Clinical care and technical recommendations for ⁹⁰yttrium microsphere treatment of liver cancer

Selective internal radiation therapy (SIRT) with 90yttrium microspheres is a relatively new clinical modality for treating non-resectable malignant liver tumours. This interventional radiology technique employs percutaneous microcatheterisation of the hepatic arterial vasculature to selectively deliver radioembolic microspheres into neoplastic tissue. SIRT results in measurable tumour responses or delayed disease progression in the majority of eligible patients with hepatocellular carcinoma or hepatic metastases arising from colorectal cancer. It has also been successfully used as palliative therapy for non-colorectal malignancies metastatic to the liver. Although most adverse events are mild and transient, SIRT also carries some risks for serious and – rarely – fatal outcomes. In particular, entry of microspheres into non-target vessels may result in radiation-induced tissue damage, such as severe gastric ulceration or radiation cholecystitis. Radiation-induced liver disease poses another significant risk. By careful case selection, considered dose calculation and meticulous angiographic technique, it is possible to minimise the incidence of such complications to less than 10% of all treatments. As the number of physicians employing SIRT expands, there is an increasing need to consolidate clinical experience and expertise to optimise patient outcomes. Authored by a panel of clinicians experienced in treating liver tumours via SIRT, this paper collates experience in vessel mapping, embolisation, dosimetry, microsphere delivery and minimisation of non-target delivery. In addition to these clinical recommendations, the authors propose institutional criteria for introducing SIRT at new centres and for incorporating the technique into multidisciplinary care plans for patients with hepatic neoplasms.