neon gas inflow port, and the inflow direction of the neon gas may intersect with the flow path direction of the first flow path 3. Here, the inflow port of neon gas is a portion where the first inflow path 7 is connected to the first flow path 3. If such a configuration is satisfied, a turbulent flow is generated when the neon gas flows into the first flow path 3, and the turbulent neon gas reacts with the γ-rays to cause the 18F of the present disclosure. The reaction vessel 10 can produce 18F more efficiently.

In particular, if the inflow direction of the neon gas from the first inflow path 7 is orthogonal to the flow path direction of the first flow path 3, turbulence is effectively generated when the neon gas flows into the first flow path 3. However, the 18F reaction vessel 10 of the present disclosure can produce 18F even more efficiently.

Further, in the 18F reaction vessel 10 of the present disclosure, as shown in FIG. 2, when the portion excluding the first site 4 and the second site 5 is the third site 12, the first site 4 in the first flow path 3 The arithmetic average roughness Ra1 obtained from the surface roughness curve may be larger than the arithmetic average roughness Ra2 obtained from the surface roughness curve of the third portion 12 in the first flow path 3. Here, the arithmetic mean roughness Ra means a value specified in JIS B 0601 (2013).

Then, if such a configuration is satisfied, the arithmetic mean roughness Ra on the surface of the first flow path 3 is constant in the first portion 4 in the first flow path 3 as compared with the case where the arithmetic mean roughness Ra is constant regardless of the location. A turbulent flow of neon gas can be effectively generated. When the first inflow path 7 is located at the first site 4, the 18F reaction vessel 10 of the present disclosure efficiently produces 18F at the first site 4 where the neon gas and the γ-ray react most. Can be done.

The arithmetic mean roughness Ra1 of the surface of the first portion 4 in the first flow path 3 may be, for example, 0.8 μm or more, and the arithmetic mean roughness of the surface of the third portion 12 in the first flow path 3 may be set. Ra2 may be, for example, 0.5 μm or less.

Further, in the 18F reaction vessel 10 of the present disclosure, the skewness Rsk obtained from the roughness curve of the surface of the first site 4 in the first flow path 3 may be smaller than 0. Here, the skewness Rsk is defined in JIS B 0601 (2013), and is an index showing the ratio of the mountain portion and the valley portion when the average height in the roughness curve is taken as the center line. And, if the skewness Rsk is smaller than 0, it indicates that the mountainous region is wider than the valley region.

If such a configuration is satisfied, impurities may be mixed in the neon gas when the neon gas is repeatedly reused, but the impurities are introduced into the valley portion of the surface of the first portion 4 in the first flow path 3. Can be trapped and removed with. Therefore, even if the neon gas is repeatedly reused, the purity of the neon gas can be maintained by removing impurities, and the 18F reaction vessel 10 of the present disclosure can efficiently produce 18F.

Here, the arithmetic mean roughness Ra1 and 2 and the skewness Rsk are the surface of the first portion 4 in the first flow path 3 and the third portion 12 in the first flow path 3 in accordance with JIS B 0601 (2013). It can be obtained by measuring each surface. As the measurement conditions, for example, the measurement length may be 2.5 mm, the cutoff value may be 0.08 mm, a stylus with a stylus radius of 2 μm may be used, and the scanning speed may be set to 0.6 mm / sec. .. Then, on each surface, at least 5 points or more may be measured and the average value may be obtained.

Next, an example of the method for producing the 18F reaction vessel 10 of the present disclosure will be described. In the following, a case where the entire 18F reaction vessel 10 is made of silicon carbide ceramics will be described as an example.

First, as a starting material, silicon carbide (SiC) powder, which is the main raw material, and boron carbide (B _4C ) powder or aluminum oxide (Al ₂ O ₃ ) powder and yttrium oxide (Y ₂ O ₃ ) as sintering aids. Prepare the powder and weigh a predetermined amount. Then, the starting raw material is put into a crusher such as a ball mill together with a predetermined amount of water as a solvent, and mixed and pulverized. Then, an appropriate amount of a binder such as polyethylene glycol or polyethylene oxide is added to form a slurry, and then the slurry is spray-granulated using a spray dryer to obtain granules.

Next, using the obtained granules, the granules are formed into a predetermined shape by a hydrostatic pressure press molding method (rubber press), a powder press molding method, or the like, and are subjected to a cutting process to obtain the first portion 4 of the 18F reaction vessel 10. , The second part 5 and the third part 13, respectively, are obtained. Next, these molded bodies are dried and degreased, placed in a baking furnace, and fired at a maximum temperature of 1800 ° C. or higher and 2100 ° C. or lower in a non-oxidizing atmosphere. After that, by performing grinding processing as necessary, the first part 4, the second part 5 and the third part 12 of the 18F reaction vessel 10 having the first flow path 3 and the second flow path 6 having an arbitrary shape are performed. To get. Then, by this grinding process, the surface texture of the surface of the first portion 4 in the first flow path 3 and the surface of the third portion 12 in the first flow path 3 can be set to arbitrary values.

Then, a glass paste prepared by mixing glass, a binder and a solvent is applied to each of the obtained joints of the first part 4, the second part 5 and the third part 12, and the first part 4 and the second part are applied. After joining the site 5 and the third site 12, heat treatment is performed at a maximum temperature of 1300 ° C. or higher and 1700 ° C. or lower in a non-oxidizing atmosphere to obtain the 18F reaction vessel 10 of the present disclosure.

1: Inlet 2: Exit 3: First flow path 4: First part 5: Second part 6: Second flow path 7: First inflow path 8: First discharge path 9: Second inflow path 10, 10a, 10b: 18F reaction vessel 11: 2nd discharge channel 12: 3rd part

Claims (6)

It has an inlet and an outlet for gamma rays, and has a first flow path inside which is a flow path for neon gas.
The first part including the entrance and the second part including the exit are made of ceramics.
When the part excluding the first part and the second part is the third part,
The arithmetic average roughness Ra1 obtained from the surface roughness curve of the first portion in the first flow path is the arithmetic average roughness Ra2 obtained from the surface roughness curve of the third portion in the first flow path. Larger 18F reaction vessel. It has an inlet and an outlet for gamma rays, and has a first flow path inside which is a flow path for neon gas.
The first part including the entrance and the second part including the exit are made of ceramics.
An 18F reaction vessel having a skewness Rsk smaller than 0 obtained from the roughness curve of the surface of the first portion in the first flow path. The 18F reaction vessel according to claim 1 or 2, further comprising a second flow path which is a flow path of the refrigerant, which is located on the outer peripheral side of the first flow path. The 18F reaction vessel according to claim 3, wherein the flow path direction of the second flow path is along the flow path direction of the first flow path. The 18F reaction vessel according to claim 4, wherein the second flow path surrounds the first flow path along the first flow path. The 18F reaction according to any one of claims 1 to 5, wherein the first flow path has an inlet for the neon gas, and the inflow direction of the neon gas intersects the flow path direction of the first flow path. container.

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