PURPOSE In Yttrium-90 (90Y) radioembolization, non-target embolization (NTE) to the stomach or sm... more PURPOSE In Yttrium-90 (90Y) radioembolization, non-target embolization (NTE) to the stomach or small bowel can result in ulceration, a rare but difficult to manage clinical complication. However, dosimetric thresholds for toxicity to these tissues from radioembolization have never been evaluated in a controlled setting. We performed an analysis of the effect of 90Y radioembolization in a porcine model at different absorbed-dose endpoints. METHODS Under approval of the University of Tennessee IACUC, 6 female pigs were included in this study. Animals underwent transfemoral angiography and infusion of calibrated dosages of 90Y resin microspheres into arteries supplying part of the gastric wall. A 99mTc-MAA simulation study was performed first to determine perfused tissue volume for treatment planning along with contrast-enhanced CT. The pigs were monitored for side effects for 9 weeks, after which time they were euthanized and their upper gastrointestinal tracts were harvested for analysis. RESULTS 90Y radioembolization was infused resulting in average absorbed doses of between 35.5 and 91.9 Gy to the gastric wall. No animal exhibited any signs of pain or gastrointestinal distress through the duration of the study. Excised tissue showed 1-2 small (<3.0 cm2) healed or healing superficial gastric lesions in 5 out of 6 animals. Histologic analysis demonstrated that lesion location was superficial to areas of abnormally high microsphere deposition. An analysis of microsphere deposition patterns within the gastric wall indicated a high preference for submucosal deposition. Dosimetric evaluation at the luminal mucosa performed based on microsphere deposition patterns confirmed that 90Y dosimetry techniques conventionally used in hepatic dosimetry provide a reasonable estimate of absorbed dose. CONCLUSION The upper gastrointestinal tract may be less sensitive to 90Y radioembolization than previously thought. Lack of charged-particle equilibrium at the luminal mucosa may contribute to decreased toxicity of 90Y radioembolization compared to external-beam radiation therapy in gastrointestinal tissue. This project was supported by SIRTex Medical Ltd.
Journal of vascular and interventional radiology : JVIR, 2016
To evaluate feasibility of left gastric artery (LGA) yttrium-90 ((90)Y) radioembolization as pote... more To evaluate feasibility of left gastric artery (LGA) yttrium-90 ((90)Y) radioembolization as potential treatment for obesity in a porcine model. This study included 8 young female pigs (12-13 weeks, 21.8-28.1 kg). Six animals received infusions of (90)Y resin microspheres (46.3-105.1 MBq) into the main LGA and the gastric artery arising from the splenic artery. Animal weight and serum ghrelin were measured before treatment and weekly thereafter. Animals were euthanized 69-74 days after treatment, and histologic analyses of mucosal integrity and ghrelin immunoreactive cell density were performed. Superficial mucosal ulcerations < 3.0 cm(2) were noted in 5 of 6 treated animals. Ghrelin immunoreactive cell density was significantly lower in treated versus untreated animals in the stomach fundus (13.5 vs 34.8, P < .05) and stomach body (11.2 vs 19.8, P < .05). Treated animals gained less weight than untreated animals over the study duration (40.2 kg ± 5.4 vs 54.7 kg ± 6.5, P = ...
Journal of Vascular and Interventional Radiology, 2016
Purpose: Bariatric arterial embolization (BAE) has been shown to decrease weight gain and alter h... more Purpose: Bariatric arterial embolization (BAE) has been shown to decrease weight gain and alter hunger and satiety hormones in animal models. However, quantitative evaluation of changes in the perfusion state in the fundus postembolization has not yet been established. The aim of this study is to describe a new technique to measure and analyze the post-embolization effects on blood volume in the porcine animal model of BAE. Materials: BAE was performed in four juvenile swine. The fundal arteries were embolized with 100-300μm Embospheres (Merit Medical) to stasis. C-arm CTs (8s DSA, 210°rotation, 0.5°/step, AXIOM Artis Zee; Siemens Healthcare) were acquired with an IA celiac injection protocol (20-25% iohexal @ 4cc/s for 48cc, with 2/3s manual x-ray delay) prior to BAE and repeated immediately after BAE and at 16 weeks post-BAE. C-arm CTs were then reconstructed using a specialized reconstruction algorithm that automatically detects the arterial input function to create parenchymal blood volume (PBV) maps (Syngo DynaPBV Body; Siemens Healthcare). PBV maps were evaluated qualitatively and quantitatively by placing regions of interest in the PBV maps (Siemens syngo X workstation) in 6 sectors encompassing the fundus, body, and antrum of the stomach. Statistical significance was determined by comparing between time points and animals using analysis of variance with repeated measures. Results: Immediately after BAE, PBV was visually decreased in fundal regions. PBV (measured as ml/1000 ml tissue) decreased post-embolization (from 32.9±1.08 to 18.1±1.08) and did not fully recover at 4 months post-embolization (19.4 ±1.18). Because of different degrees of regional embolization, no distinct pattern of decreased blood volume was demonstrated by sector in the limited number of animal studies. Conclusions: The c-arm CT PBV imaging technique can provide a quantitative assessment of the effects of BAE in porcine animal model. Current data suggests perfusion may be modulated long-term post-embolization. This technique may provide a tool by which variables in BAE (bead size, % of fundus embolized, etc.) can be assessed in a quantitative fashion.
Series in Medical Physics and Biomedical Engineering, 2011
... Radiology, 258, 182–191, 2011. Barnett, BP, J. Ruiz-Cabello, P. Hota, MJ Shamblott, C. Lauzon... more ... Radiology, 258, 182–191, 2011. Barnett, BP, J. Ruiz-Cabello, P. Hota, MJ Shamblott, C. Lauzon, P. Walczak, WD Gilson, VP Chacko, DL Kraitchman, A. Arepally, JWM Bulte. ... Kraitchman, DL, AW Heldman, E. Atalar, LC Amado, BJ Martin, MF Pittenger, JM Hare, and JW Bulte. ...
Feasibility of in vivo transvenous intravascular magnetic resonance (MR) imaging of the human art... more Feasibility of in vivo transvenous intravascular magnetic resonance (MR) imaging of the human arterial wall was determined. All subjects provided written informed consent, and institutional review board approved the study. Six arteries in six patients were imaged with a guidewire placed in the iliac vein (n = 5) or left renal vein (n = 1). Pre- and postcontrast T1-weighted and T2-weighted transvenous MR imaging were performed. An atherosclerotic plaque with a fibrous cap was identified on 27 (42%) of 64 images of veins without stents; intimal hyperplasia in a renal artery with a stent was identified on 12 images. Contrast-to-noise ratios (CNRs) on arterial wall postcontrast T1-weighted images were superior to those on images obtained with other sequences (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .001), and the postcontrast images demonstrated the greatest number of plaques with a low-signal intensity core and fibrous cap. Preliminary results show that transvenous MR imaging is feasible for high-spatial-resolution imaging of the arterial wall and atherosclerotic plaque. Postcontrast T1-weighted imaging affords greatest CNR for the arterial wall.
Journal of Vascular and Interventional Radiology, 2008
All the experiments of this study were approved by an institutional animal care and use committee... more All the experiments of this study were approved by an institutional animal care and use committee. VX2 carcinoma was grown in livers of 30 rabbits. In 20 rabbits, AS 2 O 3 (4 mg/kg) was administered through the hepatic artery (nϭ10, group 1) or ear vein (nϭ10, group 2) 30 minutes before RF ablation (125 mA Ϯ 35; 90°C Ϯ 5°C). As a control group, 10 rabbits were treated with RF ablation alone. RF was intentionally applied to peripheral margin of the tumor so that ablation can cover the tumor and adjacent hepatic parenchyma. Coagulation areas of the tumor and adjacent parenchyma of the three groups were compared with Kruskal-Wallis and Mann-Whitney U-test. RESULTS: Overall coagulation area (including the tumor and adjacent parenchyma) measured 139.0 Ϯ 27.4 mm 2 in group 1, 104.6 Ϯ 32.3 in group 2, and 72.9 Ϯ 18.3 in the control group (p Ͻ 0.04). The coagulation area of the tumor was significantly larger in group 1 (91.5 Ϯ 24.0 mm 2) than group 2 (54.5 Ϯ 30.1, pϭ0.02) and the control group (49.8 Ϯ 24.3, p Ͻ 0.01). The ratios of the coagulated tumor area to the coagulated hepatic parenchyma were 2.2 Ϯ 1.2 in group 1, 1.2 Ϯ 0.9 in group 2, and 1.0 Ϯ 0.4 in the control group (p Ͻ 0.03). CONCLUSION: RF-induced coagulation area can be increased by intraarterial or intravenous administration of AS 2 O 3. Intraarterial administration of AS 2 O 3 may be helpful for selective coagulation of the tumor.
Wie reagiert unser Geschmackssinn auf süß oder umami schmeckende Stoffe? T. Hofmann et al. stelle... more Wie reagiert unser Geschmackssinn auf süß oder umami schmeckende Stoffe? T. Hofmann et al. stellen im Aufsatz auf S. 2268 ff. Stoffe vor, die diese Geschmackseindrücke hervorrufen, und diskutieren die Aktivierung der Geschmacksrezeptoren und die ...
PURPOSE In Yttrium-90 (90Y) radioembolization, non-target embolization (NTE) to the stomach or sm... more PURPOSE In Yttrium-90 (90Y) radioembolization, non-target embolization (NTE) to the stomach or small bowel can result in ulceration, a rare but difficult to manage clinical complication. However, dosimetric thresholds for toxicity to these tissues from radioembolization have never been evaluated in a controlled setting. We performed an analysis of the effect of 90Y radioembolization in a porcine model at different absorbed-dose endpoints. METHODS Under approval of the University of Tennessee IACUC, 6 female pigs were included in this study. Animals underwent transfemoral angiography and infusion of calibrated dosages of 90Y resin microspheres into arteries supplying part of the gastric wall. A 99mTc-MAA simulation study was performed first to determine perfused tissue volume for treatment planning along with contrast-enhanced CT. The pigs were monitored for side effects for 9 weeks, after which time they were euthanized and their upper gastrointestinal tracts were harvested for analysis. RESULTS 90Y radioembolization was infused resulting in average absorbed doses of between 35.5 and 91.9 Gy to the gastric wall. No animal exhibited any signs of pain or gastrointestinal distress through the duration of the study. Excised tissue showed 1-2 small (<3.0 cm2) healed or healing superficial gastric lesions in 5 out of 6 animals. Histologic analysis demonstrated that lesion location was superficial to areas of abnormally high microsphere deposition. An analysis of microsphere deposition patterns within the gastric wall indicated a high preference for submucosal deposition. Dosimetric evaluation at the luminal mucosa performed based on microsphere deposition patterns confirmed that 90Y dosimetry techniques conventionally used in hepatic dosimetry provide a reasonable estimate of absorbed dose. CONCLUSION The upper gastrointestinal tract may be less sensitive to 90Y radioembolization than previously thought. Lack of charged-particle equilibrium at the luminal mucosa may contribute to decreased toxicity of 90Y radioembolization compared to external-beam radiation therapy in gastrointestinal tissue. This project was supported by SIRTex Medical Ltd.
Journal of vascular and interventional radiology : JVIR, 2016
To evaluate feasibility of left gastric artery (LGA) yttrium-90 ((90)Y) radioembolization as pote... more To evaluate feasibility of left gastric artery (LGA) yttrium-90 ((90)Y) radioembolization as potential treatment for obesity in a porcine model. This study included 8 young female pigs (12-13 weeks, 21.8-28.1 kg). Six animals received infusions of (90)Y resin microspheres (46.3-105.1 MBq) into the main LGA and the gastric artery arising from the splenic artery. Animal weight and serum ghrelin were measured before treatment and weekly thereafter. Animals were euthanized 69-74 days after treatment, and histologic analyses of mucosal integrity and ghrelin immunoreactive cell density were performed. Superficial mucosal ulcerations < 3.0 cm(2) were noted in 5 of 6 treated animals. Ghrelin immunoreactive cell density was significantly lower in treated versus untreated animals in the stomach fundus (13.5 vs 34.8, P < .05) and stomach body (11.2 vs 19.8, P < .05). Treated animals gained less weight than untreated animals over the study duration (40.2 kg ± 5.4 vs 54.7 kg ± 6.5, P = ...
Journal of Vascular and Interventional Radiology, 2016
Purpose: Bariatric arterial embolization (BAE) has been shown to decrease weight gain and alter h... more Purpose: Bariatric arterial embolization (BAE) has been shown to decrease weight gain and alter hunger and satiety hormones in animal models. However, quantitative evaluation of changes in the perfusion state in the fundus postembolization has not yet been established. The aim of this study is to describe a new technique to measure and analyze the post-embolization effects on blood volume in the porcine animal model of BAE. Materials: BAE was performed in four juvenile swine. The fundal arteries were embolized with 100-300μm Embospheres (Merit Medical) to stasis. C-arm CTs (8s DSA, 210°rotation, 0.5°/step, AXIOM Artis Zee; Siemens Healthcare) were acquired with an IA celiac injection protocol (20-25% iohexal @ 4cc/s for 48cc, with 2/3s manual x-ray delay) prior to BAE and repeated immediately after BAE and at 16 weeks post-BAE. C-arm CTs were then reconstructed using a specialized reconstruction algorithm that automatically detects the arterial input function to create parenchymal blood volume (PBV) maps (Syngo DynaPBV Body; Siemens Healthcare). PBV maps were evaluated qualitatively and quantitatively by placing regions of interest in the PBV maps (Siemens syngo X workstation) in 6 sectors encompassing the fundus, body, and antrum of the stomach. Statistical significance was determined by comparing between time points and animals using analysis of variance with repeated measures. Results: Immediately after BAE, PBV was visually decreased in fundal regions. PBV (measured as ml/1000 ml tissue) decreased post-embolization (from 32.9±1.08 to 18.1±1.08) and did not fully recover at 4 months post-embolization (19.4 ±1.18). Because of different degrees of regional embolization, no distinct pattern of decreased blood volume was demonstrated by sector in the limited number of animal studies. Conclusions: The c-arm CT PBV imaging technique can provide a quantitative assessment of the effects of BAE in porcine animal model. Current data suggests perfusion may be modulated long-term post-embolization. This technique may provide a tool by which variables in BAE (bead size, % of fundus embolized, etc.) can be assessed in a quantitative fashion.
Series in Medical Physics and Biomedical Engineering, 2011
... Radiology, 258, 182–191, 2011. Barnett, BP, J. Ruiz-Cabello, P. Hota, MJ Shamblott, C. Lauzon... more ... Radiology, 258, 182–191, 2011. Barnett, BP, J. Ruiz-Cabello, P. Hota, MJ Shamblott, C. Lauzon, P. Walczak, WD Gilson, VP Chacko, DL Kraitchman, A. Arepally, JWM Bulte. ... Kraitchman, DL, AW Heldman, E. Atalar, LC Amado, BJ Martin, MF Pittenger, JM Hare, and JW Bulte. ...
Feasibility of in vivo transvenous intravascular magnetic resonance (MR) imaging of the human art... more Feasibility of in vivo transvenous intravascular magnetic resonance (MR) imaging of the human arterial wall was determined. All subjects provided written informed consent, and institutional review board approved the study. Six arteries in six patients were imaged with a guidewire placed in the iliac vein (n = 5) or left renal vein (n = 1). Pre- and postcontrast T1-weighted and T2-weighted transvenous MR imaging were performed. An atherosclerotic plaque with a fibrous cap was identified on 27 (42%) of 64 images of veins without stents; intimal hyperplasia in a renal artery with a stent was identified on 12 images. Contrast-to-noise ratios (CNRs) on arterial wall postcontrast T1-weighted images were superior to those on images obtained with other sequences (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .001), and the postcontrast images demonstrated the greatest number of plaques with a low-signal intensity core and fibrous cap. Preliminary results show that transvenous MR imaging is feasible for high-spatial-resolution imaging of the arterial wall and atherosclerotic plaque. Postcontrast T1-weighted imaging affords greatest CNR for the arterial wall.
Journal of Vascular and Interventional Radiology, 2008
All the experiments of this study were approved by an institutional animal care and use committee... more All the experiments of this study were approved by an institutional animal care and use committee. VX2 carcinoma was grown in livers of 30 rabbits. In 20 rabbits, AS 2 O 3 (4 mg/kg) was administered through the hepatic artery (nϭ10, group 1) or ear vein (nϭ10, group 2) 30 minutes before RF ablation (125 mA Ϯ 35; 90°C Ϯ 5°C). As a control group, 10 rabbits were treated with RF ablation alone. RF was intentionally applied to peripheral margin of the tumor so that ablation can cover the tumor and adjacent hepatic parenchyma. Coagulation areas of the tumor and adjacent parenchyma of the three groups were compared with Kruskal-Wallis and Mann-Whitney U-test. RESULTS: Overall coagulation area (including the tumor and adjacent parenchyma) measured 139.0 Ϯ 27.4 mm 2 in group 1, 104.6 Ϯ 32.3 in group 2, and 72.9 Ϯ 18.3 in the control group (p Ͻ 0.04). The coagulation area of the tumor was significantly larger in group 1 (91.5 Ϯ 24.0 mm 2) than group 2 (54.5 Ϯ 30.1, pϭ0.02) and the control group (49.8 Ϯ 24.3, p Ͻ 0.01). The ratios of the coagulated tumor area to the coagulated hepatic parenchyma were 2.2 Ϯ 1.2 in group 1, 1.2 Ϯ 0.9 in group 2, and 1.0 Ϯ 0.4 in the control group (p Ͻ 0.03). CONCLUSION: RF-induced coagulation area can be increased by intraarterial or intravenous administration of AS 2 O 3. Intraarterial administration of AS 2 O 3 may be helpful for selective coagulation of the tumor.
Wie reagiert unser Geschmackssinn auf süß oder umami schmeckende Stoffe? T. Hofmann et al. stelle... more Wie reagiert unser Geschmackssinn auf süß oder umami schmeckende Stoffe? T. Hofmann et al. stellen im Aufsatz auf S. 2268 ff. Stoffe vor, die diese Geschmackseindrücke hervorrufen, und diskutieren die Aktivierung der Geschmacksrezeptoren und die ...
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