Analysis of setup errors of two different headrest fixation methods in radiotherapy for head and neck tumors by using kilovoltage cone-beam computed tomography
	    		
		   		
		   			
		   		
	    	
    	 
    	10.3760/cma.j.cn115355-20191225-00593
   		
        
        	
        		- VernacularTitle:利用千伏级锥形束计算机断层扫描分析头颈部肿瘤放疗中两种不同头枕固定方式的摆位误差
 
        	
        	
        	
        		- Author:
	        		
		        		
		        		
			        		Youhai XIE
			        		
			        		
			        		
			        			1
			        			
			        		
			        		
			        		
			        		
			        		;
		        		
		        		
		        		
			        		Changyou ZHONG
			        		
			        		;
		        		
		        		
		        		
			        		Hezhong YANG
			        		
			        		;
		        		
		        		
		        		
			        		Zhendong JIANG
			        		
			        		
		        		
		        		
		        		
		        		
		        			
			        		
			        		Author Information
			        		
		        		
		        		
			        		
			        		
			        			1. 广东省梅州市人民医院放射治疗室 514021
			        		
		        		
	        		
        		 
        	
        	
        	
        	
            
            
            	- From:
	            		
	            			Cancer Research and Clinic
	            		
	            		 2020;32(7):498-501
	            	
            	
 
            
            
            	- CountryChina
 
            
            
            	- Language:Chinese
 
            
            
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		        	Abstract:
			       	
			       		
				        
				        	Objective:To investigate setup errors of two fixation methods of transparent head pillow and vacuum bag head pillow in patients with head and neck tumors when undergoing radiotherapy.Methods:A total of 40 patients with head and neck tumors undergoing radiotherapy admitted to Meizhou People's Hospital of Guangdong Province from January 2017 to December 2018 were selected and randomly divided into the control group (transparent head pillow fixation) and the research group (vacuum bag head pillow fixation), with 20 cases in each group. Kilovoltage cone-beam computed tomography (CBCT) was used to obtain the registration image data of each patient for 10 times during the linear accelerator treatment. The linear and rotational positioning errors of two groups were also analyzed.Results:The linear setup errors in the direction of left-right (X-axis), head-foot (Y-axis) and front-back (Z-axis) were (1.1±0.8) mm, (0.9±0.8) mm and (1.2±0.9) mm in the study group, and (1.3±1.1) mm, (1.1±1.1) mm and (1.4±1.1) mm in the control group. The rotation setup error of X-axis, Y-axis, Z-axis was (0.73±0.52) °, (1.08±0.89) ° and (0.89±0.74) °, respectively in the study group, and (0.81±0.69) °, (1.38±1.05) °, (0.88±0.70) °, respectively in the control group. The difference of linear setup error in Y-axis and Z-axis was statistically significant ( P = 0.016, P = 0.004). The difference of rotation setup error in X-axis and Y-axis was statistically significant ( P = 0.036, P = 0.001). Conclusion:The vacuum pillow is better than the transparent pillow in improving the rotation error and linear error for patients with head and neck tumors undergoing radiotherapy.