A first-in-human phase I imaging study using hyperpolarized 1 c-13 pyruvate (h-Py) in patients (pts) with localized prostate cancer (l-PCa)
Abstract only 4660 Background: Preclinical studies demonstrated that the conversion of h-Py to hyperpolarized 13 C lactate (h-lac) is detectable on MRI-spectroscopy and is a useful marker of differentiation in PCa. H-Py MRI provides more than 10,000-fold enhancement in signal to noise ratio (SNR), a...
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Published in | Journal of clinical oncology Vol. 30; no. 15_suppl; p. 4660 |
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Main Authors | , , , , , , , , , , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
20.05.2012
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Online Access | Get full text |
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Summary: | Abstract only
4660
Background: Preclinical studies demonstrated that the conversion of h-Py to hyperpolarized
13
C lactate (h-lac) is detectable on MRI-spectroscopy and is a useful marker of differentiation in PCa. H-Py MRI provides more than 10,000-fold enhancement in signal to noise ratio (SNR), allowing for rapid detection of metabolic alterations in vivo. Hyperpolarized compounds have not been previously studied in man. Methods: Pts with biopsy-proven untreated l-PCa were enrolled in a phase I study of h-Py MRI. Following a modified 3+3 design, 6 pts were enrolled at each dose level (0.14, 0.28 and 0.43 mL/Kg): 3 to monitor kinetics of h-Py, and 3 to evaluate the spatial distribution of metabolism in PCa and normal prostate (nl-P). An expansion cohort of 15 pts explored the biological variability of metabolism. A dynamic nuclear polarization (DNP) system, the first human system anywhere, generated and delivered 230 mM sterile h-Py. IV injection of h-Py was followed by imaging with a 3T MR scanner with custom transmit and receive coils. Monitoring included EKG, vital signs, and laboratory testing. Results: 31 pts were imaged. 23 pts had Gleason (G) 6, 6 pts G7, and 2 pts G8 PCa. Median age was 63 years (range 45-75); median PSA was 5.9 ng/mL (1.88-20.2). No dose limiting toxicities or >grade (gr) 2 toxicity was observed. Toxicity included: gr 1dysgeusia (6 pts), gr 1 hypokalemia, gr 1 hypocalcemia, gr 1 dizziness, and gr 2 diarrhea (1 pt each). Median time from dissolution of the agent to delivery into patients was 66 seconds (43-88). Signals from h-Py and h-Lac were seen in PCa and nl-P at all doses; 0.43 mL/Kg showed the best SNR and discrimination between PCa and nl-P and was therefore established as the phase II dose. There appeared to be an association between h-Lac levels and PCa grade. Conclusions: H-py metabolic imaging has minimal toxicity and provides the ability to discriminate Ca from nl-P based on increased levels of h-lac. The correlation with grade and changes with therapy require further study. |
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ISSN: | 0732-183X 1527-7755 |
DOI: | 10.1200/jco.2012.30.15_suppl.4660 |