摘要
目的比较胸中段、胸下段食管癌三维适形放疗(CRT)和调强放疗(IMRT)两种不同治疗方式,三种射野设计计划中靶区剂量及正常组织受量。方法选取10例在我院治疗的食管癌患者的定位,正确定义GTV、CTV、PTV,设计三种照射方式:三野适形,为前后对照射野加一个侧野,加楔形板;5野调强,角度选择为均匀5野的变化型态;7野调强,角度选择为均匀分摊。处方剂量为50Gy,主要比较以下观察指标:PTV≥95%剂量,适合度(CI);肺总的V5、V10、V20、Dmean,脊髓的Dmax,心脏的V40。结果靶区剂量分布,三种方法差异不明显。正常组织心脏受量无差异性;脊髓受量三野适形计划比两种调强计划稍高;肺各项观察指标无差异性,综合比较三野适形计划优于两种调强计划。结论胸中段、胸下段食管癌调强放疗无优势,适形放疗稍优。
Objective To compare the dose distribution between three -dimensional conformal radiotherapy （3DCRT） and intensity- modulated radiotherapy （IMRT） in treating esophageal carcinoma （middle thoracic section and under thoracic section） and to select reasonable treatment methods for esophagus cancer. Methods Ten cases with cancer of the middle thoracic section and under thoracic section esophagus were chosen for a retrospective treatment - planning study. 3DCRT and IMRT plans were created for each patient：Some critical indicators were envolved in evaluing the treatment plans of IMRT （SB and 7B） and 3DCRT （3B）, such as, PTV coverage and dose -volumes to irradiated normal structures. Evaluation indicators ：prescription of 50Gy. total lung volume （ VS, V10, V20 ）, mean lung dose（ MLD ）, spinal cord （ Dmax ）, heart （V40） and conformality index（CI）. Each plan was evaluated with respect to dose distribution, dose -volume histograms （ DVHs）, and additional dosimetric endpoints described below. Results There is no significance of CRT and IMRT technique in protection of total lung volume, mean lung dose, spinal cord（ Dmax）, target , CI and heart.Conclusion As To radiotherapy of esophagus cancer of the middle thoracic section and under thoracic section, IMRT has no advantage compared with 3DCRT, the selection of plan should be adapted to the situations of every patient.
出处
《中国辐射卫生》
2011年第3期265-267,共3页
Chinese Journal of Radiological Health
