[ABSTRAK
Dosimetri CT scan dapat dilakukan dengan menggunakan konsep CTDI, MonteCarlo, atau dengan pengukuran langsung dalam fantom fisis. Pengukuranlangsung menggunakan thermoluminescent dosimeter (TLD) merupakan proseduryang rumit dan membutuhkan waktu yang lama. Saat ini sudah tersedia filmradiochromic yang dapat digunakan di radiologi. Pada penelitian ini dilakukanpengukuran distribusi dosis radiasi dalam fantom Rando menggunakan filmGafchromic XR-QA2 dan TLD. Film Gafchromic XR-QA2 dan TLD dikalibrasidi CT scanner Siemens Sensation 64. Pengukuran distribusi dosis dengan filmdilakukan pada faktor pitch 0.8, 1.0, dan 1.4. Film Gafchromic XR-QA2disisipkan diantara slab 22-23 (Film A), 23-24 (Film B), dan slab 24-25 (Film C).Pengukuran distribusi dosis dengan TLD dilakukan dalam slab nomor 23 denganfaktor pitch 1.4. Film Gafchromic XR-QA2 yang telah dieksposi dipindai denganflatbed scanner Epson Perfection V700 Photo. Dosis serap tulang belakang padaFilm A, Film B, dan Film C yang dieksposi dengan faktor pitch 1.4 secaraberturut-turut adalah 2.0 mGy, 1.9 mGy, dan 2.2 mGy. Berdasarkan profil dosis,rata-rata dosis serap pada film yang dieksposi dengan faktor pitch 1.0 dan 1.4secara berturut-turut adalah 8% dan 24% lebih tinggi dibanding rata-rata dosisserap pada film yang dieksposi dengan faktor pitch 0.8. Rentang dosis hasilpengukuran dengan TLD adalah (1.9 ± 0.1) – (2.3 ± 0.2) mGy dan rentang dosishasil pengukuran dengan film Gafchromic XR-QA2 adalah 1.8 – 2.3 mGy denganperbedaan maksimum 10.6%. Perbedaan tersebut masih berada dalam rentangkeakurasian TLD yaitu < 15%. Berdasarkan hasil tersebut, film Gafchromic XRQA2dapat digunakan untuk pengukuran dosis CT scan selanjutnya.
ABSTRACT
Computed tomography (CT) dosimetry can be approached by using CTDImethod, Monte Carlo computer technique, and direct measurement withinphysical phantom. Direct measurement using thermoluminescent dosimeters(TLDs) is a laborious procedure. Radiochromic film for radiology application wasavailable. In this study, dose distribution within adult anthropomorphic physicalphantom was measured using TLD and Gafchromic XR-QA2 film. TLD andGafchromic XR-QA2 film was calibrated on CT scanner Siemens Sensation 64.Gafchromic XR-QA2 film was sandwiched between slab Rando phantom number22-23 (Film A), 23-24 (Film B), and 24-25 (Film C). Pitch factor 0.8, 1.0, and 1.4were used. TLDs were placed at the holes in the slab number 23 ofanthropomorphic phantom. TLDs were scanned using pitch factor 1.4. Afterexposure, Gafchromic XR-QA2 film was digitized using Epson Perfection V700Photo flatbed scanner. Absorbed dose at vertebra on Film A, Film B, and Film Cwhich exposed by using pitch 1.4 respectively were 2.0 mGy, 1.9 mGy, and 2.2mGy. Based on dose profile, average dose of XR-QA2 film which exposed byusing pitch 1.0 and 1.4 respectively were 8% and 24% higher than average dose ofXR-QA2 film which exposed by pitch 0.8. TLDs dose range were (1.9 ± 0.1) –(2.3 ± 0.2) mGy and Gafchromic XR-QA2 film dose range were 1.8 – 2.3 mGywith maximum difference 10.6%. The difference is still within the range of TLDaccuracy, < 15%. Based on this result, Gafchromic XR-QA2 film can be used tomeasure CT dose, Computed tomography (CT) dosimetry can be approached by using CTDImethod, Monte Carlo computer technique, and direct measurement withinphysical phantom. Direct measurement using thermoluminescent dosimeters(TLDs) is a laborious procedure. Radiochromic film for radiology application wasavailable. In this study, dose distribution within adult anthropomorphic physicalphantom was measured using TLD and Gafchromic XR-QA2 film. TLD andGafchromic XR-QA2 film was calibrated on CT scanner Siemens Sensation 64.Gafchromic XR-QA2 film was sandwiched between slab Rando phantom number22-23 (Film A), 23-24 (Film B), and 24-25 (Film C). Pitch factor 0.8, 1.0, and 1.4were used. TLDs were placed at the holes in the slab number 23 ofanthropomorphic phantom. TLDs were scanned using pitch factor 1.4. Afterexposure, Gafchromic XR-QA2 film was digitized using Epson Perfection V700Photo flatbed scanner. Absorbed dose at vertebra on Film A, Film B, and Film Cwhich exposed by using pitch 1.4 respectively were 2.0 mGy, 1.9 mGy, and 2.2mGy. Based on dose profile, average dose of XR-QA2 film which exposed byusing pitch 1.0 and 1.4 respectively were 8% and 24% higher than average dose ofXR-QA2 film which exposed by pitch 0.8. TLDs dose range were (1.9 ± 0.1) –(2.3 ± 0.2) mGy and Gafchromic XR-QA2 film dose range were 1.8 – 2.3 mGywith maximum difference 10.6%. The difference is still within the range of TLDaccuracy, < 15%. Based on this result, Gafchromic XR-QA2 film can be used tomeasure CT dose] |
T43863-Emidatul Manzil.pdf :: Unduh