STANDARIZATION OF THE TARGET VOLUME FOR THE CONFORMATION RADIOTHERAPY OF CANCER OF THE MAXILLARY SINUS

Abstract

Conformation mechanism is capable of fitting the high dose region to the shape and size of any tumor. In case of the conformation radiotherapy for cancer of the maxillary sinus, the shapes of the target volume and the transverse section of the patient's face are considerably constant in every patients. The axial transverse tomograms of the maxillary sinus in 52 cases with cancer of the maxillary sinus were traced and the shape of the target volume was decided on each case. From these procedures it was found out, that the shape of the transverse section of the patient's face can be substituted by the long oval of Haynes's with the maximal difference of 3 mm (about 3% difference of the TPR). Three kinds of cam (small, middle and large size) were prepared on the practical application of this method, because the figure of the transverse section of the patient could be also classified three kinds of long oval of Haynes. The TPR and the dose can be easily calculated from these standardized figures.