Dados do Trabalho

Título

Nanobrachytherapy: Analysis of the increase in dose deposition resulting from the effects of the interaction between gold nanoparticles and irradiation with Ir-192.

Introdução

Radiotherapy aims to realize tumor control using ionizing radiation sources, ensuring the least possible damage to adjacent healthy tissues. Among the efforts to develop new techniques that intensify the effect of radiation on tumor volume, recent studies indicate that the use of high-Z materials combined with radiotherapy as an alternative for this. Thus, the combination of brachytherapy with gold nanoparticles emerged as a proposal to maximize the efficiency of the treatment, aiming to reduce the toxicity. Therefore, this work analyzed the increase in dose deposition resulting from the effects of the interaction between gold nanoparticles and irradiation with Ir-192 brachytherapy source, using Monte Carlo Simulation with PENELOPE code.

Objetivo

Evaluate the increase in dose deposition resulting from the incorporation of gold nanoparticles in a semi-realistic cell model using Monte Carlo simulation with the PENELOPE package.

Método

Two scenarios were simulated: 1 - A single 400 nm diameter gold nanoparticle simulating an agglomerate of nanoparticles was incorporated in the nucleolus of a 13 μm diameter adapted cell filled with water; 2 - This same 400 nm nanoparticle was incorporated into the region of the cell referring to the endoplasmic reticulum. In addition, a control simulation was performed with the cell without the presence of the nanoparticle. The effect of gold nanoparticles on the dose deposition was simulated using a Ir-192 spectrum. The Dose Enhancement Factor was calculated for the two studied scenarios.

Resultados

The dose Enhancement Factor was calculated as a function of the nanoparticle distance for all simulated conditions. Preliminary results showed that the maximum DEF value for scenario 1 was 1.78282 ± 0.07131. For the second scenario the maximum DEF value was 1.10998 ± 0.00609.

Conclusão

The use of gold nanoparticles can provide a more effective tumor control when located in the vicinity of the DNA, as there is an increase in dose deposition around it.

Palavras-chave

brachytherapy, nanoparticles, PENELOPE