scholarly journals Radioactive microspheres—see and destroy

2013 ◽  
Vol 10 (3) ◽  
pp. 124-124
Author(s):  
Magdalena E. Morawska
2020 ◽  
Vol 27 (10) ◽  
pp. 1600-1615 ◽  
Author(s):  
Jorge Aramburu ◽  
Raúl Antón ◽  
Alejandro Rivas ◽  
Juan C. Ramos ◽  
Bruno Sangro ◽  
...  

Radioembolization (RE) is a valuable treatment for liver cancer. It consists of administering radioactive microspheres by an intra-arterially placed catheter with the aim of lodging these microspheres, which are driven by the bloodstream, in the tumoral bed. Even though it is a safe treatment, some radiation-induced complications may arise. In trying to detect or solve the possible incidences that cause nontarget irradiation, simulating the particle- hemodynamics in hepatic arteries during RE by computational fluid dynamics (CFD) tools has become a valuable approach. This paper reviews the parameters that influence the outcome of RE and that have been studied via numerical simulations. In this numerical approach, the outcome of RE is regarded as successful if particles reach the artery branches that feed tumor-bearing liver segments. Up to 10 parameters have been reviewed. The variation of each parameter actually alters the hemodynamic pattern in the vicinities of the catheter tip and locally alters the incorporation of the particles into the bloodstream. Therefore, in general, the local influences of these parameters should result in global differences in terms of particle distribution in the hepatic artery branches. However, it has been observed that under some (qualitatively described) appropriate conditions where particles align with blood streamlines, the local influence resulting from a variation of a given parameter vanishes and no global differences are observed. Furthermore, the increasing number of CFD studies on RE suggests that numerical simulations have become an invaluable research tool in the study of RE.


1975 ◽  
Vol 48 (1) ◽  
pp. 51-60 ◽  
Author(s):  
D. J. Warren ◽  
J. G. G. Ledingham

1. Total renal blood flow and its distribution within the renal cortex of the conscious rabbit were studied with radioactive microspheres of 15 and 25 μm diameter. 2. The reliability of the microsphere technique was influenced by microsphere diameter and number (dose). The optimum microsphere diameter for determination of flow distribution in the rabbit kidney was 15 μm and dose 100–150 000 spheres. 3. Spheres of 15 μm nominal diameter were randomly distributed within the renal cortex of adult rabbits. The larger spheres in batches nominally 15 μm in diameter in young rabbits and 25 μm diameter in adult rabbits were preferentially distributed to the superficial cortex. 4. In adult rabbits 15 μm diameter spheres lodged in glomerular capillaries. Larger spheres occasionally lodged in interlobular arteries causing intrarenal haemorrhage. 5. Microspheres of 15 μm caused a decrease in renal clearance of creatinine and of p-aminohippurate when the total injection dose was about 200 000 spheres. These effects were greater when the injection dose was increased to 500 000 spheres. 6. The reduction in total renal blood flow observed with large doses of spheres largely reflected decreased outer cortical flow, as measured by a second injection of spheres, and confirmed by a decrease in p-aminohippurate extraction. 7. The reproducibility of multiple injection studies was limited by these intrarenal effects of microspheres. 8. Total renal blood flow measured in six rabbits in acute experiments by the microsphere technique was 107 ± 12 (mean±sd) ml/min and by p-aminohippurate clearance was 100 ± 10 ml/min. 9. Total renal blood flow in twelve conscious, chronically instrumented rabbits was 125 ± 11 ml/min, of which 92 ± 6 ml/min was distributed to the superficial cortex and 33 ± 4 ml/min to the deep cortex.


1987 ◽  
Vol 96 (4) ◽  
pp. 341-348 ◽  
Author(s):  
Daniel Zaluzec ◽  
Joseph Ramzy ◽  
Robert Wotring ◽  
Lincoln Gray

Chickens were injected with 9-micron-diameter radioactive microspheres. Cochleas were removed through the external auditory meatus, and the positions of all embedded microspheres were drawn under camera-lucida. Constant measurements of arterial pressures and postinjection blood-gas determinations confirmed that injections were made into normal circulatory systems. The averaged estimate of cochlear blood flow in chickens is 0.75 μl/min. Variability in these data from chickens is similar to that reported from mammals. A potentially important but puzzling observation is an inverse relationship between blood flow to the cochlea and to the brain. The ease of cochlear extraction makes chickens ideal models for study of cochlear blood flow.


Author(s):  
J.-P. Steib ◽  
P. Kehr ◽  
B. Moyses ◽  
G. Lang ◽  
F. Leculée

1983 ◽  
Vol 245 (5) ◽  
pp. H734-H740
Author(s):  
G. I. Russell ◽  
R. F. Bing ◽  
J. D. Swales ◽  
H. Thurston

The hemodynamic changes associated with reversal of Goldblatt two-kidney, one-clip hypertension in conscious rats were studied using radioactive microspheres. In both the early phase (less than 6 wk from clipping) when plasma renin was elevated and the chronic phase (greater than 4 mo) when plasma renin was normal, hypertension was maintained by elevated peripheral resistance. Unclipping or removal of the ischemic kidney normalized blood pressure within 24 h by reduction in peripheral resistance. In early-phase hypertension blood pressure remained normal at 60 days after nephrectomy or unclipping, but in chronic-phase hypertension blood pressure was significantly elevated at 60 days after nephrectomy despite a similar fall in peripheral resistance. Plasma renin fell to normal or subnormal values after reversal in both early and chronic hypertension. Thus reversal of hypertension is associated with a rapid reduction in peripheral resistance even in longstanding hypertension. Since removal of the ischemic kidney and unclipping were equally effective, reversal must depend on either inhibition of a pressor system derived from the ischemic kidney or activation of a peripheral vasodepressor system not dependent on a revascularized kidney.


1973 ◽  
Vol 35 (1) ◽  
pp. 148-154 ◽  
Author(s):  
J P Archie ◽  
D E Fixler ◽  
D J Ullyot ◽  
J I Hoffman ◽  
J R Utley ◽  
...  

1998 ◽  
Vol 275 (1) ◽  
pp. H110-H115 ◽  
Author(s):  
Matthijs F. M. Van Oosterhout ◽  
Frits W. Prinzen ◽  
S. Sakurada ◽  
Robb W. Glenny ◽  
J. Robert S. Hales

The accuracy of the fluorescent (FM) and radioactive microsphere (RM) techniques is similar in acute experiments but has not been established in chronic experiments. In the present study various combinations (at least pairs) of FM and/or RM labels were injected simultaneously between 2 mo and 5 min before each animal was killed. Blood flow was determined in many organs. Intramethod mean difference and variation did not change over time for FM but increased significantly for RM (from 1.8 ± 1.4 to 25.6 ± 21.8% and from 4.4 ± 3.2 to 32.4 ± 23.0% at 5 min and 2 mo, respectively). Also the FM-RM intermethod mean difference and variation increased (from −0.5 ± 8.5 to 40.8 ± 23.8% and from 23.6 ± 4.6 to 71.8 ± 34.3%, respectively). After 2 mo, blood flow estimations were 20–50% lower with the various RM, whereas brain and liver blood flow values varied even more between isotopes. Underestimation started within 1 day for51Cr and within 2 wk for141Ce,95Nb, and85Sr. We conclude that FM are superior to RM for blood flow determination in experiments lasting longer than 1 day, presumably because of leaching of isotopes from RM.


1973 ◽  
Vol 118 (4) ◽  
pp. 814-819 ◽  
Author(s):  
MICHAEL E. SIEGEL ◽  
FRANK A. GIARGIANA ◽  
BUCK A. RHODES ◽  
ROBERT I. WHITE ◽  
HENRY N. WAGNER

1975 ◽  
Vol 9 (2) ◽  
pp. 91-97
Author(s):  
J. Papadimitriou ◽  
N. Gazetopoulos ◽  
A. Fotopoulos ◽  
A. Marselos ◽  
C. Tountas

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