Figure 2: The following (A-H) are from a patient with neuroendocrine liver metastases who received whole liver 90Y microsphere therapy. A. Coronal view of a diagnostic CT scan used for radiation treatment planning as the source of obtaining normal liver and tumor volume data. B. Software dose calculation screenshot in coronal view. Green structures are from 99mTc-MAA SPECT. The pretreatment diagnostic CT scan was manually co- registered to the SPECT scan and the normal liver and tumor outlined on each CT axial slice. Radiation cumulative doses are represented by isodose curves overlying the liver and a small amount of adjacent right kidney, duodenum and gastric antrum. C. Axial image from pretreatment diagnostic CT scan. D. Screenshot of axial view of dose calculation software showing mostly right hepatic lobe and a portion of the caudate lobe with isodose curves overlaid. E. Coronal view obtained by 99mTc-MAA SPECT scintigraphy highlighting the heterogeneous areas of increased albumin particle deposition in tumor versus normal liver. The tumor to normal ratio was greater than 9:1 via ROI measurements. F. Bremsstrahlung SPECT imaging obtained 30 minutes after implantation of 90Y microspheres, coronal view. The count numbers and resolution are significantly less than the pretreatment MAA scintigraphy, however focal uptake in multiple tumors can be seen. G. Three-dimensional reconstruction of the pretreatment diagnostic CT scans in coronal view. This image was created by standard radiation treatment planning software for external beam therapy. This is the current method used by the authors to acquire volumetric data of normal liver and tumor for 90Y microsphere activity planning. H. Cumulative dose volume histogram of normal liver and tumor showing relative sparing of normal liver.