Usefulness of 99mTc-Pertechnetate SPECT-CT in Thyroid Tissue Volumetry: Phantom Studies and a Clinical Case Series.
SPECT
SPECT-CT
Thyroid
hyperthyroidism
theragnostics
thyroid tissue volumetry
Journal
Current radiopharmaceuticals
ISSN: 1874-4729
Titre abrégé: Curr Radiopharm
Pays: United Arab Emirates
ID NLM: 101468718
Informations de publication
Date de publication:
2022
2022
Historique:
received:
23
07
2021
revised:
18
10
2021
accepted:
25
10
2021
pubmed:
14
1
2022
medline:
29
7
2022
entrez:
13
1
2022
Statut:
ppublish
Résumé
An accurate measurement of the target volume is of primary importance in theragnostics of hyperthyroidism. Our purpose was to evaluate the accuracy of a threshold-based isocontour extraction procedure for thyroid tissue volumetry from SPECT-CT. Cylindrical vials with a fixed volume of 99mTcO4 at different activities were inserted into a neck phantom in two different thickness settings. Images were acquired by orienting the phantom in different positions, i.e., 40 planar images and 40 SPECT-CT. The fixed values of the isocontouring threshold for SPECT and SPECT-CT were calculated by means of linear and spline regression models. Mean, Median, Standard Deviation, Standard Error, Mean Absolute Percentage Error and Root Mean-Square Error were computed. Any difference between the planar method, SPECT and SPECT-CT and the effective volume was evaluated by means of ANOVA and posthoc tests. Moreover, planar and SPECT-CT acquisitions were performed in 8 patients with hyperthyroidism, considering relevant percentage differences greater than > 20% from the CT gold standard. Concerning phantom studies, the planar method shows higher values of each parameter than the other two methods. SPECT-CT shows lower variability. However, no significant differences were observed between SPECT and SPECT-CT measurements. In patients, relevant differences were found in 7 out of 9 lesions with the planar method, in 6 lesions with SPECT, but in only one with SPECT-CT. Our study confirms the superiority of SPECT in volume measurement if compared with the planar method. A more accurate measurement can be obtained from SPECT-CT.
Sections du résumé
BACKGROUND
BACKGROUND
An accurate measurement of the target volume is of primary importance in theragnostics of hyperthyroidism.
OBJECTIVE
OBJECTIVE
Our purpose was to evaluate the accuracy of a threshold-based isocontour extraction procedure for thyroid tissue volumetry from SPECT-CT.
METHODS
METHODS
Cylindrical vials with a fixed volume of 99mTcO4 at different activities were inserted into a neck phantom in two different thickness settings. Images were acquired by orienting the phantom in different positions, i.e., 40 planar images and 40 SPECT-CT. The fixed values of the isocontouring threshold for SPECT and SPECT-CT were calculated by means of linear and spline regression models. Mean, Median, Standard Deviation, Standard Error, Mean Absolute Percentage Error and Root Mean-Square Error were computed. Any difference between the planar method, SPECT and SPECT-CT and the effective volume was evaluated by means of ANOVA and posthoc tests. Moreover, planar and SPECT-CT acquisitions were performed in 8 patients with hyperthyroidism, considering relevant percentage differences greater than > 20% from the CT gold standard.
RESULTS
RESULTS
Concerning phantom studies, the planar method shows higher values of each parameter than the other two methods. SPECT-CT shows lower variability. However, no significant differences were observed between SPECT and SPECT-CT measurements. In patients, relevant differences were found in 7 out of 9 lesions with the planar method, in 6 lesions with SPECT, but in only one with SPECT-CT.
CONCLUSION
CONCLUSIONS
Our study confirms the superiority of SPECT in volume measurement if compared with the planar method. A more accurate measurement can be obtained from SPECT-CT.
Identifiants
pubmed: 35021984
pii: CRP-EPUB-120109
doi: 10.2174/1874471015666220111145550
doi:
Substances chimiques
Radiopharmaceuticals
0
Sodium Pertechnetate Tc 99m
A0730CX801
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
205-217Informations de copyright
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