Article Figures & Data
Figures
- FIG 1.
HP-13C imaging of DIPG. HP-13C EPI of a 9-year-old male participant (P-01) with DIPG following injection of HP [1-13C]pyruvate. Maps of the temporally summed signal from HP [1-13C]pyruvate and downstream metabolites [1-13C]lactate and [13C]bicarbonate are overlaid on 1H FLAIR images, along with the ratio of [1-13C]lactate to [1-13C]pyruvate, which removes the shading of 13C hardware sensitivity. Within the hyper- and hypointense T2 lesion indicated by the yellow arrows, there is a subtle increase in [1-13C]lactate signal relative to the normal-appearing contralateral brain stem. The ratio of [1-13C]lactate to [1-13C]pyruvate also demonstrates a local maximum in this anatomic lesion (yellow arrow). Pyr indicates pyruvate; Lac, lactate; Bicarb, bicarbonate; AU, arbitrary units.
- FIG 2.
HP-13C spectroscopy of DIPG. HP-13C EPSI of a 12-year-old male participant (P-02) with DIPG following injection of HP [1-13C]pyruvate. Temporally summed 13C spectra are shown together with their spatial correspondence to a 1H FLAIR image from the center of the 2-cm-thick 13C volume (A). Spectra from normal-appearing tissue (B) and the lesion (C) illustrate individual HP metabolite resonances. The [13C]bicarbonate resonance is aliased from 160.8 ppm. Pyr indicates [1-13C]pyruvate; Pyr-H2O, [1-13C]pyruvate-hydrate; Lac, [1-13C]lactate; Bic, [13C]bicarbonate; Ala, [1-13C]alanine exclusively from outside the brain.
Tables
Demographics Consented (n = 12) Age (median) (range) (yr) 14 (8–17) Males (No.) (%) 10 (83) Treatment (No. of patients) Completed protocol therapy 6 Eligible, withdrawna 6 Completed 13C injection (n = 6) Age (median) (range) (yr) 14 (10–17) Males (No.) (%) 5 (83) Diagnosis (anatomic location) (No.) (%) Diffuse intrinsic pontine glioma (pons) 3 (50) Craniopharyngioma (suprasellar) 1 (17) Medulloblastoma (posterior fossa) 1 (17) Pineoblastoma (pineal gland) 1 (17) Dose level (No. of patients) Dose level 1 3 Dose level 2 3 Safety (No. of events) Dose level toxicity 0 Adverse events 0 ↵a Withdrawn due to the following: technical issue with MR imaging scanner (n = 1) or generating HP [1-13C]pyruvate (n = 3); change in participant choice to participate (n = 1); or disease progression before participation and participant did not return to University of California, San Francisco for follow-up treatment (n = 1).
Participant ID EPA Conc. (µM) [1-13C] Pyruvate Conc. (mM) Volume Injected (mL) Polarization (%) Temp. (oC) pH Time to Injection (sec) P-01 1.6 230 23.0 44.0 34.6 7.7 56 P-02 0.6 232 21.8 42.5 31.9 7.6 75 P-03 0.5 235 16.0 38.8 31.0 7.7 66 P-04 0.3 230 36.0 38.1 30.7 7.7 53 P-05 0.5 231 20.8 43.9 32.1 7.6 55 P-06 1.4 242 22.2 33.6 30.9 7.5 70 Note:—EPA indicates electron paramagnetic agent; Conc., concentration; Temp, temperature.
