Patients cohort is composed of 50 consecutive patients both male and female with hepatic malignancies, refered to our nuclear medicine department in the process of radioembolization between January 2010- August 2015. 26 of the patients were examined with Tc99-MAA and SPECT-CT and 24 patients were examined with Tc99-MAA , SPECT-CT and PET-CT. Our study protocol was as follows:

1. Collection of anamnestic data
2. Calculation of liver tumor volume with quantification software
3. Evaluation of the liver tumor involvement
4. Evaluation of liver to lung shunt
5. Calculation dose of SIRTEX
6. Y90 imaging
7. Follow Up

The description of the various stages that the patient goes through SIRTex treatment in the department of nuclear medicine and their roll in the study is as following:

The first stage is dedicated to the evaluation of the patient's illegibility for the treatment.

1. In Angiography department
2. In Nuclear medicine department assessment of liver-lung shunting (planar images). Followed by SPECT-CT of the upper abdomen. SPECT with Low dose CT is used to identify a leak to the stomach, duodenum and mesentery, as well as to assess uptake of Tc-99m-MAA in tumor lesions. In order to increase SPECT-CT resolution and sensitivity we co-registrated SPECT-CT with diagnostic CT provided from previous contrast enhanced CT or PET-CT. In this procedure, the Low dose CT is used as bridge between diagnostic CT and the functional imaging SPECT.
3. Calculation dose of Sirtex therapy. At this stage the purpose of the study will be to investigate the added value of SPECT-CT in the estimation of Tc-99m-MAA uptake in tumor lesions.

The second stage is dedicated to the assessment Y-90-SIRTex uptake in liver tumors and to exclude extra hepatic leak. Several hours after treatment patients perform SPECT-CT using Brummshtrullung emission or PET-CT with the peak Zr-90.

At this stage , in our study, we will compare liver lesions uptake of Tc-99m-MAA in the SPECT-CT to lesions uptake of Y-90 -SIRT SPECT/PET-CT as well as to assess if SPECT-CT withTc-99m-MAA may be used as a predictor of Y-90-SIRTex uptake in liver lesion. Does SPECT-CT with Tc-99m-MAA change patient managment.

The third stage of the study is the collection and monitoring of post treatment outcome data.

Inclusion Criteria:

• 1. Age ≥ 18. 2. Patients with malignancy of the liver (metastasis or primary tumor) who were treated with Y90 SIRT and were refered to the nuclear medicine department for a PET-CT.

Exclusion Criteria:

• 1. Age < 18. 2. Pregnant woman 3. Children and legally incompetent.

patients treated with Yttrium-90 SIRT for liver malignancies