Purpose: Implementing intensity-modulated brachytherapy (IMBT) techniques with high-energy sources like 60Co has always been challenging due to the clinical limitations of the applicator dimensions. This study aims to investigate using tungsten trioxide nanoparticles/epoxy composite as a shielding material to enhance the protective properties of a redesigned applicator. Materials and Methods: The Geant4 application to tomographic emission, the Geant4-based Monte Carlo dose calculation engine (version 9.0), was used to simulate the shielding composite and the IMBT technique with a voxelated patient-based phantom. To evaluate the effectiveness of the new shielding material, IMBT plans created with the redesigned applicator were compared with those with a conventional applicator. 60Co and 192Ir were utilized, and in the same high-risk clinical target volumes D90, the D2cc for the bladder and rectum were evaluated in 18 patients with vaginal cancer. Results: For the IMBT plans with the 60Co source, the use of the redesigned applicator decreased the D2cc of the bladder and rectum by 11.1% and 12.8%, respectively, while for those with the 192Ir source, the reduction was 16.6% and 18.7%, respectively. Nevertheless, there was an insignificant alteration in the absorbed dose parameter (D90) for the target using both sources. Conclusion This study demonstrates that tungsten trioxide nanoparticle/epoxy composite can be advantageous in tackling radiation shielding concerns. Enhancing the shielding properties of this composite, considering the size limitations of applicators, leads to improved protection of organs at risk, such as the bladder and rectum. This substance can be considered a promising shielding material in the construction of applicators.

Purpose: Implementing intensity-modulated brachytherapy (IMBT) techniques with high-energy sources like 60Co has always been challenging due to the clinical limitations of the applicator dimensions. This study aims to investigate using tungsten trioxide nanoparticles/epoxy composite as a shielding material to enhance the protective properties of a redesigned applicator. Materials and Methods: The Geant4 application to tomographic emission, the Geant4-based Monte Carlo dose calculation engine (version 9.0), was used to simulate the shielding composite and the IMBT technique with a voxelated patient-based phantom. To evaluate the effectiveness of the new shielding material, IMBT plans created with the redesigned applicator were compared with those with a conventional applicator. 60Co and 192Ir were utilized, and in the same high-risk clinical target volumes D90, the D2cc for the bladder and rectum were evaluated in 18 patients with vaginal cancer. Results: For the IMBT plans with the 60Co source, the use of the redesigned applicator decreased the D2cc of the bladder and rectum by 11.1% and 12.8%, respectively, while for those with the 192Ir source, the reduction was 16.6% and 18.7%, respectively. Nevertheless, there was an insignificant alteration in the absorbed dose parameter (D90) for the target using both sources. Conclusion This study demonstrates that tungsten trioxide nanoparticle/epoxy composite can be advantageous in tackling radiation shielding concerns. Enhancing the shielding properties of this composite, considering the size limitations of applicators, leads to improved protection of organs at risk, such as the bladder and rectum. This substance can be considered a promising shielding material in the construction of applicators.

Purpose: Implementing intensity-modulated brachytherapy (IMBT) techniques with high-energy sources like 60Co has always been challenging due to the clinical limitations of the applicator dimensions. This study aims to investigate using tungsten trioxide nanoparticles/epoxy composite as a shielding material to enhance the protective properties of a redesigned applicator. Materials and Methods: The Geant4 application to tomographic emission, the Geant4-based Monte Carlo dose calculation engine (version 9.0), was used to simulate the shielding composite and the IMBT technique with a voxelated patient-based phantom. To evaluate the effectiveness of the new shielding material, IMBT plans created with the redesigned applicator were compared with those with a conventional applicator. 60Co and 192Ir were utilized, and in the same high-risk clinical target volumes D90, the D2cc for the bladder and rectum were evaluated in 18 patients with vaginal cancer. Results: For the IMBT plans with the 60Co source, the use of the redesigned applicator decreased the D2cc of the bladder and rectum by 11.1% and 12.8%, respectively, while for those with the 192Ir source, the reduction was 16.6% and 18.7%, respectively. Nevertheless, there was an insignificant alteration in the absorbed dose parameter (D90) for the target using both sources. Conclusion This study demonstrates that tungsten trioxide nanoparticle/epoxy composite can be advantageous in tackling radiation shielding concerns. Enhancing the shielding properties of this composite, considering the size limitations of applicators, leads to improved protection of organs at risk, such as the bladder and rectum. This substance can be considered a promising shielding material in the construction of applicators.

Purpose: Implementing intensity-modulated brachytherapy (IMBT) techniques with high-energy sources like 60Co has always been challenging due to the clinical limitations of the applicator dimensions. This study aims to investigate using tungsten trioxide nanoparticles/epoxy composite as a shielding material to enhance the protective properties of a redesigned applicator. Materials and Methods: The Geant4 application to tomographic emission, the Geant4-based Monte Carlo dose calculation engine (version 9.0), was used to simulate the shielding composite and the IMBT technique with a voxelated patient-based phantom. To evaluate the effectiveness of the new shielding material, IMBT plans created with the redesigned applicator were compared with those with a conventional applicator. 60Co and 192Ir were utilized, and in the same high-risk clinical target volumes D90, the D2cc for the bladder and rectum were evaluated in 18 patients with vaginal cancer. Results: For the IMBT plans with the 60Co source, the use of the redesigned applicator decreased the D2cc of the bladder and rectum by 11.1% and 12.8%, respectively, while for those with the 192Ir source, the reduction was 16.6% and 18.7%, respectively. Nevertheless, there was an insignificant alteration in the absorbed dose parameter (D90) for the target using both sources. Conclusion This study demonstrates that tungsten trioxide nanoparticle/epoxy composite can be advantageous in tackling radiation shielding concerns. Enhancing the shielding properties of this composite, considering the size limitations of applicators, leads to improved protection of organs at risk, such as the bladder and rectum. This substance can be considered a promising shielding material in the construction of applicators.

Purpose: Implementing intensity-modulated brachytherapy (IMBT) techniques with high-energy sources like 60Co has always been challenging due to the clinical limitations of the applicator dimensions. This study aims to investigate using tungsten trioxide nanoparticles/epoxy composite as a shielding material to enhance the protective properties of a redesigned applicator. Materials and Methods: The Geant4 application to tomographic emission, the Geant4-based Monte Carlo dose calculation engine (version 9.0), was used to simulate the shielding composite and the IMBT technique with a voxelated patient-based phantom. To evaluate the effectiveness of the new shielding material, IMBT plans created with the redesigned applicator were compared with those with a conventional applicator. 60Co and 192Ir were utilized, and in the same high-risk clinical target volumes D90, the D2cc for the bladder and rectum were evaluated in 18 patients with vaginal cancer. Results: For the IMBT plans with the 60Co source, the use of the redesigned applicator decreased the D2cc of the bladder and rectum by 11.1% and 12.8%, respectively, while for those with the 192Ir source, the reduction was 16.6% and 18.7%, respectively. Nevertheless, there was an insignificant alteration in the absorbed dose parameter (D90) for the target using both sources. Conclusion This study demonstrates that tungsten trioxide nanoparticle/epoxy composite can be advantageous in tackling radiation shielding concerns. Enhancing the shielding properties of this composite, considering the size limitations of applicators, leads to improved protection of organs at risk, such as the bladder and rectum. This substance can be considered a promising shielding material in the construction of applicators.

Purpose: The present study was conducted to compare dosimetric parameters for the heart and left lung between free breathing (FB) and deep inspiration breath hold (DIBH) and determine the most important potential factors associated with increasing the lung dose for left-sided breast radiotherapy using image analysis with 3D Slicer software. Materials and Methods: Computed tomography-simulation scans in FB and DIBH were obtained from 17 patients with left-sided breast cancer. After contouring, three-dimensional conformal plans were generated for them. The prescribed dose was 50 Gy to the clinical target volume. In addition to the dosimetric parameters, the irradiated volumes and both displacement magnitudes and vectors for the heart and left lung were assessed using 3D Slicer software. Results: The average of the heart mean dose (Dmean) decreased from 5.97 to 3.83 Gy and V25 from 7.60% to 3.29% using DIBH (p < 0.001). Furthermore, the average of Dmean for the left lung was changed from 8.67 to 8.95 Gy (p = 0.389) and V20 from 14.84% to 15.44% (p = 0.387). Both of the absolute and relative irradiated heart volumes decreased from 42.12 to 15.82 mL and 8.16% to 3.17%, respectively (p < 0.001); however, these parameters for the left lung increased from 124.32 to 223.27 mL (p < 0.001) and 13.33% to 13.99% (p = 0.350). In addition, the average of heart and left lung displacement magnitudes were calculated at 7.32 and 20.91 mm, respectively. Conclusion The DIBH is an effective technique in the reduction of the heart dose for tangentially treated left sided-breast cancer patients, without a detrimental effect on the left lung.