Category: Molecular Imaging

PSMA-PET Reduces Prostate Deaths

Posted on by Brian Casey

Using PSMA-PET instead of conventional imaging to stage patients with recurrent prostate cancer could reduce deaths by 13% and lead to improved quality of life. The new paper in JAMA Network Open confirms the value of PSMA imaging compared to traditional imaging approaches. 

Recurrent prostate cancer is one of the trickiest cancers to manage, especially as biochemical recurrence can occur in up to half of patients getting local treatment. 

  • PSA tests work well for detecting rising prostate antigen levels that could signify recurrence, but it can be difficult to locate recurrent cancer with existing imaging tools like CT and bone scans.

PET using a new generation of PSMA tracers offers a better solution thanks to tracers that target the PSMA protein that builds up on the surface of prostate cancer cells.

  • Previous studies have shown that PSMA-PET is more sensitive and specific for detecting recurrent prostate cancer, especially at lower PSA levels – but the modality’s long-term effects haven’t been explored. 

In the new study, researchers wanted to investigate the impact of switching to PSMA-PET on mortality and quality of life using statistical modeling to predict outcomes from three imaging approaches …

  • Conventional imaging with CT and bone scan.
  • CT and bone scan followed by PSMA-PET for negative or equivocal cases.
  • PSMA-PET alone.

They then projected outcomes for a hypothetical population of 1k patients with biochemically recurrent prostate cancer, defined as a persistent or rising PSA of 0.20 ng/mL after prostatectomy or PSA 2.0 ng/mL or higher following radiation therapy. They found …

  • PSMA-PET had the lowest number of prostate cancer deaths at 512, compared to conventional imaging plus PSMA-PET (520) or just conventional imaging (587).
  • PSMA-PET diagnosed 611 patients with metastasis compared to 630 with conventional imaging plus PSMA-PET and 297 with only conventional imaging.
  • PSMA-PET yielded 824 more quality-adjusted life years per 1k patients than conventional imaging.

The Takeaway

The findings are not only good news for patients with recurrent prostate cancer, they are also a boon for developers of commercially available PSMA-PET radiotracers like Lantheus Medical Imaging’s Pylarify (approved in 2021), Telix Pharmaceuticals’ Illuccix (approved in 2021), and Blue Earth Diagnostics’ Posluma (approved in 2023). 

Next-Generation Brain PET

Posted on by Brian Casey

A new paper in JNM includes the first human images acquired with a next-generation dedicated brain PET/CT scanner that could create a new standard for neurological research. United Imaging’s NeuroEXPLORER scanner has sensitivity and spatial resolution “an order of magnitude” better than existing technology. 

In addition to its value as a clinical tool, PET has carved out a research role for investigating some of the most fundamental questions about brain function and pathology. 

  • Commercial whole-body scanners can be used for research, but dedicated brain systems like the High Resolution Research Tomograph (HRRT) offer even higher resolution for imaging tiny structures in the brain. 

NeuroEXPLORER was developed by a consortium that includes United Imaging, UC Davis, and Yale University to adapt for dedicated brain imaging the long-axis PET technology found in United’s uEXPLORER total-body PET/CT system. 

  • NeuroEXPLORER was a highlight at the recent SNMMI 2024 conference, and images acquired with the system won the show’s coveted Image of the Year honors.

In the new study, researchers go into more detail about NeuroEXPLORER’s specifications, which include … 

  • An extended axial field of view (FOV) of 49.5cm for higher sensitivity
  • Transverse spatial resolution ranging from 1.64-2.51mm at full-width half-maximum
  • Average time-of-flight resolution of 236 picoseconds
  • NEMA sensitivities of 46.0 and 47.6 kcps/MBq at center and 10cm offset, and absolute sensitivity of 11.8% at the center of the FOV

Such high sensitivity and spatial resolution enables tasks “previously considered difficult or impossible,” like imaging focal tracer uptake of small subcortical regions or low-density binding sites like cortical dopamine receptors. 

  • What’s more, NeuroEXPLORER’s long axial length enables high-quality imaging of the spinal cord and carotid arteries.

Now for the disclaimer: United Imaging notes that NeuroEXPLORER has not been submitted to the FDA for clearance and at present is only for research use; the company’s uEXPLORER scanner does have clearance and is in operation at several commercial sites. 

The Takeaway

Publication in a journal of the first human images from NeuroEXPLORER are an exciting development and underscore the potential of dedicated brain PET to advance research into neurological function and pathology. Whether the scanner develops into a clinical tool remains to be seen.

Headlines from SNMMI 2024

Posted on by Brian Casey

SNMMI 2024 wrapped up this week in Toronto, Canada, with the conference once again demonstrating the utility of nuclear medicine and molecular imaging for applications ranging from neurology to oncology to therapeutics. 

An annual SNMMI highlight is always the Image of the Year designation, and this year’s meeting didn’t disappoint. 

  • The honor went to a set of ultra-high-resolution brain PET images acquired with United Imaging’s NeuroEXPLORER (NX) scanner, a PET/CT system that the company developed with Yale and UC Davis and introduced last year for research use (although a clinical introduction could be forthcoming). 

The NX system sports a cylindrical design with a 52.4cm diameter and long axial field-of-view of 49.5cm; in the talk presented at SNMMI, researchers compared it to high-resolution research tomograph images with tracers targeting different dopamine receptors and transporters.

  • Researchers said the NX system had “exceptional” resolution in cortex and subcortical structures, with “low noise and exquisite resolution,” and predicted NX would “dramatically expand the scope of brain PET studies.”

Other important presentations at SNMMI included papers finding … 

  • An AI algorithm developed at Johns Hopkins detected six different types of cancer and automatically quantified tumor burden on whole-body PET/CT scans
  • In a study of 10.5k patients, AI that analyzed SPECT/CT images was able to predict all-cause mortality with an AUC of 0.77 by using CT attenuation correction scans to calculate risk factors like coronary artery calcium
  • Cognitive training is less effective in older adults who have beta-amyloid deposits in the brain on PET scans
  • An ultra-low-dose PET protocol presented by researchers from Bern University Hospital in Switzerland and Siemens Healthineers used deep learning reconstruction for a 50X reduction in PET radiation dose, to 0.15 mSv
  • A gallium-68 FAPI-based PET radiotracer was more accurate than fluorine-18 FDG for systemic staging of newly diagnosed breast cancer
  • A new chelating agent that binds radiometals to the parts of molecules that target cancer reduced off-target toxicity in PSMA radiopharmaceutical therapy
  • A combination of alpha- and beta-radionuclide therapy that combined actinium-225 with lutetium-177 worked well for colorectal cancer in a preclinical study
  • Research sponsored by Novartis on radioligand therapy for prostate cancer with lutetium-177 PSMA-617 (Pluvicto) was chosen as Abstract of the Year

The Takeaway

This year’s SNMMI presentations highlight the exciting advances taking place in nuclear medicine and molecular imaging, with the rise of theranostics giving the field an entirely new wrinkle that places it even closer to the center of precision medicine. Perhaps a new letter – T – will need to be added to the conference before too long.

The Case for 18F-NaF PET/CT Bone Metastases Detection

Posted on by Jake Fishman

Results from the MITNEC-A1 trial are in, and they further support using 18F-NaF PET/CT to detect bone metastases in patients with prostate and breast cancer, while bolstering its case for replacing 99mTc-MDP as the “bone imaging radiopharmaceutical of choice.”

The prospective, multicenter, single-cohort, phase 3 trial enrolled 261 breast and prostate cancer patients (57 & 204) who had high risk or suspected bone metastasis, scanning each participant with 18F-NaF PET/CT and 99mTc-MDP SPECT. 

Two experts interpreted the scans, which were later compared to 24-month follow-up results, revealing that 42% of the patients had bone metastases (109), and finding that 18F-NaF PET/CT diagnosed bone metastases with far higher…

  • Accuracy – 84.3% vs. 77.4%
  • Sensitivity – 78.9% vs. 63.3%
  • Negative Predictive Value – 85.4% vs. 76.9%

The MITNEC-A1 trial stands on the shoulders of a growing list of studies that support 18F-NaF PET/CT for bone metastases detection, and these latest results make the transition to 18F-NaF PET/CT “appealing” to this study’s authors. 

The next step in that transition process will likely be exploring 18F-NaF PET/CT’s cost-effectiveness versus bone scintigraphy with 99mTc-MDP SPECT, potentially leading to more widespread adoption.

The Takeaway

It’s historically been a challenge to detect prostate and breast cancer bone metastases. Although there’s more research to be done, it appears that 18F-NaF PET/CT might help overcome that challenge, and become bone imaging’s new radiopharmaceutical of choice.

GE Healthcare Launches All-Digital Omni Legend PET/CT

Posted on by Jake Fishman

GE Healthcare announced a major update to its molecular imaging lineup, launching the all-digital Omni Legend PET/CT.

The FDA-cleared and CE-marked Omni Legend is the first product to launch from GE’s new Omni PET/CT platform, and leverages an array of new technologies that drive big improvements to image quality, workflow efficiency, clinical versatility, and precision medicine. 

  • dBGO Detector – The Omni Legend is highlighted by its new digital BGO detector (dBGO), which provides 2.2-times higher sensitivity, 16% to 20% improved small lesion detection, and 53% faster PET scans.
  • Precision DL – GE’s new Precision DL software expands the Omni Legend’s support for tracers “beyond FDG” (using image processing) and enhances image quality (using deep learning image reconstruction).
  • Clinical Versatility – The above combination of sensitivity, image quality, and tracer compatibility allows the Omni Legend PET/CT to support a wider range of oncology, cardiac, and neuro use cases, in addition to supporting the diagnostics role within theranostics.
  • Efficiency Forward – In addition to faster scan times, the Omni Legend supports GE’s efficiency solutions that streamline calibration (data quality assurance), simplify protocol selection (new UI), and reduce labor for patient positioning (AI-based Auto Positioning Camera).
  • Future Ready – Like GE’s other recent advanced imaging launches, the Omni platform is built to support future upgrades, covering all core dimensions of PET/CT imaging (axial FOV, detector, software, CT, tracers, etc.).

The Takeaway

A completely new PET/CT platform doesn’t come along very often, and GE Healthcare seems to have made the most of this rare occasion with Omni PET/CT, bringing many improvements that imaging teams are seeking today, along with the theranostics support and component upgradability that should pay off in the future.

SubtlePET Validations

Posted on by Jake Fishman

Two new studies out of France added to the growing field of evidence supporting Subtle Medical’s SubtlePET solution, with each confirming that it allows shorter-duration PET exams without affecting image quality. 

The first study, published in EJNMMI Physics, proclaimed SubtlePET “ready to be used in clinical practice for half-time or half-dose acquisitions” after it restored 18F-FDG PET/CT exams from three different scanners without impacting diagnostic confidence.

The researchers performed 18F-FDG PET/CT exams on 110 patients, producing full-acquisition, 50%-reduced, and 66%-reduced images (PET100, PET50, and PET33). They then denoised the images with SubtlePET and had two senior nuclear physicians evaluate them, finding that SubtlePET improved:

  • PET33 image quality from 16.7% to 86.7% “interpretable” & 0% to 26.7% “good”
  • PET50 image quality from 83.6% to 100% “interpretable” & 1.8% to 84.5% “good”
  • High-BMI patients’ PET100 exams from 60% to 80% “good” image quality (both were 100% interpretable)

The second study out of France’s Baclesse Cancer Center further confirmed that SubtlePET preserves 18F-FDG PET image quality with half-duration exams. 

The researchers performed 90-second and 45-second 18F-FDG PET/CT exams on 195 patients (PET90 & PET45), and then used SubtlePET to denoise the 45-second images, finding that:  

  • PET45 exams produced mediocre image quality (8% poor, 68% moderate) and achieved an 88.7% lesion concordance rate with PET90
  • After SubtlePET enhancement, PET45’s image quality matched PET90 (both 92% good, 8% moderate) and achieved a 97.7% lesion concordance rate with PET90
  • 7 of the discordant lesions (0.8%) were only detected with PET90 and 13 (1.5%) were exclusively detected with SubtlePET-enhanced PET45 images

The Takeaway
May was a particularly big research month, but SubtlePET has been on an academic hot streak for over a year, including at least three previous studies validating its performance with lower radiotracer dosage and faster acquisition times.

Subtle Medical’s marketing currently appears to focus on SubtlePET’s support for shorter scans, but it’s easy to see how patients and clinicians would welcome both shorter scans and lower radiotracer dosage, and the research increasingly seems to validate both use cases.

BAMF & United Imaging’s Precision Medicine Milestone

Posted on by Jake Fishman

BAMF Health took a big step in its precision medicine strategy, installing United Imaging’s uEXPLORER total-body PET/CT scanner as it prepares to open its theranostics treatment center. 

Founded in 2018, BAMF Health (Bold Advanced Medical Future) has applied a unique approach to developing advanced treatments, combining the world’s “most advanced” radiopharmacy, its proprietary AI platform, and top molecular imaging technology to deliver hyper-personalized and targeted treatments.

Installing United Imaging’s uEXPLORER total-body PET/CT scanner represents a key final addition to BAMF Health’s precision medicine stack, and makes it the first institution in the US using total-body PET for theranostics. More importantly, the uEXPLORER will allow BAMF Health to deliver more effective and efficient theranostics treatments by:

  • Imaging patients’ entire bodies in a single scan (vs. “eyes to thighs”)
  • Detecting and targeting signs of cancer smaller than two millimeters (vs. 1 cm)
  • Scanning patients in just one minute (vs. up to 1hr)
  • Reducing radiation dosage by up to 40x

BAMF Health’s launch might also represent an early theranostics paradigm shift, highlighting the potential role of private clinics (vs. academic/large institutions) and total-body PET/CT systems (vs. “whole”) with the advanced therapy.

BAMF Health will begin treating patients for prostate cancer and neuroendocrine tumors at its Michigan-based clinic this summer, but plans to deliver a wide range of personalized treatments that extend well beyond cancer in the future (e.g. Alzheimer’s, Parkinson’s, cardiac diseases, endometriosis, chronic pain) and treat patients from around the country.

The Takeaway

Although BAMF Health still has a lot to prove, its upcoming clinical launch might be a key milestone in the evolution of theranostics and molecular imaging.

Get every issue of The Imaging Wire, delivered right to your inbox.

You might also like..

Select All

You're signed up!

It's great to have you as a reader. Check your inbox for a welcome email.

-- The Imaging Wire team

You're all set!