A study recently published in The Journal of Nuclear Medicine revealed a new tool based on imaging to assess prostate cancer recurrence in patients after radical prostatectomy. The study was led by researchers at the Technische Universität München in Germany and is entitled “Evaluation of Hybrid 68Ga-PSMA Ligand PET/CT in 248 Patients with Biochemical Recurrence After Radical Prostatectomy.”
Prostate cancer is the second most common cancer in men, with almost one million new cases diagnosed every year worldwide. It is estimated that one in every seven men will be diagnosed with this cancer during their lifetimes. It is a curable cancer that can range from slow-growing tumors (more common) to rapidly progressing aggressive tumors, which are more difficult to treat. Early detection and treatment of prostate cancer is therefore crucial. The diagnosis can be made through a blood test for prostate-specific antigens (PSA, a protein produced by prostate cells).
One of the treatment options for prostate cancer is radical prostatectomy, where the prostate gland and some of the surrounding tissue is surgically removed. However, a considerable number of patients who undergo prostatectomy later experience an increase in PSA levels, representing a biochemical recurrence linked to higher risk for cancer recurrence.
It is known that prostate-specific membrane antigen (PSMA) expression is increased in prostate cancer cells. A ligand of PSMA was recently developed, named 68Ga-PSMA (Glu-NH-CO-NH-Lys-(Ahx)-[68Ga(HBED-CC)]). In the present study, the research team assessed the detection rate of 68Ga-PSMA by imaging through PET/CT (positron emission tomography/computed tomography) in 248 patients with biochemical recurrence (median PSA level of 1.99 ng/mL) after radical prostatectomy.
Researchers found that the novel 68Ga-PSMA-ligand PET/CT had substantially higher detection rates of PSMA in patients with biochemical recurrence after radical prostatectomy in comparison to other imaging methods. In this cohort, 89.5% of the patients (222 patients) were found to have pathologic findings and higher levels of PSMA. Remarkably, this technique allowed the identification of positive cases even in the clinically important range of low PSA values (< 0.5 ng/mL).
“The study is the first to examine this highly promising PET tracer in the use of a homogeneous patient collective consisting of only those with biochemical recurrence after radical prostatectomy. It found superb detection rates compared to other tracers, like choline, or imaging modalities, like MRI. For patients, this means that the referring urologist can receive earlier and more precise information about the site and extent of metastatic disease. Physicians will also be better able estimate whether a PSMA-PET scan might be useful in a specific setting,” explained the study’s lead author Dr. Matthias Eiber in a news release.
Early discovery of prostate cancer recurrence is crucial and can strongly influence the clinical management of the disease. “These findings will certainly enhance the use of PET in the diagnostic workup of patients with recurrent prostate cancer. When regulatory hurdles and reimbursement issues are overcome, this tracer might gain significant acceptance beyond Europe,” concluded Dr. Eiber.