Selective internal radiation therapy (SIRT) has emerged as a viable strategy for the treatment of incurable hepatic cancers. Although SIRT is a well-known therapy, continuous improvement in personalised dosimetry is required to improve the treatment planning and delivery of therapy. The ability to precisely foresee, plan, and administer the ideal dose to the tumour and non-tumoral tissues, including a final validation of the dose distribution, is the primary principle of radiation. The main way for safely personalised therapy for a maximum response while respecting normal tissue tolerances is to know the true absorbed dose to tissue compartments. Recent clinical studies highlighted the significance of personalised dosimetry to make it safer and more effective. Quantification of the absorbed dose distribution is of utmost importance in SIRT 90Y to optimise the hepatocellular carcinoma (HCC) treatment. The aim of this article was to review various dosimetric approaches in quantifying the absorbed dose of tumours and healthy liver tissue in 90Y SIRT. This article also compares the capabilities of organ-level dosimetry, voxel-level dosimetry and Monte Carlo simulation in assessing the absorbed dose in organs especially liver. The quantification of absorbed dose influences 90Y SIRT tumour dosimetry, while healthy liver absorbed dose values were comparable for all investigated imaging data. Personalised dosimetry for the tumour and healthy liver parenchyma after 90Y SIRT is recommended for patient-tailored therapy with enhanced therapeutic outcomes and for the safe administration of additional treatment cycles.