# A Novel F-18 PET Myocardial Perfusion Radiopharmaceutical based on Rhodamine Dyes

> **NIH NIH R01** · BOSTON CHILDREN'S HOSPITAL · 2020 · $464,993

## Abstract

Project Summary
Cardiovascular disease is responsible for more than 600,000 deaths each year in the US, and more than half
of these are due to coronary heart disease (CHD). Myocardial perfusion imaging (MPI) is one of the most
effective tools for assessing CHD, and according to the most recent estimate, this technique accounts for
>50% of all nuclear medicine studies in adults, nearly 6 million scans in 2014. At present, most of these studies
are carried out using 99mTc-MIBI and 99mTc-tetrofosmin, despite the significant limitations of SPECT (single
photon emission computed tomography) for MPI including lower spatial resolution than PET (positron-emission
tomography); the lack of routine attenuation corrections, which are of particular importance in an increasingly
obese population; and the challenge of measuring myocardial blood flow (MBF), which is critical to accurately
evaluating global ischemia and microvessel disease. This investigation, “A Novel F-18 PET Myocardial
Perfusion Radiopharmaceutical based on Rhodamine Dyes,” builds upon a currently funded project of the
same title, 1 R01 HL108107-01, that concludes on 1/31/2017. As in the foundational R01, the primary
objective of this project is to develop an 18F-labeled radiopharmaceutical for PET imaging of
myocardial perfusion. The Specific Aims of the original project have been largely fulfilled; and thus, while our
central hypothesis remains the same, i.e., that a PET myocardial perfusion imaging agent can be developed
based on an 18F-labeled rhodamine dye, we have gathered sufficient preliminary results to initiate a first-in-
human-study in the next project period. We have demonstrated that 18F-labeled rhodamine dyes accumulate
impressively in the heart, which confirms their significant potential as PET MPI radiopharmaceuticals. The
central hypothesis of this proposal is, therefore, unchanged: A PET radiopharmaceutical for the
evaluation of myocardial perfusion can be developed based on an 18F-labeled rhodamine dye. We have
tested and validated this basic premise in our laboratory and found that the 18F-labeled diethyleneglycol ester
derivative of rhodamine 6G ([18 F]Rho6G) shows very high accumulation in the heart, minimal accumulation in
the liver, and rapid blood clearance. While 18 F-Rho6G has shown great promise as an MPI agent, we do not
yet know if it will perform optimally in humans. Thus, we will explore additional rhodamine-like compounds as
potential PET radiotracers for MPI. Accordingly, the new Specific Aims will first build upon our findings with 18F-
Rho6G by a) carrying out a first-in-human study with [18F]Rho6G; b) measuring the extraction fraction of 18F-
Rho6G, a critical parameter for a clinically useful MPI radiopharmaceutical; and c) evaluating a number of
novel rhodamine derivatives and also assessing alternatives cores in anticipation of the possible need for an
alternative to rhodamine dyes for human use. Our successful accomplishment of these Specific Aims will...

## Key facts

- **NIH application ID:** 9983130
- **Project number:** 5R01HL108107-08
- **Recipient organization:** BOSTON CHILDREN'S HOSPITAL
- **Principal Investigator:** ALAN Brent PACKARD
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $464,993
- **Award type:** 5
- **Project period:** 2011-04-01 → 2023-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9983130

## Citation

> US National Institutes of Health, RePORTER application 9983130, A Novel F-18 PET Myocardial Perfusion Radiopharmaceutical based on Rhodamine Dyes (5R01HL108107-08). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/9983130. Licensed CC0.

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