Bluegrass Regional Imaging

PET/CT Helps Detect Recurring Prostate Cancer Earlier than Ultrasound, CT and MRI

A PET/CT scan with the imaging agent choline helps detect recurring prostate cancer earlier than conventional imaging technologies for some patients who have already had their prostates removed, according to a study in the September issue of The Journal of Nuclear Medicine.

 Prostate cancer is the most common type of cancer found in American men, other than skin cancer, and is the second leading cause of cancer death in men (behind lung cancer).  According to the American Cancer Society, one man in 6 will get prostate cancer during his lifetime and one man in 35 will die from it.

According to the study, many men diagnosed with prostate cancer choose to have a radical prostatectomy, which involves surgical removal of the entire gland and surrounding tissue.  However, prostate cancer recurs within five years in as many as 30 percent of these patients.  Physicians monitor patients who have undergone the procedure by checking levels of prostate-specific antigen (PSA) in the blood.  If PSA is detected after radical prostatectomy, known as biochemical relapse, then imaging techniques are essential to determine whether and exactly where is the body the cancer has recurred.

The study included 190 men who had previously undergone radical prostatectomy and had experienced a biochemical recurrence of prostate cancer.  The patients were grouped according to PSA levels and studied with C-choline PET/CT.  The researchers found that whole-body C-choline PET/CT imaging proved to be significantly better than conventional imaging technologies in detecting prostate cancer in patients who have experienced a biochemical relapse after prostatectomy.

"In most patients with biochemical relapse after radical prostatectomy, conventional imaging methods, such as CT,MRI, and bone scintigraphy, often return false-negative results, meaning that the imaging techniques fail to detect cancer that is present in the body,"said Paolo Castellucci, M.D., of the nuclear medicine unit, hematology-oncology and laboratory medicine department, Azienda Ospedaliero-Universitaria di Bologna Policlinico S. Orsola-Malpghi, University of Bologna, Italy, ad lead author of the study.

"Our study found that for some patients, PET/CT with choline can improve the detection of cancer soon after PSA levels are measured.  This enables physicians to tailor treatment to individual patients in the early stages of recurrence, thus increasing their chances of recovery," said Castellucci.

Researchers also found a strong association between PET/CT detection of recurrent cancer, PSA levels, and PSA kinetics.  They suggest that based on the results, only patients with a high probability of having a positive scan based on PSA levels and kinetics should undergo choline PET/CT scans can be reduced and early detection of prostate cancer relapse can be improved.

Source: Society of Nuclear Medicine;  Health Imaging