In a first for the Western Cape, nuclear medicine physician Dr Marguerite Morkel and her team recently treated a prostate cancer patient with targeted alpha therapy (TAT) at Mediclinic Panorama.

Use of TAT for prostate cancer

Targeted alpha therapy (TAT) is a novel cancer treatment that delivers cytotoxic doses of alpha radiation to tumour cells, killing these malignant cells with minimal damage to the surrounding healthy tissue. For the first time in the Western Cape, nuclear medicine specialist Dr Marguerite Morkel used this innovative therapy to treat a 70-year-old prostate cancer patient at Mediclinic Panorama.

In this case, TAT was employed to target the prostate-specific membrane antigen (PSMA), a protein found in large amounts in prostate cancer cells. Actinium-225 PSMA (225Ac-PSMA) binds to this antigen, delivering potent alpha particle radiation directly to the cancer cells, which lowers the risk of damage to surrounding healthy tissue.

Nuclear medicine practice

Dr Morkel is managing director of Dr H.R. Morkel Inc, a nuclear medicine and molecular imaging practice based at Mediclinic Panorama founded by her father, nuclear physician Dr Heinz Morkel. The practice has served the Western Cape private sector for more than 30 years. He too was part of the six-strong team that performed the ground-breaking treatment, along with fellow nuclear physician Dr Maxine Fletcher, also based at the practice.

“Our mission is to improve healthcare by staying abreast with the latest innovations in nuclear medicine and molecular imaging,” he says.

“Currently, we are the only private facility treating patients with metastatic castrate resistant prostate cancer (mCRPC) with targeted beta therapy – Lutetium – 177 PSMA (Lu-PSMA) – which has been performed for the past few years,” Dr Marguerite Morkel adds.

Therapeutic potential

Dr Fletcher is excited about the efficacy and benefits of 225Ac-PSMA. “It’s a novel treatment option for patients with mCRPC,” she says. “Preliminary results obtained in these patients have shown its therapeutic potential based on its high level of energy transfer due to the radiation emissions produced by the alpha particles.

“A radioactive part (225Ac) is combined with a non-radioactive part that is specific to prostate cancer (PSMA). This combination is used to target and treat prostate tumour cells, resulting in minimal effects on neighbouring cells and tissues. In fact, 225Ac-PSMA has shown remarkable therapeutic efficacy in mCRPC patients and has not only fewer, but also less severe side-effects than chemotherapy.”

What is nuclear medicine?

Nuclear medicine is a branch of medical imaging that uses small amounts of radioactive material to diagnose and determine the severity of or treat a variety of diseases. This includes various types of cancers, heart disease, gastrointestinal, endocrine, neurological disorders, and other abnormalities within the body.