Volume of prophylactic irradiation to neck for stage N0 nasopharyngeal carcinoma patients treated with intensity-modulated radiotherapy
	    		
		   		
		   			
		   		
	    	
    	 
    	10.3760/cma.j.issn.1004-4221.2013.02.013
   		
        
        	
        		- VernacularTitle:基于调强放疗N0期鼻咽癌颈部预防照射的选择
 
        	
        	
        	
        		- Author:
	        		
		        		
		        		
			        		Lei ZENG
			        		
			        		;
		        		
		        		
		        		
			        		Chunyan CHEN
			        		
			        		;
		        		
		        		
		        		
			        		Xueming SUN
			        		
			        		;
		        		
		        		
		        		
			        		Fei HAN
			        		
			        		;
		        		
		        		
		        		
			        		Xiaowu DENG
			        		
			        		;
		        		
		        		
		        		
			        		Taixiang LU
			        		
			        		
		        		
		        		
		        		
		        		
		        		
			        		
			        		
		        		
	        		
        		 
        	
        	
        	
        		- Publication Type:Journal Article
 
        	
        	
        		- Keywords:
        			
	        			
	        				
	        				
			        		
				        		Nasopharyngeal neoplasms / radiotherapy;
			        		
			        		
			        		
				        		Radiotherapy,intensity-modulated;
			        		
			        		
			        		
				        		Prophylactic irradiation to the neck;
			        		
			        		
			        		
				        		Prognosis
			        		
			        		
	        			
        			
        		
 
        	
            
            
            	- From:
	            		
	            			Chinese Journal of Radiation Oncology
	            		
	            		 2013;(2):133-137
	            	
            	
 
            
            
            	- CountryChina
 
            
            
            	- Language:Chinese
 
            
            
            	- 
		        	Abstract:
			       	
			       		
				        
				        	Objective To investigate the volume of prophylactic irradiation to the neck for stage N0 nasopharyngeal carcinoma (NPC) patients treated with intensity-modulated radiotherapy (IMRT).Methods Retrospective analysis was performed on the clinical records of 270 patients with stage N0 NPC (based on the 6th version of AJCC/UICC staging system),who underwent IMRT as the initial treatment in our center from 2003 to 2008.Among all the patients,171 received prophylactic upper-neck irradiation,and 99 prophylactic whole-neck irradiation.All of them received 6-MV X-ray IMRT to the primary focus of NPC and the lymphatic drainage area in the upper neck (Levels Ⅱ,Ⅲ,and Ⅴ A lymph nodes) at doses of 68 Gy/30fractions and 54 Gy/30 fractions over 6 weeks.In addition,the patients receiving prophylactic whole-neck irradiation had the lower neck and supraclavicular fossae treated by anterior neck semi-field conventional technique at a dose of 50 Gy/25 fractions.Results The median follow-up was 65.1 months (range 4-106months),and the follow-up rate was 93%.The patients undergoing prophylactic upper-neck irradiation and prophylactic whole-neck irradiation had 5-year disease specific survival rates of 95.3% and 91.9% (x2 =0.76,P =0.384),relapse-free survival rates of 99.4% and 99.0% (x2 =1.18,P =0.278),and distant metastasis-free survival rates of 98.8% and 94.9% (x2 =2.31,P =0.128).The 5-year distant metastasisfree survival rate was significantly higher in patients without retropharyngeal lymph node (RLN) metastasis than in those with RLN metastasis (99.4% vs.93.7%,x2 =8.96,P =0.003).Grade 1-2 mucositis and pharyngitis were the most common acute adverse reactions in patients.At 24 months after IMRT,no grade 3 or 4 xerostomia and trismus were developed.Conclusions Prophylactic irradiation to the upper neck may be feasible for stage N0 NPC patients treated with IMRT.It is reasonable in the 7th version of AJCC/UICC staging system that NPC with negative cervical lymph nodes and positive RLNs is reclassified to stage N1.