Radiation Medicine and Protection最新文献

Obesity, hyperglycemia, hypertension, hypertriglyceridemia and low high-density lipoprotein cholesterol are the typical features of Metabolic syndrome (MetS). Exploring the risk factors would benefit for prevention control. Several studies have revealed an association between ionizing radiation (IR) exposure and MetS, likely attributable to production of reactive oxygen species (ROS), oxidative stress, DNA damage. Understanding the health effects of IR exposure, which have long been overlooked, would improve knowledge on MetS and help identify effective strategies for targeted prevention of MetS. In this review, we first highlight the importance of IR and MetS, providing information on the wide use of IR in the field, IR-induced damage, and the prevalence and burden of MetS. Then, we summarize the findings association between IR and various components of MetS addressing the dual effects of IR on MetS in a dose-response manner. Although there remain unresolved challenges, study on the association of radiation and MetS could open new perspectives in the future.

Objective

To explore the value of Endostar in the clinical application of locally advanced cervical cancer.

Methods

A total of 107 patients with locally advanced cervical cancer who received concurrent chemoradiotherapy (CCRT) in the Department of Radiotherapy, the First Affiliated Hospital of Soochow University and Changzhou No.2 People's Hospital between January 2018 and December 2020 were enrolled in this retrospective study. There were 30 cases in the Endostar combined with CCRT (E-CCRT) group and 77 in the CCRT group. Propensity score matching (PSM) was used to reduce confounding factors. The short-term efficacy and long-term survival rate were compared between the E-CCRT group and the CCRT group.

Results

After matching, the objective response rates in the E-CCRT group and CCRT group were 86.7% and 63.3%, respectively, with statistically significant difference (χ² = 4.356, P ​= ​0.037). But there were no statistically significant differences in the disease control rates (96.7% vs. 86.7%, χ² = 0.873, P ​= 0.350), 3-year overall survival (OS) rates (86.7% vs. 83.3%, P ​= ​0.681), and 3-year disease-free survival (DFS) rates (both 76.7% and 76.7%, P ​= ​0.869). There was no statistically significant difference in the incidence of adverse reactions between the two groups.

Conclusions

E-CCRT can improve the response of locally advanced cervical cancer patients without increasing the occurrence of adverse reactions, and has the potential to become a new treatment regimen for cervical cancer.

Objective

To develop a computational model of a multi-detector CT scanner (MDCT), which could be used to simulate the signal of each detector element in the MDCT by using the Monte Carlo method.

Methods

The CT scanner was modelled, including the X-ray source, the bowtie filter, the collimator, the couch and the detector panel. Under a general scanning condition, the signal in each detector element was simulated based on the model by using the MCNPX code. Both the energy spectra at different tube voltages and energy deposition in the detector panel at different collimations were simulated to test the robustness of the MDCT model built in this study. Furthermore, the simulated signals in each detector element were compared with their recorded signals. The accuracies were evaluated by the relative root mean square error (RRMSE) and the structural similarity (SSIM) for each detector element and the whole detector panel, respectively.

Results

The simulated energy spectra before and after passing through the phantom and simulated energy deposition in the detector panel were rational. In the scan range from the apex of lung to pubic symphysis, the RRMSE of the 18 axial projections ranged from 0.02 to 0.17, with an average of 0.08. And the SSIMs were calculated to be 0.979 and 0.976 for projections with the largest peak signal and the smallest peak signal, respectively.

Conclusions

The computational model of the MDCT developed in this study is accurate and successful, it is helpful for further accurate simulations of the radiation dose and image quality of the MDCT.

Objective

To clarify the length and volume reduction of seminal vesicles (SVs) after neo-adjuvant hormonal therapy (NHT), in order to help contour the optimal SV included into high-dose clinical target volume (CTV) for radiotherapy in intermediate- and high-risk patients.

Methods

MR images both before and after NHT (5.3 ​± ​2.2 months) were collected from thirty-one patients with cT2-4N0M0 prostate cancer. SV volume was measured in axial T1WI, while SV length was obtained in a reconstructed oblique coronary plane through its long axial from a 3D sequence.

Results

SVs showed evident reduction both in length and volume (length: median 12.1%, range 4.0%–28.0%; volume: median 39.9%, range 9.4%–66.2%). For SVs with and without MR detected involvement, length shortening were (16.7 ​± ​4.8)% and (11.1 ​± ​4.4)% (P ​< ​0.001); for involved SVs and lesions, volume reduction were (41.0 ​± ​16.0)% and (66.3 ​± ​14.4)%, respectively (P ​< ​0.001), both indicating a more sensitive response to NHT of the involved portion than normal SV.

Conclusions

Both volume and length of the SV will be reduced after receiving NHT. Besides, the invaded segments shrink more than normal SV tissue, indicating that SV portion included within the CTV can be reduced.

Objective

To investigate the differences in small intestinal toxicity and taxonomic composition, diversity, and functional pathways of gut microbiome and metabolome after different radiotherapies in mouse colorectal cancer (CRC) model.

Methods

Azoxymethane/dextran sodium sulfate (AOM/DSS)-induced mouse CRC model was treated with single pulse FLASH-RT (dose rate 100 ​Gy/s) or CONV-RT (dose rate 2 ​Gy/min) at whole abdomen. At 12 ​d after radiotherapy, sections of small intestinal tract tissue were dissected for hematoxylin and eosin (HE) staining and the fresh feces were collected for 16S ribosomal RNA (rRNA) microbiome sequencing and liquid chromatography and mass spectrometry (LC-MS) metabolomics sequencing to assess changes in the gut microbiota and metabolites. Microbial high-throughput 16S rRNA data was analyzed with QIIME2 and LEfSe softwares. ProteoWizard, XCMS and Ropls softwares were used for LC-MS analysis.

Results

HE staining showed that FLASH-RT maintained small intestinal integrity and reduced the radiotherapy-induced injury. Sequencing analysis of gut fecal microbiome showed that phylum Bacteroidetes and genera Prevotella and Lactobacillus of microbial community were increased after FLASH-RT. Metabolomics sequencing analysis revealed that the metabolites after FLASH-RT were enriched in amino acid metabolism, while cholesterol metabolism was top enriched after CONV-RT.

Conclusions

FLASH-RT significantly mitigates the small intestine tissue damage compared with CONV-RT. FLASH-RT and CONV-RT have different impact on gut microbiota and its metabolites. Our results provide a theoretical basis for the early evaluation, prediction and individualized treatment of the irradiation effect after novel FLASH-RT on tumors through the evaluation of intestinal microbiota and metabolites.

Objective

To explore the toxicity and cellular uptake of the self-synthesized second mitochondria-derived activator of caspase (SMAC) mimetic TP-WY-1345 polypeptide and its radiosensitizing effect on non-small cell lung cancer (NSCLC).

Methods

A fluorescence microscope was used to observe the uptake efficiency of TP-WY-1345 by human NSCLC cells H1299. Toxicity of the TP-WY-1345 peptide in normal cells was examined in human embryonic lung fibroblasts MRC5. CCK-8 and clone formation experiments were performed to detect the radiosensitizing effect of TP-WY-1345 in the H1299 ​cells. The AutoDock Vina simulation software was employed to predict the binding efficiency of TP-WY-1345 to the inhibitor of apoptosis proteins (IAPs). Moreover, Western blot and qPCR experiments were carried out to determine the protein and gene expressions, and the flow cytometry (FCM) technique was used to detect the apoptosis level under different conditions.

Results

TP-WY-1345 can be self-synthesized, and significant green fluorescence was observed in H1299 2 ​h and 6 ​h after incubation with TP-WY-1345. The cell counting and CCK-8 results showed that 10 ​μmol/L and 20 ​μmol/L TP-WY-1345 did not produce a significant toxic effect on the MRC5 cells (P ​> ​0.05). Compared with the single ionizing radiation group, the cell viability and clone formation of H1299 ​cells were significantly inhibited after treatment with TP-WY-1345 at a concentration of 50 ​μmol/L (P ​< 0.05). The sensitivity enhancement ratio (SER) was calculated to be 1.14. Moreover, the binding efficiency of TP-WY-1345 to cIAP1 protein was predicted to be −7.3, and this strong binding force was demonstrated by Western blot. TP-WY-1345 inhibited the protein and mRNA expressions of cIAP1 and further increased the apoptosis level of the H1299 ​cells at 24 ​h ​(P ​< ​0.01) and 48 ​h after radiation (P ​< ​0.05).

Conclusion

SMAC mimetic TP-WY-1345 can enter the H1299 ​cells and produce a radiosensitizing effect by increasing the level of radiation-induced apoptosis of the cells. There, TP-WY-1345 is expected to become a new generation of radiosensitizing drugs.

Objective

To understand differential effects on induction of genotoxicity and genomic instability (GI) by high-LET particle radiation and low-LET photon radiation, based on ground-based experiments using total body irradiation (TBI) of mice with Fe-particle radiation and X-ray radiation.

Methods

TBI was delivered to C57BL/6J Jms strain female mice of 8 weeks old at a dose ranging from 0.1 to 3.0 Gy of Fe-particle radiation or at a dose ranging from 0.1 to 5.0 Gy of X-ray radiation. Induction of genotoxicity and GI by TBI was determined respectively at 1 and 2 months after exposure using frequency of micronuclei in bone marrow erythrocytes as the endpoint. Inhibition of bone marrow cell proliferation by TBI was measured as reduced erythropoiesis. Physiological conditions were also investigated.

Results

TBI, regardless of the type of radiation, caused statistically significant increase in genotoxicity at 1 month after exposure, but did not induce GI at 2 months after exposure even at higher doses (>1.0 Gy). The dose-response curve for the frequency of micronucleated polychromatic erythrocytes induced by Fe-particle radiation and X-ray radiation was y ​= ​0.7798 ​+ ​1.7889x– 0.5978x² (R² = 0.8109) and y ​= ​0.7421 ​+ ​1.3792x – 0.2588 x² (R² = 0.8081), respectively. The dose-response curve for the frequency of micronucleated normochromatic erythrocytes induced by Fe-particle radiation and X-ray radiation was y ​= ​0.7191 ​+ ​1.4545x – 0.4978x² (R² = 0.7047) and y ​= ​0.658 ​+ ​1.344x – 0.2531x² (R² = 0.7853), respectively. In general, high-LET Fe-particle radiation was more efficient in inducing genotoxicity than low-LET X-ray radiation at lower doses (<0.5 Gy).

Conclusions

These results further confirm that exposure to TBI, even at higher doses and regardless the type of radiation, does not induce GI in C57BL/6J strain mice measured as increased micronuclei in bone marrow erythrocytes. These findings indicate that radiation-induced GI is mouse strain dependent and suggest that more comprehensive studies should be done to explore the late health consequences from exposure to high-LET radiation at low doses.

Objective

To construct a novel polygenic risk scoring model, in order to predict the benefits of radiosensitivity in patients with non-metastatic breast cancer (NMBC).

Methods

A total of 450 NMBC patients from The Cancer Genome Atlas (TCGA) were enrolled and randomly assigned 6:4 (training vs. validation). The empirical Bayes differential analysis was used to perform differential expression analysis, univariate Cox regression and Kaplan-Meier analysis were used to screen for prognosis-related genes. Finally, LASSO regression and stepwise regression were used to select key prognostic-related genes. We constructed a multivariate Cox proportional risk regression model using key genes. The pRRophetic function was used to predict drug sensitivity of radiosensitivity (RS) and radioresistance (RR) groups for adjuvant therapy.

Results

Eight genes (AMH, H2BU1, HOXB13, TMEM132A, TMEM270, ODF3L1, RIIAD1 and RIMBP2) were screened to build a polygenic risk scoring model. The region of characteristic (ROC) curves were drawn based on the 3-, 5- and 10-year overall survival (OS), with area under curves (AUCs) of 0.816, 0.822 and 0.806, respectively. RS and RR can be effectively distinguished according to the risk score of 2.004. Gene set enrichment analysis (GSEA) showed that necroptosis was significantly enriched in RS, while complement and coagulation cascade, JAK-STAT and PPAR signaling pathways were significantly enriched in RR. Alternatively, for those radioresistant patients, the chemotherapy drugs that might be more helpful are Cisplatin, Docetaxel, Methotrexate and Vinblastine with higher drug sensitivity.

Conclusion

The polygenic risk scoring model showed prediction for the benefit of radiotherapy in NMBC patients, which might be used to guide clinical practice.

Objective

To evaluate the knowledge of CT technologists and radiographers concerning CT parameters, in order to keep CT users be aware of all CT parameters and their impact on image quality and patient dose while keeping their knowledge up to date.

Methods

This cross-sectional descriptive-analytic study was conducted in Zanjan province, Iran, using a valid and reliable online questionnaire with 53 questions distributed to 153 radiology personnel. Each questionnaire included questions about demographic characteristics and CT parameters, including kVp, mAs, image noise, slice thickness, pitch and automatic tube current modulation (ATCM), and the effects of these parameters on image quality and radiation dose.

Results

A response rate of 61.0% (94/153) was achieved. This study enrolled 30 radiographers and 64 CT technologists. There was no significant difference in the mean scores of the two groups (52.16 $\pm$ 9.90 vs. 56.09 $\pm$ 12.00, t ​= ​−1.545, P ​= ​0.126). CT personnel had the highest and lowest knowledge scores in image reconstruction (t ​= ​−28.33, P ​= ​0.001) and mAs (t ​= ​4.27, P ​= ​0.590), respectively, whereas radiographers had the highest and lowest knowledge scores in the fields of image noise (t ​= ​9.85, P ​= ​0.015) and kVp (t ​= ​−12.73, P ​= ​0.007), respectively.

Conclusions

The total knowledge scores of CT technologists and radiographers for various scan parameters affecting image quality and dose were insufficient. Thus, it is recommended that regular retraining courses be held to enhance and update technologists’ knowledge.

Objective

To evaluate the knowledge and practices of Moroccan physicians in terms of radioprotection of patients when prescribing computed tomography (CT) procedures.

Methods

This is a cross-sectional study in which a questionnaire with 23 multiple-choice questions was sent to prescribers of CT examinations such as radiotherapists (RMs), other medical specialists (OMSs), general practitioners (GPs) and residents/interns (R/Is). The first eight questions asked about the demographics of the participants, while the remaining questions asked about knowledge of ionizing radiation examinations, doses received, relative risks, and patient radiation safety training.

Results

A total of 223 physicians participated in this survey. Radiation therapists, considered as the reference group, had a better knowledge of irradiating and non-irradiating imaging compared to the other groups (P ​= ​0.003). Thus, 67% of the reference group declared to take into account the number of scans performed by the patient during the last year, unlike the other groups (P ​= ​0.002). Furthermore, the knowledge of the different groups about the risks related to exposure to ionizing radiation was globally low (2%) (P ​= ​0.73). Regardless of their specialties and seniority, only 12% of the participants informed the patient at the time of prescription about the risks of X-rays. Finally, only 21% of the participants declared having had training in radiation protection, with no significant differences between the subgroups (P ​= ​0.832).

Conclusions

The results obtained are similar to those reported in previous studies. They show that Moroccan prescribers have a low level of knowledge of the risks associated with CT examinations. Training on patient radiation protection should be included in the initial curriculum of interns and the continuing professional development of physicians should be reinforced.