News | Radiopharmaceuticals and Tracers | January 06, 2017

Novel Anti-PSMA Imaging Agent Quickly Identifies Prostate Cancer Lesions

PET agent also identifies more disease sites than conventional imaging, including bone metastases

January 6, 2017 — New research demonstrates that a novel imaging agent can quickly and accurately detect metastasis of prostate cancer, even in areas where detection has previously been difficult. Published in the December issue of The Journal of Nuclear Medicine, the Phase 1 dose-escalation study of Zr-89-desferrioxamine-IAB2M (Zr-89-Df-IAB2M), an anti-PSMA (prostate-specific membrane antigen) minibody, in patients with metastatic prostate cancer shows its effectiveness in targeting both bone and soft tissue lesions.

“This agent is imaged faster than other PSMA-targeting imaging antibodies due to its small size and has been shown to be safe for patients,” explained Neeta Pandit-Taskar, M.D., of the Memorial Sloan Kettering Cancer Center in New York City. “The radiotracer combines a small amount of the radioactive material zirconium-89 with a fragment of an antibody called a minibody. This minibody has anti-PSMA qualities and attaches to overexpression of the enzyme on the exterior of prostate cancer cells, wherever they may have traveled in the body. Particles emitted from the site are then detected by positron emission tomography (PET). The resulting scan highlights ‘hot spots’ of PSMA overexpression.”

She added, “Using this agent, we can detect the prostate cancer cells that have metastasized to bone — one of the most difficult areas to evaluate using standard methods.”

For the study, 18 patients were imaged with the new agent using PET/CT (computed tomography) as well as a variety of conventional imaging modalities, including CT, magnetic resonance imaging (MRI), molecular bone scan (SI) and PET with fluorodeoxyglucose (FDG-PET). Suspected disease sites were then selected and biopsied.

Both skeletal and nodal lesions were detected with Zr-89-Df-IAB2M; scans were positive in 17 of the 18 patients, with bone lesions targeted in nine and soft tissue disease seen in 14. In comparison, bone scans with more traditional agents (Tc-99m-methylene diphosphonate and FDG) were positive for bone lesions in nine and six patients, respectively; for nodal/soft tissue disease, CT and FDG scans were positive in 14 and 10 patients, respectively. In two patients, a single site of disease per patient was identified only by the minibody. In total, Zr-89-Df-IAB2M imaging detected 147 bone and 82 soft-tissue or nodal lesions.

“Results of imaging with this Zr-89 radiolabeled minibody have shown that we are able to detect more disease sites in patients than with conventional imaging,” Pandit-Taskar stated. “We hope that with further development this technology will help us in earlier and more accurate assessment of disease and assist in clinical decision-making.”

She pointed out, “With further validation, this agent could potentially be used for targeted biopsies, which could lead to more appropriate, timely treatment for prostate cancer patients. It may also have potential use in targeted radiotherapy.”

For more information: www.jnm.snmjournals.org

Related Content

MRI, imaging diagnostic error rates, lower back, The Spine Journal, Hospital for Special Surgery study
News | Business | January 12, 2017
A new clinical study published Dec. 20, 2016, in The Spine Journal reveals significant variability in provider quality...
Medrad Intego PET Infusion System, recall
News | Nuclear Imaging | January 12, 2017
January 12, 2017 — Bayer Healthcare has initiated a recall of all its Medrad Intego PET Infusion System Source Admini
Mirada Medical, RSNA 2016, XD:PACS, molecular imaging, nuclear imaging
Technology | PACS | January 06, 2017
Mirada Medical showcased its latest XD:PACS (picture archiving and communication system) range of molecular imaging...
SPECT-CT, 3-D printing, University of Wurzburg, Germany, Johannes Tran-Gia, dosimetry calibration

SPECT/CT reconstructions and VOIs used for determination of calibration factors for the adult kidney filled with Lu-177 (A) and the corresponding sphere filled with I-131 (B). Credit: University of Würzburg

News | 3-D Printing | January 06, 2017
In nuclear medicine, the goal is to keep radiation exposure at a minimum, while obtaining quality images. Optimal...
short-term sleep deprivation, heart function, cardiac magnetic resonance, CMR, RSNA 2016
News | Cardiac Imaging | January 05, 2017
Too little sleep takes a toll on your heart, according to a new study presented at the 2016 annual meeting of the...
Nuclear cardiology, dose reduction, myocardial perfusion imaging
News | Nuclear Imaging | January 05, 2017
January 5, 2017 — Working in concert, the American Society of Nuclear Cardiology (ASNC), the Intersocietal Accreditat
MRI, fetal brain abnormalities, 20-week ultrasound scan, improved diagnosis, The Lancet
News | Magnetic Resonance Imaging (MRI) | January 05, 2017
An extra scan using magnetic resonance imaging (MRI) could help more accurately detect brain abnormalities and give...
brain rust, MRI, schizophrenia, American College of Neuropsychopharmacology, ACNP, Fei Du
News | Neuro Imaging | January 04, 2017
A damaging chemical imbalance in the brain may contribute to schizophrenia, according to research presented at the...
metastatic colorectal cancer, mCRC, Sirtex, NCCN guidelines, Y-90 microspheres
News | Radiation Therapy | January 03, 2017
Sirtex Medical Limited announced in December that SIR-Spheres Y-90 resin microspheres have been included as a Category...
Elder abuse, radiologists can detect elder abuse, medical imaging
News | Imaging | January 02, 2017
January 2, 2017 — Radiologists may be uniquely positioned to identify elder abuse, but they do not have training or e
Overlay Init