Early detection of the cancerous process would benefit greatly from imaging at the cellular and molecular level. Increased
glucose demand has been recognized as one of the hallmarks of cancerous cells (the "Warburg effect"), hence
glucose and its analogs are commonly used for
cancer imaging. One example is FDG-PET technique, that led to the use of chemical exchange saturation transfer (CEST) MRI of
glucose ("glucoCEST") for
tumor imaging. This technique combines high-resolution MRI obtained by conventional imaging with simultaneous molecular information obtained from the exploitation of agents with exchangeable
protons from
amine,
amide or
hydroxyl residues with the water signal. In the case of glucoCEST, these agents are based on
glucose or its analogs. Recently, preclinical glucoCEST studies demonstrated the ability to increase the sensitivity of MRI to the level of metabolic activity, enabling identification of
tumor staging, biologic potential, treatment planning,
therapy response and local recurrence, in addition to guiding target biopsy for clinically suspected
cancer. However, natural
glucose limits this method because of its rapid conversion to
lactic acid, leading to reduced CEST effect and short signal duration. For that reason, a variety of
glucose analogs have been tested as alternatives to the original glucoCEST. This review discusses the merits of these analogs, including new data on
glucose analogs heretofore not reported in the literature. This summarized preclinical data may help strengthen the translation of CEST MRI of
glucose analogs into the clinic, improving
cancer imaging to enable early intervention without the need for invasive techniques. The data should also broaden our knowledge of fundamental biological processes.