THE PLANNING AND IMMOBILIZATION TECHNIQUES USED IN IRRADIATION OF T1 GLOTTIC LARYNX CANCER PATIENTS

Surgery and radiation therapy produces comparable successful cure rates in the treatment of early glottic larynx cancer. However irradiation has some advantages of producing best functional results and the least risk of serious complications. The success of radiotherapy depends on optimal localizations, good treatment planning and the maintenance of the same treatment volume during the treatment period. To immobilize the patient we use a thermoplastic material (ORFIT) in our department. By using the CT scan of larengeal cancer patients, computer generated dosimetry has been obtained in MEVAPLAN. To identify the optimum dosimetry by Co-60 or 6 MV x-rays different techniques were investigated in 6 T1 larynx cancer patients who were treated between Aug-1991 and May-1992. Amongst the techniques used, parallel opposed fields and 30° wedge filters 6 MV x-rays produced better dose distribution.