A research group led by Dr. Timothy Scholl at the Imaging Research Laboratories of the Robarts Research Institute (Western University) is focusing on developing new agents and imaging methods to image cellular metabolism, tissue pH and the concentration of endogenous sodium in tissue.

Dr. Scholl recently led a novel prostate imaging study to non-invasively assess tumour aggressiveness. Using a novel detection system that he developed for measurement of sodium with MRI in the prostate, he imaged men with biopsy-proven prostate cancer prior to surgery. He compared tissue sodium concentration measured in prostate tumours with pathological assessment after prostatectomy. The results showed a very strong correspondence between sodium concentration in tumours and their aggressiveness. This suggests that sodium MRI combined with standard MRI protocols could potentially discriminate between indolent and aggressive disease. With further research, it may be possible that this combined imaging could ultimately replace serial biopsies for active surveillance of men with low- and intermediate-risk prostate cancer.

Tumour metabolism changes rapidly in response to therapy compared with morphological or functional changes. Prompt characterization of metabolism can provide timely therapeutic assessment to determine if a treatment has elicited the desired effect or whether another therapy should be considered. Magnetic resonance spectroscopic imaging (MRSI) of in vivo metabolism of ¹³C-enriched contrast agents is an emerging method for molecular imaging of disease. One of Dr. Scholl’s research interests is the use of hyperpolarized ¹³C-enriched compounds to measure metabolic changes within tumours as they respond to therapy. In a preclinical ¹³C imaging study, he demonstrated that measurement of tumor metabolism with hyperpolarized [1-¹³C]pyruvate MRSI can detect very early changes in lactate dehydrogenase activity in response to therapy. These changes, which were apparent as early as within two days of initiation of treatment, were correlated with subsequent measurements of tumor response or progression assessed by tumor volume measurements. Early assessment of therapeutic response is highly desirable in aggressive cancers to prompt alternative or salvage therapies or to improve end-of-life care.