ABSTRAK
Digitally reconstructed radiographs (DRRs) merupakan citra hasil rekonstruksidata set citra CT simulator yang digunakan untuk verifikasi dalam perencanaanradioterapi eksternal. Penelitian ini mencoba untuk mengimplementasikanalgoritma ray casting dan hardware texture mapping sehingga dapatmenghasilkan citra DRR. Akuisisi citra CT simulator dilakukan terhadap fantommodifikasi, fantom Catphan, dan fantom RANDO. Citra CT simulator kemudiandikomputasi dengan menggunakan algoritma yang digunakan serta algoritma didalam treatment planning system (TPS). Evaluasi hasil citra DRR dilakukansecara kuantitatif dan kualitatif. Evaluasi kuantitatif meliputi evaluasi keakurasiangeometri, evaluasi kontras tinggi, evaluasi kontras rendah, evaluasi uniformitas,dan evaluasi running time. Evaluasi kualitatif berupa kuesioner yang berisipendapat praktisi radioterapi mengenai kualitas citra DRR dalam hal kontras,resolusi, dan uniformitas. Hasil evaluasi kuantitatif menunjukkan kualitas citraDRR dari algoritma dalam penelitian ini hampir sama dengan algoritma di dalamTPS dan hasil tersebut didukung oleh hasil evaluasi kualitatif.

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ABSTRACT
Digitally reconstructed radiographs (DRRs) are the CT simulator imagereconstruction that used for verification in external radiotherapy planning. Thisthesis aims to implementation of ray casting and hardware texture mappingalgorithm to produce DRR images. CT image acquisition is made to modificationphantom, Catphan phantom, and RANDO phantom. These images then computedbecome DRR images using ray casting and hardware texture mapping algorithm,as well as the algorithm used in the treatment planning system (TPS) . Evaluationof the DRR images conducted quantitatively and qualitatively. Quantitativeevaluation includes evaluation of geometric accuracy, high contrast, low contrast,grey scale uniformity running time. Qualitative evaluations are questionnaireswhich contain the opinion of radiotherapy practitioners regarding DRR imagequality in terms of contrast, resolution, and grey scale uniformity. Quantitativeevaluation shows that there are some similarities of DRR image quality betweenalgorithm used in this thesis study is similar to the algorithm in the TPS. This alsosupported by the results of a qualitative evaluation.