AI linear accelerator for POM Gen cancer patients

Cancer patients will soon receive pin-point precision treatment with Papua New Guinea's first AI-powered Linear Accelerator installed at the Port Moresby General Hospital Comprehensive Cancer Center.

The Elekta Linear Accelerator from the United States is housed inside Bunker One, a full concrete structure with walls about 1.5 meters thick designed to safely contain radiation.

Chief Executive Officer of PomGen, Dr. Paki Molumi, said this is the first of its kind in the country, and a major upgrade from the old cobalt source machine in Lae.

 "Radiotherapy machine, it's a linear accelerator from Elekta. Compare this to the one in Lae, it's a cobalt source. The thing about radiotherapy machines, if it's cobalt, it's going to burn your skin. It will burn your muscles all the way to get into the target.

Whereas this latest machine, it subtracts everything and only targets the cancer. Precisely, to the point of a pin. We are so lucky we are building this at a time of the AI age. Machines now have inbuilt AI to assist technicians," Dr. Molumi said.

Unlike the cobalt source which releases continuous radiation, the linear accelerator generates radiation on demand by electricity when patients are being treated.

Bunker Two will house a bigger TrueBeam machine, another version of Elekta to complement the first machine and treat different types of cancers depending on depth – neck, abdomen and other deep-seated organs.

According to Dr. Molumi, the radiation oncologist will decide which bunker a patient goes to, adding that the second machine is yet to be procured, with funding hoped for in the 2027 Budget.

For safety, bunkers are fitted with laser beams that pick-up movement and automatically shut down the machine if someone enters during radiation. Operators monitor patients from a shielded monitoring station with computers and cameras.

To make patients feel at home, Dr. Molumi said sterile walls will be covered with murals with PNG cultural designs.

He explained that the treatment workflow is linked, cancer is mapped out and programmed in the Planning CT room, and that information is fed into the linear accelerator to apply treatment directly to the planned field.

After treatment, response will be monitored in nuclear medicine through (Positron Emission Tomography) or PET Scan and Single Photon Emission Computed Tomography (SPECT or CT) machines.

A SPECT/CT machine is a hybrid imaging system that combines SPECT with X‑ray Computed Tomography (CT) to provide both functional and anatomical imaging in a single scan. 

Patients are injected with radioactive material with a half-life of 3-4 hours and kept in uptake rooms before scanning. The scan shows at cellular level whether chemotherapy or radiotherapy is curing the patient.

"After treatment is done, we will need to monitor at molecular level, because you don't know whether your radiotherapy or chemotherapy is actually curing this patient. That's where you get a PET scan. You can actually see the function at cellular level, whether treatment is responding.

Then you can increase dose, reduce dose, or look for other ways," Dr. Molumi explained.

The facility will be able to treat 30 to 60 patients per day when both machines are running.