Prostate Cancer Proton Therapy Simulation Based On Homogeneous Water Equivalent Thickness Pencil Beam Model

Muhammad Fitriadi, Heri Sutanto, Pandji Triadyaksa, Rizki Budiman, Heri Sutanto, Pandji Triadyaksa, Rizki Budiman

Abstract


Terapi proton merupakan modalitas penting dalam pengobatan kanker prostat karena kemampuannya untuk memberikan dosis yang tepat ke volume target dengan paparan minimal pada jaringan sehat melalui karakteristik Puncak Bragg. Studi ini bertujuan untuk mengembangkan model simulasi berkas pensil yang terintegrasi dengan Ketebalan Setara Air (WET) homogen menggunakan platform simulasi Monte Carlo Geant4 (versi 11.2.1) untuk meningkatkan akurasi dan efisiensi perencanaan dosis. Simulasi dilakukan pada phantom manusia berdasarkan ICRP 145 dengan resolusi detektor 1 mm. Puncak Bragg yang Tersebar (SOBP) dioptimalkan pada tiga sudut iradiasi (0°, 45°, 90°) menggunakan fungsi Kuadrat Terkecil Linier (lsqlin) untuk mencapai dosis konstan (Dconst) di seluruh wilayah plateau. Hasil menunjukkan ketidakpastian jangkauan proton <1 mm dengan Dconst optimal pada sudut 0°, 45°, dan 90° masing-masing sebesar 0,66, 0,62, dan 0,53 nGy/proton, yang mencakup kedalaman 7,32-10,21 cm, 9,68-12,48 cm, dan 17,26-20,13 cm. Integrasi WET homogen berhasil menyederhanakan beban komputasi sambil mempertahankan akurasi tinggi, sehingga dapat diintegrasikan ke dalam sistem perencanaan terapi konvensional. Model ini menawarkan solusi efisien untuk fasilitas dengan kapasitas terbatas, meskipun validasi klinis lebih lanjut dengan data pasien nyata masih diperlukan untuk memastikan kemampuan adaptasi terhadap variasi anatomi individu.


Keywords


Bragg Peak, Prostate Cancer, Pencil Beam, Geant4 Simulation, Proton Therapy, Water Equivalent Thickness.

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DOI: http://dx.doi.org/10.52155/ijpsat.v55.2.7837

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