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Rapley M, Freitas V, Weinberg IN, Baldassi B, Poladyan H, Waterston M, Ghai S, Taeb S, Bubon O, Reznik A, Mulligan AM. Case report: Possible role of low-dose PEM for avoiding unneeded procedures associated with false-positive or equivocal breast MRI results. Front Oncol 2024; 14:1405404. [PMID: 39091907 PMCID: PMC11291220 DOI: 10.3389/fonc.2024.1405404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 07/05/2024] [Indexed: 08/04/2024] Open
Abstract
Contrast-enhanced breast magnetic resonance imaging (MRI) is currently recommended as a screening tool for high-risk women and has been advocated for women with radiologically dense breast tissue. While breast MRI is acknowledged for its high sensitivity (with an exception for lower-grade ductal carcinoma in situ (DCIS) where emerging techniques like diffusion-weighted imaging offer improvement), its limitations include sensitivity to hormonal changes and a relatively high false-positive rate, potentially leading to overdiagnosis, increased imaging uncertainty, and unnecessary biopsies. These factors can exacerbate patient anxiety and impose additional costs. Molecular imaging with breast-targeted Positron Emission Tomography (PET) has shown the capability to detect malignancy independent of breast density and hormonal changes. Furthermore, breast-targeted PET has shown higher specificity when compared with MRI. However, traditional PET technology is associated with high radiation dose, which can limit its widespread use particularly in repeated studies or for undiagnosed patients. In this case report, we present a clinical application of low-dose breast imaging utilizing a breast-targeted PET camera (Radialis PET imager, Radialis Inc). The case involves a 33-year-old female patient who had multiple enhanced lesions detected on breast MRI after surgical removal of a malignant phyllodes tumor from the right breast. A benign core biopsy was obtained from the largest lesion seen in the left breast. One month after the MRI, 18F-fluorodeoxyglucose (18F-FDG) PET imaging session was performed using the Radialis PET Imager. Although the Radialis PET Imager has proven high count sensitivity and the capability to detect breast lesions with low metabolic activity (at a dose similar to mammography), no areas of increased 18F-FDG uptake were visualized in this particular case. The patient underwent a right-sided nipple-sparing mastectomy and left-sided lumpectomy, with bilateral reconstruction. The excised left breast tissue was completely benign, as suggested by both core biopsy and the PET results. The case presented highlights a promising clinical application of low-dose breast-targeted PET imaging to mitigate the uncertainty associated with MRI while keeping radiation doses within the safe range typically used in X-ray mammography.
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Affiliation(s)
- Madeline Rapley
- Department of Physics, Lakehead University, Thunder Bay, ON, Canada
| | - Vivianne Freitas
- Temerty Faculty of Medicine, Joint Department of Medical Imaging, University of Toronto, Toronto, ON, Canada
| | | | | | | | | | - Sandeep Ghai
- Temerty Faculty of Medicine, Joint Department of Medical Imaging, University of Toronto, Toronto, ON, Canada
| | - Samira Taeb
- Department of Research, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
| | - Oleksandr Bubon
- Department of Physics, Lakehead University, Thunder Bay, ON, Canada
- Radialis Inc., Thunder Bay, ON, Canada
| | - Alla Reznik
- Department of Physics, Lakehead University, Thunder Bay, ON, Canada
- Thunder Bay Regional Health Sciences Centre, Thunder Bay, ON, Canada
| | - Anna Marie Mulligan
- Laboratory Medicine Program, University Health Network – Toronto General Hospital Site, University of Toronto, Toronto, ON, Canada
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Baldassi B, Poladyan H, Shahi A, Maa-Hacquoil H, Rapley M, Komarov B, Stiles J, Freitas V, Waterston M, Aseyev O, Reznik A, Bubon O. Image quality evaluation for a clinical organ-targeted PET camera. Front Oncol 2024; 14:1268991. [PMID: 38590664 PMCID: PMC10999605 DOI: 10.3389/fonc.2024.1268991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 03/12/2024] [Indexed: 04/10/2024] Open
Abstract
Introduction A newly developed clinical organ-targeted Positron Emission Tomography (PET) system (also known as Radialis PET) is tested with a set of standardized and custom tests previously used to evaluate the performance of Positron Emission Mammography (PEM) systems. Methods Imaging characteristics impacting standardized uptake value (SUV) and detectability of small lesions, namely spatial resolution, linearity, uniformity, and recovery coefficients, are evaluated. Results In-plane spatial resolution was measured as 2.3 mm ± 0.1 mm, spatial accuracy was 0.1 mm, and uniformity measured with flood field and NEMA NU-4 phantom was 11.7% and 8.3% respectively. Selected clinical images are provided as reference to the imaging capabilities under different clinical conditions such as reduced activity of 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (18F-FDG) and time-delayed acquisitions. SUV measurements were performed for selected clinical acquisitions to demonstrate a capability for quantitative image assessment of different types of cancer including for invasive lobular carcinoma with comparatively low metabolic activity. Quantitative imaging performance assessment with phantoms demonstrates improved contrast recovery and spill-over ratio for this PET technology when compared to other commercial organ-dedicated PET systems with similar spatial resolution. Recovery coefficients were measured to be 0.21 for the 1 mm hot rod and up to 0.89 for the 5 mm hot rod of NEMA NU-4 Image Quality phantom. Discussion Demonstrated ability to accurately reconstruct activity in tumors as small as 5 mm suggests that the Radialis PET technology may be well suited for emerging clinical applications such as image guided assessment of response to neoadjuvant systemic treatment (NST) in lesions smaller than 2 cm. Also, our results suggest that, while spatial resolution greatly influences the partial volume effect which degrades contrast recovery, optimized count rate performance and image reconstruction workflow may improve recovery coefficients for systems with comparable spatial resolution. We emphasize that recovery coefficient should be considered as a primary performance metric when a PET system is used for accurate lesion size or radiotracer uptake assessments.
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Affiliation(s)
- Brandon Baldassi
- Department of Physics, Lakehead University, Thunder Bay, ON, Canada
| | | | - Anirudh Shahi
- Department of Physics, Lakehead University, Thunder Bay, ON, Canada
| | | | - Madeline Rapley
- Department of Physics, Lakehead University, Thunder Bay, ON, Canada
| | | | - Justin Stiles
- Department of Physics, Lakehead University, Thunder Bay, ON, Canada
| | - Vivianne Freitas
- Department of Medical Imaging, University Health Network, Sinai Health System, Women’s College Hospital, Toronto, ON, Canada
- Department of Medical Imaging, University of Toronto, Toronto, ON, Canada
| | | | - Olexiy Aseyev
- Department of Medical Oncology, Thunder Bay Regional Health Sciences Center, Thunder Bay, ON, Canada
| | - Alla Reznik
- Department of Physics, Lakehead University, Thunder Bay, ON, Canada
- Radialis Inc., Thunder Bay, ON, Canada
| | - Oleksandr Bubon
- Department of Physics, Lakehead University, Thunder Bay, ON, Canada
- Radialis Inc., Thunder Bay, ON, Canada
- Thunder Bay Regional Health Research Institute, Thunder Bay, ON, Canada
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Barreto DS, Rapelyea JA. Low-Dose Positron Emission Mammography: A Novel, Promising Technique for Breast Cancer Detection. Radiol Imaging Cancer 2024; 6:e240006. [PMID: 38334472 PMCID: PMC10988329 DOI: 10.1148/rycan.240006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 01/17/2024] [Accepted: 01/22/2024] [Indexed: 02/10/2024]
Affiliation(s)
- David S. Barreto
- From the Department of Radiology, The George Washington University School of Medicine and Health Sciences, 2150 Pennsylvania Ave NW, Washington, DC 20037
| | - Jocelyn A. Rapelyea
- From the Department of Radiology, The George Washington University School of Medicine and Health Sciences, 2150 Pennsylvania Ave NW, Washington, DC 20037
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