In:
Current Radiopharmaceuticals, Bentham Science Publishers Ltd., Vol. 15, No. 3 ( 2022-09), p. 205-217
Abstract:
An accurate measurement of the target volume is of primary importance
in theragnostics of hyperthyroidism. Objective: Our purpose was to evaluate the accuracy of a threshold-based isocontour extraction procedure
for thyroid tissue volumetry from SPECT-CT. 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: 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. Conclution: 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.
Type of Medium:
Online Resource
ISSN:
1874-4710
DOI:
10.2174/1874471015666220111145550
Language:
English
Publisher:
Bentham Science Publishers Ltd.
Publication Date:
2022
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