Feasibility of temporary protective embolization of normal liver tissue using degradable starch microspheres during radioembolization of liver tumours

To describe a new approach to protect nontarget healthy liver tissue using degradable starch microspheres (DSM) as a short-term embolizate during radioembolization of liver tumours with Y-90 microspheres. Between December 2011 and July 2012 radioembolization was performed in 54 patients. Five of these patients (three women, two men; mean age 67 years) underwent protective temporary embolization using DSM (EmboCeptA (R) S) of normal liver tissue that could not be excluded from the area treated by radioembolization through catheter repositioning. Clinical symptoms, laboratory findings, preinterventional imaging, and Tc-99m-MAA and bremsstrahlung SPECT/CT, as well as baseline and follow-up imaging with F-18-FDG PET/CT and MRI, were evaluated in relation to the technical and clinical success of the protective embolization. Temporary embolization of arteries supplying normal liver tissue using DSM was technically successful in all five patients. Tc-99m-MAA SPECT/CT performed in the first two patients after DSM injection showed no increased pulmonary shunting compared to the MAA test injection without DSM. Bremsstrahlung SPECT/CT after radioembolization demonstrated satisfactory irradiation of the tumour and successful protection of normal liver tissue. There were only mild hepatotoxic effects (grade 1) on laboratory follow-up examinations, and no adverse events associated with DSM embolization or radioembolization were recorded. Temporary embolization with DSM before radioembolization is feasible and can effectively protect areas of normal liver tissue from irradiation and avoid permanent embolization if other methods such as catheter repositioning are not possible due to the location of the metastases.