CAJ | 학술논문

背景与目的:胸上段食管癌所处的解剖特点导致其放疗计划的制订难度很大,而调强放疗(intensity-modulated radiotherapy,IMRT)有可能克服上述难题.本研究比较分析IMRT和三维适形放疗(conformal radiotherapy,CRT)在胸上段食管癌的剂量学优劣,为IMRT在食管癌的临床应用提供参考.方法:选择胸上段食管癌11例进行研究.在实际治疗采用的CRT计划基础上,每一病例再设计一5野IMRT计划进行对比.对比内容包括相关靶区和危及器官的剂量体积直方图参数.结果:肿瘤及相邻组织的计划靶区可见IMRT和CRT计划之间的平均剂量、最大剂量、包含99%和95%靶区的剂量均很接近(P＞0.05),但IMRT较CRT的适形指数好(0.68±0.04 vs.0.46±0.11,P＜0.01).IMRT对锁骨上区的剂量均匀性较CRT更好,二者的非均匀指数分别为1.17±0.05和1.33±0.15(P=0.01).IMRT计划中脊髓计划区的最高受量明显较CRT的低(44.4 Gy vs.52.5 Gy,P＜0.05);10 Gy以上的肺受照体积为(32±6)%,也明显较CRT计划的(35±9)%低(P＜0.05).结论:对胸上段食管癌,调强放疗较适形放疗有更好的剂量适形性,可更有效保护脊髓,并显著降低肺10 Gy以上剂量的受照体积.
배경여목적:흉상단식관암소처적해부특점도치기방료계화적제정난도흔대,이조강방료(intensity-modulated radiotherapy,IMRT)유가능극복상술난제.본연구비교분석IMRT화삼유괄형방료(conformal radiotherapy,CRT)재흉상단식관암적제량학우렬,위IMRT재식관암적림상응용제공삼고.방법:선택흉상단식관암11례진행연구.재실제치료채용적CRT계화기출상,매일병례재설계일5야IMRT계화진행대비.대비내용포괄상관파구화위급기관적제량체적직방도삼수.결과:종류급상린조직적계화파구가견IMRT화CRT계화지간적평균제량、최대제량、포함99%화95%파구적제량균흔접근(P＞0.05),단IMRT교CRT적괄형지수호(0.68±0.04 vs.0.46±0.11,P＜0.01).IMRT대쇄골상구적제량균균성교CRT경호,이자적비균균지수분별위1.17±0.05화1.33±0.15(P=0.01).IMRT계화중척수계화구적최고수량명현교CRT적저(44.4 Gy vs.52.5 Gy,P＜0.05);10 Gy이상적폐수조체적위(32±6)%,야명현교CRT계화적(35±9)%저(P＜0.05).결론:대흉상단식관암,조강방료교괄형방료유경호적제량괄형성,가경유효보호척수,병현저강저폐10 Gy이상제량적수조체적.
Background and Objective: Treatment planning for radiotherapy of upper thoracic esophageal carcinoma is challenging due to the anatomical features. The difficulty may be resolved by intensity-modulated radiotherapy (IMRT).This study was to compare the dosimetric advantages of IMRT to that of conformal radiotherapy (CRT) for upper thoracic esophageal carcinoma, and to explore the clinical application of IMRT. Methods: Eleven patients with upper thoracic esophageal carcinoma were enrolled. In addition to the actually used CRT plan,a five-field IMRT plan was generated for each case. The parameters of dose volume histogram for targets and organs at risk were compared between two techniques. Results: For the planning target volume (PTV) of tumor and para-tumor tissues, the mean dose, maximal dose, doses covering 99% and 95% volume were similar in IMRT and CRT plans (P＞0.05). However, IMRT plan had a higher conformity index than CRT plan (0.68 ±0.04 vs. 0.46 0.11, P＜0.01). For the PTV of supraclavicular region, IMRT plan showed a better dose heterogeneity index than CRT plan (1.17 0.05 vs. 1.33 0.15, P=0.01). IMRT plan had lower maximal dose to the planning risk volume of the spinal cord (44.4 Gy vs, 52.5 Gy, P＜0.05) and lower lung volume received dose of 10 Gy or higher [(32 6)%vs. (35 9)%, P＜0.05] than CRT plan. Conclusion: For the upper thoracic esophageal carcinoma,IMRT has more conformal distribution of dose and better spinal cord sparing than CRT, and can reduce the volume of lung that received dose of 10 Gy or higher.