Prostate cancer may be suspected if blood tests show an elevated level of PSA (prostate specific antigen) level or an abnormal feeling prostate gland on digital rectal examination. Patients would then need to undergo biopsy of the prostate gland to confirm or exclude the presence of cancerous cells.
Over the last decade, imaging and visualization of prostate cancer has significantly improved with the use of high magnetic field strength (3 Tesla) MRI scanners. This has led to more urologists (who treat men with possible prostate cancer) to request imaging of the prostate cancer before biopsy, so as to provide a “road map” to target suspicious lesions.
If cancer is diagnosed, treatment has to be tailored according to the severity of disease. Patients with high risk disease may be offered surgery to remove the prostate gland (radical prostatectomy) or radical radiotherapy to cure the disease.
It is crucial for urologists and radiation oncologists to have accurate information on the extent of disease before embarking on either surgery or radiotherapy. If the disease has spread beyond the prostate gland into distant lymph nodes or bones, then patient is unlikely to be cured with surgery or radiation to the prostate gland.
In the last few years, Mercy Radiology has led the way in this country by providing a prostate cancer specific scan to image the extent of disease in the body.
PSMA (prostate specific membrane antigen) is a prostate cancer specific marker. By combining PSMA with a hybrid PET/CT scanner, radiologists are able to detect small deposits of cancer that are impossible to detect with traditional scans such as CT or bone scans. For example, tiny deposits of cancer may be seen in otherwise normal appearing small lymph nodes. The test is also more sensitive than traditional bone scans in picking up cancer cells which has spread to the skeleton.
Results of a recent scientific study assessing impact of PSMA PET/CT, funded by the Prostate Cancer Foundation NZ and led by Mercy Radiology PET/CT specialist, Dr Remy Lim was presented at this year’s NZ Royal College of Radiologists Annual Scientific Meeting in Queenstown
Dr Lim and his team showed that a PSMA PET/CT scan has the potential to prevent non-curative surgery in over a quarter of men diagnosed with high risk disease. Without a PSMA PET/CT scan, these patients would have put themselves through major surgery but later found that the disease had already spread outside the prostate gland.
Dr Lim and his team also showed in a different study that the PSMA PET/CT scan is sensitive in detecting where disease has recurred following curative treatment such as radical prostatectomy.
The next chapter of this remarkable prostate specific imaging marker is cancer specific treatment. By partnering with Prostate Cancer Foundation NZ again, Dr Lim’s Mercy Radiology team is now conducting a pilot study to assess feasibility of administering a prostate cancer specific radioactive treatment, called Lutetium-177 PSMA, for patients with progressive, disseminated disease who have exhausted all other forms of palliative treatment.
As the treatment is highly “targeted”, Lutetium-177 PSMA will eliminate only prostate cancer cells while leaving healthy cells intact, sparing patients from many of the side effects normally associated with other forms of chemotherapy or hormone therapy.
If successful, the treatment is likely to be available to other patients for the first time in New Zealand, highlighting the ways in which successful collaboration between Prostate Cancer Foundation NZ and clinical partners will ultimately benefit patient care.