Adjuvant holmium-166 radioembolization after radiofrequency ablation in early-stage hepatocellular carcinoma patients: a dose-finding study (HORA EST HCC trial)

Purpose: The aim of this study was to investigate the biodistribution of (super-)selective trans-arterial radioembolization (TARE) with holmium-166 microspheres (¹⁶⁶Ho-MS), when administered as adjuvant therapy after RFA of HCC 2–5 cm. The objective was to establish a treatment volume absorbed dose that results in an absorbed dose...

Polymeric micelles and the Dy-166/Ho-166 generator: A study of the loading mechanism of Dy/Dy-166 and Ho-166 into PCL-b-PEO polymeric micelles for imaging and cancer treatment

A radioisotope used in radionuclide therapy is Holmium-166 (Ho-166). The treatment effectiveness of Ho-166 could be improved by the use of a so called in vivo Dysprosium-166(Dy-166)/Ho-166 generator. The application of this generator is hindered by an effect called internal conversion (IC). This affect can arise after the decay of Dy-166 to Ho...

Increasing Specific Activity of ¹⁶⁶Ho through Szilard-Chalmers Effect in ¹⁶⁵Ho-loaded Zeolite A

Holmium-166 is a promising radionuclide for therapeutic and imaging applications due to its advantageous decay characteristics. However, these applications require or would benefit from a higher specific activity of ¹⁶⁶Ho than that obtained via a ¹⁶⁵Ho(n,γ)¹⁶⁶Ho reaction by irradiating a pure ¹⁶⁵Ho...

Iron oxide nanoparticles as carriers for the Dy-166/Ho-166 in vivo generator: A study into the characteristics and retention of Dy and Ho in iron oxide nanoparticles

Background:<br/>Cancer is one of the leading causes of death worldwide. Targeted radionuclide therapy has become a important treatment, this is when a carrier molecule is attached to a radionuclide to deliver cytotoxic radiation levels to diseased cells. β<br/>− emitters are frequently used in RNT because they have a long penetration depth, such...

Core–shell structured gold nanoparticles as carrier for ¹⁶⁶Dy/¹⁶⁶Ho in vivo generator

Background: Radionuclide therapy (RNT) has become a very important treatment modality for cancer nowadays. Comparing with other cancer treatment options, sufficient efficacy could be achieved in RNT with lower toxicity. β⁻ emitters are frequently used in RNT due to the long tissue penetration depth of the β⁻ particles....

Intratumoral holmium microsphere injection in pancreatic cancer

Introduction: Pancreatic adenocarcinoma holds one of the worst prognosis of all known malignancies. Local treatment options for patients with unresectable pancreatic cancer may increase tumor control and benefit patient survival. This study aimed to test the feasibility of a possible new treatment method utilizing intratumoral holmium...

Dedicated holmium microsphere administration device for MRI-guided interstitial brain microbrachytherapy

Microbrachytherapy with radioactive holmium-166 (166Ho) microspheres (MS) has the potential to be an effective treatment method for brain malignancies. Direct intratumoural delivery of 166Ho-MS and dose coverage of the whole tumour are crucial requirements. However, currently no dedicated instruments for controlled intratumoural delivery...

Heating properties of holmium doped nanoparticles: For image guided thermo-brachytherapy

Because diagnostics have improved tremendously, nowadays breast cancer is more frequently detected at an early stage. Long-term prognosis is excellent and therefore the new treatment should focus on minimizing long-term side effects and treatment burden. This research proposes cancer treatment using nanoparticles (NPs) for a combination of heat...

Development of a holmium microsphere administration device for treatment of brain malignancies

Brain cancer is a major health problem and currently used treatment methods are considered suboptimal. Micro-brachytherapy with radioactive Holmium-166 showed to be an effective palliative care method for primary and metastatic brain tumors and intratumoral administration with holmium microspheres (HoMS) showed very promising results with...

Radioactive holmium phosphate microspheres for cancer treatment

The aim of this study was the development of radioactive holmium phosphate microspheres (HoPO₄-MS) with a high holmium content and that are stable in human serum for selective internal radiation therapy (SIRT) of liver cancer. To this end, holmium acetylacetonate microspheres (HoAcAc-MS) were prepared (34.2 ± 1.0 µm in diameter,...

Radioactive Holmium Acetylacetonate Microspheres for Interstitial Microbrachytherapy: An In Vitro and In Vivo Stability Study

Purpose The clinical application of holmium acetylacetonate microspheres (HoAcAcMS) for the intratumoral radionuclide treatment of solid malignancies requires a thorough understanding of their stability. Therefore, an in vitro and an in vivo stability study with HoAcAcMS was conducted. Methods HoAcAcMS, before and after neutron irradiation, were...

Holmium-166 poly(L-lactic acid) microsphere radioembolisation of the liver: Technical aspects studied in a large animal mode

Neutron activation of holmium poly(L-lactic acid) microspheres for hepatic arterial radioembolization: A validation study

Poly(L-lactic acid) microspheres loaded with holmium-166 acetylacetonate (166Ho-PLLA-MS) are a novel microdevice for intra-arterial radioembolization in patients with unresectable liver malignancies. The neutron activation in a nuclear reactor, in particular the gamma heating, damages the 166Ho-PLLA-MS. The degree of damage is dependent on the...

Lanthanide 4f-level location in lanthanide doped and cerium-lanthanide codoped NaLaF4 by photo- and thermoluminescence

Photo- and thermoluminescence (TL) spectra of NaLaF4:Ln3+ (Ln = Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm) and NaLaF4:Ce3+, Ln3+ (Ln = Nd,Sm,Ho,Er,Tm) are presented and used together with the empirical Dorenbos model in order to establish the 4f energy level positions of all tri- and divalent lanthanide ions doped in NaLaF4. The information will be...

Clinical effects of transcatheter hepatic arterial embolization with holmium-166 poly(l-lactic acid) microspheres in healthy pigs

Purpose The aim of this study is to evaluate the toxicity of holmium-166 poly(l-lactic acid) microspheres administered into the hepatic artery in pigs. Methods Healthy pigs (20–30 kg) were injected into the hepatic artery with holmium-165-loaded microspheres (165HoMS; n?=?5) or with holmium-166-loaded microspheres (166HoMS; n?=?13). The...

Lanthanide-Loaded Liposomes for Multimodality Imaging and Therapy

Many advanced molecular imaging agents are currently being investigated preclinically. Especially, liposomes, have proven to be very promising carrier systems for diagnostic agents for use in single-photon emission computed tomography (SPECT) or magnetic resonance imaging (MRI), as well as for therapeutic agents to treat diseases such as cancer....