Fronts of the field

Molecular imaging uses a small radioactive tracer injected into the body and a PET or SPECT camera to show where a specific protein sits on a tumour, so doctors can pick the right treatment and check it is working.

Radioligand therapy attaches a radioactive particle to a molecule that homes in on a tumour, so the radiation is delivered from the inside of the cancer rather than from an external beam.

Alpha therapy uses a heavier type of radioactive particle that travels only a few cell widths but hits much harder, aimed at cancer cells that have stopped responding to the gentler beta-particle treatments.

The radioactive ingredients in these medicines are made in a small number of ageing reactors and accelerators worldwide, and demand is now growing faster than that supply.

Making one of these medicines means attaching a radioactive atom to a targeting molecule and getting it sterile and out the door within hours, before it decays away — a manufacturing problem unlike almost any other medicine.

Dosimetry works out exactly how much radiation dose a patient's tumour and healthy organs actually receive, so treatment can in principle be tailored to the person rather than given as one fixed dose to everyone.

Brain PET scans can now show the sticky protein clumps of Alzheimer's disease directly, and are also used to see how far a brain tumour has spread and whether radiotherapy scarring looks like tumour regrowth.

A radioactive tracer injected into the bloodstream lights up on a scanner wherever the heart muscle is getting enough blood flow, so doctors can see blocked arteries without surgery.

The same FDG tracer used to find cancer also lights up sites of infection and inflammation, which helps doctors find hidden abscesses, infected joint replacements or heart-valve infections that scans and blood tests alone can miss.

Some radioactive drugs are built to home in on damaged bone rather than the tumour itself, easing bone pain from cancer that has spread to the skeleton and, in one case, helping patients live longer.

Radioembolisation delivers tiny radioactive beads directly into the blood vessels feeding a liver tumour through a catheter, so the radiation stays concentrated in the liver instead of spreading through the whole body.

Getting one of these radioactive medicines approved and then actually paid for is its own specialised process, separate from ordinary drugs, and the rules for who pays what changed again for 2026 in the US.