Johan Andoyo Effendi Noor, Johan Andoyo Effendi
Brawijaya University Malang

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PERKIRAAN DISTRIBUSI DOSIS EKIVALEN FOTON PADA PASIEN RADIOTERAPI LINAC 15 MV Febriantoko, Adiar; Noor, Johan Andoyo Effendi; Sofyan, Hasnel
Physics Student Journal Vol 2, No 1 (2014)
Publisher : Department of Physics - Faculty of Science

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Linac (linear accelerator) telah digunakan dalam radioterapi eksternal. Pengoperasiannya dengan energi lebih dari 8 MV akan menimbulkan radiasi sekunder berupa neutron maupun prompt gamma. Penelitian ini dilakukan pengukuran dosis ekivalen foton untuk mengetahui distribusi dosis pada bagian permukaan tubuh pasien dan bagian organ kritis pasien ketika proses radiasi berlangsung, yang menggunakan detektor pasif TLD-100H (LiF:Mg, Cu, P). Distribusi dosis ekivalen foton pada bagian permukaan (depan) diperoleh dari penyinaran mesin linac 15 MV dengan dosis target 2 Gy dan 3 Gy pada berkisar antara 0,35 mSv- 452 mSv dan antara 0,44 mSv – 474 mSv dengan ketidakpastian ±3% yang diperoleh dari kalibrasi TLD-100H. Dosis ekivalen foton di bagian dalam fantom yang diperoleh dari penyinaran mesin linac 15 MV dengan dosis target 2 Gy dan 3 Gy berkisar antara 0,28 mSv – 2074 mSv dengan ketidakpastian ±3% dan antara 0,37 mSv- 2980 mSv dengan ketidakpastian ±3%. Variasi dosis tersebut dipengaruhi oleh letak titik pada fantom. Selain itu, diketahui pula bahwa besar dosis ekivalen sebanding dengan dosis terapi yang diberikan.
IMPLEMENTATION OF AAPM TG-218 FOR PATIENT SPECIFIC QUALITY ASSURANCE (PSQA) IN THE CASE OF THORACIC TARGET REGION USING IMRT RADIOTHERAPY TECHNIQUE WITH EPID aSi-1200 Listiono, Firza Indrastata; Noor, Johan Andoyo Effendi; Herwiningsih, Sri; Dwiyono, Agustinus Gatot; Martono, Sri; Nugroho, Rafiq Sulistyo; Petrarizky, Alfred Julius
Indonesian Physical Review Vol. 8 No. 3 (2025)
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/ipr.v8i3.502

Abstract

The implementation of Patient-Specific Quality Assurance (PSQA) is crucial for ensuring the accuracy and safety of Intensity-Modulated Radiation Therapy (IMRT). This study evaluates the application of AAPM TG-218 recommendations in PSQA for thoracic region treatment using the IMRT technique. The study compares two PSQA methods, Perpendicular Composite (PC) and Perpendicular Field-by-Field (PFF), using Electronic Portal Imaging Device (EPID). Measurements were conducted on 10 IMRT patients using a Varian TrueBeam Linac and Eclipse TPS. The Gamma Index (GI) analysis with criteria 3%/3 mm, 3%/2 mm, and 2%/2 mm was used to assess dose distribution accuracy. The results indicate that the average Gamma Passing Rate (GPR) for 3%/2 mm criteria exceeded 95%, which is appropriate with AAPM TG-218 standards. However, stricter criteria (2%/2 mm) did not reach the minimum recommended values. The study suggests that PSQA using EPID with the PFF method under rotational gantry conditions is the most suitable approach for thoracic IMRT treatment verification. The local standardization recommendations from the results of this study can be used as a reference for determining methodological standards in cases of the thoracic region in the IMRT technique to increase efficiency in clinical applications with similar PSQA dosimetry.
Review Impact of Compressed Breast Thickness and Exposure Parameters on Mean Glandular Dose (MGD) in Full-Field Digital Mammography Examination Victory, Vivi Sumanti; Noor, Johan Andoyo Effendi; Widodo, Chomsin Sulistya; Arifin, Zaenal
Journal of Physics and Its Applications Vol 7, No 4 (2025): November 2025
Publisher : Diponegoro University Semarang Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jpa.v7i4.27371

Abstract

The purpose of this paper is to review and summarize the relationship between the average mammary gland dose (MGD) and compressed breast thickness (CBT) in digital mammography. The relationship between MGD and CBT, measured using a dosimeter, shows that the thicker the breast, the higher the MGD. However, the relationship between MGD and CBT using patient data (i.e., actual MGD values) may not be directly proportional to CBT because it can be influenced by other factors, such as age. MGD values are directly proportional to CBT when based on phantom measurements. Across various brands and types of mammography units, MGD values are not always directly proportional due to differences in K patterns (incident air kerma), which create different automatic exposure control (AEC) modes. In conclusion, CBT has a complex relationship with MGD. In general, MGD is positively correlated with CBT because increasing breast thickness requires a higher radiation dose to produce optimal image quality. However, this relationship is not always linear and can be negatively correlated under certain conditions, considering the influence of other parameters that can affect both CBT and MGD.