Radiation Medicine and Protection最新文献

{"title":"Monte Carlo simulations for targeted beta therapy: An optimization for liver lesions and comparison of dose distributions in other organs","authors":"Ayhan Kara,&nbsp;Emil Mammadzada","doi":"10.1016/j.radmp.2023.11.001","DOIUrl":"10.1016/j.radmp.2023.11.001","url":null,"abstract":"<div><h3>Objective</h3><p>To optimize targeted beta therapy for liver lesions in adult male phantom by comparing the efficacy and safety profiles of five different beta-emitting radionuclides: ⁹⁰Y, ¹⁶⁶Ho, ¹⁵³Sm, ⁴⁷Sc, and ¹⁷⁷Lu.</p></div><div><h3>Methods</h3><p>This study includes Monte Carlo simulations of the behavioral characteristics of five different beta emitters that have current or potential use in targeted beta therapy. The energy loss of beta particles moving within the material through ionization or chemical processes, the energy transferred to the material, the energy lost by beta particles along the distance traveled within the tissue, and consequently, the stopping power are calculated using the Bethe-Bloch formula. The CSDA (continuous slowing-down approximation) range of beta particles within the tissue is examined using ESTAR and GEANT codes, while the stopping power of the tissue is investigated using FLUKA, ESTAR, and GEANT codes. Tissue dose calculations for the target organ are obtained using the IDAC-Dose2.1 and MIRDcalc simulation programs, using parameters such as absorbed dose per accumulated activity (<em>S</em>-factor) and specific absorbed fraction (SAF). Additionally, dose and flux values are obtained using the PHITS program.</p></div><div><h3>Results</h3><p>The behaviors and dose contribution of beta particles in liver tissue have been addressed in various ways. ⁹⁰Y, which has the highest average beta energy, was observed to provide a higher absorbed dose value in the liver compared to other beta-emitting isotopes, while the lowest absorbed dose was observed with ¹⁷⁷Lu. In other organs, it has been observed that ⁹⁰Y and ⁴⁷Sc contribute to a higher absorbed dose compared to other beta-emitting isotopes.</p></div><div><h3>Conclusions</h3><p>This study emphasizes the complexity and significance of targeted beta therapy optimization.</p></div>","PeriodicalId":34051,"journal":{"name":"Radiation Medicine and Protection","volume":"4 4","pages":"Pages 244-252"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S266655572300062X/pdfft?md5=4a375c76f3f7953726c80c0729ea90e1&pid=1-s2.0-S266655572300062X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135566787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating a novel protective agent against radiation-induced acute intestinal injury","authors":"Xin He ,&nbsp;Jing Wu ,&nbsp;Yinping Dong ,&nbsp;Wenxuan Li ,&nbsp;Xinyue Wang ,&nbsp;Qidong Huo ,&nbsp;Tongpeng Yue ,&nbsp;Yiliang Li ,&nbsp;Bin Wu ,&nbsp;Deguan Li","doi":"10.1016/j.radmp.2023.10.004","DOIUrl":"10.1016/j.radmp.2023.10.004","url":null,"abstract":"<div><h3>Objective</h3><p>To develop and synthesize a novel derivative of ethyl pyruvate, named TZC02, and investigate its radioprotective effects against ionizing radiation (IR)-induced intestinal injury in mice.</p></div><div><h3>Methods</h3><p>Male C57BL/6J mice weighing (20 ​± ​2) g in the survival experiment were randomly divided into five groups (<em>n</em> ​= ​10 in each): control group, IR group, IR ​+ ​TZC02 (50 ​mg/kg) group, IR ​+ ​TZC02 (100 ​mg/kg) group, and IR ​+ ​TZC02 (200 ​mg/kg) group. Mice's survival rates were monitored for 7 ​d. In other experiments, the male mice were randomly divided into three groups (<em>n</em> ​= ​5 per group): control group, IR group, and IR ​+ ​TZC02 (100 ​mg/kg) group. TZC02 was intragastrically administered 1 ​h before 12 ​Gy abdominal γ-ray irradiation (ABI) and 24 h, 48 h after irradiation, respectively. Three days after IR exposure, small intestinal tissues were collected and the number of small intestinal crypts was determined using hematoxylin &amp; eosin (H&amp;E) staining. Immunohistochemical analysis was used to assess the regenerative capacity of the small intestine (SI) and radiation-induced damage, stemness markers or DNA repair surrogates, including Ki67, lysozyme, and villus. The expressions of histone H2AX phosphorylation (γH2AX) and caspase-3 were evaluated through immunofluorescence analyses. Additionally, <em>in vitro</em> cultured small intestinal organoids were employed to investigate the effects of TZC02 on SI regeneration after irradiation.</p></div><div><h3>Results</h3><p>The administration of TZC02 significantly improved the 7 ​d- survival rate of mice exposed to 12 ​Gy ABI (<em>P</em> ​&lt; ​0.05). Compared to the IR group, TZC02 treatment attenuated the decrease of SI Ki67-positive cells [(59.60 ​± ​6.33) <em>vs.</em> (37.70 ​± ​7.82), <em>t</em> ​= ​11.89, <em>P</em> ​&lt; ​0.0001) and Paneth cells [(9.90 ​± ​1.37) <em>vs.</em>(5.50 ​± ​1.71) , <em>t</em> ​= ​6.02, <em>P</em> ​&lt; ​0.001) in five crypts, and reduced structural damage to the SI [villus height, (349.49 ​± ​60.17) μm <em>vs.</em> (294.72 ​± ​40.09) ​μm; <em>t</em> ​= ​3.39; <em>P</em> &lt; ​0.05]. TZC02 also significantly decreased the crypt apoptosis detected by caspase-3 [(10.75 ​± ​1.26) <em>vs.</em> ​(29.83 ​± ​2.56), <em>t</em> ​= ​13.39, <em>P</em> ​&lt; ​0.0001) and DNA damage detected by gH2AX [(10.40 ​± ​1.14) <em>vs.</em> ​(29.60 ​± ​2.70), <em>t</em> ​= ​10.13, <em>P</em> ​&lt; ​0.0001)]. The organoid survival 7 ​d post-irradiation further confirmed the protective effects of TZC02 (area of organoids, (0.119 ​± ​0.081) ​mm² <em>vs.</em> ​(0.080 ​± ​0.037) ​mm²; <em>t</em> ​= ​2.30; <em>P</em> ​&lt; ​0.05).</p></div><div><h3>Conclusions</h3><p>This study demonstrate that TZC02 can offer effective protection against IR-induced intestinal injury, suggesting its potential as a promising protective compound for patients treated with radiotherapy.</p></div>","PeriodicalId":34051,"journal":{"name":"Radiation Medicine and Protection","volume":"4 4","pages":"Pages 221-226"},"PeriodicalIF":0.0,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666555723000564/pdfft?md5=c8169ffca07f354c783dc39d775dfa5b&pid=1-s2.0-S2666555723000564-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135811174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predicting late radiation-induced xerostomia in nasopharyngeal carcinoma based on radiomics features extracted from T2WI images of parotids","authors":"Yonghui Qin ,&nbsp;Cheng Chang ,&nbsp;Li Huang ,&nbsp;Yong Yin ,&nbsp;Ruozheng Wang","doi":"10.1016/j.radmp.2023.06.002","DOIUrl":"10.1016/j.radmp.2023.06.002","url":null,"abstract":"<div><h3>Objective</h3><p>To explore the value of radiomics features extracted from the T2-weighted imaging (T2WI) images of parotids in predicting late radiation-induced xerostomia in nasopharyngeal carcinoma (NPC) patients after radiotherapy (RT).</p></div><div><h3>Methods</h3><p>A retrospective analysis was conducted for 123 NPC patients who received RT at the Affiliated Tumour Hospital of Xinjiang Medical University from January 2019 to March 2021. All the patients underwent MRI pre-RT and post-RT. They were randomly divided into a training set and a testing set at a ratio of 4:1 using a random number table, with the former and the latter comprising 98 and 25 cases, respectively. The ipsilateral parotid gland (iPG) and the contralateral parotid gland (cPG) were delineated on T2WI images pre-RT and post-RT as regions of interest (ROIs). A total of 851 radiomics features were extracted from each ROI. Spearman analysis was used to remove redundant features, and the recursive feature elimination (RFE) method was then used to determine useful features. Using radiomics features extracted from images pre-treatment, images post-treatment, and differences between images pre- and post-treatment, this study constructed three radiomic models, namely the pre-treatment radiomics model (preRT), the post-treatment radiomics model (postRT), and the delta-radiomics model (DeltaRT). Then, this study plotted the receiver operating characteristic (ROC) curves based on the late radiation-induced xerostomia grades of patients post-RT. Furthermore, the models’ effectiveness and performance in predicting late radiation-induced xerostomia and advanced radioactive xerostomia was evaluated. In addition, the area under the curve (AUC), sensitivity, specifi<strong>c</strong>ity, accuracy, precision, and negative predictive value (NPV) were calculated.</p></div><div><h3>Results</h3><p>Among the features extracted from bilateral parotid glands (PGs), 20 were determined pre-RT (six from iPG and 14 from cPG), 19 were determined post-RT (six from iPG and 13 from cPG), and 20 were derived from the DeltaRT (20 from cPG). The PGs pre-RT and post-RT in the training set had AUCs of 0.902 (95% <em>CI</em>: 0.895–0.909) and 0.761 (95% <em>CI</em>: 0.744–0.778), respectively, while those in the testing set had AUCs of 0.740 (95% <em>CI</em>: 0.504–0.983) and 0.701 (95% <em>CI</em>: 0.478–0.924), respectively. In contrast, the AUC of the cPG derived from the DeltaRT was 0.867 (95% <em>CI</em>: 0.856–0.878) in the training set and 0.851 (95% <em>CI</em>: 0.697–0.999) in the testing set.</p></div><div><h3>Conclusions</h3><p>There are significant correlations between radiomics features extracted from MRI T2WI images of parotids and late radiation-induced xerostomia in NPC patients. Among the radiomics features, the changes in cPG features pre-RT and post-RT have higher accuracy in predicting late radiation-induced xerostomia.</p></div>","PeriodicalId":34051,"journal":{"name":"Radiation Medicine and Protection","volume":"4 3","pages":"Pages 125-129"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49655588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An analysis of the status of diagnostic radiology equipment in China","authors":"Shuxia Hao,&nbsp;Mengxue Li,&nbsp;Shengnan Fan,&nbsp;Hui Xu,&nbsp;Jinsheng Cheng,&nbsp;Jun Deng","doi":"10.1016/j.radmp.2023.08.001","DOIUrl":"10.1016/j.radmp.2023.08.001","url":null,"abstract":"<div><h3>Objective</h3><p>To analyze the current situation of diagnostic radiology equipment in Chinese mainland and to understand changes in the past 20 years, including gaps with other countries, in order to provide a scientific basis for the government to formulate relevant policies and regulations, and supplement Chinese data for international organizations.</p></div><div><h3>Methods</h3><p>This survey adopted a uniformly designed questionnaire, which was completed by the investigators or the respondents. The survey was distributed to all medical institutions that provided diagnostic radiology services in 31 provinces, autonomous regions, and municipalities, excluding Hong Kong, Macao, Taiwan, and military, China.</p></div><div><h3>Results</h3><p>The survey showed that in the past 20 years, the number of medical institutions and diagnostic radiology equipment per million population in China has increased substantially. Dental radiology equipment increased nine-fold, and mammography equipment and computed tomography scanners showed a nearly five-fold increase. The four types of diagnostic radiology equipment, general diagnostic, fluoroscopic, mammography, and computed tomography, were associated with the population. Dental radiology equipment and bone mineral densitometers were related only to the gross domestic product (GDP). A large gap remains in the diagnostic radiology equipment per million population between China and the equipment of health-care level (HCL) I countries.</p></div><div><h3>Conclusions</h3><p>An imbalance in the number of units of diagnostic radiology equipment per million population was observed in the different regions, China. Various types of diagnostic radiology equipment, especially mammography equipment and computed tomography scanners, need to be deployed to meet the medical needs of different populations.</p></div>","PeriodicalId":34051,"journal":{"name":"Radiation Medicine and Protection","volume":"4 3","pages":"Pages 170-175"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42380101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Construction of voxel-based Portunus haanii phantom and its absorbed fractions and specific absorbed fractions calculation based on Monte Carlo simulations","authors":"Yaqin Zhang ,&nbsp;Chunhui Gong ,&nbsp;Chang Guo ,&nbsp;Peng Wang ,&nbsp;Wenjun Wang ,&nbsp;Pengtao Cao ,&nbsp;Qiang Li ,&nbsp;Yi Yang","doi":"10.1016/j.radmp.2023.06.001","DOIUrl":"https://doi.org/10.1016/j.radmp.2023.06.001","url":null,"abstract":"<div><h3>Objective</h3><p>To build the database of the absorbed fractions (AFs) and specific absorbed fractions (SAFs), in order to accurately assess the internal radiation dose in non-human biota.</p></div><div><h3>Methods</h3><p>A voxel-based <em>Portunus haanii</em> phantom was established based on the computed tomography (CT) images. A set of AFs and SAFs were calculated with Monte Carlo toolkit Geant4 for the emission of monoenergetic photons and electrons with energies ranging from 10 ​keV to 5 ​MeV.</p></div><div><h3>Results</h3><p>The mass of the voxel-based <em>Portunus haanii</em> phantom (392.2 ​g) was in agreement with the actual mass (389.2 ​g), indicating the reliability of the phantom. The calculated AFs and SAFs, based on the voxel-based <em>Portunus haanii</em> phantom, provided precise and reliable data for conducting internal radiation dose calculations specifically tailored to the Chinese Red Swimming Crab (<em>Portunus haanii</em>). The results indicated that the self-AFs and self-SAFs were affected by both the radiation energy and the mass of the source/target organ. Moreover, the AFs and SAFs for cross irradiation, were not only dependent on the energy and the mass of the target organ, but also on the relative position of the source and target organs.</p></div><div><h3>Conclusion</h3><p>These results serve as a valuable resource for accurately evaluating the internal radiation exposure of this species.</p></div>","PeriodicalId":34051,"journal":{"name":"Radiation Medicine and Protection","volume":"4 3","pages":"Pages 159-164"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49729658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nomogram for predicting the overall survival of patients after D2/R0 resection and chemoradiotherapy for stage III gastric cancer or gastroesophageal junction cancer","authors":"Jinming Shi ,&nbsp;Wenzhe Kang ,&nbsp;Songlin Gao ,&nbsp;Wenyang Liu ,&nbsp;Yuan Tang ,&nbsp;Ning Li ,&nbsp;Qiang Zeng ,&nbsp;Huiying Ma ,&nbsp;Haoyue Li ,&nbsp;Yantao Tian ,&nbsp;Jing Jin","doi":"10.1016/j.radmp.2023.07.002","DOIUrl":"10.1016/j.radmp.2023.07.002","url":null,"abstract":"<div><h3>Objective</h3><p>To explore the independent factors associated with the overall survival (OS) after D2/R0 resection and adjuvant chemoradiotherapy(CRT) for stage III gastric cancer (GC) and gastroesophageal junction (GEJ) cancer, and establish and validate a nomogram model to predict the OS in this patient population.</p></div><div><h3>Methods</h3><p>A total of 569 stage III GC or GEJ cancer patients who underwent D2/R0 resection and adjuvant CRT at our center from January 2013 to May 2018 were retrospectively enrolled in this study. The patients were randomly divided into training and validation cohorts in a 3:1 ratio. In the training cohort, univariate and multivariate analysis were conducted to identify clinical factors associated with OS, and a nomogram model was established on the basis of the independent factors. The concordance index (C-index) and the calibration curve were used to validate the prediction power of the nomogram.</p></div><div><h3>Results</h3><p>Overall, 427 and 142 patients were enrolled in the training and validation cohorts, respectively. In the univariate and multivariate analyses, age, Lauren's classification, TNM stage, and administration of adjuvant CRT were independent factors for OS to construct the nomogram. The C-index values were 0.654 and 0.613 in the training and validation cohorts, respectively. The calibration curves were identical to the actual OS. Risk stratification based on the nomogram model showed good risk stratification for OS in both groups.</p></div><div><h3>Conclusion</h3><p>Our study included adjuvant CRT as a predictive factor and established a nomogram model for predicting the OS in patients with stage III GC or GEJ after D2/R0 resection and adjuvant therapy. This nomogram could facilitate more individualized prediction of OS in clinical practice.</p></div>","PeriodicalId":34051,"journal":{"name":"Radiation Medicine and Protection","volume":"4 3","pages":"Pages 130-135"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49255080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation on the radioactivity levels of seawater, sediments, and biota in Daya Bay, China","authors":"Fan Cui ,&nbsp;Honghui Huang ,&nbsp;Yi Shen ,&nbsp;Zhan Tan ,&nbsp;Pengxiang Qu ,&nbsp;Ming Dai ,&nbsp;Hongwei Yu ,&nbsp;Weixu Huang ,&nbsp;Zixiang Wu ,&nbsp;Huifeng Chen ,&nbsp;Weizhen Guo ,&nbsp;Yuxin Jia ,&nbsp;Yanbing Liu","doi":"10.1016/j.radmp.2023.07.004","DOIUrl":"10.1016/j.radmp.2023.07.004","url":null,"abstract":"<div><h3>Objective</h3><p>To investigate the radioactivity levels of seawater, sediments, and biota in the Daya Bay sea area, China, in order to establish the radioactivity baseline values, and provide basic data for the assessment of potential radiological risks that might result from the application of nuclear technology or human activities.</p></div><div><h3>Methods</h3><p>Samples of seawater, sediments, and biota were collected from the Daya Bay sea area and analyzed. Their radioactivity baseline data were then compared with information from other regions in China and around the world reported in related literature.</p></div><div><h3>Results</h3><p>For the seawater samples, the activity concentrations of natural radionuclide ⁴⁰K were 9.9–10.4 Bq/L, while ²³⁸U, ²²⁶Ra, ²¹⁰Pb, ¹³⁷Cs, and ¹¹⁰Ag^m were below the minimum detectable activity (MDA). Regarding the sediment samples, the activity concentrations of ²³⁸U, ²²⁸Ra, ²²⁶Ra, ²¹⁰Pb, ⁴⁰K, and ¹³⁷Cs were 38.1–40.4, 49.1−53.7, 32.6−38.6, 59−95, 590−650, and 0.48–0.88 Bq/(kg dry weight), respectively, while ¹¹⁰Ag^m was below the MDA. For the marine shrimps in the biota samples, the activity concentrations of ²²⁸Ra, ²²⁶Ra, ⁴⁰K, and ¹³⁷Cs were 1.14–2.75, 0.17−0.43, 63–76, and 0.038–0.045 Bq/(kg wet weight), respectively, while ²³⁸U, ²¹⁰Pb, and ¹¹⁰Ag^m were all below the MDA. Furthermore, for the marine fishes in the biota samples, the activity concentrations of ²²⁸Ra, ²²⁶Ra, ²¹⁰Pb, ⁴⁰K, and ¹³⁷Cs were 2.1–19.7, 0.32–3.78, &lt;2.2–2.8, 59–70, and &lt;0.007–0.026 Bq/(kg wet weight), respectively, while ²³⁸U and ¹¹⁰Ag^m were all below the MDA. ²²⁸Ra was found to be concentrated in <em>Osteomugil ophuyseni</em> with 19.7 Bq/(kg wet weight).</p></div><div><h3>Conclusions</h3><p>The radioactivity levels of seawater and marine sediments in the Daya Bay sea area are within the range of the normal background values. <em>Osteomugil ophuyseni</em> exhibited higher concentrations of ²²⁸Ra than other species in this study, while the other species in the biota show no significant difference in the radioactivity levels from data in relevant literature.</p></div>","PeriodicalId":34051,"journal":{"name":"Radiation Medicine and Protection","volume":"4 3","pages":"Pages 165-169"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49222176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clinical evaluation of 4D dynamic dose for thoracic tumor stereotactic body radiation therapy with variable parameters","authors":"Yiling Zeng ,&nbsp;Yu Chang ,&nbsp;Sheng Zhang ,&nbsp;Jun Han ,&nbsp;Hongyuan Liu ,&nbsp;Feng Xiao ,&nbsp;Bo Pang ,&nbsp;Bin Hu ,&nbsp;Junping Cheng ,&nbsp;Hong Quan ,&nbsp;Zhiyong Yang","doi":"10.1016/j.radmp.2023.07.003","DOIUrl":"10.1016/j.radmp.2023.07.003","url":null,"abstract":"<div><h3>Objective</h3><p>To evaluate the dose uncertainty in stereotactic body radiation therapy induced by respiratory motion using a 4D dynamic dose (4DDD) reconstruction method.</p></div><div><h3>Methods</h3><p>A retrospective analysis was conducted on five lung cancer patients who received static intensity-modulated radiation therapy. The 4DDD was constructed using beam delivery log files, four-dimensional computed tomography (4DCT) scans, and treatment plans. To evaluate the impact of respiratory motion, 4DDD calculations were performed with 10 starting phases for each field. A total of 270 field doses were simulated and calculated. The differences between the cumulative volume histogram in whole-course treatment and the field doses' gamma passing rate (GPR) were compared. The correlations between plan complexity metrics and the dose deviation caused by respiratory motion were evaluated independently. The phase distributions of 398 subfields were calculated and evaluated for the influence of dose rate and breathing frequency.</p></div><div><h3>Results</h3><p>The GPRs of all fields were different among various starting phases, with the highest range from 62.20% to 76.87% for 2 mm/3% GPR. The deviation of mean point dose was (5.42 ​± ​5.21) %, and the deviation in the mean dose and <span><math><mrow><msub><mi>D</mi><mrow><mn>98</mn><mo>%</mo></mrow></msub></mrow></math></span> within the internal gross tumor volume were (0.97 ​± ​0.71) % and (0.77 ​± ​0.53) %, respectively. There was a significant correlation between the beam aperture-to-volume (BA2V) ratio and the average 2 mm/2% GPR (<em>R ​=</em> 0.601, <em>P</em> ​&lt; ​0.01). Lower dose rates led to a more homogeneous distribution of phases among subfields (<em>t</em> ​= ​44.100, <em>P</em> ​&lt; ​0.001).</p></div><div><h3>Conclusions</h3><p>Different beam starting phases had a limited impact on the overall treatment evaluation. However, the respiratory motion could be observed to induce dose deviations using the 4DDD reconstruction model, particularly for fields with small BA2V.</p></div>","PeriodicalId":34051,"journal":{"name":"Radiation Medicine and Protection","volume":"4 3","pages":"Pages 150-158"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47689090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Attenuation properties of 3D-printed materials for an Ir-192 high dose rate source using Valencia skin applicators","authors":"Jie Zhang ,&nbsp;Wenjun Zhang ,&nbsp;Bo Yang ,&nbsp;Zhequn Liu ,&nbsp;Lang Yu ,&nbsp;Jie Qiu ,&nbsp;Fuquan Zhang","doi":"10.1016/j.radmp.2023.07.001","DOIUrl":"https://doi.org/10.1016/j.radmp.2023.07.001","url":null,"abstract":"<div><h3>Objective</h3><p>To evaluate the physical properties of commonly used 3D-printed materials and the dose attenuation around a high-dose-rate ¹⁹²Ir source, in order to provide a reference for selecting appropriate 3D-printed materials for brachytherapy.</p></div><div><h3>Methods</h3><p>Fifteen 3D-printed materials (12 non-metallic material and 3 metallic material) were assessed. Each material was fabricated into a wafer with a diameter of 30 ​mm and thickness of 3 ​mm using 3D printing. The CT number of each material was measured, and attenuation measurements were conducted with a Valencia skin applicator and well-type ionization chamber. ¹⁹²Ir was used as the radioactive source, and the attenuated ionization charges were normalized against that obtained in the presence of a solid water phantom at the same depth.</p></div><div><h3>Results</h3><p>The CT number of nylon was (−7.78 ​± ​3.36) HU, closest to water among all materials. The CT numbers of the other 11 non-metallic materials were below 300 HU. Moreover, the CT number of the Al alloy was (1,350.89 ​± ​374.55) HU, while the CT numbers of the Ti alloy and stainless steel exceeded 2,976 HU, reaching the upper limit of the CT number range. The results of the attenuation measurements were normalized with the solid water phantom. The average attenuation coefficients of a polyamide, epoxy resin, photosensitive resin, carbon fiber, silica gel, Al alloy, Ti alloy, and stainless steel were 1.003, 0.994, 0.992, 0.995, 0.995, 0.967, 0.939, and 0.866, respectively.</p></div><div><h3>Conclusions</h3><p>Among the common 3D-printed materials with a density similar to that of water, nylon exhibited the best performance, while the metallic materials caused significant dose attenuation and exhibited CT number distortion. As a result, care should be taken when metallic materials are used as 3D-printed materials for brachytherapy.</p></div>","PeriodicalId":34051,"journal":{"name":"Radiation Medicine and Protection","volume":"4 3","pages":"Pages 145-149"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49705862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proteomic analysis of acute radiation-induced rectal injury in rats","authors":"Yue Zhu ,&nbsp;Jun Dai ,&nbsp;Xiaopeng Xu ,&nbsp;Yi Gao ,&nbsp;Weidong Shen ,&nbsp;Shuyu Zhang ,&nbsp;Pengfei Liu","doi":"10.1016/j.radmp.2023.08.003","DOIUrl":"10.1016/j.radmp.2023.08.003","url":null,"abstract":"<div><h3>Objective</h3><p>To comprehensively elucidate overall protein alterations associated with acute radiation-induced rectal injury in rats.</p></div><div><h3>Methods</h3><p>A rat model of acute radiation-induced rectal injury was established by irradiating rectal segments with a single dose of 17.5 ​Gy X-rays. These segments were then collected at 7 d and 10 ​d post-irradiation. Tandem mass tag-based quantitative proteomic analysis was then performed.</p></div><div><h3>Results</h3><p>65,526 peptides were identified, corresponding to 8,088 proteins. Hematoxylin-eosin staining revealed characteristic epithelial cell degeneration and necrosis, intestinal gland atrophy and dilatation, and interstitial inflammatory cell infiltration. Inflammation was more pronounced in the 10 d irradiation group than in the 7 d irradiation group. Overall, 127 up- and 108 downregulated proteins were identified at 7 d post-irradiation, and 122 up- and 44 downregulated proteins were identified at 10 d post-irradiation. Notably, 17 up- and 6 downregulated proteins were consistently co-expressed at both time points. The expression of three of these proteins was validated via real-time quantitative PCR: polypeptide YY (Pyy), thymidylate synthase (Tyms), and tetraspanin (CD9). Tyms transcript levels were significantly higher in irradiated rectal tissues (<em>P</em> ​&lt; ​0.05). Pyy transcript levels were significantly higher at both time points (<em>P</em> ​&lt; ​0.05). Finally, CD9 mRNA expression was significantly lower in both the 7 d and 10 d irradiation groups (<em>P</em> ​&lt; ​0.05).</p></div><div><h3>Conclusions</h3><p>The potential targets were found to prevent and treat acute radiation-induced rectal injury in clinical practice.</p></div>","PeriodicalId":34051,"journal":{"name":"Radiation Medicine and Protection","volume":"4 3","pages":"Pages 117-124"},"PeriodicalIF":0.0,"publicationDate":"2023-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43059927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}