The dosimetry for radiocolloid therapy of cystic craniopharyngiomas is investigated. Analytical calculations based on the Loevinger and the Berger formulas for electrons and photons, respectively, are compared with Monte Carlo simulations. The role of the material of which the colloid introduced inside the craniopharyngioma is made of as well as that forming the cyst wall is analyzed. It is found that the analytical approaches provide a very good description of the simulated data in the conditions where they can be applied (i.e., in the case of a uniform and infinite homogeneous medium). However, the consideration of the different materials and interfaces produces a strong reduction of the dose delivered to the cyst wall in relation to that predicted by the Loevinger and the Berger formulas.
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http://dx.doi.org/10.1118/1.1599653 | DOI Listing |
J Environ Radioact
December 2024
Institute of geology of ore deposits, petrography, mineralogy, and geochemistry, Russian Academy of sciences, Staromonetny 35, 119017, Moscow, Russia.
A necessary condition for the sustainable development of nuclear power is the safe disposal of vitrified high-level radioactive waste from the processing of spent nuclear fuel in underground repositories. Their safety depends on the rate of radionuclide transport by groundwater from the repository to the biosphere. A significant fraction of the radionuclides is carried by groundwater in colloidal form.
View Article and Find Full Text PDFEur J Nucl Med Mol Imaging
January 2022
Antwerp University Hospital, Drie Eikenstraat 655, 2650, Edegem, Belgium.
Purpose: Radiosynoviorthesis (RSO) using the intraarticular application of beta-particle emitting radiocolloids has for decades been used for the local treatment of inflammatory joint diseases. The injected radiopharmaceuticals are phagocytized by the superficial macrophages of the synovial membrane, resulting in sclerosis and fibrosis of the formerly inflamed tissue, finally leading to reduced joint effusion and alleviation of joint pain.
Methods: The European Association of Nuclear Medicine (EANM) has written and approved these guidelines in tight collaboration with an international team of clinical experts, including rheumatologists.
EJNMMI Phys
March 2020
Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX, Utrecht, The Netherlands.
Background: Intrahepatic dosimetry is paramount to optimize radioembolization treatment accuracy using radioactive holmium-166 microspheres (Ho). This requires a practical protocol that combines quantitative imaging of microsphere distribution with automated and robust delineation of the volumes of interest. To this end, we propose a dual isotope single photon emission computed tomography (SPECT) protocol based on Ho therapeutic microspheres and technetium-99 m (Tc) stannous phytate, which accumulates in healthy liver tissue.
View Article and Find Full Text PDFAustralas Phys Eng Sci Med
September 2018
Department of Neurosurgery, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Over 90% of craniopharyngeal brain tumors are cystic, which enables the injection of beta emitters such as phosphorus-32 (P) radio-colloid into cysts for their treatment. The aim of this study was to evaluate the clinical and theoretical modelling of Bremsstrahlung radiation dose resulting from stereotactic radio-colloid therapy of cystic craniopharyngioma tumors with P. P radio-colloid with appropriate activity concentration was injected to a head phantom, and then the Bremsstrahlung radiation spectrum and planar images were obtained using a gamma camera.
View Article and Find Full Text PDFEur J Nucl Med Mol Imaging
October 2013
Joint Department of Physics, Institute of Cancer Research, Sutton, London, SM2 5NG, UK,
Purpose: (32)P-chromic phosphate colloid treatments of astrocytoma and craniopharyngioma cystic brain tumours in paediatric patients are conventionally based on a sphere model under the assumption of uniform uptake. The aims of this study were to determine the distribution of the absorbed dose delivered by (32)P on a patient-specific basis and to evaluate the accuracy with which this can be predicted from a pretherapy administration of (99m)Tc-Sn colloid.
Methods: Three patients were treated with (32)P-chromic phosphate colloid following (99m)Tc-Sn colloid administrations.
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