鼻咽癌放疗中影像所示肿瘤退缩情况与远期预后的关系

目的]分析放射治疗中鼻咽增强螺旋CT或增强MRI所示肿瘤退缩情况与长期疗效的关系。方法]2001年6月至2003年8月,100例经病理证实的初治鼻咽癌患者在我院接受根治性放射治疗。所有病例在放射治疗前及放疗至50Gy时行螺旋CT或MRI检查评价治疗效果，按WHO标准．分别测量并记录肿瘤最大横截面积（S0为治疗前，S50为放疗至50Gy时）。按肿瘤最大横截面积的消退率（Rs）进行分组：Rs=（S0-S50）／S0。按Rs≥0．9，0．9〉Rs≥0．7，Rs〈0．7分三组．分别定义为高度敏感组（HSG），中度敏感组（MSG）和低度敏感组（LSC）。结果]全组患者5年局部控制率（LCR）、无远处转移生存率（DMFS）、无瘤生存率（DFS）、疾病相关生存率（DSS）、总生存率（OS）分别为78.3％、80．8％、63．1％、71．6％和60．4％。HSG、MSG、LSG组的5年LCR分别为94．4％、85．6％、62．3％（P=0．004），5年DFS分别为82．1％、75．1％、43.3％（P=0．005）。3组5年DMFS、DSS、OS无显著性差异（P值分别为0．346、0．394和0．590）。Cox多因素分析结果显示5年LCR与消退率分组、患者年龄及放疗前肿瘤大小具有显著相关性.结论]放射治疗中复查鼻咽增强螺旋CT或增强MRI所示肿瘤退缩情况对肿瘤局部控制率具有很好的预测价值，但需进一步加大样本量临床研究证实。

Relationship Between Tumor Regression During Radiotherapy and Long-Term Outcome in Nasopharyngeal Cancer

Purpose] To investigate the relationship between tumor regression during radiotherapy and long-term outcome in nasopharyngeal cancer. Methods] From June 2001 to August 2003, 100 cases with primary nasopharyngeal carcinoma pathologically proved were treated with radiotherapy. CT or MRI was examined before radiotherapy and at a cumulate dose of 50Gy. The primary tumor size was defined as SO before radiotherapy and as S50 when the patients received 50Gy dose. The rate of regression was defined as Rs=（S0-S50）/S0. The patients were grouped by Rs≥0.9,0.9〉Rs≥0.7,Rs〈0.7 as high sensitive group （HSG）, moderate sensitive group （MSG） and low sensitive group （LSG）. Results] Five-year local control rate （LCR）, distant metastases-free survival （DMFS）, disease-free survival （DFS）, disease-specific survival （DSS） and overall survival （OS） were 78.3%, 80.8%, 63.1%, 71.6% and 60.4% respectively. The 5-year LCR and 5-year DFS were 94.4% and 82.1% in HSG, 85.6% and 75.1% in MSG, and 62.3% and 43.3% in LSG, respectively（P=0.004 and P=0.005）. There was no significant difference in the 5-year DMFS, DSS and OS among the three groups （P=0.346, P=0.394 and P=0.590）. Cox regression analysis showed that Rs classification, age and the tumor size before treatment was the factors correlated with LCR. Conclusion] Treatment response during radiotherapy could predict status of local control and long-term outcome in nasopharyngeal cancer. The result should be approved further by clinical report with large number cases.