Dual PET and Near-Infrared Fluorescence Imaging Probes as Tools for Imaging in Oncology

Abstract

OBJECTIVE The purpose of this article is to summarize advances in PET fluorescence resolution, agent design, and preclinical imaging that make a growing case for clinical PET fluorescence imaging. CONCLUSION Existing SPECT, PET, fluorescence, and MRI contrast imaging techniques are already deeply integrated into the management of cancer, from initial diagnosis to the observation and management of metastases. Combined positron-emitting fluorescent contrast agents can convey new or substantial benefits that improve on these proven clinical contrast agents.

18F-Positron Emitting/Trimethine Cyanine-Fluorescent Contrast for Image-Guided Prostate Cancer Management

“…A single injection of a PET/FL probe allows for (i) presurgical planning, in which PSMA+ primary cancer and lymph node metastases are resolved in PET/MR and PET/CT; (ii) intraoperative, fluorescent-guided resection of a primary tumor and lymph nodes (0.5–72 h after injection); and (iii) margin confirmation in triplicate, i.e., by the surgeon in vivo, with fluorescence, postsurgery, within an open surgical site; by the surgeon ex vivo, by fluorescence in excised tissue; and by the pathologist in fluorescent or nonfluorescent histopathology. 25 [ 19 F]- 4 will be important in intraoperative, frozen section margin determination. Frozen sections are less accurate than permanent, formalin-fixed histopathologic analysis.…”

A near-infrared probe for non-invasively monitoring cerebrospinal fluid flow by 18F-positron emitting tomography and fluorescence

“…Notably, two lateral ventricles were observable through the unprocessed brain in the IR783-AMBF 3 fluorescent channel. In our previous publication using Fc-AMBF 3 [20,21], these ventricles were difficult to visualize without sectioning the brain due to the strong absorption of exciting and emitted short wavelength photons by overlying brain tissue [2]. Fluorescent histology of a coronal section (− 19.11 mm, ant.…”

“…Yet, no current single imaging modality is ideal, as each individual imaging modality is limited by unique temporal, spatial, and depth (through-tissue) resolutions [1]. One popular strategy in the development of more universal contrast agents is to combine different imaging modalities with synergistic properties, where one modality will complement the resolution shortcomings of another imaging modality [2]. One good combination is positron emission tomography (PET) and fluorescence imaging.…”

“…Moreover, while PET emissions can be non-invasively quantitated through a patient's body, fluorescence imaging is ideal for visualizing submicron, histologic structure in superficial tissue. Therefore, by combining 18 F-PET and fluorescent imaging modalities within a single molecule, we can transcend the molecular resolution limits of any one imaging modality [2,[7][8][9].…”

“…A popular strategy for indicating CNS damage is to introduce a contrast agent into the CNS [12][13][14][15][16][17], but tracking small molecules deep within the CNS represents a particular challenge for multiple reasons: (1) Toxicity to structures within the CNS result in particularly morbid prognoses; therefore, it is crucial that new contrast be useful at low concentrations to ensure non-toxicity [18]. (2) Dense tissue and the thick bone that shield the CNS can scatter both exciting and emitting photons, thereby reducing the quality of certain imaging modalities significantly. 3Media such as CSF can move a molecule, thereby quickly reducing the usefulness of slower image acquisition strategies that involve faster scanning or signal averaging [13,15,19].…”