Blank stares. That’s what Gabriel Lim usually gets when people hear what he does for a living – he’s a Senior Principal Nuclear Medicine Technologist at Singapore General Hospital.

“Some of them think I help to build nuclear bombs,” the allied health professional says half-jokingly. It isn’t entirely surprising, given that he works in Singapore’s only full-fledged nuclear medicine department, belonging to a small but fast-growing medical niche.

To set the record straight, he came to this interview prepped with a detailed definition: A Nuclear Medicine Technologist is someone trained in the use of medical equipment such as a gamma camera or single-photon emission computed tomography (SPECT)/CT scanner and positron emission tomography (PET)/CT scanner to image specific radiopharmaceuticals. The images provide information pertaining to the patient’s organ and bodily functions, allowing the Nuclear Medicine Clinician to make medical diagnosis.

Patients who visit Gabriel and his team either consume or are injected with a radioactive tracer drug. After a period of absorption, the Nuclear Medicine Technologist uses specialised imaging equipment to study how well certain organs are functioning.

Compared to fast-paced radiography scans, like general x-rays and CT, nuclear medicine scans require longer imaging time, but provides a detailed picture of a patient’s organ function. “For example, we are able to see which of the 2 kidneys is functioning better relative to the other, how efficiently the heart is pumping, determine the time it takes a meal to move through a person’s stomach, where cancer cells are located and detect stress injury on bones. It’s not just taking a [simple] picture,” says Gabriel.

The rise of nuclear medicine
Gabriel spent 11 years as a radiographer before venturing into the world of nuclear medicine. “In my student days, nuclear medicine wasn’t as popular or vibrant,” he says.

These days however, nuclear medicine is now front and centre in oncology and other medical specialties, thanks to PET/CT scans, which can be used to detect cancer, assess effectiveness of cancer treatments, assess heart function and infection and study brain functions.

“There are various trials with specific drugs for Alzheimer’s and Parkinson’s. This is especially useful for Singapore’s greying population. The use of PET/CT as a tool to image brain amyloid levels and evaluate clinical symptoms can help with the early detection of these diseases. The ability to image such biomarkers allows evaluation of early drug intervention or look for measures to slow down disease progression,” This would allow patients to plan and cope with their condition in advance. Gabriel shares.
Other than diagnostic imaging, nuclear medicine is used also for cancer therapy, such as in the targeted treatment of thyroid cancer using radioactive iodine – I131 and Yttrium 90 microspheres for liver cancer, minimising harm to normal cells.

The radiation in nuclear medicine can also be used as treatment when the cancer is deemed inoperable, such as in Lu177 PRRT (Peptide Receptor Radionuclide Therapy) for neuroendocrine tumours and Lu177- PSMA (Prostate Specific Membrane Antigen) for prostate cancer, explains Gabriel.

For the love of nuclear medicine
It started off as a “try and see how” stint when an opening in nuclear medicine became available, but Gabriel has since spent 15 years (and counting) in the department and now mostly splits his time between training and clinical work.

“I stayed here this long because there are so many interesting things happening daily. It didn’t take me long to realise that more will come from nuclear medicine,” he says.

Gabriel remains humble despite being one of the most experienced professionals in his field in Singapore. “I’m still learning, and it’s still very engaging! In future there’ll be more and more targeted drugs for specific medical conditions,” he says. “With PET/CT, more people, patients and doctors alike, will get to know other things about nuclear medicine.”

However, as with all patient-facing roles, Gabriel encounters his share of challenging moments on the job. Many patients come in for a scan, not knowing that the entire process may take anything between 45 minutes to three hours, depending on the type of scan and even the physical size of the patient for a full-body scan affects the scan time. Time consuming scans may be uncomfortable or inconvenient for elderly patients and the wait may cause patients with cancer to be even more anxious than they already are, says Gabriel. He takes it all in his stride by staying calm and practicing firmness (or flexibility) when needed.

On the bright side, it is also the patients that keep Gabriel motivated at the end of the day. “I spend a lot of time in the PET /CT scanning room. Some patients come many times for their ‘follow up’ scans, and they become almost like friends and relatives,” he says.

SGH isn’t the only PET centre in Singapore. They can go to any other place, but they say “I still come here because you’re around,” shares Gabriel with a smile. He fondly shares a story of a patient’s wife who trooped all the way to Killiney Road to buy a box of curry puffs for the team. He says, “It shows that they appreciate what you do. These are the ones who make you feel like your hard work has paid off.”