scholarly journals ANALISIS DOSIS RADIASI PADA JARINGAN TUMOR DENGAN SIMULASI PROGRAM MCNP-5

Author(s):  
Tumpal Pandiangan ◽  
Ika Bali

Direct measurement of each radiation dose to the patient's organs is not possible. In general, to estimate the dose absorbed by human organs is approached by measurements in human phantoms, but this approach is still too rough because the composition of phantoms is not easily made the same as the actual organ composition. Currently, for important matters such as the accuracy of determining the absorption dose by human organs, the Monte Carlo simulation method (MCNP) with special software is used. This has led to a growing desire for scientists to make the transition from using phantoms to computing software for medical physics applications. However, until now no comprehensive document has been written to introduce the use of the MCNP program to simulate its application in medical physics. The purpose of this study was to analyze the absorbed dose of gamma radiation in tumor tissue in the breast by simulating changes in distance and tumor size using the MCNP-5 program. This can be useful in ensuring the application of radiation protection to the patient and the environment in which the patient is located. The results showed that the radiation dose in cell 1 (tumor tissue) with a change in the distance between the radiation source and cell 1 was getting bigger, resulting in a decrease in the dose in cell 1, while the effect of cell volume 1 was greater, the greater the dose received by cell 1. In addition, through this simulation it can be seen that for each addition of 1 cm3 the volume of cell 1 for tumor tissue can increase the absorption energy by 3.5x10e-12 Gray. Keywords: MCNP-5; simulation; radiation dose; tumor tissue AbstrakPengukuran setiap dosis radiasi pada organ pasien tidak dimungkinkan secara langsung. Pada umumnya untuk memperkirakan dosis yang diserap oleh organ tubuh manusia didekati dengan pengukuran pada phantom manusia, namun pendekatan ini juga masih terlalu kasar karena komposisi phantom tidak mudah dibuat sama dengan komposisi organ yang sebenarnya. Sehingga saat ini, untuk hal-hal yang penting seperti ketepatan penentuan dosis serap oleh organ tubuh manusia, digunakan metode simulasi Monte Carlo (MCNP) dengan perangkat lunak khusus. Hal ini mendorong meningkatnya keinginan para ilmuwan melakukan transisi dari penggunaan phantom ke penggunaan komputasi perangkat lunak untuk aplikasi fisika medis. Namun sampai saat ini belum tersedia dokumen komprehensif yang ditulis untuk memperkenalkan penggunaan program MCNP guna mensimulasikan aplikasinya dalam fisika medis. Tujuan penelitian ini adalah menganalisis dosis serap radiasi gamma pada jaringan tumor di payudara melalui simulasi perubahan jarak dan besar tumor menggunakan program MCNP-5. Hal ini dapat berguna dalam memastikan penerapan proteksi radiasi pada pasien dan lingkungan tempat pasien. Hasil penelitian menunjukkan dosis radiasi pada sel 1 (jaringan tumor) dengan perubahan jarak antara sumber radiasi dengan sel 1 semakin besar, mengakibatkan besar dosis di sel 1 semakin menurun, sedangkan pengaruh volume sel 1 yang semakin besar maka dosis yang diterima sel 1 semakin besar juga. Selain itu, melalui simulasi ini dapat diketahui untuk setiap penambahan 1 cm3 volume sel 1 jaringan tumor dapat meningkatkan energi serap sebesar 3,5x10e-12 Gray.

2018 ◽  
Vol 18 (02) ◽  
pp. 191-197
Author(s):  
Masoumeh Hoseinnezhad ◽  
Mohammad Mahdavi ◽  
Seyyed R. M. Mahdavi ◽  
Mobarake Mahdavizade

AbstractPurposeThe purpose of this study was to determine the dose enhancement factor (DEF) of gold nanoparticles in a dosimeter gel and construct percentage depth dose curves, using the Optical CT system and the Monte Carlo simulation model, to determine the effect of increasing the dose caused by increasing the concentration of gold nanoparticles at depths in the gel.Materials and methodsThe Magic-f Gel was made based on the relevant protocol in the physics lab. To determine the amount of the increase in the absorbed dose, the gold nanoparticles were added to the gel and irradiated. An increase in the dose after adding nanoparticles to the gel vials was estimated both with the Optical CT system and by the Monte Carlo simulation method.ResultsDose enhancement curves for doses of 2, 4 and 6 Gy were prepared for gel vials without adding nanoparticles, and nanoparticle gels at concentrations 0·17, 3 and 6 mM. Also, the DEF was estimated. For the 0·17 mM molar gel, the DEF for 2, 4 and 6 Gy was 0·7, 0·743 and 0·801, respectively. For the 3 mM gel, it was 1·98, 2·5 and 2·2, and for the 6 mM gel, it was 37·4, 4·24 and 4·71, respectively.ConclusionThe enhancement of the dose after adding gold nanoparticles was confirmed both by experimental data and by simulation data.


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.


2021 ◽  
Author(s):  
Hemn Salh ◽  
Fatih Külahcı ◽  
Serpil Aközcan

Abstract A spatial simulation method in .mp4 format was proposed to determine Fukushima radioactive fallout transport and the Absorbed Dose Rate, Annual Effective Dose Equivalent, and Excess Lifetime Cancer Risk were determined for 10 months after the accident (March 11 2011). The findings of this study demonstrate that an appropriate ARIMA model can be applied for radiation dose time-series in the case of nuclear reactor accidents like Chernobyl and Fukushima to predict the future air dose rates, which can provide valuable information in determining the evacuation zones, decontamination processes, and radiation protection progresses. The model forecasted results and the actual observation data in the same period shows a gradual decrease in the air dose rates during the prediction period. Moreover, there is a good agreement between them as the prediction and observation scatter plot follows each other with small variations. These results provide important insights into the predictability of ARIMA models; thus, the models were utilized to forecast the air dose rates for the period (January 2020 - October 2020).


2020 ◽  
Vol 190 (2) ◽  
pp. 158-164
Author(s):  
Zahra Pourhabib ◽  
Hassan Ranjbar ◽  
Ali Bahrami Samani

Abstract 188Re and 186Re are two applicable rhenium medical radioisotopes with complementary features that make them beneficial for different sizes of tumours. The aim of this study is to investigate 188/186Re-HEDP efficacy as a cocktail by calculating absorbed radiation dose in human organs based on biodistribution data obtained by injecting it to normal rats. Three rats were sacrificed at different time intervals and the percentage of injected dose per gram of each organ was measured by direct counting from rat data. By calculating accumulated activities in each organ and extrapolating rat data to human data by the radiation dose assessment resource method and by using OLINDA/EXM software, the injected dose in various human organs was obtained. The calculated absorbed dose showed that the 188/186Re-HEDP has noticeable properties that can be more helpful in comparison with using each of the rhenium radioisotopes separately.


2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Irfan Fetahović ◽  
Milić Pejović ◽  
Miloš Vujisić

This paper investigates the behavior of semiconductor memories exposed to radiation in order to establish their applicability in a radiation environment. The experimental procedure has been used to test radiation hardness of commercial semiconductor memories. Different types of memory chips have been exposed to indirect ionizing radiation by changing radiation dose intensity. The effect of direct ionizing radiation on semiconductor memory behavior has been analyzed by using Monte Carlo simulation method. Obtained results show that gamma radiation causes decrease in threshold voltage, being proportional to the absorbed dose of radiation. Monte Carlo simulations of radiation interaction with material proved to be significant and can be a good estimation tool in probing semiconductor memory behavior in radiation environment.


2021 ◽  
Author(s):  
Omaima Essaad Belhaj ◽  
Hamid Boukhal ◽  
El Mahjoub Chakir

The different codes based on the Monte Carlo method, allows to make simulations in the field of medical physics, so the determination of all the magnitudes of radiation protection namely the absorbed dose, the kerma, the equivalent dose, and effective, what guarantees the good planning of the experiment in order to minimize the degrees of exposure to ionizing radiation, and to strengthen the radiation protection of patients and workers in clinical environment as well as to respect the 3 principles of radiation protection ALARA (As Low As Reasonably Achievable) and which are based on: -Justification of the practice -Optimization of radiation protection -Limitation of exposure.


Cancers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1889
Author(s):  
Arthur Bongrand ◽  
Charbel Koumeir ◽  
Daphnée Villoing ◽  
Arnaud Guertin ◽  
Ferid Haddad ◽  
...  

Proton therapy (PRT) is an irradiation technique that aims at limiting normal tissue damage while maintaining the tumor response. To study its specificities, the ARRONAX cyclotron is currently developing a preclinical structure compatible with biological experiments. A prerequisite is to identify and control uncertainties on the ARRONAX beamline, which can lead to significant biases in the observed biological results and dose–response relationships, as for any facility. This paper summarizes and quantifies the impact of uncertainty on proton range, absorbed dose, and dose homogeneity in a preclinical context of cell or small animal irradiation on the Bragg curve, using Monte Carlo simulations. All possible sources of uncertainty were investigated and discussed independently. Those with a significant impact were identified, and protocols were established to reduce their consequences. Overall, the uncertainties evaluated were similar to those from clinical practice and are considered compatible with the performance of radiobiological experiments, as well as the study of dose–response relationships on this proton beam. Another conclusion of this study is that Monte Carlo simulations can be used to help build preclinical lines in other setups.


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