Feature | June 17, 2013

PET/MR Effective for Imaging Recurrent Prostate Cancer

Study reveals new hybrid molecular imaging system is as good as PET/CT gold standard for restaging patients with metastatic prostate cancer

 Prostate MRI showing tumor 2_From Philips MRI webinar for ITN

When prostate cancer makes a comeback, it becomes increasingly important to have exceptional imaging available to find all possible regions where cancer has spread to other parts of the body, or metastasized, in order to plan the best possible treatment. A relatively new imaging system that simultaneously combines positron emission tomography and magnetic resonance (PET/MR) demonstrates a higher capacity for mapping recurrent prostate cancer than the already high standard of integrated PET and computed tomography (PET/CT), say researchers presenting a study at the Society of Nuclear Medicine and Molecular Imaging’s 2013 Annual Meeting.

PET/MR provides superb soft tissue contrast with its MR component, compared to PET/CT, which focuses more on structure and density imaging with CT. This study ushers PET/MR into the ring of clinical practice by exhibiting clear benefits for prostate cancer patients with metastatic tumors.

In this comparative study recurrent prostate cancer is imaged both with PET/MR and PET/CT with the molecular imaging agent C-11 choline, which was approved for this use by the U.S. Food and Drug Administration (FDA) last year. Choline is a naturally occurring B vitamin complex that is avidly bound by prostate cells upon injection, even those that have traveled through the bloodstream and taken up residence to develop metastatic tumors elsewhere, which is especially likely in the lymph nodes and in bone. 

“The combination of PET, here with C-11 choline, and functional MRI provides complementary information that increases diagnostic certainty with higher detection rates, especially for more precise localization of recurrence. This could help to better tailor specific therapy, e.g., radiation of the pelvis versus antihormonal therapy, for patients with metastatic prostate cancer,” said Matthias Eiber, MD, lead scientist for the study from TU Muenchen in Munich, Germany.

Methodology included a study population of 31 patients who had both PET/CT and PET/MR performed for restaging of recurrent prostate cancer with single injection of the imaging agent C-11 choline. PET/CT scans occurred about five minutes after injection, and PET/MR scans occurred about 51 minutes after injection. Scans were interpreted separately and all detected lesions were categorized according to suspected metastases as definitely, probably or indeterminately metastatic. Researchers discovered that PET/MR found more areas of metastases—17 in 12 different patients—when compared to PET/CT, which found 12 areas of metastases in eight subjects. PET/MR also found more lymph node metastases, 42 versus 39 areas of interest with PET/CT. The same held true for bone metastases, which were detected in 17 areas for five patients with PET/MR and 14 areas for four patients with PET/CT. 

Simultaneous PET/MR is comparable to—if not more powerful than—PET/CT for recurrent prostate cancer. The only obvious challenge was a longer scan time than PET/CT, but it was found to be tolerable by patients undergoing PET/MR. PET/MR additionally offers considerably lower radiation exposure compared to PET/CT. As many of these patients often get a series of examinations in the course of their disease, despite their high average age, radiation protection could be another argument for the promotion of PET/MR. This molecular imaging technique can now be considered a conceivable alternative to PET/CT for restaging prostate metastases, especially when small local tumor recurrences are involved.

“In principle, whole-body integrated PET/MR is a technique that is officially commercially available; however, so far only a limited number of these scanners have been installed worldwide,” said Eiber. “Showing a concrete example of how combining PET and functional MR imaging benefits patients with metastatic prostate cancer could potentially motivate continued PET/MR research in this field.”

Scientific Paper 343: Matthias Eiber, Michael Souvatzoglou, Tobias Maurer, Sibylle Ziegler, Ernst Rummeny, Markus Schwaiger, Ambros Beer, Radiology, TU Muenchen, Munich, Germany; Nuclear Medicine, TU Muenchen, Munich, Germany; Urology, TU Muenchen, Munich, Germany, “Initial experience in restaging of patients with recurrent prostate cancer: Comparison of 11C-Choline-PET/MR and 11C-Choline-PET/CT,” SNMMI’s 60th Annual Meeting, June 8–12, 2013, Vancouver, British Columbia.

For more information: www.snmmi.org

Related Content

It covers every major modality, including breast imaging/mammography, fixed and portable C-arms (cath, IR/angio, hybrid, OR), CT, MRI, nuclear medicine, radiographic fluoroscopy, ultrasound and X-ray
News | Radiology Imaging | July 29, 2020
July 29, 2020 — IMV Medical Information, part of Scien...
Prostate biopsy with cancer probability (blue is low, red is high). This case was originally diagnosed as benign but changed to cancer upon further review. The AI accurately detected cancer in this tricky case. Image courtesy of Ibex Medical Analytics

Prostate biopsy with cancer probability (blue is low, red is high). This case was originally diagnosed as benign but changed to cancer upon further review. The AI accurately detected cancer in this tricky case. Image courtesy of Ibex Medical Analytics

News | Prostate Cancer | July 28, 2020
July 28, 2020 — A study published in 
PET/CT imaging showing uptake and retention of 86Y-NM600 (imaging agent) in immunocompetent mice bearing prostate tumors. PET imaging data was employed to estimate tumor dosimetry and prescribe an immunomodulatory 90Y-NM600 (therapy agent) injected activity. Image courtesy of R Hernandez et al., University of Wisconsin-Madison, WI.

PET/CT imaging showing uptake and retention of 86Y-NM600 (imaging agent) in immunocompetent mice bearing prostate tumors. PET imaging data was employed to estimate tumor dosimetry and prescribe an immunomodulatory 90Y-NM600 (therapy agent) injected activity. Image courtesy of R Hernandez et al., University of Wisconsin-Madison, WI.

News | PET-CT | July 15, 2020
July 15, 2020 — ...
Adult male with decades of right neck pain, discomfort and tightening following birth injury. The patient had failed multiple standard therapeutic maneuvers before presenting for 18F-FDG PET/MR imaging. Images shows abnormally elevated FDG uptake (white arrows; SUVmax = 1.2) observed in a linear pattern in the space in the posterolateral right neck, between the oblique capitis inferior and the semispinalis capitis muscles, where the greater occipital nerve resides. By comparison, the same region on the cont

Adult male with decades of right neck pain, discomfort and tightening following birth injury. The patient had failed multiple standard therapeutic maneuvers before presenting for 18F-FDG PET/MR imaging. Images shows abnormally elevated FDG uptake (white arrows; SUVmax = 1.2) observed in a linear pattern in the space in the posterolateral right neck, between the oblique capitis inferior and the semispinalis capitis muscles, where the greater occipital nerve resides. By comparison, the same region on the contralateral, asymptomatic side of the neck has an SUVmax = 0.7. This result encouraged a surgeon to explore the area. The surgeon ultimately found a collection of small arteries wrapped around the nerve in this location. The small arteries underwent lysis by the surgeon and the patient reported tremendous relief of symptoms. (A) Coronal thick slab MIP of 18F-FDG PET. (B) Axial LAVA FLEX MRI through the cervical spine. (C) Axial PET at the same slice as the axial MRI. (D) Fused axial PET/MRI. Image courtesy of Cipriano, et al., Stanford University, CA.

News | SNMMI | July 14, 2020
July 14, 2020 — A new molecular imaging approach utilizing 18F-FDG...
Researchers reviewed results of prostate biopsies on over 3,400 men who had targets identified on prostate MRI and found that the positive predictive value of the test for prostate cancer was highly variable at different sites
News | Prostate Cancer | July 01, 2020
July 1, 2020 — Prostate MRI is an emerging technology used to identify and guide treatment for...
Nuclear Cardiology Optimistic About Return to Pre-COVID-19 Exam Levels. An American Society of Nuclear Cardiology (ASNC) member survey are confident nuclear cardiology volumes will return to pre-pandemic levels. #COVID19 #SARScov2
News | Nuclear Imaging | June 01, 2020
June 1, 2020 — While acknowledging the challenges their specialty is facing, more than two-thirds of respondents to a
Maximum-intensity projections, transaxial fusion, and PET images of 18F-PSMA1007 (A-C) and 68Ga-PSMA-11 (D-F) PET/CT scans of 67-y-old patient with GS 8 and PSA 4.9 ng/mL. Marked uptake is seen in urinary bladder and left ureter (arrow) on maximum-intensity projection image of 68Ga-PSMA-11 (D), as opposed to nearly negligible 18F-PSMA-1007 urinary excretion (A). Dominant lesion in left prostatic lobe is evident on both scans (arrowheads). However, second lesion is seen in right lobe only on 18F-PSMA-1007 sc

Maximum-intensity projections, transaxial fusion, and PET images of 18F-PSMA1007 (A-C) and 68Ga-PSMA-11 (D-F) PET/CT scans of 67-y-old patient with GS 8 and PSA 4.9 ng/mL. Marked uptake is seen in urinary bladder and left ureter (arrow) on maximum-intensity projection image of 68Ga-PSMA-11 (D), as opposed to nearly negligible 18F-PSMA-1007 urinary excretion (A). Dominant lesion in left prostatic lobe is evident on both scans (arrowheads). However, second lesion is seen in right lobe only on 18F-PSMA-1007 scan (arrow in C), later verified on pathology as true malignant lesion. Images created by J. Kuten et al., Tel-Aviv Sourasky Medical Center, Tel-Aviv, Israel.

News | Prostate Cancer | May 12, 2020
May 12, 2020 — The novel radiopharmaceutical 18F-PSMA-1007 is both effective and readily available for detecting mali