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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

Comparison of Isodose Curves Measured Experimentally with Gel and Calculated by MC Calculations at two Different Slices for18 MV (Varian linac) External Radiotherapy Procedure
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Figure 5: Comparison of Isodose Curves Measured Experimentally with Gel and Calculated by MC Calculations at two Different Slices for18 MV (Varian linac) External Radiotherapy Procedure

Mentions: The isodose curves of the bladder and prostate (with and without the presence of GNPs) which were measured experimentally and calculated by MC simulations in the pelvic phantom in two different slices, located at A) X=+ 0.4 cm and B) X=0 cm, for the external radiotherapy procedure are presented in figure 5.


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)

Comparison of Isodose Curves Measured Experimentally with Gel and Calculated by MC Calculations at two Different Slices for18 MV (Varian linac) External Radiotherapy Procedure
© Copyright Policy
Related In: Results  -  Collection

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

Figure 5: Comparison of Isodose Curves Measured Experimentally with Gel and Calculated by MC Calculations at two Different Slices for18 MV (Varian linac) External Radiotherapy Procedure
Mentions: The isodose curves of the bladder and prostate (with and without the presence of GNPs) which were measured experimentally and calculated by MC simulations in the pelvic phantom in two different slices, located at A) X=+ 0.4 cm and B) X=0 cm, for the external radiotherapy procedure are presented in figure 5.

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