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Autoradiography imaging in targeted alpha therapy with Timepix detector.

A L Darwish R, Staudacher AH, Bezak E, Brown MP - Comput Math Methods Med (2015)

Bottom Line: These data are required to estimate the absorbed dose on a cellular level as alpha particles have a limited range and traverse only a few cells.Results show that alpha particle, photon, electron, and muon tracks were detected and resolved by Timepix detector.The current study demonstrated that individual alpha particle emissions, resulting from targeted alpha therapy, can be visualised and quantified using Timepix detector.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Physics, Royal Adelaide Hospital, Adelaide, Australia ; School of Chemistry and Physics, University of Adelaide, Adelaide, Australia.

ABSTRACT
There is a lack of data related to activity uptake and particle track distribution in targeted alpha therapy. These data are required to estimate the absorbed dose on a cellular level as alpha particles have a limited range and traverse only a few cells. Tracking of individual alpha particles is possible using the Timepix semiconductor radiation detector. We investigated the feasibility of imaging alpha particle emissions in tumour sections from mice treated with Thorium-227 (using APOMAB), with and without prior chemotherapy and Timepix detector. Additionally, the sensitivity of the Timepix detector to monitor variations in tumour uptake based on the necrotic tissue volume was also studied. Compartmental analysis model was used, based on the obtained imaging data, to assess the Th-227 uptake. Results show that alpha particle, photon, electron, and muon tracks were detected and resolved by Timepix detector. The current study demonstrated that individual alpha particle emissions, resulting from targeted alpha therapy, can be visualised and quantified using Timepix detector. Furthermore, the variations in the uptake based on the tumour necrotic volume have been observed with four times higher uptake for tumours pretreated with chemotherapy than for those without chemotherapy.

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Related in: MedlinePlus

Measured alpha particle hits per unit tumour area per 1 hour for two groups of tumour sections: 4 sections with and 3 sections without application of chemotherapy prior to administration of Th-227 radioimmunoconjugate.
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Related In: Results  -  Collection


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fig7: Measured alpha particle hits per unit tumour area per 1 hour for two groups of tumour sections: 4 sections with and 3 sections without application of chemotherapy prior to administration of Th-227 radioimmunoconjugate.

Mentions: As shown in Figure 7, the recorded alpha particle hits for each sample were corrected for radioactive decay (based on the time elapsed between the Th-227 administration and Timepix measurement), the area of each sample, and total acquisition time, resulting in the alpha particle acquisition rate between 27.6 and 44.8 hits/cm2·hour for tumour sections of mice not previously given chemotherapy and between 94.0 and 206.8 hits/cm2·hour for sections that were treated with chemotherapy followed by 227Th-DAB4.


Autoradiography imaging in targeted alpha therapy with Timepix detector.

A L Darwish R, Staudacher AH, Bezak E, Brown MP - Comput Math Methods Med (2015)

Measured alpha particle hits per unit tumour area per 1 hour for two groups of tumour sections: 4 sections with and 3 sections without application of chemotherapy prior to administration of Th-227 radioimmunoconjugate.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4320936&req=5

fig7: Measured alpha particle hits per unit tumour area per 1 hour for two groups of tumour sections: 4 sections with and 3 sections without application of chemotherapy prior to administration of Th-227 radioimmunoconjugate.
Mentions: As shown in Figure 7, the recorded alpha particle hits for each sample were corrected for radioactive decay (based on the time elapsed between the Th-227 administration and Timepix measurement), the area of each sample, and total acquisition time, resulting in the alpha particle acquisition rate between 27.6 and 44.8 hits/cm2·hour for tumour sections of mice not previously given chemotherapy and between 94.0 and 206.8 hits/cm2·hour for sections that were treated with chemotherapy followed by 227Th-DAB4.

Bottom Line: These data are required to estimate the absorbed dose on a cellular level as alpha particles have a limited range and traverse only a few cells.Results show that alpha particle, photon, electron, and muon tracks were detected and resolved by Timepix detector.The current study demonstrated that individual alpha particle emissions, resulting from targeted alpha therapy, can be visualised and quantified using Timepix detector.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Physics, Royal Adelaide Hospital, Adelaide, Australia ; School of Chemistry and Physics, University of Adelaide, Adelaide, Australia.

ABSTRACT
There is a lack of data related to activity uptake and particle track distribution in targeted alpha therapy. These data are required to estimate the absorbed dose on a cellular level as alpha particles have a limited range and traverse only a few cells. Tracking of individual alpha particles is possible using the Timepix semiconductor radiation detector. We investigated the feasibility of imaging alpha particle emissions in tumour sections from mice treated with Thorium-227 (using APOMAB), with and without prior chemotherapy and Timepix detector. Additionally, the sensitivity of the Timepix detector to monitor variations in tumour uptake based on the necrotic tissue volume was also studied. Compartmental analysis model was used, based on the obtained imaging data, to assess the Th-227 uptake. Results show that alpha particle, photon, electron, and muon tracks were detected and resolved by Timepix detector. The current study demonstrated that individual alpha particle emissions, resulting from targeted alpha therapy, can be visualised and quantified using Timepix detector. Furthermore, the variations in the uptake based on the tumour necrotic volume have been observed with four times higher uptake for tumours pretreated with chemotherapy than for those without chemotherapy.

Show MeSH
Related in: MedlinePlus