Groundbreaking molecular imaging for prostate cancer to be available in New Zealand
Hybrid imaging, combining computed tomography (CT) and molecular imaging using positron emission tomography (PET), is taking prostate cancer scanning to the next level in New Zealand.
Mercy PET/CT in Epsom, Auckland will soon be offering a groundbreaking molecular imaging in the form of gallium-68 labelled with prostate specific membrane antigen (PSMA PET/CT). In combination with high definition CT scan, this “one stop” scanning technique has been shown to be superior in detecting presence of prostate cancer cells in lymph nodes, solid organs or bones.
Current imaging has been very limited in detecting prostate cancer spread outside of the prostate gland accurately. This is because current CT scan interpretation requires a lymph node to be the size of a small grape before they are considered to be abnormal. At this size however, there would be approximately 1 million cancer cells already contained within the node.
To evaluate for spread of disease to the bones, the commonly performed bone scan relies on bone destruction incited by prostate cancer cells for the test to be positive. However, other pathologies such as arthritis, fracture or inflammation may also cause positive findings, often confusing the picture.
PSMA, on the other hand, is an enzyme that is found in abundance on the cell surface of prostate cancer cells. By targeting this enzyme, the cancer cells can be imaged directly with a PET scanner, thus obviating the need to rely solely on size or bone destruction for detection of disease. For instance, with PSMA PET/CT a lymph node the size of a peppercorn will be abnormally “hot” if it harbors prostate cancer cells.
For patients with newly diagnosed high risk prostate cancer the test may be useful in excluding presence of prostate cancer cells outside of the gland. This would then allow local treatment options such as radiotherapy or surgery to be carried out as definitive treatment for patients’ disease.
Unfortunately, for a small proportion of patients, prostate cancer will recur elsewhere in the body following definitive treatment after a period of time, usually detected by rising PSA level. In this situation, PSMA PET/CT can also be performed to determine location and extent of recurrent disease. If recurrence is limited to a single lymph node for example, localized radiation or surgery may be an option. Thus, commencement of systemic treatment such as hormone therapy or chemotherapy may be deferred, sparing patients from associated side effects.
Whilst PSMA PET/CT has been available in Australia and Europe for the last 12-18 months, Mercy PET/CT is proud to be the first imaging centre in New Zealand to offer this test as of October 2015. Call us at (09) 623 5862 or visit our website at www.radiology.co.nz for more details.