Yttrium-90 or Y-90 is a commonly used isotope in the medical field specially in departments like nuclear medicine and radiation oncology for radiation therapy. This radioisotope is relied upon to provide a prescribed amount of radiation to a targeted area , such as a tumor. One of the most common uses of Y90 is during an internal radiation therapy called radioembolization.
Radioembolization or Transarterial Radioembolization using Y-90 involves the use of glass/ resin spheres that are filled with the isotope and placed directly into the blood supply of the liver tumor through a minimally invasive procedure. These spheres get lodged within the tumor itself. The doctors then block off the blood vessels to prevent blood flow (embolization). These Y-90 labelled spheres then get to work by radiating and destroying the tumor.
Commonly, Y-90 labelled spheres are used for the treatment of liver tumors, primary hepatocellular carcinoma (HCC) and unresectable primary colorectal cancer that has metastasized to the liver. And sometimes in the treatment of Neuroendocrine Tumors (NETs) by labelling them with somatostatin receptor analog like Dotatoc or Dotatate. This is known as Y-90 PRRT.
In some cases, doctors uses Y-90 PRRT by itself or use it along with Lutetium Therapy in an alternating kind of protocol, so that the patient receives one dose of Lutetium PRRT that’s followed by a dose of Y90, followed by Lutetium and then followed by Y-90 again. This is, what doctors call, Tandem Therapy and has proven to be effective in patients who have got large volume diseases.
In terms of side-effects, there have been speculations that use of Y-90 actually causes collateral damage to the liver. In fact, this is far from the truth. The tissue path length of Y-90 is very short and although Y-90 is a high energy b emitter, it does not penetrate beyond the tumor and the tissues around the liver are spared. The Y-90 only targets the tumor. However, there is one concern regarding the use of Y90 – Y90 is relatively more nephrotoxic than Lutetium, which means that as compared to Lutetium that causes barely any damage to the renal function, Y-90, being a more potent radioisotope has the potential to cause renal damage. This is why doctors use Y-90 extremely judiciously and whenever it is used, it is used with proper renal protection protocols. Actually, Y-90 is nothing to be scared of. With proper precautions, Y90 is extremely beneficial for patients with specific liver conditions and can make a lot of difference to the disease outcome.