See the published version of this preprint at EJNMMI Physics.
This is a preprint, a preliminary version of a manuscript that has not completed peer review at a journal. Research Square does not conduct peer review prior to posting preprints. The posting of a preprint on this server should not be interpreted as an endorsement of its validity or suitability for dissemination as established information or for guiding clinical practice.
Learn more about In Review
A new preprint design is coming!
We have improved readability, clarity, accessibility, and opportunities for engagement.
Original research
Federica Fioroni
Corresponding Author
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Background: Internal dosimetry evaluation consists of a multi-step process ranging from imaging acquisition to absorbed dose calculations. Assessment of uncertainty is complicated and, for that reason, it is commonly ignored in clinical routine. However, it is essential for adequate interpretation of the results. Recently, the EANM published a practical guidance on uncertainty analysis for molecular radiotherapy based on the application of the law of propagation of uncertainty. In this study, we investigated the overall uncertainty on a sample of patient following the EANM guidelines. The aim of this study was to provide an indication of the typical uncertainties that may be expected from performing dosimetry, to determine parameters that have the greatest effect on the accuracy of calculations and to consider the potential improvements that could be made if these effects were reduced.
Results: Absorbed doses and the relative uncertainties were calculated for a sample of 49 patients and a total of 154 tumours. A wide range of relative absorbed dose uncertainty values was observed (14 - 102%). Uncertainties associated with each quantity along the absorbed dose calculation chain (i.e. Volume, Recovery Coefficient, Calibration Factor, Activity, Time-Activity Curve Fitting, Time-Integrated Activity and Absorbed Dose) were estimated. An equation was derived to describe relationship between the uncertainty in the absorbed dose and the volume. The largest source of error was the VOI delineation. By postulating different values of FWHM, the impact of the imaging system spatial resolution on the uncertainties was investigated.
Discussion: To the best of our knowledge, this is the first analysis of uncertainty in molecular radiotherapy based on a cohort of clinical cases. Wide inter-lesion variability of absorbed dose uncertainty was observed. Hence, a proper assessment of the uncertainties associated with the calculations should be considered as a basic scientific standard. A model for a quick estimate of uncertainty without implementing the entire error propagation schema, which may be useful in clinical practice, was presented. Ameliorating spatial resolution may be in future the key factor for accurate absorbed dose assessment.
Keywords
MRT, RPT, Radionuclide therapy, PRRT, dosimetry, accuracy, uncertainty analysis
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
The full text of this article is available to read as a PDF.
This is a list of supplementary files associated with this preprint. Click to download.
Loading...
Badges
Prescreen
This manuscript passed our Prescreen assessment
Complete author information
Appropriate declaration statements
Potential risks to human health
Prescreen
Peer Review Timeline
CURRENT STATUS: Published
View the published article at EJNMMI Physics.
Version 3
Posted 11 Sep, 2020
No community comments so far
Review #1 received
Received 16 Sep, 2020
Editorial decision: Accept
On 16 Sep, 2020
Review #2 received
Received 15 Sep, 2020
Reviewers invited
Invitations sent on 08 Sep, 2020
Reviewer #1 agreed
On 08 Sep, 2020
Reviewer #2 agreed
On 08 Sep, 2020
Editor assigned
On 07 Sep, 2020
Submission checks complete
On 06 Sep, 2020
Editor invited
On 06 Sep, 2020
No comments provided
Editorial decision: Major Revision
On 11 Aug, 2020
Review #2 received
Received 02 Aug, 2020
Review #1 received
Received 02 Aug, 2020
Reviewer #1 agreed
On 18 Jul, 2020
Reviewer #2 agreed
On 18 Jul, 2020
Reviewers invited
Invitations sent on 14 Jul, 2020
Editor assigned
On 13 Jul, 2020
Submission checks complete
On 12 Jul, 2020
Editor invited
On 12 Jul, 2020
No comments provided
Editorial decision: Major Revision
On 15 Jun, 2020
Review #2 received
Received 09 Jun, 2020
Review #1 received
Received 02 Jun, 2020
Reviewer #1 agreed
On 25 May, 2020
Reviewer #2 agreed
On 25 May, 2020
Reviewers invited
Invitations sent on 12 May, 2020
Editor assigned
On 11 May, 2020
Editor invited
On 10 May, 2020
Submission checks complete
On 08 May, 2020
First submitted
On 06 May, 2020
Metrics
Comments: 0
PDF Downloads: ...
HTML Views: ...
Learn more about our company.
A new preprint design is coming!
We have improved readability, clarity, accessibility, and opportunities for engagement.
See the published version of this preprint at EJNMMI Physics.
This is a preprint, a preliminary version of a manuscript that has not completed peer review at a journal. Research Square does not conduct peer review prior to posting preprints. The posting of a preprint on this server should not be interpreted as an endorsement of its validity or suitability for dissemination as established information or for guiding clinical practice.
Learn more about In Review
Original research
Federica Fioroni
Corresponding Author
Badges
Prescreen
This manuscript passed our Prescreen assessment
Complete author information
Appropriate declaration statements
Potential risks to human health
Prescreen
Peer Review Timeline
CURRENT STATUS: Published
View the published article at EJNMMI Physics.
Version 3
Posted 11 Sep, 2020
No community comments so far
Review #1 received
Received 16 Sep, 2020
Editorial decision: Accept
On 16 Sep, 2020
Review #2 received
Received 15 Sep, 2020
Reviewers invited
Invitations sent on 08 Sep, 2020
Reviewer #1 agreed
On 08 Sep, 2020
Reviewer #2 agreed
On 08 Sep, 2020
Editor assigned
On 07 Sep, 2020
Submission checks complete
On 06 Sep, 2020
Editor invited
On 06 Sep, 2020
No comments provided
Editorial decision: Major Revision
On 11 Aug, 2020
Review #2 received
Received 02 Aug, 2020
Review #1 received
Received 02 Aug, 2020
Reviewer #1 agreed
On 18 Jul, 2020
Reviewer #2 agreed
On 18 Jul, 2020
Reviewers invited
Invitations sent on 14 Jul, 2020
Editor assigned
On 13 Jul, 2020
Submission checks complete
On 12 Jul, 2020
Editor invited
On 12 Jul, 2020
No comments provided
Editorial decision: Major Revision
On 15 Jun, 2020
Review #2 received
Received 09 Jun, 2020
Review #1 received
Received 02 Jun, 2020
Reviewer #1 agreed
On 25 May, 2020
Reviewer #2 agreed
On 25 May, 2020
Reviewers invited
Invitations sent on 12 May, 2020
Editor assigned
On 11 May, 2020
Editor invited
On 10 May, 2020
Submission checks complete
On 08 May, 2020
First submitted
On 06 May, 2020
Metrics
Comments: 0
PDF Downloads: ...
HTML Views: ...
License:
This work is licensed under a CC BY 4.0 License. Read Full License
View the published article at EJNMMI Physics.
Background: Internal dosimetry evaluation consists of a multi-step process ranging from imaging acquisition to absorbed dose calculations. Assessment of uncertainty is complicated and, for that reason, it is commonly ignored in clinical routine. However, it is essential for adequate interpretation of the results. Recently, the EANM published a practical guidance on uncertainty analysis for molecular radiotherapy based on the application of the law of propagation of uncertainty. In this study, we investigated the overall uncertainty on a sample of patient following the EANM guidelines. The aim of this study was to provide an indication of the typical uncertainties that may be expected from performing dosimetry, to determine parameters that have the greatest effect on the accuracy of calculations and to consider the potential improvements that could be made if these effects were reduced.
Results: Absorbed doses and the relative uncertainties were calculated for a sample of 49 patients and a total of 154 tumours. A wide range of relative absorbed dose uncertainty values was observed (14 - 102%). Uncertainties associated with each quantity along the absorbed dose calculation chain (i.e. Volume, Recovery Coefficient, Calibration Factor, Activity, Time-Activity Curve Fitting, Time-Integrated Activity and Absorbed Dose) were estimated. An equation was derived to describe relationship between the uncertainty in the absorbed dose and the volume. The largest source of error was the VOI delineation. By postulating different values of FWHM, the impact of the imaging system spatial resolution on the uncertainties was investigated.
Discussion: To the best of our knowledge, this is the first analysis of uncertainty in molecular radiotherapy based on a cohort of clinical cases. Wide inter-lesion variability of absorbed dose uncertainty was observed. Hence, a proper assessment of the uncertainties associated with the calculations should be considered as a basic scientific standard. A model for a quick estimate of uncertainty without implementing the entire error propagation schema, which may be useful in clinical practice, was presented. Ameliorating spatial resolution may be in future the key factor for accurate absorbed dose assessment.
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
The full text of this article is available to read as a PDF.
This is a list of supplementary files associated with this preprint. Click to download.
Loading...