Prostate cancer “game changer”
membrane antigen) that are found on the surface of these cells in 9095% of men with prostate cancer. It then emits damaging beta particles, which locally irridate and kill the cancer cells without harming surrounding tissue and causing unpleasant side effects. that everything that was diseased got radiated. I was ecstatic when I saw that.”
At the moment Lutetium-177 is seen as the ambulance at the bottom of the cliff but the day may come when it is a possible option for treatment earlier in the progression of prostate cancer.
“It’s the new kid on the block, still very experimental and it has to prove itself, which is quite a process,” says Dr Lim. “But the results so far have been amazing.”
Using Lutetium-177 has followed on from an earlier scientific study Dr Lim led, also backed by Mercy Radiology and the Prostate Cancer Foundation of New Zealand.
Several years ago he began looking into a different way of using scans to better detect prostate cancer thanks to PSMA — those same proteins on the surface of cancer cells. He injected a radioactive tracer called Gallium-68 (Gallium 68-PSMA) which, like Lutetium-177, also attaches to the PSMA proteins on prostate cancer cells. However, instead of killing them, it sends out radiation which can be picked up by a PET/CT scanner.
This makes it easier to see if the cancer cells have spread beyond the prostate gland.
“You can’t really see the cancer cells [using traditional CT scans] in lymph nodes until they are the size of a blueberry, which is about 10mm. Now we can pick them up when they are the size of a peppercorn – that’s around 2-3mm — or smaller.
Knowing the location and size of the cancer means treatment can be more accurately tailored to the patient. Another benefit is that scans using Gallium-68 to identify tiny deposits of prostate cancer may be able to spare those men whose cancer has already spread from the prostate to other parts of the body from having surgery or radiotherapy that won’t help them and could leave them with significant side effects.
“There are two options if we are trying to cure prostate cancer — one is surgery to remove the prostate and the other is radiation therapy to the prostate gland,” explains Dr Lim. “Both are major and have the risk of side effects, such as incontinence and impotence.
However, if the disease has already spread beyond the prostate, putting the patient through a major surgical procedure — that isn’t going to achieve what it is meant to and could leave them with side effects — is doing them a disservice.”
Forty-nine high-risk patients took part in the study, all of whom were due to have their prostates surgically removed. Scans using Gallium-68 found that in a quarter of the men, the cancer had already spread. It was bad news for them, but better that they knew that before undergoing a major operation that wouldn’t help, says Dr Lim.
Having this information can also have an impact on public hospitals, saving them from performing futile prostate removal operations that cost around $30,000 each. In comparison, the cost of the scan is just under $3000.
The breakthroughs can make a big difference when it comes to managing treatment for patients with prostate cancer, says Dr Lim, but of course all men should remember that the most important message is to see their GPs for check-ups if they are over 50, or over 40 and have a family history of prostate cancer. Symptoms like difficulty urinating or blood in the urine should be checked out immediately.
“As with any cancer, early