Dosimetry of Boron Neutron Capture Therapy in Lung Carcinoma Treatment with Monte Carlo N-Particle eXtended (MCNPX)

HELMI TANTHAWI, Dr. Ir. Andang Widiharto, M.T.; Prof. Yohannes Sardjono

2014 | Skripsi | TEKNIK NUKLIR

Telah dilakukan penelitian mengenai pengukuran fluks neutron dan perhitungan laju dosis serta waktu iradiasi pada Boron Neutron Capture Therapy (BNCT) pada kasus kanker paru-paru dengan menggunakan program Monte CarloN-Particle eXtended (MCNPX) . Prinsip kerja BNCT terletak pada reaksi antara boron-10 yang telah disuntikkan ke dalam tubuh dengan neutron termal yang akan menghasilkan ion lithium-7 dan partikel alfa. Penelitian ini menggunakan model phantom pria yang diyang dirancang di Oak Ridge National Laboratory (ORNL). Sumber neutron yang digunakan ialah hasil improvisasi desain Compact deterium-tritium (DT) Neutron Generator dari desain konseptual Compact deuterium-deuterium (DD) Neutron Generator yang dikembangkan di Departemen Teknik Elektro, Institut Teknologi Kavala, Yunani yang telah memenuhi kriteria dari IAEA. Variabel yang digunakan ialah konsetrasi boron-10 pada jaringan target dengan variasi 20; 25; 30; 35; 40 dan 45 mikrogr/gr. Secara ideal, dosis yang diharapkan kontribusinya dalam BNCT ialah dosis alfa namun dosis sekunder; i.e. dosis hamburan neutron, proton dan gamma yang disebabkan oleh interaksi neutron termal dengan jaringan tubuh tidak dapat dikesampingkan. Variasi konsentrasi boron-10 tersebut menghasilkan laju dosis masing-masing ialah 0,003145; 0,003657; 0,00359; 0,00385; 0,0438 dan 0,00476 Gy/sec, dan waktu iradiasi yang dibutuhkan dalam terapi untuk masing-masing variabel ialah 375,34; 357,55; 287,58,; 284,95; 237,84 dan 219,84 menit .

Studies were caried out to calculate the neutron flux, dose rates and irradiation time of Boron Neutron Capture Therapy (BNCT) in lung carcinoma treatment by means of Monte Carlo N-Particle eXtended (MCNPX). BNCT works based on the reaction of low energy neutrons with injected boron-10 producing a lithium-7 ion and alpha particle. The study utilized Oak Ridge National Laboratory (ORNL) male phantom model to construct lungs and Organs at Risk (OAR). The neutron source was an improvised conceptual design of Compact deuterium-tritium (DT) Neutron Generator from developed design of Compact deuterium-deuterium (DD) Neutron Generator at Department of Electrical Engineering, Kavala Institute of Technology, Greece which fulfilled the recommended parameter by International Atomic Energy Agency (IAEA). Moreover, the concentration of boron-10 in cancer tissue was varied in the study with 20, 25, 30, 35, 40 and 45 mikrogr/gr cancer tissues. Ideally, the expected primary dose in the therapy is alpha dose, but the secondary dose; i.e. neutron scattering, proton and gamma dose that are caused due to the interaction of thermal neutron with spectra of tissue cannot be simply omitted. The variations of boron-10 concentration in tissue resulted in the dose rate of each variables respectively were 0.003145, 0.003657, 0.00359, 0.00385, 0.00438 and 0.00476 Gy/sec, while the irradiation time needed in therapy for each variables respectively were 375.34, 357.55, 287.58, 284.95, 237.84 and 219.84 minutes.

Kata Kunci : lung carcinoma, Boron Neutron Capture Therapy, Compact DT Neutron Generator, boron-10, Monte Carlo N-Particle eXtended.