A detailed experimental and Monte Carlo analysis of gold nanoparticle dose enhancement using 6 MV and 18 MV external beam energies in a macroscopic scale

2021 ◽  
Vol 171 ◽  
pp. 109638
Author(s):  
Tara Gray ◽  
Nema Bassiri ◽  
Shaquan David ◽  
Devanshi Yogeshkumar Patel ◽  
Sotirios Stathakis ◽  
...  
2005 ◽  
Vol 32 (6Part11) ◽  
pp. 2022-2023 ◽  
Author(s):  
J Monroe ◽  
J Hainfeld ◽  
J Sohn ◽  
B Wessels

2019 ◽  
Vol 20 (2) ◽  
pp. 176-187 ◽  
Author(s):  
Hamda Khan ◽  
Umair Aziz ◽  
Zafar Ullah Koreshi

: The energy deposition and radiation dose from commonly used radioisotopes, 125I,103Pd, and 131Cs, used for brachytherapy of cancers is estimated using Monte Carlo (MC) simulations. To enhance the dose, gold nanoparticle (GNP) solutions are injected into the tumor; this results in more effective and shorter therapy duration. It is thus important to estimate the dose enhancement factor (DEF) achievable by a radioisotope. The research presented in this paper thus focuses on a comparative analysis of radioisotopes. To estimate the radiation dose, the Monte Carlo N-particle code MCNP5 was used for a coupled photon-electron simulation of radiation transport from radiation emanating from seeds of radioisotopes implanted in the prostate at positions prescribed to deliver effective doses to the tumor while protecting neighbouring vital organs such as the rectum and urethra. The quantities tallied were the energy deposition (F6 tally) and the pulse heights (*F8 tally) in specified energy bins. The energy deposited in the tumor was used to estimate the absorbed dose to the prostate incorporating the transformations of the radioisotopes during decay. The absorbed dose was subsequently estimated for a GNP-tissue solution with a concentration of 25 mg Au/g of prostate tissue, modelled as a homogenous mixture. From the simulations, it was found that the lifetime absorbed dose is ~96 Gy from 98 seeds, each of 0.31 mCi, of 125I; ~102 Gy, from 115 seeds, each of 1.4 mCi, of 103Pd, and ~90 Gy from 131Cs seeds replacing 103Pd seeds of the same initial activity. The main advantage of 131Cs, over 125I and 103Pd, is observed in the larger dose rate (~26 cGy/hr) delivered initially i.e. in the first few days which is 1.5 and 5.7 times higher than that for 103Pd and 125I. The absorbed dose for 125I, 103Pd and 131Cs increases to ~245, ~130, ~187 Gy respectively with GNP-tissue solution of 25 mg Au/g tissue. From the analysis, it is found that while the lifetime absorbed dose of all three radioisotopes is of the same order, there are advantages in using 131Cs; these advantages are further quantified. ABSTRAK: Pemendapan tenaga dan dos sinaran radiasi daripada radioisotop yang biasa digunakan, 125I,103Pd, dan 131Cs, digunakan bagi terapibraki kanser dianggar menggunakan simulasi Monte Carlo (MC). Bagi meningkatkan dos, larutan partikel nano emas (GNP) telah disuntik ke dalam tumor; ini lebih memberi kesan dan mengurangkan masa terapi. Oleh itu, adalah penting menganggar faktor dos penggalak (DEF) dapat dicapai dengan radioisotop. Kajian ini mengfokuskan pada analisis perbandingan radioisotop. Bagi menganggarkan dos radiasi, kod Monte Carlo N-partikel MCNP5 telah digunakan pada simulasi pasangan foton-elektron pengangkutan radiasi daripada pancaran radioaktif benih radioisotop yang ditanam dalam prostat pada posisi yang disebut bagi mencetuskan dos penghantaran yang berkesan pada sel tumor. Dalam masa sama melindungi organ penting seperti rektum dan uretra. Kuantiti diselaras dengan pemendapan tenaga (selaras F6) dan ketinggian denyut (selaras *F8) dalam aras tenaga sebenar. Tenaga yang dienap dalam sel tumor ini telah digunakan bagi menganggarkan dos serapan pada prostat dengan menggabungkan transformasi radioisotop ketika susutan. Dos yang diserap telah kemudiannya dianggarkan bagi larutan tisu-GNP dengan ketumpatan 25 mg Au/g tisu prostat, dimodelkan sebagai campuran homogen. Daripada simulasi, dapatan kajian menunjukkan dos diserap sebanyak ~96 Gy daripada 98 benih, setiap satu daripada 0.31 mCi, 125I; ~102 Gy, dari 115 benih, setiap 1.4 mCi, dari 103Pd, dan ~90 Gy daripada benih 131Cs menggantikan benih 103Pd pada pemulaan aktiviti yang sama. Keistimewaan utama adalah 131Cs, ke atas 125I dan 103Pd, telah dilihat dalam kadar dos lebih besar (~26 cGy/hr) dikeluarkan pada pemulaannya iaitu dalam beberapa hari pertama iaitu 1.5 dan 5.7 kali lebih tinggi daripada 103Pd dan 125I. Dos yang diserap pada 125I, 103Pd dan 131Cs bertambah kepada ~245, ~130, ~187 Gy masing-masing dengan larutan tisu-GNP sebanyak 25 mg Au/g tisu. Hasil analisis menunjukkan penyerapan seumur hidup dos diserap pada ketiga-ketiga radioisotop dalam aturan yang sama, ini adalah keistimewaan menggunakan 131Cs; keistimewaan ini akan terus diuji pada masa depan dan diukur kuantitinya.


2011 ◽  
Vol 38 (6Part17) ◽  
pp. 3595-3595
Author(s):  
T Marques ◽  
F Scuch ◽  
O Baffa ◽  
P Nicolucci

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1751
Author(s):  
Mehwish Jabeen ◽  
James C. L. Chow

Ever since the emergence of magnetic resonance (MR)-guided radiotherapy, it is important to investigate the impact of the magnetic field on the dose enhancement in deoxyribonucleic acid (DNA), when gold nanoparticles are used as radiosensitizers during radiotherapy. Gold nanoparticle-enhanced radiotherapy is known to enhance the dose deposition in the DNA, resulting in a double-strand break. In this study, the effects of the magnetic field on the dose enhancement factor (DER) for varying gold nanoparticle sizes, photon beam energies and magnetic field strengths and orientations were investigated using Geant4-DNA Monte Carlo simulations. Using a Monte Carlo model including a single gold nanoparticle with a photon beam source and DNA molecule on the left and right, it is demonstrated that as the gold nanoparticle size increased, the DER increased. However, as the photon beam energy decreased, an increase in the DER was detected. When a magnetic field was added to the simulation model, the DER was found to increase by 2.5–5% as different field strengths (0–2 T) and orientations (x-, y- and z-axis) were used for a 100 nm gold nanoparticle using a 50 keV photon beam. The DNA damage reflected by the DER increased slightly with the presence of the magnetic field. However, variations in the magnetic field strength and orientation did not change the DER significantly.


Sign in / Sign up

Export Citation Format

Share Document