Evaluation with two different dosimetric methods by using rando phantom of dosimetric paramethers obtained from treatment planning system

Radiotherapy is a multidisciplinary approach. Quality of the treatment is provided with everyone who works systematic and correctly in this multidisciplinary field. The purpose of this thesis is, verification of the plan which is prepared in three dimensional treatment planning system (TPS) and evaluating the dosimetric methods in use.Two plans with the same geometry but different dose fractions were prepared with TPS. While determining the dose values of both plans, dosimetric properties of the films (film - dose curves and dose values that make films reach saturation) were taken into consideration. Plans were made with 6MV X - energy, the field size of 7cm x 7cm and 4 different gantry angles. Dosimetric assessment of the prepared plans was first made with film dosimetry. The first process for film dosmetry was made by taking the calibration shots and than shooting the quality control films. Kodak EDR2 and Kodak XOMAT V films were used for film dosimetry. At the second stage of the thesis, mesurements were taken with ion chamber for dosimetric evaluation of the plans. The measurements were taken by placing the ion chamber to the slot which is specially made for ion chambers on rando phantom. Five measurements were taken from each measurement points. Comparison was made between average of five meaurements and calculated values by TPS.As a result of this thesis, the error rate of the measurements made with ion chamber was found between 1.91% and 1.99%, the error rate of the measurement made with film dosimetry was found between ± 3.8% and ± 4.2%. The results are seemed to be consistent with literature studies.Keywords : Dosimeter, Treatment Planning System, Rando Phantom, Film Dosimetry