利用计算机对肺及纵膈肿瘤照射野的设计探讨

胸部肿瘤以往多采用二野前后对穿照射及前后野加水平野照射,使其脊髓及胸骨受量偏高,纵膈剂量低,高剂量区常位于靶区之外,剂量分布不合理。放射治疗时,要求减少脊髓,正常肺及胸骨的受量(后者尤其对青少年),提高靶区的致死量。作者利用Philips-oss治疗计划系统,选择肺癌及纵膈肿瘤各一例。根据胸部的解剖位置,采用三野成角加楔形板,经治疗计划系统内存参数处理后,绘制出剂量分布曲线,其优点是靶区内剂量分布均匀。在肺癌及纵膈肿瘤达到致死量的同时,脊髓,正常肺组织及胸骨受量减少或为零。

Utilization of Oncology Support: System for Designing of Irradiaition Field for Lung Cancer and Mediastinum Tumor

Malignant tumors in the chest were used to be irradiated by means of the "opposite anteroposterior" fields or/and a horizontal field as a supplement. This method usually results in high doses at spinal cord and sternum and relative lower doses at mediastinum, and so high dose volume is deposited outside the target volume. Such a dose distribution does not meet the needs of the radiotherapy. In order to minimize the doses at spinal cord, health lung and sternum (the latter is more important for children and young people) and increase the doses at the target volume, the authors designed a set of radiation treatment plans with Oncology Support System (philips). The plans consist of a pair of inclined opposite fields and an oblique angle field with wedge filter. The various parameters were processed by the computer, and the isodose curve diagrams were drawed and compared Advantages of this design are as follows: dose distribution in the target volume is homogeneous, not' only the death doses at the tumor region of lung and mediastinum are achieved, but also the doses at spinal cord and health lung and sternum are markedly decreased or even zero.