New PSMA Marker Increases Accuracy for Prostate Cancer Detection
PSMA, a new radioactive marker, detects tumour centres and metastases more precisely than choline PET/CT.
If the PSA level rises again after treatment of prostate cancer, this may be a possible indication of relapse (recurrence). PSMA imaging with a newly developed slightly radioactive marker for PET (positron emission tomography) detects tumour centres and metastases even more precisely than conventional choline PET/CT, which is still standard in many hospitals. Since 2014, the West German Prostate Center has been using the new PSMA PET marker in cooperation with the Clinic and Polyclinic for Nuclear Medicine at the University Hospital Cologne.
With the PSMA marker, we can achieve an even better contrast between tumor and healthy tissue,"explains Dr. Neubauer from the West German Prostate Center. While doctors reach certain limits with conventional choline PET/CT, the new substance can also be used to detect recurrence tumours with PSA values below 1.0. The sensitivity in very small bone metastases is also significantly better.(1/2)"Not only patients with a recurrence benefit from this, but also men who continue to be suspected of prostate cancer, although the tissue sample has so far been unable to detect a tumour," said the urologist from Cologne.
Precise even with PSA values below 1.0
The innovative substance binds exclusively to the protein PSMA (prostate specific membrane antigen), which is produced in prostate carcinomas and their metastases in up to ten times higher concentrations. The more aggressive the tumor is, the more PSMA binds the tumor cells to their surface. In men with a healthy prostate, on the other hand, protein occurs only in very small amounts. If the slightly radioactively marked PSMA marker (so-called tracer) is injected into the patient's bloodstream, this is increasingly enriched in the tumor tissue and can be made visible using the PET method. The PET examination is carried out in the Department of Nuclear Medicine at the University Hospital Cologne on a modern PET/CT scanner, which is particularly sensitive and requires less radiation than conventional devices.
The examination by means of PSMA PET/CT improves diagnostics and further therapy planning. For example, we can make a clear distinction between local treatment such as radiotherapy for a patient with a relapse of prostate cancer, and systemic treatment such as chemotherapy or hormone therapy.(3)"If we are able to treat local recurrences and metastases more specifically in the future, this in turn increases the cure or survival rate," said Neubauer. Since November 2014, in cooperation with the Department of Nuclear Medicine at the University Hospital Cologne, there has even been the option of a PSMA-supported therapy of PSMA-positive metastases, in which the PSMA tumor detector is coupled with a therapeutically effective beta emitter.
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