An automated voxelized dosimetry tool for radionuclide therapy based on serial quantitative SPECT/CT imaging

Bone scintigraphy with combined single-photon emission computed tomography (SPECT) and computed tomography (CT) has become widely used for the detection of bone metastases. However, calculation of the semi-quantitative standardized uptake value (SUV) requires measurement of the pre- and post-injection radioactivity of the radiopharmaceutical. This study aimed to compare measured and fixed input radioactivity values for quantitative SPECT/CT bone imaging to examine whether the fixed measurement method of radiopharmaceutical radioactivity could be used as an alternative method. Four different methods were used to quantify the Tc-99m hydroxymethylene diphosphonate input radioactivity: (A) measured pre- and post-injection radioactivity values; (B) measured pre-injection and fixed post-injection radioactivity values; (C) fixed pre-injection and measured post-injection radioactivity values; (D) fixed pre- and post-injection radioactivity values. All SPECT/CT acquisitions were analyzed using bone SPECT analysis software, and the semi-quantitative parameters (SUVpeak and SUVmean) were recorded and compared for each analytical method. Two semi-quantitative parameters showed significant differences between analytical methods A and B, A and D, and C and D. However, an additional subgroup analysis performed on patients whose median post-injection measured radioactivity value was <1.5 MBq showed no significant differences in parameters between all analytical methods. Measurement of the radiopharmaceutical radioactivity can be an alternative method because it reduces the volume of radioactivity post-injection. The simplified fixed measurement method of radiopharmaceutical radioactivity can be used as an alternative method in cases when measuring the radioactivity in quantitative bone SPECT/CT imaging is missed.

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Physical quantities useful for quality control of quantitative SPECT/CT imaging

Nuclear Medicine Review ◽

10.5603/nmr.2021.0020 ◽

2021 ◽

Vol 24 (2) ◽

pp. 93-98

Author(s):

Sara Kurkowska ◽

Bożena Birkenfeld ◽

Hanna Piwowarska-Bilska

Keyword(s):

Quality Control ◽

Ct Imaging ◽

Quantitative Spect ◽

Physical Quantities

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What validation tests can be done by the clinical medical physicist while waiting for the standardization of quantitative SPECT/CT imaging?

10.21203/rs.3.rs-118913/v1 ◽

2020 ◽

Author(s):

Hanna Piwowarska-Bilska ◽

Aleksandra Supińska ◽

Bożena Birkenfeld

Keyword(s):

Nuclear Medicine ◽

Activity Concentration ◽

Total Activity ◽

Ct Imaging ◽

Calibration Factor ◽

Recovery Coefficient ◽

Quantitative Spect ◽

Gamma Cameras ◽

Reconstruction Methods ◽

Accuracy Of Measurements

Abstract Objective The aim of the study was to assess the accuracy of quantitative SPECT/CT imaging in a clinical setting and to compare test results from two nuclear medicine departments.Methods Phantom studies were carried out with two gamma cameras manufactured by GE Healthcare: Discovery NM/CT 670 and NM/CT 850, used in two nuclear medicine departments.Results The convergence of activity concentration recovery was validated for the two gamma cameras operating in two medical centres using a homogeneous 3D phantom. The comparison of results revealed a 5% difference in the calibration factor Bg. cal; 6% difference in COV, and a 0.6% difference in total activity deviation ∆Atot.Recovery coefficients (RCmax) for activity concentration in spheres of the anthropomorphic phantom was measured for different image reconstruction techniques. RCmax was in the range of 0.2-0.4 for the smallest sphere (ϕ10 mm), and 1.3-1.4 for the largest sphere (ϕ37 mm). Conversion factors for SUVmax and SUVmean for the gamma camera systems used were 0.99 and 1.13, respectively.Conclusions 1) Measurements taken in our study confirmed the clinical suitability of 5 parameters of image quality (Bg. cal- background calibration factor, ∆Atot- total activity deviation, COV- noise level estimation, QH- hot contrast, AM-accuracy of measurements or RC- recovery coefficient) for the validation of SPECT/CT system performance in terms of correct quantitative acquisitions of images. 2) This work shows that absolute SPECT/CT quantification is achievable in clinical nuclear medicine centers. Results variation of quantitative analyzes between centers is mainly related to the use of different reconstruction methods. 3) It is necessary to standardize the technique of measuring the SUV conversion factor obtained with different SPECT/CT scanners.

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Can the Standardized Uptake Values derived from Diagnostic 68Ga-DOTATATE PET/CT Imaging Predict the Radiation Dose delivered to the Metastatic Liver NET Lesions on 177Lu-DOTATATE Peptide Receptor Radionuclide Therapy?

Journal of Postgraduate Medicine Education and Research ◽

10.5005/jp-journals-10028-1050 ◽

2013 ◽

Vol 47 (1) ◽

pp. 7-13 ◽

Cited By ~ 5

Author(s):

Baljinder Singh ◽

Vikas Prasad ◽

Christiane Schuchardt ◽

Harshad Kulkarni ◽

Richard P Baum

Keyword(s):

Radiation Dose ◽

Radionuclide Therapy ◽

Peptide Receptor Radionuclide Therapy ◽

Ct Imaging ◽

Neuroendocrine Neoplasms ◽

Liver Lesions ◽

Peptide Receptor ◽

Standardized Uptake Values ◽

Pet Ct ◽

Metastatic Liver

ABSTRACT Introduction Neuroendocrine neoplasms express somatostatin receptors, enabling the use of somatostatin analogs for molecular imaging, when labeled with the positron-emitter 68Ga for receptor positron emission tomography/computed tomography (PET/CT), and targeted radionuclide therapy, when labeled with beta-emitters, e.g. 90Y and 177Lu. Aim To investigate if 68Ga-DOTATATE PET-derived standardized uptake values (SUV) correlate with the dose delivered to the liver lesions following 177Lu-DOTATATE radionuclide therapy in patients with neuroendocrine neoplasms. Materials and methods Twelve adult (8M: 4F; mean age: 55.9 ± 14.5 years; range: 23-78 years) patients with documented neuroendocrine tumor (NET) disease and liver metastases were enrolled in the study. Ten patients were subjected to 68Ga-DOTATATE and one patient each underwent 68Ga-DOTATOC and 68Ga-DOTANOC diagnostic PET/CT imaging. Subsequently, on the basis of positive PET/CT scan findings for the metastatic NET disease, all these patients were subjected to peptide receptor radionuclide therapy (PRRNT) with 177Lu-DOTATATE. The reconstructed PET/CT data was used to calculate the SUVs on the identifiable liver lesions. The scintigraphic data acquired (anterior and posterior whole body images) following therapeutic doses of 177Lu-DOTATATE were subjected to the quantitative analysis (HERMES workstation and OLINDA/EXM software) to calculate the dose delivered to the hepatic lesions. Results The initial results of this preliminary study indicate poor correlation between SUV and the tumor dose and the linear regression analysis provided R2 values which explained only a small fraction of the total variance. Conclusion The SUVs derived from 68Ga-DOTA-peptide PET/CT images should be used with caution for the prediction of tumor dose on 177Lu-DOTA-peptide therapy as there are large intra- and interpatient variability. Further studies with large numbers of patients are warranted to establish such a correlation between SUV, tumor dose and the response assessment. How to cite this article Singh B, Prasad V, Schuchardt C, Kulkarni H, Baum RP. Can the Standardized Uptake Values derived from Diagnostic 68Ga-DOTATATE PET/CT Imaging Predict the Radiation Dose delivered to the Metastatic Liver NET Lesions on 177Lu-DOTATATE Peptide Receptor Radionuclide Therapy? J Postgrad Med Edu Res 2013;47(1):7-13.

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