Analisa Kurva PDD Dan Profile Dose Berkas Elektron Pesawat Linac Varian Clinac Cx

Abstract

Linac (linear Accelerator) is a radiotherapy device that utilizes high energy radiation to kill cancer cells. Every radiotherapy equipment such as Linac must be calibrated periodically. One of them is monthly quality control which aims to test the performance of Linac so that the quality of the output of the radiation beam can be guaranteed. Quality control conducted covers measurement of Percentage Depth Dose (PDD) and Dose Profile. So that in this paper we will analyze the electron beam of Linac Therapeutic Clinics Variants plane of RSUD Provinsi NTB. In PDD measurements, the Linac Variant Clinac CX electron beam energy 4, 6, 9, 12, and 15 MeV planes are used in the radiation field size 15  15 cm 2 . Meanwhile, the dose profile was measured in the radiation fields 10  10 cm 2 and 25  25 cm 2 using blue phantom, (reference and field) detectors which are equipped with a computer control units (CCU) and carried out for crossline and inline directions at Dmax depth and certain depth with 100 cm SSD. The measurement results show that the greater the electron energy used, the maximum dose (Dmax) obtained is getting smaller, but the maximum dose depth increase. The measurement results are still within the tolerance range of ± 0.2. While the results of the Dose Profile measurements show a field size of 25  25 cm 2 more flatness and symmetry than a 10  10 cm 2 field both for inline and crossline directions and still within measurement tolerances limit 4.5% - 7% for flatness and  2 % for symmetry.