Abstract |
18F-fluorodihydrotestosterone (18F-FDHT) PET/CT potentially provides a noninvasive method for assessment of androgen receptor expression in patients with metastatic castration-resistant prostate cancer (mCRPC). The objective of this study was to assess simplified methods for quantifying 18F-FDHT uptake in mCRPC patients and to assess effects of tumor perfusion on these 18F-FDHT uptake metrics. Methods: Seventeen mCRPC patients were included in this prospective observational multicenter study. Test and retest 30-min dynamic 18F-FDHT PET/CT scans with venous blood sampling were performed in 14 patients. In addition, arterial blood sampling and dynamic 15O-H2O scans were obtained in a subset of 6 patients. Several simplified methods were assessed: Patlak plots; SUV normalized to body weight (SUVBW), lean body mass (SUVLBM), whole blood (SUVWB), parent plasma activity concentration (SUVPP), area under the parent plasma curve (SUVAUC,PP), and area under the whole-blood input curve (SUVAUC,WB); and SUVBW corrected for sex hormone-binding globulin levels (SUVSHBG). Results were correlated with parameters derived from full pharmacokinetic 18F-FDHT and 15O-H2O. Finally, the repeatability of individual quantitative uptake metrics was assessed. Results: Eighty-seven 18F-FDHT-avid lesions were evaluated. 18F-FDHT uptake was best described by an irreversible 2-tissue-compartment model. Replacing the continuous metabolite-corrected arterial plasma input function with an image-derived input function in combination with venous sample data provided similar Ki results (R2 = 0.98). Patlak Ki and SUVAUC,PP showed an excellent correlation (R2 > 0.9). SUVBW showed a moderate correlation to Ki (R2 = 0.70, presumably due to fast 18F-FDHT metabolism. When calculating SUVSHBG, correlation to Ki improved (R2 = 0.88). The repeatability of full kinetic modeling parameters was inferior to that of simplified methods (repeatability coefficients > 36% vs. < 28%, respectively). 18F-FDHT uptake showed minimal blood flow dependency. Conclusion:18F-FDHT kinetics in mCRPC patients are best described by an irreversible 2-tissue-compartment model with blood volume parameter. SUVAUC,PP showed a near-perfect correlation with the irreversible 2-tissue-compartment model analysis and can be used for accurate quantification of 18F-FDHT uptake in whole-body PET/CT scans. In addition, SUVSHBG could potentially be used as an even simpler method to quantify 18F-FDHT uptake when less complex scanning protocols and accuracy are required.
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Authors | Gerbrand M Kramer, Maqsood Yaqub, Herbert A Vargas, Robert C Schuit, Albert D Windhorst, Alfonsus J M van den Eertwegh, Astrid A M van der Veldt, Andries M Bergman, Eva M Burnazi, Jason S Lewis, Sua Chua, Kevin D Staton, Brad J Beattie, John L Humm, Ian D Davis, Andrew J Weickhardt, Andrew M Scott, Michael J Morris, Otto S Hoekstra, Adriaan A Lammertsma |
Journal | Journal of nuclear medicine : official publication, Society of Nuclear Medicine
(J Nucl Med)
Vol. 60
Issue 9
Pg. 1221-1227
(09 2019)
ISSN: 1535-5667 [Electronic] United States |
PMID | 30850488
(Publication Type: Journal Article, Multicenter Study, Observational Study, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
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Copyright | © 2019 by the Society of Nuclear Medicine and Molecular Imaging. |
Chemical References |
- 16-fluorodihydrotestosterone
- Fluorine Radioisotopes
- Radiopharmaceuticals
- Dihydrotestosterone
- Fluorine-18
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Topics |
- Aged
- Aged, 80 and over
- Body Weight
- Dihydrotestosterone
(analogs & derivatives, pharmacokinetics)
- Fluorine Radioisotopes
(pharmacokinetics)
- Humans
- Image Processing, Computer-Assisted
- Kinetics
- Male
- Middle Aged
- Neoplasm Metastasis
- Positron Emission Tomography Computed Tomography
- Prospective Studies
- Prostatic Neoplasms, Castration-Resistant
(diagnostic imaging)
- Radiopharmaceuticals
(pharmacokinetics)
- Reproducibility of Results
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