pairings

An early trial gave the prostate cancer radiotherapy Pluvicto together with the tablet olaparib, on the idea that the pill makes the radiation harder for the cancer cell to repair. Most men's PSA fell, but this is still a small early-stage study, not proof it helps people live longer.

For some pancreatic neuroendocrine tumours, doctors add two chemotherapy tablets (capecitabine and temozolomide) to the radioactive PRRT treatment. Trial data suggest the combination may control the pancreatic tumours for longer than either treatment alone, though it caused more blood-count side effects in one gut-tumour subgroup.

Small early trials are giving liver-directed radiation beads (TARE) together with the immunotherapy drug durvalumab for liver cancer that cannot be operated on. Early results show high tumour shrinkage rates, but these are small studies and it is not yet proven that the combination helps people live longer than either treatment alone.

When the standard radioactive prostate cancer treatment (177Lu-PSMA) stops working, some clinics switch to a more powerful alpha-particle version (225Ac-PSMA) as a rescue option. It can bring PSA down in about half of patients, but people who have already failed the beta treatment tend to respond less well and for a shorter time than those who have never had it.

When lutetium radioligand therapy stops working, alpha-emitting versions can still control the disease.

After lutetium therapy stops working, an actinium version of the same drug can still produce responses.

In the trial that got 177Lu-PSMA-617 (Pluvicto) approved, everyone had already been treated with a taxane chemotherapy drug like docetaxel and with a hormone pill first. That is the treatment order the approval is based on, though a newer trial is now testing whether Pluvicto can be used earlier, before chemotherapy.

Before giving the radioactive lymphoma treatment Zevalin, doctors first give a dose of the antibody drug rituximab. This clears out normal B-cells in the blood so the radioactivity goes to the lymphoma more precisely, and it is a mandatory step on the drug's official label, not an optional extra.

Before starting the neuroendocrine tumour treatment Lutathera, patients get a somatostatin-receptor PET scan to confirm the tumour actually has the right target for the drug to lock onto. Lutathera's approval and use are built around this scan-first rule.

The scan shows whether the target is there; the treatment uses the same address. Only patients whose tumours light up are treated.

SSTR PET followed by PRRT is the original theranostic pair: the scan with the diagnostic isotope decides who gets the same molecule with the therapeutic isotope.

In Hodgkin lymphoma, a PET scan taken partway through chemotherapy is used to decide whether to keep the same treatment, drop a harsh drug, or step up to something stronger. Trials show this scan-guided approach keeps most patients well without adding one particular lung-damaging drug.

Two large trials tested whether liver-directed radiation beads work better than the pill sorafenib for advanced liver cancer. Neither trial found the radiation beads extended life more than the pill, though patients had fewer side effects and better quality of life with the beads.

Giving the bone-targeting radiotherapy radium-223 together with the hormone drug abiraterone does not help patients live longer and roughly doubles or triples the risk of a broken bone compared with abiraterone alone. This combination is no longer recommended.