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.