Analisis Perubahan Teknik Radioterapi Imrt Menjadi 3D-CRT Pada Kasus Retinoblastoma Pediatrik Di Instalasi Radioterapi RSUD Welas Asih Provinsi Jawa Barat

Abstract

Retinoblastoma is the most common intraocular malignancy in children and requires appropriate radiotherapy management to achieve optimal tumor control while minimizing radiation exposure to surrounding healthy tissues. Advanced radiotherapy techniques such as Intensity-Modulated Radiation Therapy (IMRT) offer superior dose conformity; however, technical limitations in clinical practice may necessitate alternative approaches such as Three-Dimensional Conformal Radiation Therapy (3D-CRT). This study aims to evaluate the dosimetric impact of transitioning from IMRT to 3D-CRT in a pediatric retinoblastoma case. A descriptive qualitative case study approach was conducted through direct observation, medical record documentation, and interviews with radiotherapy professionals. The patient received a total radiation dose of 45 Gy in 25 fractions, consisting of 20 fractions using IMRT and 5 fractions using 3D-CRT. Dosimetric evaluation was performed using Dose Volume Histogram (DVH) analysis to assess Planning Target Volume (PTV) coverage and dose constraints to Organs at Risk (OAR). The results showed that more than 95% of the PTV received the prescribed dose, while doses to OARs such as the eye, optic nerve, lens, brainstem, and brain remained within acceptable tolerance limits. These findings indicate that the transition from IMRT to 3D-CRT was able to maintain adequate target dose coverage and keep OAR doses within safe limits from a dosimetric perspective.