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

Chest CT images in a 34-year-old man with fever for 4 days. Positive result of reverse-transcription polymerase chain reaction assay for severe acute respiratory syndrome coronavirus 2 using a swab sample was obtained on February 8, 2020. Dates of examination are shown on images. A, Chest CT scan with magnification of lesions in coronal and sagittal planes shows a nodule with reversed halo sign in left lower lobe (box) at the early stage of the pneumonia. B, Chest CT scans in different axial planes and coro

Chest CT images in a 34-year-old man with fever for 4 days. Positive result of reverse-transcription polymerase chain reaction assay for severe acute respiratory syndrome coronavirus 2 using a swab sample was obtained on February 8, 2020. Dates of examination are shown on images. A, Chest CT scan with magnification of lesions in coronal and sagittal planes shows a nodule with reversed halo sign in left lower lobe (box) at the early stage of the pneumonia. B, Chest CT scans in different axial planes and coronal reconstruction show bilateral multifocal ground-glass opacities. The nodular opacity resolved.

News | Coronavirus (COVID-19) | November 29, 2020
November 29, 2020 — The Radiological Society of North America (...
During active surveillance, prostate cancer is carefully monitored for signs of progression through regular prostate-specific antigen (PSA) screening, prostate exams, imaging, and repeat biopsies.

Getty Images

News | Prostate Cancer | November 18, 2020
November 18, 2020 — ...
Penn study supports the use of more testicular shielding for men and children during diagnostics

Getty Images

News | Radiology Imaging | November 16, 2020
November 16, 2020 — Early and repeated exposures to diagnostic imaging, such as X-rays and...
Shine Test System paired with the world’s strongest commercial fusion neutron generator manufactured by Phoenix. It can break apart low-enriched uranium to produce moly-99 for medical isotope production.

Shine Test System paired with the world’s strongest commercial fusion neutron generator manufactured by Phoenix. It can break apart low-enriched uranium to produce moly-99 for medical isotope production.

Feature | Nuclear Imaging | November 12, 2020 | By Willow Ascenzo
Medical imaging procedures such as single-photon emission computed tomography (...
Minimizing delays to treatment could improve cancer survival rates, say researchers

Getty Images

News | Radiation Oncology | November 10, 2020
November 10, 2020 — People whose treatment for cancer is delayed by even one month have in many cases a 6 to 13% high
In this retrospective cohort study of men with low-risk prostate cancer followed up for a median of 7.6 years, African American men, compared with non-Hispanic White men, had a statistically significant increased 10-year cumulative incidence of disease progression and definitive treatment, but not metastasis or prostate cancer–specific mortality

Getty Images

News | Prostate Cancer | November 04, 2020
November 4, 2020 — Previous studies have shown that African American men are 2.4 times as likely to die from...