Effect of skin color on the setup of surface optical system in radiotherapy / 中华放射肿瘤学杂志

Objective:To investigate the sensitivity of the Catalyst HD in monitoring different skin colors, and assess the effect of skin color on the setup uncertainties using this system in radiotherapy.Methods:The standard cards guiding skin color and the cylinder model guiding quality control in radiotherapy were utilized to simulate the patients’ positioning. During the first monitoring, Catalyst HD was employed to acquire the image of the phantom as the reference image after conventional positioning (indoor laser+ phantom marking). When it was not the first monitoring, the couch was moved (-5 to 5 mm, step length of 2 mm) and Catalyst HD was adopted to obtain the surface image after conventional positioning. The bed deviation and corresponding setup errors monitored by Catalyst HD for different skin colors were recorded in the anterior-posterior (AP), superior-inferior (SI) and left-right (LR) direction, respectively.Results:During Catalyst HD monitoring, the integration time and gain were increased with the darker color. The logarithm of integration time and gain was significantly linearly negatively correlated with the same color ( R2>0.9). When the color difference with 1Y01SP was ΔE≤189, there was a significant correlation between the bed deviation and corresponding setup errors monitored by Catalyst HD in the SI and LR directions (R SI>0.5, R LR>0.5, R AP>0.9). The Catalyst HD monitoring was rapid and stable. When 218≤ΔE≤253, the correlation coefficients of them in the LR were R LR<0.3 and the Catalyst HD monitoring was stable. When 254≤ΔE≤285, the Catalyst HD failed to monitor stably. When ΔE>318, it failed to monitor this skin color. Conclusions:Gain, integration time and color have a certain correlation. The Catalyst HD can accurately monitor the setup errors within a specific range of skin color.

The effect of age on skin elasticity and setup error in optical surface image-guided radiotherapy / 中华放射肿瘤学杂志

Objective To investigate the correlation between skin elasticity and setup error in optical surface image-guided radiotherapy.Methods The skin elasticity (R7) data of the head,chest and abdomen were extracted and analyzed its correlation with age by systematic literature review.Fifty-four patients diagnosed with nasopharyngeal carcinoma,breast cancer and cervical cancer were recruited in this study.Firstly,the patients were positioned based on the room laser and markers.Subsequently,the patient position was verified by the Varian On-Board Imager,and then C-Rad Catalyst was adopted to obtain surface images in two states (mask or non-mask) as reference images.In the subsequent fraction treatment,after initial positioning,the local calibration was performed by Catalyst,and setup errors in three directions were recorded.Meanwhile,the patient setup was verified by CBCT twice a week.The Pearson correlation analysis was performed to analyze the correlation between setup error and age.Results The skin elasticity was negatively correlated with aging (P＜0.01).The correlation coefficient between random error and age in headand-neck cancer were 0.645,0.624 and 0.866 in the AP,SI and LR directions (all P＜0.05) for male patients without mask,respectively.The system error was significantly correlated with age in the LR direction (P＜0.05) for male patients,and in the AP direction (P＜ 0.05) for female patients with head-and-neck cancer without mask.The setup error had a significant correlation with skin elasticity in male patients with head-and-neck cancer,and the sequence of absolute value of correlation coefficient was LR ＞ SI ＞ AP.Conclusion In optical surface-guided radiotherapy of head and neck cancer,skin elasticity may be a significant index for assessing the setup errors in male patients.

The effect of age on skin elasticity and setup error in optical surface image-guided radiotherapy / 中华放射肿瘤学杂志

Objective@#To investigate the correlation between skin elasticity and setup error in optical surface image-guided radiotherapy.@*Methods@#The skin elasticity (R7) data of the head, chest and abdomen were extracted and analyzed its correlation with age by systematic literature review. Fifty-four patients diagnosed with nasopharyngeal carcinoma, breast cancer and cervical cancer were recruited in this study. Firstly, the patients were positioned based on the room laser and markers. Subsequently, the patient position was verified by the Varian On-Board Imager, and then C-Rad Catalyst was adopted to obtain surface images in two states (mask or non-mask) as reference images. In the subsequent fraction treatment, after initial positioning, the local calibration was performed by Catalyst, and setup errors in three directions were recorded. Meanwhile, the patient setup was verified by CBCT twice a week. The Pearson correlation analysis was performed to analyze the correlation between setup error and age.@*Results@#The skin elasticity was negatively correlated with aging (P<0.01). The correlation coefficient between random error and age in head-and-neck cancer were 0.645, 0.624 and 0.866 in the AP, SI and LR directions (all P<0.05) for male patients without mask, respectively. The system error was significantly correlated with age in the LR direction (P<0.05) for male patients, and in the AP direction (P<0.05) for female patients with head-and-neck cancer without mask. The setup error had a significant correlation with skin elasticity in male patients with head-and-neck cancer, and the sequence of absolute value of correlation coefficient was LR>SI>AP.@*Conclusion@#In optical surface-guided radiotherapy of head and neck cancer, skin elasticity may be a significant index for assessing the setup errors in male patients.

Inhibitory effect of connexin43 protein on autophagy in cisplatin-resistant testicular cancer I-10 cells / 南方医科大学学报

OBJECTIVE@#To investigate the effect of connexin43 (Cx43) protein on autophagy in cisplatin (DDP)-resistant testicular cancer I-10 cells.@*METHODS@#The expression of Cx43 proteins in testicular cancer I-10 cells and I-10/DDP cells were detected with Western blotting. I-10/DDP cells were transfected with a full- length mouse Cx43 vector (mCx43) Lipofectamine, the empty vector or Lipofectamine (blank control group), and the changes in the expressions of LC3 and p62 proteins were determined with Western blotting. mCherry-GFP-LC3B transfection and transmission electron microscopy were used to analyze the changes in autophagy of the cells with Cx43 overexpression.@*RESULTS@#Cx43 was significantly decreased in I-10/DDP cells compared with I-10 cells ( < 0.01). Transfection of the I-10/DDP cells with mCx43 vector resulted in significantly increased Cx43 expression in the cells ( < 0.01) and caused significantly decreased expression of LC3-Ⅱ ( < 0.01) and increased expression of p62 ( < 0.05) as compared with the negative control cells. Both transmission electron microscopy and mCherry-GFP-LC3B transfection showed that the number of autophagosomes was obviously reduced in mCx43-transfected cells as compared with the negative control cells.@*CONCLUSIONS@#Cx43 inhibits autophagy in cisplatin-resistant testicular cancer I-10 /DDP cells.

Clinical application of Catalyst system in cervical cancer radiotherapy / 中华放射肿瘤学杂志

Objective To evaluate the clinical application of Catalyst system in positioning patients during cervical cancer radiotherapy,and to analyze its correlation with the bladder volume and body mass index (BMI) of patients.Methods A total of 33 patients diagnosed with cervical cancer from July to December 2017 in our hospital were included in the study.All patients were auxiliary positioned by an optical surface imaging system (C-Pad Catalyst) before each treatment.The CBCT imaging was executed twice a week.The setup errors from Catalyst and CBCT in the anterior-posterior (AP),superior-inferior (SI) and leg-fight (LR) directions were recorded.Each patient's bladder volume and BMI were also recorded.Results The setup errors between Catalyst with masks and CBCT had the significant difference in SI (P＜0.05) and LR (P＜0.05).For Catalyst without masks,the setup errors with the bladder volume of 200-300 ml had the significant association in SI (R=-0.316,P＜0.05).For the bladder volume of＞300 ml,the setup errors for Catalyst with masks had the significant association in AP (R=-0.493,P＜0.05),and that without masks had the significant association in SI and LR (R=0.335,P＜0.05,R=-0.348,P＜0.05).For patients of＜25 kg/m2,setup errors for Catalyst with masks had the significant association with the BMI in LR (R=0.197,P＜0.05);for ≥ 25 kg/m2,that with masks had the significant association in AP and SI (R =0.818,P＜0.05;R=-0.498,P＜0.05),that without masks had the significant association in AP and LR (R=0.652,P＜0.05;R=-0.558,P＜0.05).Conclusion Unlike CBCT system,the patient positioning by Catalyst system was easily affected by the bladder volume and BMI of patients.