Comparative Analysis of OAR and PTV Radiation Dose Achievements for Planning 3D-CRT and IMRT Radiotherapy Techniques for Nasopharyngeal Cancer

A comparison has been conducted between the 3D-CRT technique and the IMRT technique on the radiation dose achievement of Planning Target Volume (PTV) and Organ at Risk (OAR) in nasopharyngeal cancer patients. This study used secondary data in the form of Dose Volume Histogram (DVH) graphs obtained from the results of the Treatment Planning System (TPS). Data analysis was carried out on the dose achievement at PTV with reference to The International Commission on Radiation Units and Measurements (ICRU) Report 62 in 1999, and the dose achievement at OAR with the guidelines of Quantitative Analysis of Normal. Tissue Effects in the Clinic (QUANTEC). The analysis was carried out on 15 nasopharyngeal cancer patients using the 3D-CRT technique and 15 nasopharyngeal cancer patients using the IMRT technique at Ken Saras Hospital, Semarang Regency. The results of the analysis showed that, in the IMRT radiation technique, the percentage of patients who received optimal radiation doses at PTV was 88.9% while for OAR, 11.85% of patients received radiation doses exceeding the QUANTEC tolerance limit. In the 3D-CRT radiation technique, the percentage of patients who received optimal radiation doses on the PTV was only 20% while for OAR, 28.9% of patients received radiation doses exceeding the QUANTEC tolerance limit. The results of the study showed that the IMRT radiation technique is more efficient for nasopharyngeal cancer therapy, because the dose achieved on the PTV is more optimal and the dose on the OAR can be minimized so that the principles of optimization and radiation limitation can be met properly. Keywords: nasopharyngeal cancer, 3D-CRT, IMRT, PTV, OAR, DVH