Quantification and dosimetry of small volumes including associated uncertainty estimation
Abstract Background Accurate quantification of radioactivity in a source of interest relies on accurate registration between SPECT and anatomical images, and appropriate correction of partial volume effects (PVEs). For small volumes, exact registration between the two imaging modalities and recovery...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2022-12-01
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| Series: | EJNMMI Physics |
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| Online Access: | https://doi.org/10.1186/s40658-022-00512-9 |
| _version_ | 1811291930634485760 |
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| author | Lily Carnegie-Peake Jan Taprogge Iain Murray Glenn D. Flux Jonathan Gear |
| author_facet | Lily Carnegie-Peake Jan Taprogge Iain Murray Glenn D. Flux Jonathan Gear |
| author_sort | Lily Carnegie-Peake |
| collection | DOAJ |
| description | Abstract Background Accurate quantification of radioactivity in a source of interest relies on accurate registration between SPECT and anatomical images, and appropriate correction of partial volume effects (PVEs). For small volumes, exact registration between the two imaging modalities and recovery factors used to correct for PVE are unreliable. There is currently no guidance relating to quantification or the associated uncertainty estimation for small volumes. Material and methods A method for quantification of small sources of interest is proposed, which uses multiple oversized volumes of interest. The method was applied to three Na[131I]I activity distributions where a Na[131I]I capsule was situated within a cylindrical phantom containing either zero background, uniform background or non-uniform background and to a scenario with small lesions placed in an anthropomorphic phantom. The Na[131I]I capsule and lesions were quantified using the proposed method and compared with measurements made using two alternative quantification methods. The proposed method was also applied to assess the absorbed dose delivered to a bone metastasis following [131I]mIBG therapy for neuroblastoma including the associated uncertainty estimation. Results The method is accurate across a range of activities and in varied radioactivity distributions. Median percentage errors using the proposed method in no background, uniform backgrounds and non-uniform backgrounds were − 0.4%, − 0.3% and 1.7% with median associated uncertainties of 1.4%, 1.4% and 1.6%, respectively. The technique is more accurate and robust when compared to currently available alternative methods. Conclusions The proposed method provides a reliable and accurate method for quantification of sources of interest, which are less than three times the spatial resolution of the imaging system. The method may be of use in absorbed dose calculation in cases of bone metastasis, lung metastasis or thyroid remnants. |
| first_indexed | 2024-04-13T04:36:49Z |
| format | Article |
| id | doaj.art-4295aca2dbba4968ae5f0d17ec01b97e |
| institution | Directory Open Access Journal |
| issn | 2197-7364 |
| language | English |
| last_indexed | 2024-04-13T04:36:49Z |
| publishDate | 2022-12-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | EJNMMI Physics |
| spelling | doaj.art-4295aca2dbba4968ae5f0d17ec01b97e2022-12-22T03:02:08ZengSpringerOpenEJNMMI Physics2197-73642022-12-019111610.1186/s40658-022-00512-9Quantification and dosimetry of small volumes including associated uncertainty estimationLily Carnegie-Peake0Jan Taprogge1Iain Murray2Glenn D. Flux3Jonathan Gear4Joint Department of Physics, Royal Marsden NHSFTJoint Department of Physics, Royal Marsden NHSFTJoint Department of Physics, Royal Marsden NHSFTJoint Department of Physics, Royal Marsden NHSFTJoint Department of Physics, Royal Marsden NHSFTAbstract Background Accurate quantification of radioactivity in a source of interest relies on accurate registration between SPECT and anatomical images, and appropriate correction of partial volume effects (PVEs). For small volumes, exact registration between the two imaging modalities and recovery factors used to correct for PVE are unreliable. There is currently no guidance relating to quantification or the associated uncertainty estimation for small volumes. Material and methods A method for quantification of small sources of interest is proposed, which uses multiple oversized volumes of interest. The method was applied to three Na[131I]I activity distributions where a Na[131I]I capsule was situated within a cylindrical phantom containing either zero background, uniform background or non-uniform background and to a scenario with small lesions placed in an anthropomorphic phantom. The Na[131I]I capsule and lesions were quantified using the proposed method and compared with measurements made using two alternative quantification methods. The proposed method was also applied to assess the absorbed dose delivered to a bone metastasis following [131I]mIBG therapy for neuroblastoma including the associated uncertainty estimation. Results The method is accurate across a range of activities and in varied radioactivity distributions. Median percentage errors using the proposed method in no background, uniform backgrounds and non-uniform backgrounds were − 0.4%, − 0.3% and 1.7% with median associated uncertainties of 1.4%, 1.4% and 1.6%, respectively. The technique is more accurate and robust when compared to currently available alternative methods. Conclusions The proposed method provides a reliable and accurate method for quantification of sources of interest, which are less than three times the spatial resolution of the imaging system. The method may be of use in absorbed dose calculation in cases of bone metastasis, lung metastasis or thyroid remnants.https://doi.org/10.1186/s40658-022-00512-9QuantificationDosimetryI-131Uncertainty estimation |
| spellingShingle | Lily Carnegie-Peake Jan Taprogge Iain Murray Glenn D. Flux Jonathan Gear Quantification and dosimetry of small volumes including associated uncertainty estimation EJNMMI Physics Quantification Dosimetry I-131 Uncertainty estimation |
| title | Quantification and dosimetry of small volumes including associated uncertainty estimation |
| title_full | Quantification and dosimetry of small volumes including associated uncertainty estimation |
| title_fullStr | Quantification and dosimetry of small volumes including associated uncertainty estimation |
| title_full_unstemmed | Quantification and dosimetry of small volumes including associated uncertainty estimation |
| title_short | Quantification and dosimetry of small volumes including associated uncertainty estimation |
| title_sort | quantification and dosimetry of small volumes including associated uncertainty estimation |
| topic | Quantification Dosimetry I-131 Uncertainty estimation |
| url | https://doi.org/10.1186/s40658-022-00512-9 |
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