Dose Optimization for Rubidium PET Imaging in Patients With Known or Suspected Ischemic Heart Disease

NCT05037799 | Unknown FDA Drug

• 1 other identifier: RUBY-DOSE
• Study Type: observational
• Target: 48
• Locations: 1 country
• Sites: 1

Brief Summary

Selection of the appropriate administered activity for each patient's body habitus is very important to obtain diagnostic image quality. Current SPECT imaging guidelines suggest "…an effort to tailor the administered activity to the patient's habitus and imaging equipment should be made… \[however\] strong evidence supporting one particular weight-based dosing scheme does not exist." An increase in body weight leads to higher fractions of attenuated and scattered photons, resulting in lower quality PET images for a given injected activity. Weight-based tracer dosing is commonly recommended as a solution in whole-body PET imaging with F-18-FDG. In contrast, Rb-82 PET imaging has traditionally been performed using a single dose (e.g. 40 mCi) administered for all patients but this is known to result in lower count-density and image quality in larger patients. This effect can be mitigated to some degree by administration of Rb-82 activity as a proportion of body weight while maintaining accuracy for the detection of disease. The objective of this project is to determine whether Rb-82 activity administered as a squared function of patient weight (quadratic dosing) can standardize PET myocardial perfusion image quality over a wide range of body weights. Sequential patients referred for dipyridamole stress Rb-82 PET perfusion imaging at the University of Ottawa Heart Institute. Patients will be divided into 4 weight groups to determine if there are significance differences in image quality or accuracy of injected Rb-82 activity between patients. Twelve (12) patients will be recruited in each of the 4 weight groups (3 in each 10 kg interval) to uniformly sample the full range of patient weights from 30 to 190 kg. Based on the previous oncology PET literature image quality is not expected to change as a function of weight, i.e. SNR and CNR will be proportional to weight0 (no weight-dependence) with quadratic dosing of Rb-82. Two operators will perform the PET image analysis as described above.

Conditions

Ischemic Heart Disease

Keywords

Rubidium-82 PET; Myocardial Perfusion Imaging; diagnostic accuracy; weight based dosing; image enhancement

Outcome Measures

Primary Outcomes (1)

• Rubidium PET image quality

  Stress gated signal-to-noise ratio measured in the left ventricle myocardium and blood cavity

  During the participant scan

Secondary Outcomes (2)

• Rubidium activity accuracy

  During the participant scan

• Rubidium timing accuracy

  During the participant scan

Study Arms (4)

Group 1

body-weight \< 50kg

Drug: Rb-82 Radioisotope

Group 2

50 kg ≤ body-weight \< 100 kg

Drug: Rb-82 Radioisotope

Group 3

100 kg ≤ body-weight \< 150 kg

Drug: Rb-82 Radioisotope

Group 4

150 kg ≤ body-weight \< 200 kg

Drug: Rb-82 Radioisotope

Interventions

Rb-82 Radioisotope DRUG

Quadratic dosing: Rubidium-82 activity prescribed as a squared function of body-weight instead of linear function of body-weight or fixed activity independent of body-weight

Also known as: PET perfusion imaging

Group 1; Group 2; Group 3; Group 4

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Male/female participants, 18 years of age or older, referred for dipyridamole stress Rb-82 PET perfusion imaging at the University of Ottawa Heart Institute.

You may qualify if:

• Patients referred to the University of Ottawa Heart Institute for clinically indicated dipyridamole stress, Rb-82 PET myocardial perfusion imaging (MPI) for diagnosis or risk stratification for myocardial ischemia.
• at least 18 years of age.

You may not qualify if:

• Patients with contraindications to dipyridamole stress PET MPI including: 1) severe reactive airway disease; 2) less than 3 days post-MI/ACS presentation; 3) unstable crescendo angina; 4) high-grade AV block; 5) allergy to dipyridamole or theophyllines; 6) caffeine within 24 hours; 7) theophyllines within 48 hours; 8) severe claustrophobia; and 9) those who may be pregnant.

Sponsors & Collaborators

• Ottawa Heart Institute Research Corporation: lead
• Jubilant DraxImage Inc.: collaborator

Study Sites (1)

University of Ottawa Heart Institute

Ottawa, Ontario, K1Y 4W7, Canada

Location

Related Publications (3)

• de Groot EH, Post N, Boellaard R, Wagenaar NR, Willemsen AT, van Dalen JA. Optimized dose regimen for whole-body FDG-PET imaging. EJNMMI Res. 2013 Aug 12;3(1):63. doi: 10.1186/2191-219X-3-63.

  PMID: 23938036 BACKGROUND

• Boellaard R, Delgado-Bolton R, Oyen WJ, Giammarile F, Tatsch K, Eschner W, Verzijlbergen FJ, Barrington SF, Pike LC, Weber WA, Stroobants S, Delbeke D, Donohoe KJ, Holbrook S, Graham MM, Testanera G, Hoekstra OS, Zijlstra J, Visser E, Hoekstra CJ, Pruim J, Willemsen A, Arends B, Kotzerke J, Bockisch A, Beyer T, Chiti A, Krause BJ; European Association of Nuclear Medicine (EANM). FDG PET/CT: EANM procedure guidelines for tumour imaging: version 2.0. Eur J Nucl Med Mol Imaging. 2015 Feb;42(2):328-54. doi: 10.1007/s00259-014-2961-x. Epub 2014 Dec 2.

  PMID: 25452219 BACKGROUND

• Koopman D, van Osch JA, Jager PL, Tenbergen CJ, Knollema S, Slump CH, van Dalen JA. Technical note: how to determine the FDG activity for tumour PET imaging that satisfies European guidelines. EJNMMI Phys. 2016 Dec;3(1):22. doi: 10.1186/s40658-016-0158-z. Epub 2016 Sep 29.

  PMID: 27682837 BACKGROUND

MeSH Terms

Conditions

Myocardial Ischemia

Interventions

Rubidium-82

Condition Hierarchy (Ancestors)

Heart Diseases; Cardiovascular Diseases; Vascular Diseases

Study Officials

• Rob deKemp, PhD

  Ottawa Heart Institute Research Corporation

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: CROSS SECTIONAL
• Target Duration: 1 Day
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 2, 2021
• First Posted: September 8, 2021
• Study Start: July 1, 2022
• Primary Completion: April 30, 2025
• Study Completion: April 30, 2025
• Last Updated: November 29, 2023

Record last verified: 2023-11

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)