PET/CT

2005 ◽  
Vol 44 (S 01) ◽  
pp. S51-S57 ◽  
Author(s):  
T. Beyer ◽  
G. Brix

Summary:Clinical studies demonstrate a gain in diagnostic accuracy by employing combined PET/CT instead of separate CT and PET imaging. However, whole-body PET/CT examinations result in a comparatively high radiation burden to patients and thus require a proper justification and optimization to avoid repeated exposure or over-exposure of patients. This review article summarizes relevant data concerning radiation exposure of patients resulting from the different components of a combined PET/CT examination and presents different imaging strategies that can help to balance the diagnostic needs and the radiation protection requirements. In addition various dose reduction measures are discussed, some of which can be adopted from CT practice, while others mandate modifications to the existing hardand software of PET/CT systems.

2018 ◽  
Vol 29 (3) ◽  
pp. 1221-1230 ◽  
Author(s):  
Eva Dyrberg ◽  
Helle W. Hendel ◽  
Tri Hien Viet Huynh ◽  
Tobias Wirenfeldt Klausen ◽  
Vibeke B. Løgager ◽  
...  

2016 ◽  
Vol 58 (7) ◽  
pp. 1031-1036 ◽  
Author(s):  
Sara Sheikhbahaei ◽  
Charles V. Marcus ◽  
Roberto S. Fragomeni ◽  
Steven P. Rowe ◽  
Mehrbod S. Javadi ◽  
...  

2010 ◽  
Vol 21 (2) ◽  
pp. 246-255 ◽  
Author(s):  
Michael A. Fischer ◽  
Daniel Nanz ◽  
Thomas Hany ◽  
Caecilia S. Reiner ◽  
Paul Stolzmann ◽  
...  

2009 ◽  
Vol 48 (05) ◽  
pp. 201-207 ◽  
Author(s):  
K. Zöphel ◽  
R. Freudenberg ◽  
L. Oehme ◽  
M. Andreeff ◽  
G. Wunderlich ◽  
...  

Summary Aim: Investigation of the biodistribution and calculation of dosimetry of Ga-68-DOTATOCfor patients imaged in the routine clinical setting for diagnosis or exclusion of neuroendocrine tumours. Patients, methods: Dynamic PET/CT-imaging (Biograph 16) was performed over 20 min in 14 patients (8 men, 6 women) after injection of (112 ± 22) MBq 68Ga-DOTATOC followed by whole body 3D-acquisition (8 bed positions, 3 or 4 min each) 30 min p.i. and 120 min p.i. Urinary tracer elimination was measured and blood activity was derived non-invasively from the blood pool of the heart. The relevant organs for dosimetry were spleen, kidneys, liver, adrenals, urinary bladder and pituitary gland. Dosimetry was performed using OLINDA/ EXM 1.0 software and specific organ uptake was expressed as standardized uptake values (SUVs). Results: Rapid physiological uptake of the radiotracer could be demonstrated in liver, spleen and kidneys, adrenals and pituitary gland (mean SUVs were 6, 20, 16, 10, and 4, respectively). Radiotracer elimination was exclusively via urine (16% of injected dose within 2h); no redistribution could be observed. The spleen and the kidneys received the highest radiation exposure (0.24 mSv/MBq, 0.22 mSv/MBq resp.), mean effective dose yielded 0.023 mSv/MBq. Conclusion: 68Ga-DOTATOC is used extensively for diagnosis of somatostatin receptor positive tumours because it has several advantages over the 111In-labelled ligand. The derived dosimetric values are lower than first approximations from the biological data of OctreoScan. The use of CT for transmission correction of the PET data delivers radiation exposure up to 1 mSv (low dose).


JAMA ◽  
2006 ◽  
Vol 296 (21) ◽  
pp. 2590 ◽  
Author(s):  
Patrick Veit-Haibach ◽  
Christiane A. Kuehle ◽  
Thomas Beyer ◽  
Hrvoje Stergar ◽  
Hilmar Kuehl ◽  
...  

2014 ◽  
Vol 42 (1) ◽  
pp. 62-67 ◽  
Author(s):  
R. Sanchez-Jurado ◽  
M. Devis ◽  
R. Sanz ◽  
J. E. Aguilar ◽  
M. d. Puig Cozar ◽  
...  

2014 ◽  
Vol 53 (05) ◽  
pp. 217-220 ◽  
Author(s):  
D. Noßke ◽  
U. Leche ◽  
G. Brix

SummaryAim: Reinvestigation of the radiation exposure of patients undergoing whole-body [18F]FDG-PET/CT examinations pursuant to the revised recommendations of the ICRP. Methods: Conversion coefficients for equivalent organ doses were determined for realistic anthropomorphic phantoms of reference persons. Based on these data, conversion coefficients for the effective dose were calculated using the revised tissue-weighting factors that account for the different radiation susceptibilities of organs and tissues, and the redefinition of the group ‘remainder tissues’. Results: Despite the markedly changed values of the equivalent organ doses estimated for FDG and of the tissue-weighting factors, the conversion coefficient for the effective dose resulting from FDG administration decreases only slightly by 10 %. For whole-body CT scans it remains even unchanged. Conclusion: The updated dose coefficients provide a valuable tool to easily assess the generic radiation risk of patients undergoing whole- body PET/CT (or PET/MRI) examinations and can be used, amongst others, for protocol optimization.


2020 ◽  
Vol 13 (3) ◽  
pp. 243-248
Author(s):  
Marco Spadafora ◽  
Laura Evangelista ◽  
Salvatore Fiordoro ◽  
Francesco Porcaro ◽  
Marilena Sicignano ◽  
...  

Purpose: The Italian Tailored Assessment of Lung Indeterminate Accidental Nodule (ITALIAN) trial is a trial drawn to determine the performance of 18F-FDG-PET/CT in patients with solitary pulmonary nodules (SPN), stratified for a different kind of risk. An additional end-point was to compare the diagnostic information and estimated dosimetry, provided by a segmental PET/CT (s-PET/CT) acquisition instead of a whole body PET/CT (wb-PET/CT), in order to evaluate if segmental thoracic PET/CT can be used in patients with SPN. Methods: 18F-FDG PET/CT of 502 patients, stratified for pre-test cancer risk, was retrospectively analyzed. FDG uptake in SPN was assessed by a 4-point scoring (4PS) system and a semiquantitative analysis using the ratio between SUVmax in SPN and SUVmean in mediastinal blood pool (BP), and between SUVmax in SPN and SUVmean in the liver (L). Histopathology and/or follow-up data were used as a standard of reference. Data obtained on the thoracic part of wb-PET/CT, defined as s - PET/CT, were compared with those deriving from wb-PET/CT. Results: SPNs were malignant in 180 patients (36%), benign in 175 (35%), and indeterminate in 147 (29%). The 355 patients diagnosed with a definitive SPN nature (malignant or benign) were considered for the analysis of PET performance. Sensitivity, specificity, positive (PPV) and negative (NPV) predictive values, and accuracy were 85.6%, 85.7%, 86%, 85.2%, and 85.6%, respectively. Sensitivity and PPV were higher in intermediate and high-risk patients. : 18F-FDG uptake indicative of thoracic and extra-thoracic lesions was detectable in 13% and 3% of the patients. Compared to wb-PET/CT, s-PET/CT could save about 2/3 of 18F-FDG dose, radiation exposure or scan-time, without affecting the clinical impact of PET/CT. Conclusion: In patients with SPN, the pre-test likelihood of malignancy stratification allows to better define PET clinical setting and its diagnostic power. In subjects with low-intermediate pre-test likelihood of malignancy, s-PET/CT might be planned in advance. The adoption of this segmental strategy could reduce radiation exposure, scan-time, and might allow individually targeted protocols.


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