EVALUATION TARGET VOLUME AND DISTRIBUTION ORGAN AT RISK IN NASOPHARYNX CANCER USING VOLUMETRIC MODULATED ARC THERAPY (VMAT)

Abstract

Background: Radiotherapy treatment for nasopharyngeal cancer can cause an increased risk of decreasing the dose to cancer tissue, increasing the dose to organs at risk (OAR), as well as increasing toxicity due to inappropriate dose distribution. Purpose: Analysis of results Dose Volume Histogram (DVH) on PTV and Organ At Risk (OAR) brainstem, spinal cord, optic nerves RT, optic nerves LT, parotid glands RT, parotid glands LT, eyes RT and eyes LT by comparing tolerance limits based on ICRU 62, as well planning Target Volume (PTV) in cases of nasopharyngeal cancer using the VMAT technique. Method: This research is descriptive and quantitative by making observations. The research period was from July to October 2023 at the This research was conducted at Department Radiotherapy in Jakarta area. The total data sample was 20 nasopharyngeal cancer patients. The total dose received by the patient was 70 Gray in 33 fractions with 6MV energy using the VMAT technique. The data analysis and decision-making were carried out using statistical tests with SPSS version 25. The statistical test uses one sample t-test to determine whether there is a difference between PTV and OAR with ICRU 62 recommendations with a p-value > 0.05. Results: PTV value and organ at risk which covers PTV 95%, PTV 100%, brainstem, spinal cord, optic nerves RT, optic nerves LT, parotid glands RT, parotid glands LT, eyes RT, eyes LT has a p-value below <0.05 indicating that PTV and OAR get a dose below the criteria set based on ICRU 62, the results of the study were adjusted to the policy of the radiotherapy department carried out in this study.