Abstract
The present invention provides isotopically labeled deoxy-glucose and derivatives thereof, methods of their preparation, ration, kits comprising them and uses thereof for spin hyperpolarized magnetic resonance imaging, utilized in the quantitative and qualitative diagnosis of states, conditions, diseases, or disorders in the body of a subject.
Claims
1. Deoxy-glucose comprising six isotopically labeled carbon atoms each of said isotopically labeled carbon atoms is directly bonded to at least one deuterium atom.
2. Deoxy-glucose according to claim 1, wherein said isotopically labeled carbon atom is .sup.13C.
3. Deoxy-glucose according to claim 1, having T.sub.1 relaxation time values of .sup.13C nuclei of between about 2 to about 60 sec.
4. Deoxy-glucose according to claim 1, further comprising at least one isotopically labeled hydrogen atom.
5. Deoxy-glucose according to claim 1, further comprising at least one fluorine atom.
6. Deoxy-glucose according to claim 1, being [.sup.13C.sub.6, D.sub.8]2-deoxyglucose.
7. Deoxy-glucose according to claim 1, being in a hyperpolarized state.
8. A composition comprising at least one deoxy-glucose comprising six isotopically labeled carbon atoms each of said isotopically labeled carbon atoms is directly bonded to at least one deuterium atom.
9. A kit comprising at least one component containing at least one deoxy-glucose comprising six isotopically labeled carbon atoms each of said isotopically labeled carbon atoms is directly bonded to at least one deuterium atom and instructions for use.
10. A kit according to claim 9, wherein said instructions are for use in diagnosing and evaluating a state, condition, or disease.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIGS. 1A-1B show the effect of glucose concentration on the T.sub.1 of glucose carbons as measured at 7 T (FIG. 1A) and at 11.8 T (FIG. 1B).
(2) FIG. 2 shows the effect of the magnetic field strength on the T.sub.1 of glucose carbons.
(3) FIG. 3 shows the effect of direct bonding between carbon-13s on each other's T.sub.1 in the glucose molecule.
(4) FIG. 4 shows the simulation for the relative imaging signal of [U-.sup.13C.sub.6, .sup.2H.sub.7]glucose compared to [1-.sup.13C]pyruvate hyperpolarized molecular probes.
(5) FIGS. 5A-5C show hyperpolarized [U-.sup.13C.sub.6, .sup.2H.sub.7]glucose in vivo images at 3 T, recorded in rats injected through the tail vein in a bolus of 12 s total duration. Images were recorded at 8 s (FIG. 5A), 12 s (FIG. 5B), and 20 s (FIG. 5C) from the onset of the bolus injection (i.e. during and after the bolus).
DETAILED DESCRIPTION OF EMBODIMENTS
(6) In order to understand the invention and to see how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings.
(7) The clinical diagnosis based on the uptake of hyperpolarized deoxy-glucose or glucose relies to a significant extent on first pass and uptake, due to the short term of exposure to the contrast media prior to imaging (approximately 30-60 s). This term encompasses both uptake rate at specific tissues as well as the flow rate to the tissue. High flow rate contributes to the accumulation of glucose signal in a tissue.
(8) The effect of glucose concentration on the T.sub.1 of its carbon positions was investigated at 7 T (FIG. 1A) and at 11.8 T (FIG. 1B) using Varian NMR spectrometers (The Netherlands). [U-.sup.13C.sub.6, .sup.2H.sub.7]glucose was obtained from Cambridge Isotopes Laboratories (Andover, Mass., USA). The T.sub.1 of [U-.sup.13C.sub.6, .sup.2H.sub.7]glucose .sup.13C's was measured using the inversion recovery pulse sequence. The T.sub.1 of glucose carbons was found to be longer in a physiological compatible solution (400 mM, solid gray columns) compared to a concentrated solution (4.03 M, diagonal pattern columns). The mean difference between the T.sub.1s of the two concentrations was 6.9 s (P=2*10.sup.6, paired t-test) at 7 T. The mean difference in T.sub.1 at 11.8 T was 4.5 s (P=4*10.sup.5, paired t-test). The labels C.sub.1 and C.sub.1 (FIG. 1-3) mark the two signals of the glucose carbon at position 1 in the and anomers. The labels C.sub.i and C.sub.i (FIG. 1-3) mark the two signals of the glucose carbon at position i in the and anomers. This investigation showed that the T.sub.1 of glucose carbons was affected by the concentration and suggested that the physiological conditions are favorable for T.sub.1 elongation. It also suggested that hyperpolarized glucose concentration should be kept at a minimum during the transfer of the hyperpolarized media from the polarizer to the subject and during the administration to the subject.
(9) The effect of the magnetic field strength on the T.sub.1 of glucose carbons was investigated at 7 T (FIG. 2, solid gray columns) and at 11.8 T (FIG. 2, diagonal pattern columns). [U-.sup.13C.sub.6, .sup.2H.sub.7]glucose T.sub.1 at 400 mM was measured using the inversion recovery pulse sequence in the two spectrometers. The T.sub.1 of glucose carbons was found to be longer in the lower magnetic field (7 T). The mean difference in T.sub.1 between the two fields was 2 s (P=6*10.sup.4, paired t-test). This suggests that the glucose carbons' T.sub.1 may be longer at clinically relevant magnetic field strengths (1.5 T and 3 T). Further studies are underway to validate this suggestion.
(10) To increase the signal of hyperpolarized deoxy-glucose and hyperpolarized glucose, stable isotope labeling by carbon-13 in all of the carbon positions was used. The effect of direct carbon-13 to carbon-13 bonding on the individual carbon-13 T.sub.1s was investigated to study the effect of these added dipolar interactions on T.sub.1 relaxation times. To this end, two compounds were investigated (both from Cambridge Isotopes Laboratories): [U-.sup.13C.sub.6, .sup.2H.sub.7]glucose (FIG. 3, solid gray columns) and [.sup.2H.sub.7]glucose (FIG. 3, diagonal pattern columns), both at 400 mM concentration. The T.sub.1 at 11.8 T was measured using the inversion recovery pulse sequence. While both compounds are fully deuterated, in the [U-.sup.13C.sub.6, .sup.2H.sub.7]glucose molecule the carbon positions are 99% occupied by .sup.13C nuclei. In the [.sup.2H.sub.7]glucose molecule, only ca. 1.1% of each of the carbon positions are occupied by .sup.13C nuclei (due to the natural abundance distribution of .sup.13C). The chance for having two directly bonded .sup.13C nuclei in this molecule is therefore 0.01% (negligible). Therefore this measurement was indicative of the T.sub.1 of singly .sup.13C labeled glucose. It was found that the T.sub.1 of glucose .sup.13Cs in a uniformly .sup.13C-labeled glucose was shorter by 3.3 s (P=1.410.sup.3, paired t-test). Therefore, it was deducted that direct bonding of additional .sup.13C nuclei led to a decrease in glucose .sup.13C T.sub.1s, due to the additional dipolar interactions. However, as can be seen in the following, this decrease in T.sub.1 did not prevent imaging of hyperpolarized [U-.sup.13C.sub.6, .sup.2H.sub.7]glucose.
(11) The fully deuterated and fully .sup.13C labeled [U-.sup.13C.sub.6, .sup.2H.sub.7]glucose has two competing properties, in terms of its potential hyperpolarized signal. On one hand, it is labeled at six positions, all with similar T.sub.1. This property can be utilized to increase the initial hyperpolarized signal sixfold. On the other hand, the T.sub.1 s of these carbon-13 nuclei are shorter than any hyperpolarized probe reported to date.
(12) To gain insight into the relative imaging signal increase that would be provided by using glucose or deoxyglucose that are fully labeled with 13C and deuterium in all positions at a hyperpolarized state, a signal enhancement simulation was performed. This simulation compared the signal expected from the deoxy-glucose or glucose molecular probe (FIG. 4, dashed line) to that of the [1-.sup.13C]pyruvate molecular probe (FIG. 4, solid line). In this calculation the following consideration were taken: 1) pyruvate was injected at a dose of 0.2 mmol/Kg (Real-Time Metabolic Imaging Proc. Natl. Acad. Sci. USA, 2006, 103, 11270-11275) and glucose was injected at a dose of 1.4 mmol/Kg (which is ca. half of the dose that is safe for injection in humans, as per the glucose tolerance test); 2) the imaging signal is greater than the spectroscopic signal by an estimated factor of approximately 2.5 (in comparison to the pyruvate study described above); 3) the initial relative imaging signal is dependent both on the dose ratio and the imaging signal strength compared to that of spectroscopy; 4) the T.sub.1 of pyruvate is 55 s; 5) the T.sub.1 of glucose is position and anomer dependent, the individual values were determined per position and were used in this calculation (8-13 s). The glucose signal at each time point was calculated as Sc.sub.i, where Sc.sub.i is the individual signal for each carbon position at a particular time point. Each Sc.sub.i was calculated according to Sc.sub.i(t)=I.sub.SNR.Math.exp(t/T.sub.1_ci), where I.sub.BNR is the initial SNR or the initial relative imaging signal (pyruvate initial signal multiplied by the dose ratio factor and the imaging/spectroscopy signal increase factor as defined above). T.sub.1_ci was individually determined per carbon position (using [U-.sup.13C.sub.6, .sup.2H.sub.7]glucose at 7 T and 400 mM, see FIG. 1). In this example it was assumed that the T.sub.1_ci of [U-.sup.13C.sub.6, .sup.2H.sub.8]deoxy-glucose is similar to that of [U-.sup.13C.sub.6, .sup.2H.sub.7]glucose.
(13) Considering a duration of approximately 30 s from dissolution start for transfer and injection, this simulation suggests a temporal window for imaging of approximately 35 s more, during which the expected signal of hyperpolarized [U-.sup.13C.sub.6, .sup.2H.sub.7]glucose is higher than that of hyperpolarized [1-.sup.13C]pyruvate (FIG. 4). The simulation also suggests that a dramatic increase in signal may be gained using hyperpolarized [U-.sup.13C.sub.6, .sup.2H.sub.7]glucose by minimizing the transfer and/or the injection duration.
(14) Hyperpolarized glucose images were recorded at 3 T in vivo. As depicted in FIG. 5, hyperpolarized [U-.sup.13C.sub.6, .sup.2H.sub.7]glucose provided a high signal on carbon-13 images recorded in vivo. Normal rats were anesthetized, and hyperpolarized [U-.sup.13C.sub.6, .sup.2H.sub.7]glucose was injected through the tail vein in a bolus of 12 s total duration. Images were recorded at 8, 12, and 20 s from the onset of the bolus injection (i.e. during and after the bolus).
(15) In the image recorded at 8 s (FIG. 5A), the inferior vena cava and the heart are clearly visible (see indicating arrows). Arterial hyperpolarized media flow at this time is not likely, as the signal in the kidneys is not yet visible. This image, which was recorded during the bolus at a very high resolution (128128 matrix, in-plane resolution of 1.56 mm), demonstrates the use of hyperpolarized glucose imaging in angiography. The signal from the injected hyperpolarized media is extremely high with no background signal.
(16) At 12 s (FIG. 5B), at the end of the bolus injection, signal intensity in the main vasculature and the heart is still high, with substantial intensity observed in the kidneys (see indicating arrows).
(17) At 20 s from bolus initiation (FIG. 5C), signal from the heart is the most intense signal in the image, about 40% higher than signal in the vasculature and 20% higher than signal in the kidneys. Still, signal in the kidneys is clearly observed, as well as signal in other tissues such as the liver (see indicating arrows and color change).
(18) The hyperpolarized glucose signal observed in the heart at 20 s from bolus start is more intense than signal in the vasculature and the kidneys. It is thus suggested that this intense signal in the heart indicates glucose uptake in the myocardium. In the anaesthetized rat, the only tissue that is expected to actively take up glucose is the myocardium, because under anesthesia it is the only active muscle. The brain, which very actively takes up glucose in conscious subjects, as seen on clinical FDG-PET images, actually has very low glucose metabolism under anesthesia, and was therefore not imaged. It is noted that heart anatomy cannot be discerned from these hyperpolarized images since the imaging time (1 s) averaged several heart beats (approximately 6 beats). However, glucose uptake by the myocardium can be determined at short time frames of the order of 20 s using gradient de-phasing of intravoxel moving spins. Using this methodology, hyperpolarized glucose or deoxyglucose signal from capillaries are diminished, while the signal of intracellular hyperpolarized glucose or deoxyglucose are imaged and indicate the level of glucose uptake in the tissue.
(19) The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgement or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavor to which this specification relates.
