8:18 AM, Abstract No. 262 - Comparison of cone beam CT angiography to pre-procedural CT or MRI for yttrium-90 hepatic dosimetry

Abstract

PurposeTo determine the difference between conventional lobar volume calculation for hepatic yttrium-90 radioembolization dosimetry planning using cone beam CT angiography compared to conventional CT lobar volume calculations.Materials and MethodsPre-procedural cross sectional imaging and mapping mesenteric angiogram on consecutive patients who underwent yttrium-90 radioembolization for primary and metastatic liver malignancy between September 2013 to September 2014 was retrospectively reviewed. All patients underwent pre-procedural imaging with computed tomography or magnetic resonance imaging. Lobar dosimetry was calculated from liver volumes using cross-sectional imaging as previously described (Salem 2006, Kennedy 2007, Lea 2014). During pre-radioembolization angiography for treatment mapping, cone beam CT angiography was performed on all patients. Cone beam CT lobar mapping was performed on a Siemens Artis DBA unit (Erlangen, Germany) by injecting the right and left hepatic arteries, sequentially, using a rate of 2 mL / minute with Isovue 300 for a volume of 24 mL. Lobar volumes were calculated by measuring the perfused liver and tumor volume. Imaging was excluded from the analysis if the entire liver could not be imaged within the cone beam CT volume or if there was significant image degradation by patient motion.Results55 patients underwent pre-radioembolization evaluation between September 2013 and September 2014. Preliminary analysis of 12 patients shows a mean lobar difference of 180.3 mL (p= 0.0505). Limitations of cone beam CT angiography include field of view not encompassing the entire volume of the liver, reflux during contrast injection, and patient motion during injection.ConclusionThere is a significant difference in hepatic lobar volumes when using conventional planning with cross-sectional imaging compared to liver perfusion volumes calculated by cone beam CT angiography. Lea has shown that calculated dosimetry does not represent administered doses. The difference may partially be corrected by cone beam CT perfusion. PurposeTo determine the difference between conventional lobar volume calculation for hepatic yttrium-90 radioembolization dosimetry planning using cone beam CT angiography compared to conventional CT lobar volume calculations. To determine the difference between conventional lobar volume calculation for hepatic yttrium-90 radioembolization dosimetry planning using cone beam CT angiography compared to conventional CT lobar volume calculations. Materials and MethodsPre-procedural cross sectional imaging and mapping mesenteric angiogram on consecutive patients who underwent yttrium-90 radioembolization for primary and metastatic liver malignancy between September 2013 to September 2014 was retrospectively reviewed. All patients underwent pre-procedural imaging with computed tomography or magnetic resonance imaging. Lobar dosimetry was calculated from liver volumes using cross-sectional imaging as previously described (Salem 2006, Kennedy 2007, Lea 2014). During pre-radioembolization angiography for treatment mapping, cone beam CT angiography was performed on all patients. Cone beam CT lobar mapping was performed on a Siemens Artis DBA unit (Erlangen, Germany) by injecting the right and left hepatic arteries, sequentially, using a rate of 2 mL / minute with Isovue 300 for a volume of 24 mL. Lobar volumes were calculated by measuring the perfused liver and tumor volume. Imaging was excluded from the analysis if the entire liver could not be imaged within the cone beam CT volume or if there was significant image degradation by patient motion. Pre-procedural cross sectional imaging and mapping mesenteric angiogram on consecutive patients who underwent yttrium-90 radioembolization for primary and metastatic liver malignancy between September 2013 to September 2014 was retrospectively reviewed. All patients underwent pre-procedural imaging with computed tomography or magnetic resonance imaging. Lobar dosimetry was calculated from liver volumes using cross-sectional imaging as previously described (Salem 2006, Kennedy 2007, Lea 2014). During pre-radioembolization angiography for treatment mapping, cone beam CT angiography was performed on all patients. Cone beam CT lobar mapping was performed on a Siemens Artis DBA unit (Erlangen, Germany) by injecting the right and left hepatic arteries, sequentially, using a rate of 2 mL / minute with Isovue 300 for a volume of 24 mL. Lobar volumes were calculated by measuring the perfused liver and tumor volume. Imaging was excluded from the analysis if the entire liver could not be imaged within the cone beam CT volume or if there was significant image degradation by patient motion. Results55 patients underwent pre-radioembolization evaluation between September 2013 and September 2014. Preliminary analysis of 12 patients shows a mean lobar difference of 180.3 mL (p= 0.0505). Limitations of cone beam CT angiography include field of view not encompassing the entire volume of the liver, reflux during contrast injection, and patient motion during injection. 55 patients underwent pre-radioembolization evaluation between September 2013 and September 2014. Preliminary analysis of 12 patients shows a mean lobar difference of 180.3 mL (p= 0.0505). Limitations of cone beam CT angiography include field of view not encompassing the entire volume of the liver, reflux during contrast injection, and patient motion during injection. ConclusionThere is a significant difference in hepatic lobar volumes when using conventional planning with cross-sectional imaging compared to liver perfusion volumes calculated by cone beam CT angiography. Lea has shown that calculated dosimetry does not represent administered doses. The difference may partially be corrected by cone beam CT perfusion. There is a significant difference in hepatic lobar volumes when using conventional planning with cross-sectional imaging compared to liver perfusion volumes calculated by cone beam CT angiography. Lea has shown that calculated dosimetry does not represent administered doses. The difference may partially be corrected by cone beam CT perfusion.