PENENTUAN DIAGNOSTIC REFERENCE LEVEL (DRL) LOKAL PADA PESAWAT SIMULATOR RADIOTERAPI KONVENSIONAL DENGAN KASUS METASTASIS OTAK DI RSUD DR. ADHYATMA, MPH

Conventional simulators in 2-dimensional (2D) radiotherapy procedures can be done with fluoroscopy and single exposure features. The most significant percentage of 2D patients in the radiotherapy installation of Dr. Adhyatma MPH Hospital, are patients with brain metastasis cases, with a percentage of 65% of all 2D patients. Therefore, this study focuses on brain metastasis cases. The feature used in the Radiotherapy Installation of Dr. Adhyatma MPH Hospital is the single exposure feature, which is identical to conventional diagnostic radiology examinations. Radiation in diagnostic radiology requires a local Diagnostic Reference Level (DRL) on a conventional radiotherapy simulator as a guideline for optimizing radiation protection for medical exposure. This study aims to determine the local DRL value of a conventional radiotherapy simulator in cases of brain metastasis and compare it with the national DRL in lateral head examinations. The local DRL value obtained is then used as a guideline in improving services to increase the quality of service to patients. The data collection method is carried out in 2 (two) ways, namely calculating the local DRL value from the ESAK value and interviews related to the quality of the resulting image. The exposure factors used in this study followed the same routine exposure factors with a tube voltage of 72 kV and a tube current of 25 mAs. The local DRL value obtained was 0.586 mGy, with a percentage difference of 51% lower than the national DRL. With this value, the quality of the resulting image is classified as optimal and easy to assess. Thus, the exposure factors in the conventional radiotherapy simulation process in cases of brain metastasis can be used as a guideline for clinical practice at RSUD dr. Adhyatma, MPH. Keywords: conventional radiotherapy simulator, 2-dimensional radiotherapy, local DRL, diagnostic patients, radiation dose.