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Effect of Gold Nanoparticles on Prostate Dose Distribution under Ir-192 Internal and 18 MV External Radiotherapy Procedures Using Gel Dosimetry and Monte Carlo Method.

Khosravi H, Hashemi B, Mahdavi SR, Hejazi P - J Biomed Phys Eng (2015)

Bottom Line: The GNP shaving 15 nm in diameter and 0.1 mM concentration were synthesized using chemical reduction method.Then, a new formulation of MAGIC-f gel was synthesized.There was a good agreement between the dose enhancement factors (DEFs) estimated with MC simulations and experiment gel measurements due to the GNPs.

View Article: PubMed Central - PubMed

Affiliation: Ph.D. Candidate, Department of Medical Physics, Tarbiat Modares University, Tehran, Iran;

ABSTRACT

Background: Gel polymers are considered as new dosimeters for determining radiotherapy dose distribution in three dimensions.

Objective: The ability of a new formulation of MAGIC-f polymer gel was assessed by experimental measurement and Monte Carlo (MC) method for studying the effect of gold nanoparticles (GNPs) in prostate dose distributions under the internal Ir-192 and external 18MV radiotherapy practices.

Method: A Plexiglas phantom was made representing human pelvis. The GNP shaving 15 nm in diameter and 0.1 mM concentration were synthesized using chemical reduction method. Then, a new formulation of MAGIC-f gel was synthesized. The fabricated gel was poured in the tubes located at the prostate (with and without the GNPs) and bladder locations of the phantom. The phantom was irradiated to an Ir-192 source and 18 MV beam of a Varian linac separately based on common radiotherapy procedures used for prostate cancer. After 24 hours, the irradiated gels were read using a Siemens 1.5 Tesla MRI scanner. The absolute doses at the reference points and isodose curves resulted from the experimental measurement of the gels and MC simulations following the internal and external radiotherapy practices were compared.

Results: The mean absorbed doses measured with the gel in the presence of the GNPs in prostate were 15% and 8 % higher than the corresponding values without the GNPs under the internal and external radiation therapies, respectively. MC simulations also indicated a dose increase of 14 % and 7 % due to presence of the GNPs, for the same experimental internal and external radiotherapy practices, respectively.

Conclusion: There was a good agreement between the dose enhancement factors (DEFs) estimated with MC simulations and experiment gel measurements due to the GNPs. The results indicated that the polymer gel dosimetry method as developed and used in this study, can be recommended as a reliable method for investigating the DEF of GNPs in internal and external radiotherapy practices.

No MeSH data available.


Related in: MedlinePlus

Treatment planning Performed on Pelvic Phantom under 18 MV External Radiotherapy Procedure by Varian 2100 linac
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Figure 2: Treatment planning Performed on Pelvic Phantom under 18 MV External Radiotherapy Procedure by Varian 2100 linac

Mentions: For the external radiotherapy, at first, the size, direction, and any other information related to the pelvic phantom dimensions were calibrated against its image. Then, by considering the size and location of the prostate in the phantom, four orthogonal radiation fields were defined for treating prostate by using Core PLAN software (Seoul C&J, South Korea). The treatment planning specifications are provided in figure 2 and table 1.


Effect of Gold Nanoparticles on Prostate Dose Distribution under Ir-192 Internal and 18 MV External Radiotherapy Procedures Using Gel Dosimetry and Monte Carlo Method.

Khosravi H, Hashemi B, Mahdavi SR, Hejazi P - J Biomed Phys Eng (2015)

Treatment planning Performed on Pelvic Phantom under 18 MV External Radiotherapy Procedure by Varian 2100 linac
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4417617&req=5

Figure 2: Treatment planning Performed on Pelvic Phantom under 18 MV External Radiotherapy Procedure by Varian 2100 linac
Mentions: For the external radiotherapy, at first, the size, direction, and any other information related to the pelvic phantom dimensions were calibrated against its image. Then, by considering the size and location of the prostate in the phantom, four orthogonal radiation fields were defined for treating prostate by using Core PLAN software (Seoul C&J, South Korea). The treatment planning specifications are provided in figure 2 and table 1.

Bottom Line: The GNP shaving 15 nm in diameter and 0.1 mM concentration were synthesized using chemical reduction method.Then, a new formulation of MAGIC-f gel was synthesized.There was a good agreement between the dose enhancement factors (DEFs) estimated with MC simulations and experiment gel measurements due to the GNPs.

View Article: PubMed Central - PubMed

Affiliation: Ph.D. Candidate, Department of Medical Physics, Tarbiat Modares University, Tehran, Iran;

ABSTRACT

Background: Gel polymers are considered as new dosimeters for determining radiotherapy dose distribution in three dimensions.

Objective: The ability of a new formulation of MAGIC-f polymer gel was assessed by experimental measurement and Monte Carlo (MC) method for studying the effect of gold nanoparticles (GNPs) in prostate dose distributions under the internal Ir-192 and external 18MV radiotherapy practices.

Method: A Plexiglas phantom was made representing human pelvis. The GNP shaving 15 nm in diameter and 0.1 mM concentration were synthesized using chemical reduction method. Then, a new formulation of MAGIC-f gel was synthesized. The fabricated gel was poured in the tubes located at the prostate (with and without the GNPs) and bladder locations of the phantom. The phantom was irradiated to an Ir-192 source and 18 MV beam of a Varian linac separately based on common radiotherapy procedures used for prostate cancer. After 24 hours, the irradiated gels were read using a Siemens 1.5 Tesla MRI scanner. The absolute doses at the reference points and isodose curves resulted from the experimental measurement of the gels and MC simulations following the internal and external radiotherapy practices were compared.

Results: The mean absorbed doses measured with the gel in the presence of the GNPs in prostate were 15% and 8 % higher than the corresponding values without the GNPs under the internal and external radiation therapies, respectively. MC simulations also indicated a dose increase of 14 % and 7 % due to presence of the GNPs, for the same experimental internal and external radiotherapy practices, respectively.

Conclusion: There was a good agreement between the dose enhancement factors (DEFs) estimated with MC simulations and experiment gel measurements due to the GNPs. The results indicated that the polymer gel dosimetry method as developed and used in this study, can be recommended as a reliable method for investigating the DEF of GNPs in internal and external radiotherapy practices.

No MeSH data available.


Related in: MedlinePlus