Bias and precision of SPECT-based 177Lu activity-concentration estimation using a ring-configured solid-state versus a dual-headed anger system
Stenvall, Anna LU ; Ceric Andelius, Irma LU ; Nilsson, Elias ; Lindvall, Albin ; Larsson, Erik LU and Gustafsson, Johan LU
(2024)
In EJNMMI Physics
11(1).
- Abstract
Background: The aim was to compare bias and precision for 177Lu-SPECT activity-concentration estimation using a dual-headed Anger SPECT system and a ring-configured CZT SPECT system. This was investigated for imaging at 208 keV and 113 keV, respectively. Methods: Phantom experiments were performed on a GE Discovery 670 system with 5/8’’ NaI(Tl) crystal (dual-headed Anger system) and a GE StarGuide (ring-configured CZT system). Six spheres (1.2 mL to 113 mL) in a NEMA PET body phantom were filled with 99mTc and 177Lu, separately. Mean relative errors and coefficients of variation (CV) in estimated sphere activity concentration were studied over six timeframes of 10 min each for the two systems. For... (More)
Background: The aim was to compare bias and precision for 177Lu-SPECT activity-concentration estimation using a dual-headed Anger SPECT system and a ring-configured CZT SPECT system. This was investigated for imaging at 208 keV and 113 keV, respectively. Methods: Phantom experiments were performed on a GE Discovery 670 system with 5/8’’ NaI(Tl) crystal (dual-headed Anger system) and a GE StarGuide (ring-configured CZT system). Six spheres (1.2 mL to 113 mL) in a NEMA PET body phantom were filled with 99mTc and 177Lu, separately. Mean relative errors and coefficients of variation (CV) in estimated sphere activity concentration were studied over six timeframes of 10 min each for the two systems. For 177Lu, similar acquisitions were also performed for an anthropomorphic phantom with two spheres (10 mL and 25 mL) in a liver with non-radioactive background and a sphere-to-background ratio of 15:1. Tomographic reconstruction was performed using OS-EM with 10 subsets with compensation for attenuation, scatter, and distance-dependent spatial resolution. For the Anger system, up to 40 iterations were used and for the ring-configured CZT system up to 30 iterations were used. Results: The two systems showed similar mean relative errors and CVs for 177Lu when using an energy window around 208 keV, while the ring-configured system demonstrated a lower bias for a similar CV compared to the Anger system for 99mTc and for 177Lu when using an energy window around 113 keV. However, total activity in the phantom tended to be overestimated in both systems for these cases. Conclusions: The ring-configured CZT system is a viable alternative to the dual-headed Anger system equipped with medium-energy collimators for 177Lu-SPECT and shows a potential advantage for activity-concentration estimation when operated at 113 keV. However, further consideration of the preservation of total activity is warranted.
(Less)
- author
- Stenvall, Anna
LU
; Ceric Andelius, Irma
LU
; Nilsson, Elias
; Lindvall, Albin
; Larsson, Erik
LU
and Gustafsson, Johan
LU
- organization
- publishing date
- 2024-12
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Cadmium-zinc-telluride, Lutetium-177, Quantitative SPECT, Ring-configured SPECT
- in
- EJNMMI Physics
- volume
- 11
- issue
- 1
- article number
- 91
- publisher
- Springer Science and Business Media B.V.
- external identifiers
-
- scopus:85208636135
- pmid:39489825
- ISSN
- 2197-7364
- DOI
- 10.1186/s40658-024-00693-5
- language
- English
- LU publication?
- yes
- id
- 85f4e064-b80d-467a-9639-b4b178313d69
- date added to LUP
- 2025-01-15 14:06:06
- date last changed
- 2025-07-17 05:15:13
@article{85f4e064-b80d-467a-9639-b4b178313d69,
abstract = {{<p>Background: The aim was to compare bias and precision for <sup>177</sup>Lu-SPECT activity-concentration estimation using a dual-headed Anger SPECT system and a ring-configured CZT SPECT system. This was investigated for imaging at 208 keV and 113 keV, respectively. Methods: Phantom experiments were performed on a GE Discovery 670 system with 5/8’’ NaI(Tl) crystal (dual-headed Anger system) and a GE StarGuide (ring-configured CZT system). Six spheres (1.2 mL to 113 mL) in a NEMA PET body phantom were filled with <sup>99m</sup>Tc and <sup>177</sup>Lu, separately. Mean relative errors and coefficients of variation (CV) in estimated sphere activity concentration were studied over six timeframes of 10 min each for the two systems. For <sup>177</sup>Lu, similar acquisitions were also performed for an anthropomorphic phantom with two spheres (10 mL and 25 mL) in a liver with non-radioactive background and a sphere-to-background ratio of 15:1. Tomographic reconstruction was performed using OS-EM with 10 subsets with compensation for attenuation, scatter, and distance-dependent spatial resolution. For the Anger system, up to 40 iterations were used and for the ring-configured CZT system up to 30 iterations were used. Results: The two systems showed similar mean relative errors and CVs for <sup>177</sup>Lu when using an energy window around 208 keV, while the ring-configured system demonstrated a lower bias for a similar CV compared to the Anger system for <sup>99m</sup>Tc and for <sup>177</sup>Lu when using an energy window around 113 keV. However, total activity in the phantom tended to be overestimated in both systems for these cases. Conclusions: The ring-configured CZT system is a viable alternative to the dual-headed Anger system equipped with medium-energy collimators for <sup>177</sup>Lu-SPECT and shows a potential advantage for activity-concentration estimation when operated at 113 keV. However, further consideration of the preservation of total activity is warranted.</p>}},
author = {{Stenvall, Anna and Ceric Andelius, Irma and Nilsson, Elias and Lindvall, Albin and Larsson, Erik and Gustafsson, Johan}},
issn = {{2197-7364}},
keywords = {{Cadmium-zinc-telluride; Lutetium-177; Quantitative SPECT; Ring-configured SPECT}},
language = {{eng}},
number = {{1}},
publisher = {{Springer Science and Business Media B.V.}},
series = {{EJNMMI Physics}},
title = {{Bias and precision of SPECT-based <sup>177</sup>Lu activity-concentration estimation using a ring-configured solid-state versus a dual-headed anger system}},
url = {{http://dx.doi.org/10.1186/s40658-024-00693-5}},
doi = {{10.1186/s40658-024-00693-5}},
volume = {{11}},
year = {{2024}},
}