Study on dose calculation of pelvic tumor radiotherapy planning based on iCBCT images
Qianfeng ZHAO, Xin MING, Bo LIU, and Chunhui TANG
In order to discuss the accuracy of iterative cone-beam computed tomography (iCBCT) image used for pelvic tumor dose calculation, thirty cases were selected from a hospital that use a Halcyon accelerator for radiotherapy. The volumetric modulated arc therapy (VMAT) plan was redesigned using Eclipse 15.6 planning system, and the setup iCBCT image acquired for the first time was registered with the planning CT image (pCT). The VMAT plan (pCT plan) of each case was transplanted to the iCBCT image, and the dose was calculated again based on the CT-relative electron density curve calibrated using the iCBCT image to generate a new treatment plan (iCBCT plan). The dosimetric parameters of the two plans were analyzed using SPSS 26.0 software to perform t-tests. The results of D2, D98, Dmean, conformity index (CI), and homogeneity index (HI) in the planning target volume dosimetry parameters of the iCBCT plan were similar to those of the pCT plan. The average differences were 0.71%, 0.53%, 0.97%, 0.25%, and 0.95%, respectively, with no statistical significance (p>0.05). Among the organs at risk, the average difference of Dmean, D5, V20, V30, and V40 between the left and right femoral head, rectum, and bladder was small, with no statistical significance (p>0.05). The parameter with the largest average difference (1.71%) was Dmean of the bladder. Compared with that of the pCT plan, the gamma pass rate of the iCBCT plan was 1%/1 mm standard (88.1±1.1)% and 2%/2 mm standard (97.8±1.2)%. Compared with the measured values, the mean difference between the isocenter dose of the two plans was 0.98% and 0.81%, respectively, with no statistical significance (p>0.05). The results show that in most pelvic cases, the results of the iCBCT images used for radiotherapy planning dose calculation are accurate and reliable, and the accuracy meets the requirements of clinical application.
  • Mar. 06, 2023
  • Journal of Radiation Research and Radiation Processing
  • Vol. 41, Issue 1, 010303 (2023)
  • DOI:10.11889/j.1000-3436.2022-0090
Epoxy-functionalized polyethylene-octene prepared by γ-ray radiation and its application in polyamide 6 toughening modification
Qingru LIANG, Zhenyan JI, Chunlei DONG, Fan ZHANG, Zhe XING, Yarui AN, and Guozhong WU
Epoxy-functionalized ethylene-octene copolymer (POE-g-PGMA) was prepared by 60Co γ-ray radiation, and polyamide 6/polyethylene-octene blend (PA6/POE) containing POE-g-PGMA was prepared by twin-screw melt extrusion. In this study, the mechanical properties, thermal properties, surface morphology, interfacial compatibility, and water absorption properties of PA6/POE blends with added POE-g-PGMA were investigated. The results showed that GMA was successfully grafted on POE by γ-ray radiation. The morphological analysis showed that the addition of POE-g-PGMA enhanced the dispersion of POE particles in the PA6 matrix. In particular, it demonstrated that with the addition of POE-g-PGMA, pure PA6 has good interfacial compatibility with POE. The results of the Molau test confirmed the compatibilization reactions between POE-g-PGMA and PA6. The thermal analysis showed that the addition of POE and POE-g-PGMA in the dispersed phase had negligible effect on the melting behavior of PA6; however, the crystallization temperature of PA6 improved by approximately 18 °C during the cooling crystallization process, and the crystallinity increased by approximately 4.5%. Furthermore, the impact strength of the compatibilized PA6/POE blend was significantly higher than that of the PA6/POE blend, with the highest value of impact strength obtained at a POE-g-PGMA content of 3% being approximately 2.75 times greater than that of pure PA6 under the experimental conditions.
  • Mar. 06, 2023
  • Journal of Radiation Research and Radiation Processing
  • Vol. 41, Issue 1, 010202 (2023)
  • DOI:10.11889/j.1000-3436.2022-0107
Variations and uncertainty in electromagnetic dose caused by weight differences of experimental animals
Yichen SUN, Dan DU, Jing LI, and Jiajin LIN
In this study, the biological electromagnetic dose variations and uncertainty caused by body weight differences in experimental animals were evaluated. An electromagnetic dose simulation environment of experimental rats under plane wave excitation was established using bio-electromagnetic simulation software and a three-dimensional digital model. The study frequency band was 0.1-6 GHz. The results showed that there was a linear relationship between the body weight of experimental rats and the whole-body average specific absorption rate under conditions of body weight disturbance. Below the resonant frequency point, the linear relationship was positive, whereas above the resonant frequency point, the linear relationship was negative. In the 1-6 GHz region, the degree of the linear fit was close to 1. The dose uncertainty for the experimental rats was investigated and a fitting calculation method was proposed. Combined with the experimental design case, the calculation process, calculation amount, and evaluation accuracy of the fitting calculation evaluation method were compared. The evaluation method had high accuracy and a low modeling calculation amount. The results of this study have certain guiding significance for the experimental design and dose evaluation of bioelectromagnetics.
  • Mar. 06, 2023
  • Journal of Radiation Research and Radiation Processing
  • Vol. 41, Issue 1, 010302 (2023)
  • DOI:10.11889/j.1000-3436.2022-0115
Therapeutic effect of Potentilla anserina L polysaccharide on mice injured by 60Co γ ray irradiation
Daiyan WU, Yangyang FENG, Linzi ZHANG, Qianqian LIU, Hangyu LI, Jianzhenma YANG, and Haibo FENG
Forty-eight mice were randomly divided into eight groups of six mice each. Group 1 was the control group, groups 2, 3, and 4 were the Potentilla anserina L drug groups, group 5 was the irradiation group, and groups 6, 7, and 8 were the irradiated Potentilla anserina L drug groups. The control group was administered distilled water by gavage for 5 d without irradiation; the irradiation groups were irradiated with 5 Gy 60Co γ rays. In the drug groups, the mice were gavaged with distilled water and Potentilla anserina L polysaccharide within 30-60 min after irradiation for 5 d and euthanized on the sixth day. The effects of different doses of Potentilla anserina L polysaccharide on the blood routine, organ index, DNA content in bone marrow, superoxide dismutase (SOD) activity, total antioxidant capacity (T-AOC), lymphocyte subpopulation ratio, and malondialdehyde (MDA) content in the mouse livers were determined. The results showed that Potentilla anserina L polysaccharide increased the erythrocyte and leukocyte counts, hemoglobin content, and erythrocyte-specific volume as well as the spleen index, liver T-AOC, SOD activity, and lymphocyte count and decreased the MDA content. The DNA coefficient of irradiated mice was improved to some extent. Potentilla anserina L polysaccharide exert good therapeutic effect on the hematopoietic and antioxidant systems and can mitigate the DNA damage of bone marrow cells in radiation-injured mice.
  • Mar. 06, 2023
  • Journal of Radiation Research and Radiation Processing
  • Vol. 41, Issue 1, 010304 (2023)
  • DOI:10.11889/j.1000-3436.2022-0080
Effects of contact glow discharge plasma on Lycium barbarum seed germination and seed treatment methodology
Wan LI, Haitao LONG, Weibing XU, Huali XUE, Wenqiang CAO, Zhaodi LI, and Lumei PU
In order to promote the germination of Lycium barbarum seeds, the Lycium barbarum seeds were treated by contact glow discharge plasma (CGDP), the effects of CGDP on germination were explored under different treatment time, voltages, and electrolyte conditions. The seed treatment process was optimized by response surface optimization design based on seed germination rate and vigor indexes. The effects of CGDP on the structure and properties of the seed coat were preliminarily studied through the detecting changes in the morphology and the contact angle of the seed coat. The results showed that the optimized conditions for seed treatment were 15 min, voltage 550 V, Na2SO4 electrolyte, and the highest seed germination rate was 95.56%. After treatment, the seed coat becomes flat, the texture is blurred, and the hydrophilicity of the seeds is enhanced; the chlorophyll content in the leaves of seedlings increases. Therefore, glow discharge plasma treatment can promote the germination and growth of Lycium barbarum seeds.
  • Mar. 06, 2023
  • Journal of Radiation Research and Radiation Processing
  • Vol. 41, Issue 1, 010401 (2023)
  • DOI:10.11889/j.1000-3436.2022-0103
Surface modification of MIL-101(Cr) metal-organic framework in tetrahydropyran aqueous solution by radiolytic method
Ming YU, Zepeng LIU, Sha LIU, Wanxin LI, Ziqiang WANG, Linfan LI, and Jingye LI
The specific surface area and surface hydrophilicity of metal-organic frameworks can be tailored by changing their central metal ions and organic ligands. In this study, the surface of the metal-organic framework MIL-101(Cr) was modified in an aqueous solution of tetrahydropyran via the radiolytic method. A large number of hydroxyl groups were introduced to the surface of MIL-101(Cr), thereby effectively improving its surface hydrophilicity and substantially increasing its specific surface area without changing its central metal ion and organic ligand. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy demonstrated that the irradiation products of tetrahydropyran were bound to the surface of MIL-101(Cr) through covalent bonding. X-ray diffractometry demonstrated that the crystal structure of the material was retained after irradiation. The specific surface area of MIL-101(Cr) significantly increased, and water contact angle tests indicated that the surface changed from hydrophobic to hydrophilic after modification. These results show that the irradiation reaction of MIL-101(Cr) with tetrahydropyran significantly improves its specific surface area and hydrophilicity. This study provides guidance on the application of the irradiation method to prepare metal-organic frameworks with various properties by simple and rapid modification.
  • Mar. 06, 2023
  • Journal of Radiation Research and Radiation Processing
  • Vol. 41, Issue 1, 010201 (2023)
  • DOI:10.11889/j.1000-3436.2022-0098
Effects of γ-ray irradiation and particle size on enzymatic hydrolysis and fermentation of reed straws
Hui QI, Liang CHEN, Xiaofen WU, An LIU, Danyang WANG, Yong ZHANG, Ming DENG, and Keqin WANG
To explore the effects of absorbed dose and particle size on enzymatic hydrolysis and fermentation of reed straws (Phragmites australias), the straws were irradiated with γ-ray irradiation at different doses (0-500 kGy) and then passed through different aperture sieves after mechanical grinding. The effects of absorbed doses and sieving aperture size on particle size distribution, comminution energy, main component content, enzymatic hydrolysis conversion rate, and ethanol conversion rate of cellulose were examined, and the optimal respective sieving aperture for reed straws with different absorbed doses were determined. The results showed that with decreasing sieve aperture size, reed straw quality decreased significantly and was negatively correlated with the absorbed dose; the comminution energy of reed straws decreased with increasing absorbed doses. With respect to consistent quality of sieved reed straws, the comminution energy increased significantly with decreasing sieving particle size. In reed straws with the same absorbed dose, the enzymatic hydrolysis conversion rate and ethanol conversion rate of cellulose increased with decreasing sieving aperture size. Compared with reed straws with particle size r ? 0.850 mm, the cellulose enzymatic hydrolysis conversion rates in reed straws with particle size r ? 0.180 mm increased by 129.20%, 85.98%, and 106.63% at absorbed doses of 0 kGy, 206 kGy, and 404 kGy, respectively, and cellulose ethanol conversion increased by 136.04%, 21.75%, and 4.39%, respectively. By compre- hensively comparing the increased ratios of comminution energy, cellulose enzymatic hydrolysis conversion rate, and cellulose ethanol conversion rate, the optimal sieving aperture of non-irradiated (0 kGy) reed straws was deter-mined to be 0.850 mm, and that of reed straws irradiated with 206 kGy or 404 kGy was determined to be 0.425 mm.
  • Mar. 06, 2023
  • Journal of Radiation Research and Radiation Processing
  • Vol. 41, Issue 1, 010402 (2023)
  • DOI:10.11889/j.1000-3436.2022-0057