Improved Local Control In The Clinical Management Of Nasopharyngeal Carcinoma (NPC): A Results Of Clinical And Dosimetry Measurement With Fractionational Stereotactic Radiotherapy (X-Ray Knife) For Challenging Nasopharynx Lesions

Part OneCharateristic of Dose Distribution and Its Clinical Appliction in Stereotactic Radiotherapy Practices with single and multispheric collimatorObjective : To measure clinical dosimetric patameters and to evaluate the accuracy of isocenter dose distribution in circular collimater fields in stereotactic radiotherapy for correctly using of stereotactic radiotherapy in clinical ptactice..Materials and Methods: Polystyrene phantom, Anthropomorphic head phantom and film-checking technique were used to measure the parameters of off-axis ratio, penumbra, steepness and flatness of isodose curves under static, single-target, and 2-targets-isocenters moving fiels condition in BrainLAB X-knife system. Conlusion: Our parameters obtained from above-mentinoed different measurement methods demonstrated that to understand thoroughly the variations of clinical dosimetric parameters at the isocenter of circular collimeter fields is one of the key factors for performing correctly the to stereotactic radiotherapy techniques in clinical practice, such as, when you choose multi-targets X-knife therapy method for the nasopharyngael carcinoma. Some suggestions were offered according to the results of our test measurements for guiding the correct application of stereotactic radiotherapy in clinical practice.Key wordsStereotactic radiotherapy,Anthropomorphic phantom,Film dosimetry,Nasopharyngeal carcinoma...