# A preclinical integrated PET/EPR imaging system

> **NIH NIH R01** · UNIVERSITY OF CHICAGO · 2020 · $348,969

## Abstract

Abstract
We propose to develop an integrated system for positron emission tomography (PET) and electron
paramagnetic resonance (EPR) simultaneous imaging of rodents for use in studying cancer and cancer
treatment. Cancer is a complex and heterogeneous functional disease. Therefore, effective treatment
of cancer shall account for the specific cellular-type populations and their states, as well as the tumor
microenvironment. In vivo imaging has an important role in providing such information. PET, already
widely used in the clinic, can measure many metabolic and physiological states of tumor, including
glucose utilization with 18F-fluorodeoxyglucose (FDG) and cell proliferation with 18F-fluorothymidine
(FLT). PET tracers for imaging tumor specific cell-membrane or intracellular molecules or genes, and
for imaging tumor microenvironment including angiogenesis and extracellular matrix, are also available
or under active development. The partial oxygen pressure, pH and interstitial inorganic phosphate in
the space surrounding the cancer cells also shall be considered as they will affect metabolic and
physiological processes, and hence the treatment outcome. Particularly, knowing the tissue oxygen
level is of importance for cancer treatment. It has been well known that hypoxic tumor cells are resistant
to various therapeutic agents. Therefore, many believe that dose painting in which the radiation dose
to the tumor is adjusted according to the local tissue oxygen level can improve cancer cure. Our recent
data in mice shows that performing dose painting based on EPR oxygen maps can reduce the radiation
dose to well-oxygenated areas of the tumor by 30%, resulting in not only improved treatment outcome
but also reduced post treatment risks and complications. To date, EPR imaging is the only proven
method for absolute in vivo measurement of the tissue oxygen level. While PET hypoxia imaging with
18F-Misonidazole (FMISO) has been investigated, FMISO uptake depends on many factors other than
tissue oxygen concentration in nontrivial ways. This can explain why similar positive results with dose
painting have not been observed in the clinic when performed based on PET-FMISO images.
 The proposed integrated system will be a powerful research tool for studying many heterogenous
functional abnormalities in tumor and for developing and improving cancer treatment. In this project,
we also will employ the developed system to conduct a small pilot study for purpose of validating the
system for real animal imaging and demonstrating its potential usefulness for studying the correlation
between PET-FMISO images and EPR oxygen maps. Such correlation, when identified, can lead to
the development of methods for correcting the PET-FMISO images such that they can be successfully
employed for dose painting to yield improved cancer cure. If successful, the clinical impact will be
significant and immediate as FMISO-PET imaging can be readily employed in the clinic.

## Key facts

- **NIH application ID:** 10032946
- **Project number:** 1R01EB029948-01
- **Recipient organization:** UNIVERSITY OF CHICAGO
- **Principal Investigator:** Boris Epel
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $348,969
- **Award type:** 1
- **Project period:** 2020-06-01 → 2024-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10032946

## Citation

> US National Institutes of Health, RePORTER application 10032946, A preclinical integrated PET/EPR imaging system (1R01EB029948-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10032946. Licensed CC0.

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