Cardiovascular and interventional radiology, Jan 21, 2016
The caudate lobe (CL) is impartial to the functional left and right hemi-liver and has outspoken ... more The caudate lobe (CL) is impartial to the functional left and right hemi-liver and has outspoken inter-individual differences in arterial vascularization. Unfortunately, this complexity is not specifically taken into account during radioembolization treatment (RE), potentially resulting in under- or overtreatment of the CL. The objective of this study was to evaluate the CL coverage in RE and determine the detection rate of the CL arteries on CT angiography during work-up. In all consecutive patients who underwent RE treatment between May 2012-January 2015, (99m)Tc-MAA SPECT/CT and posttreatment scans ((90)Y-bremsstrahlung SPECT/CT, (90)Y-PET/CT, or (166)Ho-SPECT/CT) were reviewed for activity in the CL. Pretreatment CT angiographies were reviewed for the visibility of the CL arteries. Eighty-two patients were treated. In 32/82 (39 %) the CL was involved. In 6/32 (19 %) patients, no activity was seen on the posttreatment scan in the CL, whereas in 40/50 (80 %) patients without CL tu...
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, Jan 23, 2016
Randomized controlled trials are investigating the benefit of hepatic radioembolization added to ... more Randomized controlled trials are investigating the benefit of hepatic radioembolization added to systemic therapy in the first/second-line treatment of patients with colorectal liver metastases (CRLM). Remarkably, administered activity may still be suboptimal, because a dose-response relationship has not been defined. The purpose of this study was to characterize the relationship between tumor absorbed dose and response after (90)Y-radioembolization treatment for CRLM. 30 patients with unresectable chemorefractory CRLM were treated with resin (90)Y-microspheres in a prospective phase II clinical trial. Tumor absorbed dose was quantified on (90)Y-PET. Metabolic tumor activity, defined as tumor lesion glycolysis (TLG*) on (18)F-FDG-PET, was measured at baseline and 1 month posttreatment. The relationship between tumor absorbed dose and posttreatment metabolic activity was assessed per metastasis, with a linear mixed effects regression model. 133 treated metastases were identified. Mea...
Journal of vascular and interventional radiology : JVIR, Jan 29, 2015
To review the safety of hepatic radioembolization (RE) in patients with high (≥ 10%) hepatopulmon... more To review the safety of hepatic radioembolization (RE) in patients with high (≥ 10%) hepatopulmonary shunt fraction (HPSF) using various prophylactic techniques. A review was conducted of 409 patients who underwent technetium 99m-labeled macroaggregated albumin scintigraphy before planned RE. Estimated pulmonary absorbed radiation doses based on scintigraphy and hepatic administered activity were calculated. Outcomes from dose reductions and adjunctive catheter-based prophylactic techniques used to reduce lung exposure were assessed. There were 80 patients with HPSF ≥ 10% who received RE treatment (41 resin microspheres for metastases, 39 glass microspheres for hepatocellular carcinoma). Resin microspheres were used in 17 patients according to consensus guideline-recommended dose reduction; 38 patients received no dose reduction because the expected lung dose was < 30 Gy. Prophylactic techniques were used in 25 patients (with expected lung dose ≤ 74 Gy), including hepatic vein ba...
Journal of Experimental & Clinical Cancer Research, 2015
Background: Liver tumors are increasingly treated with radioembolization. Here, we present first ... more Background: Liver tumors are increasingly treated with radioembolization. Here, we present first evidence of catheter design effect on particle-fluid dynamics and downstream branch targeting during microsphere administrations. Materials and methods: A total of 7 experiments were performed in a bench-top model of the hepatic arterial vasculature with recreated hemodynamics. Fluorescent microspheres and clinically used holmium microspheres were administered with a standard microcatheter (SMC) and an anti-reflux catheter (ARC) positioned at the same level along the longitudinal vessel axis. Catheter-related particle flow dynamics were analyzed by reviewing video recordings of UV-light illuminated fluorescent microsphere administrations. Downstream branch distribution was analyzed by quantification of collected microspheres in separate filters for two first-order branches. Mean deviation from a perfectly homogenous distribution (DHD) was used to compare the distribution homogeneity between catheter types.
Purpose To study the comparative short-term safety and efficacy of transcatheter arterial chemoem... more Purpose To study the comparative short-term safety and efficacy of transcatheter arterial chemoembolization (TACE) with drug-eluting LC Beads loaded with doxorubicin (DEBDOX), doxorubicin-eluting QuadraSpheres (hqTACE), and conventional TACE using ethiodized oil for superselective C-arm computed tomography (CT)-guided treatment of hepatocellular carcinoma (HCC) after the onset of drug shortages. Materials and Methods From March 2010 to March 2011, 166 patients with HCC were treated with 232 superselective TACE procedures using C-arm cone-beam CT at one institution. Patients underwent treatment depending on the availability of materials after the onset of drug shortages. Conventional TACE with doxorubicin, cisplatin, and Ethiodol was performed for 159 procedures, DEBDOX TACE was performed for 47, and hqTACE was performed for 26. Toxicity and objective response were compared at 3 months after treatment. Data were stratified for the high-risk population (Child-Pugh class B, performance...
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, Jan 23, 2015
Sodium (18)F-fluoride ((18)F-NaF) PET/CT imaging is a promising imaging technique for assessment ... more Sodium (18)F-fluoride ((18)F-NaF) PET/CT imaging is a promising imaging technique for assessment of atherosclerosis, but is hampered by a lack of validated quantification protocols. Both personal characteristics and technical factors can affect quantification of arterial (18)F-NaF uptake. This study investigated if blood activity, renal function, injected dose, circulating time, and PET/CT system affect quantification of arterial (18)F-NaF uptake. Eighty-nine healthy subjects were prospectively examined by (18)F-NaF PET/CT imaging. Arterial (18)F-NaF uptake was quantified at the level of the ascending aorta, aortic arch, descending thoracic aorta, and coronary arteries by calculating the maximum (18)F-NaF activity (NaFmax), the maximum target-to-background ratio (TBRmax/mean), and the maximum blood subtracted (18)F-NaF activity (bsNaFmax). Multivariable linear regression assessed the effect of personal characteristics and technical factors on quantification of arterial (18)F-NaF upt...
Cardiovascular and interventional radiology, Jan 12, 2015
To optimize a C-arm computed tomography (CT) protocol for radioembolization (RE), specifically fo... more To optimize a C-arm computed tomography (CT) protocol for radioembolization (RE), specifically for extrahepatic shunting and parenchymal enhancement. A prospective development study was performed per IDEAL recommendations. A literature-based protocol was applied in patients with unresectable and chemorefractory liver malignancies undergoing an angiography before radioembolization. Contrast and scan settings were adjusted stepwise and repeatedly reviewed in a consensus meeting. Afterwards, two independent raters analyzed all scans. A third rater evaluated the SPECT/CT scans as a reference standard for extrahepatic shunting and lack of target segment perfusion. Fifty scans were obtained in 29 procedures. The first protocol, using a 6 s delay and 10 s scan, showed insufficient parenchymal enhancement. In the second protocol, the delay was determined by timing parenchymal enhancement on DSA power injection (median 8 s, range 4-10 s): enhancement improved, but breathing artifacts increas...
Current anatomical classifications do not include all variants relevant for radioembolization (RE... more Current anatomical classifications do not include all variants relevant for radioembolization (RE). The purpose of this study was to assess the individual hepatic arterial configuration and segmental vascularization pattern and to develop an individualized RE treatment strategy based on an extended classification. The hepatic vascular anatomy was assessed on MDCT and DSA in patients who received a workup for RE between February 2009 and November 2012. Reconstructed MDCT studies were assessed to determine the hepatic arterial configuration (origin of every hepatic arterial branch, branching pattern and anatomical course) and the hepatic segmental vascularization territory of all branches. Aberrant hepatic arteries were defined as hepatic arterial branches that did not originate from the celiac axis/CHA/PHA. Early branching patterns were defined as hepatic arterial branches originating from the celiac axis/CHA. The hepatic arterial configuration and segmental vascularization pattern c...
European journal of nuclear medicine and molecular imaging, Jan 28, 2015
Fusion dual-tracer SPECT imaging enables physiological rather than morphological voxel-based part... more Fusion dual-tracer SPECT imaging enables physiological rather than morphological voxel-based partitioning and dosimetry for (90)Y hepatic radioembolization (RE). We evaluated its prognostic value in a large heterogeneous cohort of patients with extensive hepatic malignancy. A total of 122 patients with primary or secondary liver malignancy (18 different cell types) underwent SPECT imaging after intraarterial injection of (99m)Tc macroaggregated albumin (TcMAA) as a simulation of subsequent (90)Y microsphere distribution, followed by administration of an excess of intravenous (99m)Tc-labelled sulphur colloid (TcSC) as a biomarker for functional liver, and a second SPECT scan. TcMAA distribution was used to estimate (90)Y radiation absorbed dose in tumour (D T) and in functional liver. Laboratory and clinical follow-up were recorded for 12 weeks after RE, and radiographic responses according to (m)RECIST were evaluated at 3 and 6 months. Dose-response relationships were determined for...
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, Jan 30, 2015
Before holmium-166 ((166)Ho) radioembolization, a small batch of the same type of microspheres is... more Before holmium-166 ((166)Ho) radioembolization, a small batch of the same type of microspheres is administered as a scout dose instead of the conventional technetium-99m macroaggregated albumin ((99m)Tc-MAA). The (166)Ho scout dose provides a more accurate and precise lung shunt assessment. However, in contrast to (99m)Tc-MAA, an unintended extrahepatic deposition of this beta-emitting scout dose could inflict radiation damage, the extent of which we aimed to quantify in this study. All patients treated with radioembolization in our institute between January 2011 and March 2014 were reviewed. Of the extrahepatic depositions of (99m)Tc-MAA on single-photon emission computed tomography (SPECT), the amount and volume were measured. These were used to calculate the theoretical absorbed dose in case a (166)Ho scout dose had been used. The extrahepatic activity was measured as the sum of all voxels of the deposition. Volumes were measured using a threshold technique including all voxels f...
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, Jan 7, 2015
Radioembolization is an established treatment modality that has been subjected to many improvemen... more Radioembolization is an established treatment modality that has been subjected to many improvements over the last decade. Developments are occurring at a high pace, affecting patient selection and treatment. The aim of this CME review is therefore to provide an overview of current practice, with a focus on recent developments in the field of radioembolization. Several practical issues and recommendations in the application of radioembolization will be discussed, ranging from patient selection to treatment response and future applications.
Patients with malignant tumors originating from the biliary tree have a poor prognosis, since onl... more Patients with malignant tumors originating from the biliary tree have a poor prognosis, since only a minority of tumors can be resected and most palliative regimens have shown only limited success. We present two patients with unresectable tumors, who were treated with trans-arterial (90)yttrium radioembolization: a patient with an infiltrating gallbladder carcinoma and a patient with an extensive intrahepatic cholangiocarcinoma. In both cases the treatment was technically feasible, effective in controlling tumor growth, and without significant side effects. In conclusion, the presented cases demonstrate the potential of (90)yttrium radioembolization as a palliative treatment option for malignant tumors of the biliary tree.
Journal of vascular and interventional radiology : JVIR, 2014
To assess the radiation exposure to individuals coming from patients after treatment with holmium... more To assess the radiation exposure to individuals coming from patients after treatment with holmium-166 ((166)Ho) microspheres. Holmium-166 radioembolization (RE) with escalating whole-liver doses of 20 Gy, 40 Gy, 60 Gy, and 80 Gy was administered to 15 patients. Exposure rates (μSv/h) from patients were measured at 1.0 m distance from a lateral and frontal position at 0, 3, 6, 24, and 48 hours after infusion. The total effective dose equivalent (TEDE) to a maximally exposed contact was calculated in accordance with guidelines of the U.S. Nuclear Regulatory Commission (NRC). Results were extrapolated to a whole-liver dose of 60 Gy used in future treatments. The median exposure rate at discharge, 48 hours after infusion, measured from a lateral position was 26 μSv/h (range, 7-45 μSv/h). Extrapolated to a whole-liver dose of 60 Gy, none of the exposure rates for the NRC contact scenario, at any time, frontal or lateral, would lead to a TEDE > 5 mSv; all patients may be released direc...
European journal of nuclear medicine and molecular imaging, 2014
Radiation pneumonitis is a rare but serious complication of radioembolic therapy of liver tumours... more Radiation pneumonitis is a rare but serious complication of radioembolic therapy of liver tumours. Estimation of the mean absorbed dose to the lungs based on pretreatment diagnostic (99m)Tc-macroaggregated albumin ((99m)Tc-MAA) imaging should prevent this, with administered activities adjusted accordingly. The accuracy of (99m)Tc-MAA-based lung absorbed dose estimates was evaluated and compared to absorbed dose estimates based on pretreatment diagnostic (166)Ho-microsphere imaging and to the actual lung absorbed doses after (166)Ho radioembolization. This prospective clinical study included 14 patients with chemorefractory, unresectable liver metastases treated with (166)Ho radioembolization. (99m)Tc-MAA-based and (166)Ho-microsphere-based estimation of lung absorbed doses was performed on pretreatment diagnostic planar scintigraphic and SPECT/CT images. The clinical analysis was preceded by an anthropomorphic torso phantom study with simulated lung shunt fractions of 0 to 30 % to d...
Cardiovascular and interventional radiology, Jan 21, 2016
The caudate lobe (CL) is impartial to the functional left and right hemi-liver and has outspoken ... more The caudate lobe (CL) is impartial to the functional left and right hemi-liver and has outspoken inter-individual differences in arterial vascularization. Unfortunately, this complexity is not specifically taken into account during radioembolization treatment (RE), potentially resulting in under- or overtreatment of the CL. The objective of this study was to evaluate the CL coverage in RE and determine the detection rate of the CL arteries on CT angiography during work-up. In all consecutive patients who underwent RE treatment between May 2012-January 2015, (99m)Tc-MAA SPECT/CT and posttreatment scans ((90)Y-bremsstrahlung SPECT/CT, (90)Y-PET/CT, or (166)Ho-SPECT/CT) were reviewed for activity in the CL. Pretreatment CT angiographies were reviewed for the visibility of the CL arteries. Eighty-two patients were treated. In 32/82 (39 %) the CL was involved. In 6/32 (19 %) patients, no activity was seen on the posttreatment scan in the CL, whereas in 40/50 (80 %) patients without CL tu...
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, Jan 23, 2016
Randomized controlled trials are investigating the benefit of hepatic radioembolization added to ... more Randomized controlled trials are investigating the benefit of hepatic radioembolization added to systemic therapy in the first/second-line treatment of patients with colorectal liver metastases (CRLM). Remarkably, administered activity may still be suboptimal, because a dose-response relationship has not been defined. The purpose of this study was to characterize the relationship between tumor absorbed dose and response after (90)Y-radioembolization treatment for CRLM. 30 patients with unresectable chemorefractory CRLM were treated with resin (90)Y-microspheres in a prospective phase II clinical trial. Tumor absorbed dose was quantified on (90)Y-PET. Metabolic tumor activity, defined as tumor lesion glycolysis (TLG*) on (18)F-FDG-PET, was measured at baseline and 1 month posttreatment. The relationship between tumor absorbed dose and posttreatment metabolic activity was assessed per metastasis, with a linear mixed effects regression model. 133 treated metastases were identified. Mea...
Journal of vascular and interventional radiology : JVIR, Jan 29, 2015
To review the safety of hepatic radioembolization (RE) in patients with high (≥ 10%) hepatopulmon... more To review the safety of hepatic radioembolization (RE) in patients with high (≥ 10%) hepatopulmonary shunt fraction (HPSF) using various prophylactic techniques. A review was conducted of 409 patients who underwent technetium 99m-labeled macroaggregated albumin scintigraphy before planned RE. Estimated pulmonary absorbed radiation doses based on scintigraphy and hepatic administered activity were calculated. Outcomes from dose reductions and adjunctive catheter-based prophylactic techniques used to reduce lung exposure were assessed. There were 80 patients with HPSF ≥ 10% who received RE treatment (41 resin microspheres for metastases, 39 glass microspheres for hepatocellular carcinoma). Resin microspheres were used in 17 patients according to consensus guideline-recommended dose reduction; 38 patients received no dose reduction because the expected lung dose was < 30 Gy. Prophylactic techniques were used in 25 patients (with expected lung dose ≤ 74 Gy), including hepatic vein ba...
Journal of Experimental & Clinical Cancer Research, 2015
Background: Liver tumors are increasingly treated with radioembolization. Here, we present first ... more Background: Liver tumors are increasingly treated with radioembolization. Here, we present first evidence of catheter design effect on particle-fluid dynamics and downstream branch targeting during microsphere administrations. Materials and methods: A total of 7 experiments were performed in a bench-top model of the hepatic arterial vasculature with recreated hemodynamics. Fluorescent microspheres and clinically used holmium microspheres were administered with a standard microcatheter (SMC) and an anti-reflux catheter (ARC) positioned at the same level along the longitudinal vessel axis. Catheter-related particle flow dynamics were analyzed by reviewing video recordings of UV-light illuminated fluorescent microsphere administrations. Downstream branch distribution was analyzed by quantification of collected microspheres in separate filters for two first-order branches. Mean deviation from a perfectly homogenous distribution (DHD) was used to compare the distribution homogeneity between catheter types.
Purpose To study the comparative short-term safety and efficacy of transcatheter arterial chemoem... more Purpose To study the comparative short-term safety and efficacy of transcatheter arterial chemoembolization (TACE) with drug-eluting LC Beads loaded with doxorubicin (DEBDOX), doxorubicin-eluting QuadraSpheres (hqTACE), and conventional TACE using ethiodized oil for superselective C-arm computed tomography (CT)-guided treatment of hepatocellular carcinoma (HCC) after the onset of drug shortages. Materials and Methods From March 2010 to March 2011, 166 patients with HCC were treated with 232 superselective TACE procedures using C-arm cone-beam CT at one institution. Patients underwent treatment depending on the availability of materials after the onset of drug shortages. Conventional TACE with doxorubicin, cisplatin, and Ethiodol was performed for 159 procedures, DEBDOX TACE was performed for 47, and hqTACE was performed for 26. Toxicity and objective response were compared at 3 months after treatment. Data were stratified for the high-risk population (Child-Pugh class B, performance...
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, Jan 23, 2015
Sodium (18)F-fluoride ((18)F-NaF) PET/CT imaging is a promising imaging technique for assessment ... more Sodium (18)F-fluoride ((18)F-NaF) PET/CT imaging is a promising imaging technique for assessment of atherosclerosis, but is hampered by a lack of validated quantification protocols. Both personal characteristics and technical factors can affect quantification of arterial (18)F-NaF uptake. This study investigated if blood activity, renal function, injected dose, circulating time, and PET/CT system affect quantification of arterial (18)F-NaF uptake. Eighty-nine healthy subjects were prospectively examined by (18)F-NaF PET/CT imaging. Arterial (18)F-NaF uptake was quantified at the level of the ascending aorta, aortic arch, descending thoracic aorta, and coronary arteries by calculating the maximum (18)F-NaF activity (NaFmax), the maximum target-to-background ratio (TBRmax/mean), and the maximum blood subtracted (18)F-NaF activity (bsNaFmax). Multivariable linear regression assessed the effect of personal characteristics and technical factors on quantification of arterial (18)F-NaF upt...
Cardiovascular and interventional radiology, Jan 12, 2015
To optimize a C-arm computed tomography (CT) protocol for radioembolization (RE), specifically fo... more To optimize a C-arm computed tomography (CT) protocol for radioembolization (RE), specifically for extrahepatic shunting and parenchymal enhancement. A prospective development study was performed per IDEAL recommendations. A literature-based protocol was applied in patients with unresectable and chemorefractory liver malignancies undergoing an angiography before radioembolization. Contrast and scan settings were adjusted stepwise and repeatedly reviewed in a consensus meeting. Afterwards, two independent raters analyzed all scans. A third rater evaluated the SPECT/CT scans as a reference standard for extrahepatic shunting and lack of target segment perfusion. Fifty scans were obtained in 29 procedures. The first protocol, using a 6 s delay and 10 s scan, showed insufficient parenchymal enhancement. In the second protocol, the delay was determined by timing parenchymal enhancement on DSA power injection (median 8 s, range 4-10 s): enhancement improved, but breathing artifacts increas...
Current anatomical classifications do not include all variants relevant for radioembolization (RE... more Current anatomical classifications do not include all variants relevant for radioembolization (RE). The purpose of this study was to assess the individual hepatic arterial configuration and segmental vascularization pattern and to develop an individualized RE treatment strategy based on an extended classification. The hepatic vascular anatomy was assessed on MDCT and DSA in patients who received a workup for RE between February 2009 and November 2012. Reconstructed MDCT studies were assessed to determine the hepatic arterial configuration (origin of every hepatic arterial branch, branching pattern and anatomical course) and the hepatic segmental vascularization territory of all branches. Aberrant hepatic arteries were defined as hepatic arterial branches that did not originate from the celiac axis/CHA/PHA. Early branching patterns were defined as hepatic arterial branches originating from the celiac axis/CHA. The hepatic arterial configuration and segmental vascularization pattern c...
European journal of nuclear medicine and molecular imaging, Jan 28, 2015
Fusion dual-tracer SPECT imaging enables physiological rather than morphological voxel-based part... more Fusion dual-tracer SPECT imaging enables physiological rather than morphological voxel-based partitioning and dosimetry for (90)Y hepatic radioembolization (RE). We evaluated its prognostic value in a large heterogeneous cohort of patients with extensive hepatic malignancy. A total of 122 patients with primary or secondary liver malignancy (18 different cell types) underwent SPECT imaging after intraarterial injection of (99m)Tc macroaggregated albumin (TcMAA) as a simulation of subsequent (90)Y microsphere distribution, followed by administration of an excess of intravenous (99m)Tc-labelled sulphur colloid (TcSC) as a biomarker for functional liver, and a second SPECT scan. TcMAA distribution was used to estimate (90)Y radiation absorbed dose in tumour (D T) and in functional liver. Laboratory and clinical follow-up were recorded for 12 weeks after RE, and radiographic responses according to (m)RECIST were evaluated at 3 and 6 months. Dose-response relationships were determined for...
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, Jan 30, 2015
Before holmium-166 ((166)Ho) radioembolization, a small batch of the same type of microspheres is... more Before holmium-166 ((166)Ho) radioembolization, a small batch of the same type of microspheres is administered as a scout dose instead of the conventional technetium-99m macroaggregated albumin ((99m)Tc-MAA). The (166)Ho scout dose provides a more accurate and precise lung shunt assessment. However, in contrast to (99m)Tc-MAA, an unintended extrahepatic deposition of this beta-emitting scout dose could inflict radiation damage, the extent of which we aimed to quantify in this study. All patients treated with radioembolization in our institute between January 2011 and March 2014 were reviewed. Of the extrahepatic depositions of (99m)Tc-MAA on single-photon emission computed tomography (SPECT), the amount and volume were measured. These were used to calculate the theoretical absorbed dose in case a (166)Ho scout dose had been used. The extrahepatic activity was measured as the sum of all voxels of the deposition. Volumes were measured using a threshold technique including all voxels f...
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, Jan 7, 2015
Radioembolization is an established treatment modality that has been subjected to many improvemen... more Radioembolization is an established treatment modality that has been subjected to many improvements over the last decade. Developments are occurring at a high pace, affecting patient selection and treatment. The aim of this CME review is therefore to provide an overview of current practice, with a focus on recent developments in the field of radioembolization. Several practical issues and recommendations in the application of radioembolization will be discussed, ranging from patient selection to treatment response and future applications.
Patients with malignant tumors originating from the biliary tree have a poor prognosis, since onl... more Patients with malignant tumors originating from the biliary tree have a poor prognosis, since only a minority of tumors can be resected and most palliative regimens have shown only limited success. We present two patients with unresectable tumors, who were treated with trans-arterial (90)yttrium radioembolization: a patient with an infiltrating gallbladder carcinoma and a patient with an extensive intrahepatic cholangiocarcinoma. In both cases the treatment was technically feasible, effective in controlling tumor growth, and without significant side effects. In conclusion, the presented cases demonstrate the potential of (90)yttrium radioembolization as a palliative treatment option for malignant tumors of the biliary tree.
Journal of vascular and interventional radiology : JVIR, 2014
To assess the radiation exposure to individuals coming from patients after treatment with holmium... more To assess the radiation exposure to individuals coming from patients after treatment with holmium-166 ((166)Ho) microspheres. Holmium-166 radioembolization (RE) with escalating whole-liver doses of 20 Gy, 40 Gy, 60 Gy, and 80 Gy was administered to 15 patients. Exposure rates (μSv/h) from patients were measured at 1.0 m distance from a lateral and frontal position at 0, 3, 6, 24, and 48 hours after infusion. The total effective dose equivalent (TEDE) to a maximally exposed contact was calculated in accordance with guidelines of the U.S. Nuclear Regulatory Commission (NRC). Results were extrapolated to a whole-liver dose of 60 Gy used in future treatments. The median exposure rate at discharge, 48 hours after infusion, measured from a lateral position was 26 μSv/h (range, 7-45 μSv/h). Extrapolated to a whole-liver dose of 60 Gy, none of the exposure rates for the NRC contact scenario, at any time, frontal or lateral, would lead to a TEDE > 5 mSv; all patients may be released direc...
European journal of nuclear medicine and molecular imaging, 2014
Radiation pneumonitis is a rare but serious complication of radioembolic therapy of liver tumours... more Radiation pneumonitis is a rare but serious complication of radioembolic therapy of liver tumours. Estimation of the mean absorbed dose to the lungs based on pretreatment diagnostic (99m)Tc-macroaggregated albumin ((99m)Tc-MAA) imaging should prevent this, with administered activities adjusted accordingly. The accuracy of (99m)Tc-MAA-based lung absorbed dose estimates was evaluated and compared to absorbed dose estimates based on pretreatment diagnostic (166)Ho-microsphere imaging and to the actual lung absorbed doses after (166)Ho radioembolization. This prospective clinical study included 14 patients with chemorefractory, unresectable liver metastases treated with (166)Ho radioembolization. (99m)Tc-MAA-based and (166)Ho-microsphere-based estimation of lung absorbed doses was performed on pretreatment diagnostic planar scintigraphic and SPECT/CT images. The clinical analysis was preceded by an anthropomorphic torso phantom study with simulated lung shunt fractions of 0 to 30 % to d...
Uploads
Papers by Marnix Lam