Liver Selective Internal Radiation Therapy with 90Y resin microspheres: Comparison between pre-treatment activity calculation methods

Yttrium-90 hepatic radioembolization: clinical review and current techniques in interventional radiology and personalized dosimetry

“…On the other hand, activities prescribed by the partition model were shown to correlate with T/N ratios and percentage tumour involvement. 16 Another recent study by Lam et al 17 involving 45 patients with colorectal liver metastasis did not show correlation between activities prescribed by the BSA method and absorbed doses averaged across the whole liver. All of these observations are not surprising given the semi-empirical nature of the BSA method because its formularism sacrifices personalization in favour of simplicity.…”

Radioembolization in Colorectal Metastases: A Review

“…26,29 Several studies have been performed to evaluate the BSA method and its correlation to absorbed doses. 29,36 In a study of 45 patients with hepatic colorectal metastasis who underwent resin microspheres treatment, there was no correlation between the prescribed activity using BSA method and doses absorbed by the liver. The authors recommended use of a methodology based on liver volume rather than BSA for calculation of the prescribed dose.…”

A review of 3D image-based dosimetry, technical considerations and emerging perspectives in 90Y microsphere therapy

“…There is a further reduction in LSF using SPECT whereby volumes of interest are used instead of planar regions. It has also recently been shown that without CT attenuation correction (AC), the LSF can be overestimated by up to 65% on average of 26 patients receiving RMS treatment, and without AC would have resulted in reduced MS activity for 7 patients and excluded 1 from treatment entirely [55].…”

“…Although it has been noted that the PM would be the preferred method of 90 Y-RE for every patient [55,56], its main drawbacks are the reliance on segmentation of tumour/non-tumour for activity determination and dosimetry purposes, and the assumption of concordance between the MAA (from which the TN ratio is calculated) and MS distribution. This assumed equivalency is a fact much disputed by recent studies, especially in liver metastases [57,58] and is described further below.…”

“…A recent study compared activity planning and dosimetry in 26 patients with RMS using 4 models (BSA, empirical and PM) showing that maximum differences in injected activities between BSA and PM methods vary from 123%-417% [55]. Although it has been noted that the PM would be the preferred method of 90 Y-RE for every patient [55,56], its main drawbacks are the reliance on segmentation of tumour/non-tumour for activity determination and dosimetry purposes, and the assumption of concordance between the MAA (from which the TN ratio is calculated) and MS distribution.…”