1.Establishment of a"#-shaped"method of radiotherapy marking of reflecting the range of respiratory motion in radiotherapy
Chenlei GUO ; Ying CAO ; Xin FENG ; Kaixuan ZHANG ; Zhen WANG ; Mingjian SUN ; Yongli SONG ; Xing LIU ; Wenyang LIU ; Jianrong DAI
China Medical Equipment 2025;22(8):52-56
Objective:To propose a novel radiotherapy marking method-the"#"-character method,which aimed at improving the accuracy and repeatability of positioning during radiotherapy.Methods:A specially"cross-shaped"stamp was designed by this study,which consisted of a handheld square base with a"cross-shaped"protrusion.Using this stamp,the extreme positions of end-expiration and end-inspiration were marked respectively at the laser-guided regions on the directly above and bilateral sides of the patient's body,and each position was printed a"+"character.Finally,a"#-shaped"signal was formed,which represented the full range of respiratory motion of patients.The study included two parts:surface displacement caused by respiration was simulated through a three-dimensional(3D)motion platform,which was used to conduct a phantom experiment for anthropomorphic dummy,A randomized controlled study involving 40 patients,who were treated between January and June 2024 at the Department of Radiotherapy,Cancer Hospital,Chinese Academy of Medical Sciences,were conducted.The cohort included 20 patients with breast tumor(Positioning the outer contour by exposing the chest)and 20 patients with thoracic tumor(fixed position of using thermoplastic film).These patients were divided into two groups for comparison,which received respectively the"#-shaped"method and the conventional"+-shaped"method.The cone-beam computed tomography(CBCT)images before treatment were used to compare the influences of the two kinds of marking methods on the positioning errors of patients with breast tumor and patients with thoracic tumor.Then,the statistical analysis was used to assess precision and accuracy of positioning.Results:The result of phantom experiment indicated that the positioning error of the"#-shaped"method was significantly better than that of the"+-shaped"method under various parameters of respiratory movement.Under three kinds of different respiratory cycles(3,4,and 5 seconds)and amplitudes(8,12,and 15 mm),the positioning errors of the"#-shaped"method were respectively(0.15±0.04)cm,(0.19±0.05)cm and(0.35±0.14)cm,while the"+-shaped"method were respectively(0.42±0.16)cm,(0.64±0.28)cm and(0.88±0.37)cm,and the differences were statistically significant(t=8.347,3.416,2.901,P<0.05).The results of actual patients indicated the positioning error[(0.97±0.32)cm]of the"#-shaped"method was significantly lower than[(1.62±0.47)cm]of the"+-shaped"method for patients with breast tumor(Positioning the outer contour by exposing the chest),and the difference was significant(t=3.615,P<0.05).On the other hand,the positioning error[(0.69±0.24)cm]of the"#-shaped"method was significantly lower than[(0.97±0.39)cm]of the"+-shaped"method for patients with thoracic tumor(fixed position of using thermoplastic film),and the difference also was significant(t=1.934,P<0.05).Conclusion:Compared to the conventional"+-shaped"method,the"#-shaped"method appears higher accuracy and repeatability during the positioning process of radiotherapy,which especially is suitable to the treatment for breast tumor and thoracic tumor that need accurately control the influences of respiratory motion.
2.Establishment of a"#-shaped"method of radiotherapy marking of reflecting the range of respiratory motion in radiotherapy
Chenlei GUO ; Ying CAO ; Xin FENG ; Kaixuan ZHANG ; Zhen WANG ; Mingjian SUN ; Yongli SONG ; Xing LIU ; Wenyang LIU ; Jianrong DAI
China Medical Equipment 2025;22(8):52-56
Objective:To propose a novel radiotherapy marking method-the"#"-character method,which aimed at improving the accuracy and repeatability of positioning during radiotherapy.Methods:A specially"cross-shaped"stamp was designed by this study,which consisted of a handheld square base with a"cross-shaped"protrusion.Using this stamp,the extreme positions of end-expiration and end-inspiration were marked respectively at the laser-guided regions on the directly above and bilateral sides of the patient's body,and each position was printed a"+"character.Finally,a"#-shaped"signal was formed,which represented the full range of respiratory motion of patients.The study included two parts:surface displacement caused by respiration was simulated through a three-dimensional(3D)motion platform,which was used to conduct a phantom experiment for anthropomorphic dummy,A randomized controlled study involving 40 patients,who were treated between January and June 2024 at the Department of Radiotherapy,Cancer Hospital,Chinese Academy of Medical Sciences,were conducted.The cohort included 20 patients with breast tumor(Positioning the outer contour by exposing the chest)and 20 patients with thoracic tumor(fixed position of using thermoplastic film).These patients were divided into two groups for comparison,which received respectively the"#-shaped"method and the conventional"+-shaped"method.The cone-beam computed tomography(CBCT)images before treatment were used to compare the influences of the two kinds of marking methods on the positioning errors of patients with breast tumor and patients with thoracic tumor.Then,the statistical analysis was used to assess precision and accuracy of positioning.Results:The result of phantom experiment indicated that the positioning error of the"#-shaped"method was significantly better than that of the"+-shaped"method under various parameters of respiratory movement.Under three kinds of different respiratory cycles(3,4,and 5 seconds)and amplitudes(8,12,and 15 mm),the positioning errors of the"#-shaped"method were respectively(0.15±0.04)cm,(0.19±0.05)cm and(0.35±0.14)cm,while the"+-shaped"method were respectively(0.42±0.16)cm,(0.64±0.28)cm and(0.88±0.37)cm,and the differences were statistically significant(t=8.347,3.416,2.901,P<0.05).The results of actual patients indicated the positioning error[(0.97±0.32)cm]of the"#-shaped"method was significantly lower than[(1.62±0.47)cm]of the"+-shaped"method for patients with breast tumor(Positioning the outer contour by exposing the chest),and the difference was significant(t=3.615,P<0.05).On the other hand,the positioning error[(0.69±0.24)cm]of the"#-shaped"method was significantly lower than[(0.97±0.39)cm]of the"+-shaped"method for patients with thoracic tumor(fixed position of using thermoplastic film),and the difference also was significant(t=1.934,P<0.05).Conclusion:Compared to the conventional"+-shaped"method,the"#-shaped"method appears higher accuracy and repeatability during the positioning process of radiotherapy,which especially is suitable to the treatment for breast tumor and thoracic tumor that need accurately control the influences of respiratory motion.
3.Efficacy of red and blue lights combined with Yufa Shengfa solution and 5% minoxidil solution in treating type Ⅰ female androgenetic alopecia
Chenlei DAI ; Jun LIU ; Xiaoming SUN ; Jinghui YANG ; Jiang MA ; Yuxuan WANG ; Juping CHEN
Journal of Clinical Medicine in Practice 2024;28(24):10-14
Objective To investigate the efficacy of red and blue lights combined with Yufa Shengfa solution and 5% minoxidil solution in treating Ludwig type Ⅰ female androgenetic alopecia. Methods A total of 160 patients with Ludwig type Ⅰ female androgenetic alopecia were randomly divided into group A (Yufa Shengfa solution combined with 5% minoxidil solution), group B (red and blue lights therapy combined with Yufa Shengfa solution), group C (red and blue lights therapy combined with 5% minoxidil solution) and group D (red and blue lights therapy combined with Yufa Shengfa solution and 5% minoxidil solution), with 40 cases in each group. All the patients orally took compound glycyrrhizin tablets and Centrum multivitamins, and the therapeutic period was 3 months. Differences in hair diameter, hair density, and the number of hair follicles with multiple hairs were compared before and after treatment. Results The hair density, hair diameter, and the number of hair follicles with multiple hairs improved significantly in 4 groups compared with those before treatment, and group D showed the best improvement in these parameters, with significant between-group differences (
4.Comparison between the Mycob.T scanner system and manual microscopy in detecting acid-fast bacilli in sputum specimens
Jing LI ; Wanqin DAI ; Chenlei YU ; Feng YUAN ; Lili WANG ; Xin SHEN ; Yuan JIANG
Shanghai Journal of Preventive Medicine 2023;35(1):51-55
ObjectiveTo compare the efficacy between the Mycob.T scanner system and manual microscopy for detecting acid-fast bacilli in sputum specimens. MethodsBetween January and November 2020, a total of 1 519 sputum samples from suspected primary tuberculosis patients from 5 designated tuberculosis hospitals in Shanghai were examined by Smear and BACTEC MGIT 960 liquid culture (liquid culture) methods. Each specimen was subiected to 2 direct smear slides. One slide was stained by Z-N method and examined with manual microscopic method. Another slide was stained and scanned by the Mycob.T system. The efficacy of manual microscopy and the Mycob.T scanner system for detecting acid-fast bacilli in sputum specimens was compared based on the result of liquid culture. Results of the repetitive scanning by the Mycob.T scanner system and the recheck of the manual microscopy were analyzed. ResultsThe average positive rate by the Mycob.T scanner system was 14.4% (219/1 519) while the average positive rate by manual microscopy was 16.3% (248/1 519). No significant difference was observed (χ2=2.13, P=0.145). Based on liquid culture confirmation results, the sensitivity of manual microscopy (60.36%) was higher than that of the Mycob.T scanner system (52.94%), and the difference is statistically significant (χ2=4.38, P=0.036). Both methods had high specificity (98.94%). The concordance of the Mycob.T scanner system and manual microscopy was 95.46%, with the kappa value of 0.826. The results of repeatability test of the Mycob.T scanner system and the recheck results of the manual microscopy showed that the coincidence rate of scanning by the Mycob.T scanner system was 99.5% (436/438), and the recheck coincidence rate by the manual microscopy was 98.6% (432/438). ConclusionThe Mycob.T scanner system have high specificity for detecting acid-fast bacilli in sputum samples and good consistency with the results of manual microscopy. Compared with manual microscopic examination, the Mycob.T scanner system can greatly alleviate the work intensity.
5.Margin expansion for treatment field of volumetric modulated arc therapy for breast cancer
Chenlei GUO ; Yingjie XU ; Jianrong DAI
Chinese Journal of Radiation Oncology 2018;27(9):845-849
Objective We developed a method to expand margin of beam aperture for VMAT treatment planning of breast cancer and evaluated its effectiveness in clinic. Methods An expanded VMAT (E-VMAT) plan for breast cancer using Pinnacle39. 10 planning system was made. A small tissue-equivalent bolus was added at the middle of the breast surface as part of the target and the VMAT plan was generated with beam aperture automatically expanded. Then the tissue-equivalent bolus was removed and the final dose distribution was calculated. Ten patients with breast cancer undergoing breast conserving surgery were tested. The dosimetrical metrics and delivery efficiency were compared between the E-VMAT plans and the routine VMAT plans. Results On the BEV view, it was observed that in E-VMAT plans the collimator and MLC leaf positions was extended outside the skin along the anterior-posterior direction of the thorax. There were no significant differences in conformity index and homogeneity index of target volume between the two types of plans and the planned delivery efficiency was consistent (P>0. 05). Conclusions The method established in this study can automatically generate expansion of VMAT beam apertures and prevent missing of target volume due to respiratory motion and/ or setup error of the patient. The method does not require programming skill and available for different treatment planning systems.


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