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Objective:To investigate the technical method and clinical efficacy of CT-guided radioactive 125I seed implantation (RISI) assisted by 3D-printed coplanar template(3D-PCT) in the treatment of metastatic tumors of chest wall, and analyze the influence of dosimetric parameters on the treatment efficacy. Methods:A retrospective analysis was conducted for 55 patients with metastatic tumors of chest wall treated with 3D-PCT-assisted 125I radioactive seed implantation in Tengzhou Central People′s Hospital from January 2014 to March 2021.Preoperative plans were made using a brachytherapy treatment planning system, and dosimetric parameters were assessed at 3d after surgery. During regular CT reexaminations after surgery, the local control rate and overall survival (OS) rate were calculated and the pain relief degree and complications were assessed. The Logrank test and Cox regression were used for univariate and multivariate analyses of local control time (LCT). Meanwhile, receiver operating characteristic (ROC) curves were plotted to analyze the critical values of dosimetric parameters and to predict the LCT. Results:The 1-, 2-, and 3-year OS rates ofthe 55 patients were 72.7% (40/55), 21.8% (12/55), and 16.4% (9/55), respectively.The local control rates of 3, 6, 12, and 24 months were 96.4%(53/55), 86.5%(45/52), 85.0%(34/40), and 91.7%(11/12), respectively. There was no statistically significant difference between postoperative and postoperative dosimetric parameters of GTV, particle number, D90, D100, V100, V150, V200, CI, EI, and HI ( P> 0.05). Compared with postoperative V90, the postoperative V90 decreased with a statistically significant difference( P=0.006). As indicated by the univariate Cox regression analysis, the pathological grade, D90, D100, V90, and V200had significant effects on the LCT( P<0.05). Among them, the pathological grade and D90 were independent influencing factors of the LCT, while the other factors showed no statistically significant difference according to the multivariate Cox regression analysis.The LCT of patients with D90≥127 Gy was significantly longer than that of patients with D90<127 Gy (χ 2=16.61, P=0.000). The pain relief rate was 80.8%(21/26) after three months. Five cases suffered from grade Ⅰ-Ⅱ radioactive dermatitis and one case experienced grade Ⅲ radioactive dermatitis. Conclusions:The 3D-PCT-assisted CT-guided 125I radioactive seed implementation can achieve precise and controllable dose and definite efficacy in the treatment of metastatic tumors of chest wall, with few complications.The LCT was remarkably prolonged in the case of D90≥127 Gy, and D90 is an independent influencing factor of the LCT.
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Objective To compare the dose distribution of postoperative plans with preoperative plans for 3D printing coplanar template assisted radioactive seed implantation,and to explore the accuracy of the technique in seed implantation.Methods From November 2015 to December 2016 a total of 32 patients were selected and underwent 3D printing coplanar template assisted radioactive seed implantation in Tengzhou Central People's Hospital of Shandong province.There were 36 implanted lesions,including l0 in the lungs,5 in neck lymphs,3 in pelvic cavities,3 in vertebral body,2 in pancreas,2 in abdominal lymph nodes,2 in portal veins,and 9 in the other parts.All patients were given preoperative planning and guided by the coplanar templates.Compared with the preoperative plan,all levels needles inserted at the same time.According to preoperative planning the implantation surgery was completed accurately.The postoperative dosimetry was evaluated.The preoperative and postoperative dosimetry parameters were compared,including Dg0,D100,V90,V100.V150,V200 and conformal index (CI),external index (EI),and homogeneity index(HI).The paired t test was used to perform the statistical analysis.Result There was no significant differences in Dg0,D100,V90,V100,V150,V200,CI,EI and HI between before and after operation(P ＞ 0.05).Conclusions The dose parameters in postplan showed no difference compared with preplan in this study.For fixed and moving organ tumors,3D printing coplanar template assisted radioactive seed implantation has good therapeutic accuracy,and may be a standardized surgicalmethod for seed implantation in the future.
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Objective:To obtain stable radioresistant non-small-cell lung cancer (NSCLC) cell lines and identify the genetic pattern of conventional fractioned and hypofractionated radiotherapy. Methods:A549 NSCLC cells were treated with 6 MV of x-rays through conventional fractionated (2 Gy, 17 f) and hypofractionated irradiation (4 Gy, 7 f) to establish a radiation resistance cell model. Tumor cell radioresistance was determined using a clonogenic assay andγ-H2AX immunofluorescence staining combined with confocal microscopy. After extracting total mRNA from the cells, a whole genome expression microarray was applied to detect differential gene expression. The genes with at least a twofold increase in expression (P<0.05) were analyzed, and the pathway (Q<0.05) methods were used to further analyze the chip results. Results:After irradiating the A549 cells, two radioresistant cell lines were obtained, namely, the A549R2Gy-R and the A549R4Gy-R cell lines. The A549R2Gy-R cell line was radioresistant to the conventional fractionated irradiation, whereas the A549R4Gy-R cell line was ra-dioresistant to hypofractionated irradiation. Microarray analysis showed that the A549R2Gy-R cells exhibited 1 701 differentially expressed genes (357 upregulated, 1 344 downregulated) compared with the parental A549 cell. By contrast, the hypofractionated irradiation-resistant A549R4Gy-R cells had 944 upregulated genes and 2 602 downregulated genes compared with the A549 cells. The A549R2Gy-R cells exhibited 318 upregulated genes and 699 downregulated genes compared with the A549R4Gy-R cells. Several signaling pathways were implicated in radioresistance when conventional fractionated radiotherapy was compared with hypofractionated irradiation radiotherapy using path way-significant enrichment analysis, especially the PI3K and Erb B channel signaling pathway kinase. Conclusion:Multiple genes and signaling pathways are involved in the development of radiation resistance in NSCLC. The underlined radioresistance mechanisms under conventional and hypofractionated radiotherapy need further study and elucidation to provide new targets for drug development.