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Molecular imaging study reveals improved detection of early recurrent prostate cancer

Research shows significant change in management

Date:
September 17, 2015
Source:
Society of Nuclear Medicine
Summary:
A recently developed drug was significantly better at detecting recurring prostate cancer in early stages, researchers report. The American Cancer Society reports that prostate cancer is the second leading cause of cancer death in American men, behind lung cancer, with about 220,800 new cases estimated in 2015.
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A recently developed drug was significantly better at detecting recurring prostate cancer in early stages, in research published in the August 2015 issue of The Journal of Nuclear Medicine. In the study, the imaging agent--Ga-68 prostate-specific membrane antigen (Ga-68 PSMA)--used with positron emission tomography and computed tomography (PET/CT), changed management in 44% more cases than another widely used agent.

"This is the first prospective comparative trial evaluating detection rates and management impact of the more widely available radiopharmaceutical F-18 fluoromethylcholine (FMC) and the recently developed Ga-68 PSMA PET tracer agent in men with prostate cancer," said Joshua James Morigi, MD, lead author of the study. "We specifically addressed men with prostate cancer and low PSA levels, at which current imaging techniques struggle in detecting disease."

The researchers, of St. Vincent's Hospital, Sydney, Australia, evaluated 39 prostate cancer patients who had rising PSA following first-round treatment and were eligible for further targeted therapy. Patients on systemic treatment were excluded. Ga-68 PSMA PET/CT, F-18 FMC PET/CT and diagnostic CT were undertaken in all patients sequentially between January and April 2015 and assessed by masked, experienced nuclear medicine physicians. Researchers then documented scan results and management impact changes, together with histological follow-up, if feasible. Of the patients enrolled, 89 percent had only their prostate gland removed, while the other 11 percent were post-radiation treatment.

"Our main finding is that even at extremely low PSA levels (<0.5), PSMA was able to detect sites of possible recurrence in 50 percent of patients while FMC detected possible recurrence in only 12.5 percent," Morigi states. "As a result of these high detection rates, PSMA also demonstrated a very high management impact in our patient cohort (63 percent), having an added value over FMC in 44 percent," he continued. "These findings have important ramifications for the management of men with early biochemical failure and suggest that imaging-guided therapy even in low PSA range may be possible."

Histological follow-up was available for 9 (24 percent) patients, and 9 out of 9 PSMA-positive lesions were consistent with prostate cancer. The one lesion positive on FMC and negative on PSMA resulted at biopsy as a false positive. Researchers concluded that in patients with biochemical failure and low PSA, PSMA demonstrated a significantly higher detection rate with a high overall impact on management. This suggests that Ga-68 PSMA PET/CT will be an effective imaging tool for early detection of prostate cancer recurrence.

The American Cancer Society reports that prostate cancer is the second leading cause of cancer death in American men, behind lung cancer, with about 220,800 new cases estimated in 2015.


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Materials provided by Society of Nuclear Medicine. Note: Content may be edited for style and length.


Journal Reference:

  1. J. J. Morigi, P. D. Stricker, P. J. van Leeuwen, R. Tang, B. Ho, Q. Nguyen, G. Hruby, G. Fogarty, R. Jagavkar, A. Kneebone, A. Hickey, S. Fanti, L. Tarlinton, L. Emmett. Prospective Comparison of 18F-Fluoromethylcholine Versus 68Ga-PSMA PET/CT in Prostate Cancer Patients Who Have Rising PSA After Curative Treatment and Are Being Considered for Targeted Therapy. Journal of Nuclear Medicine, 2015; 56 (8): 1185 DOI: 10.2967/jnumed.115.160382

Cite This Page:

Society of Nuclear Medicine. "Molecular imaging study reveals improved detection of early recurrent prostate cancer: Research shows significant change in management." ScienceDaily. ScienceDaily, 17 September 2015. <www.sciencedaily.com/releases/2015/09/150917135223.htm>.
Society of Nuclear Medicine. (2015, September 17). Molecular imaging study reveals improved detection of early recurrent prostate cancer: Research shows significant change in management. ScienceDaily. Retrieved May 23, 2017 from www.sciencedaily.com/releases/2015/09/150917135223.htm
Society of Nuclear Medicine. "Molecular imaging study reveals improved detection of early recurrent prostate cancer: Research shows significant change in management." ScienceDaily. www.sciencedaily.com/releases/2015/09/150917135223.htm (accessed May 23, 2017).

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