Molecular imaging agent detects metastatic prostate cancer
MedWire News: Clinical trial results show that a novel molecular imaging agent used in the restaging of recurrent prostate cancer can accurately differentiate between recurrence within the prostate and cancer that has metastasized elsewhere in the body.
The research team notes that discrimination between local, regional, or distant recurrence is vital for appropriate disease management.
“Despite definitive treatment, about 30% of prostate cancers recur,” explained David Schuster from Emory University in Atlanta, Georgia, USA who presented the research at the annual meeting of the Society of Nuclear Medicine in Salt Lake City, USA, this week.
“This troubling statistic led our research team to diligently work on developing new techniques to more effectively detect and diagnose recurrent prostate tumors and associated cancers that have spread to nearby tissues and organs,” he added.
The anti-1 amino 3 [18F] flurocyclobutane-1-carboxylic acid (anti-18F-FBCB) radiotracer – a synthetic amino acid analog similar to the naturally occurring amino acid leucine – was developed at Emory University and tested on a group of 83 patients with elevated prostate-specific antigen (PSA) readings and negative bone scans after treatment for prostate cancer.
Patients underwent a positron emission tomography scan of the abdomen and pelvis at 4, 17, and 29 minutes after being injected with 200–485 MBq of anti-18F-FBCB. The presence or absence of disease was confirmed by tissue correlation, as well as by further imaging, and laboratory and clinical consensus.
Among the 62 patients with data available, anti-18F-FBCB detected 60% and 15% of positive and negative disease presence, respectively, and 15% and 11% of false positive and false negative disease, respectively, in the prostate bed and/or seminal vesicles.
This gave a sensitivity of 84% and a specificity of 50% for the ability of anti-18F-FBCB to detect recurrence within the prostate, with an accuracy of 74%, report Schuster and team.
Furthermore, anti-18F-FBCB detected 60% of truly positive, 36% of truly negative, 4% of falsely positive, and 0% of falsely negative extraprostatic disease.
“In the detection of extraprostatic recurrence, sensitivity is 100%, specificity is 90%, and accuracy 96%,” report the researchers.
Aggressively multiplying cancer cells will absorb more anti-18F-FBCB to facilitate the production of the proteins they require to proliferate, the researchers explain.
Schuster hopes that the findings may lead to custom-tailored treatments for prostate cancer patients that cater to their specific tumor type and progression of disease.
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By Sarah Guy