Radioembolization With Holmium-166 Polylactic Acid Microspheres: Distribution of Residual Activity in the Delivery Set and Outflow Dynamics During Planning and Treatment Procedures

Published on Feb 25, 2021in Journal of Endovascular Therapy3.102
· DOI :10.1177/1526602821996719
Robert Drescher5
Estimated H-index: 5
,
Robert Drescher5
Estimated H-index: 5
+ 3 AuthorsMartin Freesmeyer14
Estimated H-index: 14
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Abstract
PURPOSE To evaluate the microsphere outflow dynamics and residual Ho-166 activity during and after transarterial radioembolization planning and treatment procedures, and to assess the distribution and predilection sites of residual activity in the proprietary delivery set and the microcatheter. MATERIALS AND METHODS Fifteen planning and 12 therapeutic radioembolization procedures were performed with poly-l-lactic acid microspheres loaded with Ho-166. The amount and distribution of residual activity was assessed by dose calibrator measurements and SPECT imaging. The activity flow profile from the microcatheter was assessed dynamically. For planning procedures, different injection methods were evaluated in order to attempt to decrease the residual activity. RESULTS The median residual activities for planning and treatment procedures using standard injection methods were 31.2% (range 17.3%-44.1%) and 4.3% (range 3.5%-6.9%), respectively. Planning residual activities could be decreased significantly with 2 injection methods similar to treatment procedures, to 17.5% and 10.9%, respectively (P = 0.002). Main predilection sites of residual microspheres were the 3-way stopcock and the outflow needle connector. During treatment procedures, more than 80% of the injected activity is transferred during the first 3 injection cycles. CONCLUSION After treatment procedures with holmium-loaded microspheres, mean residual activity in the delivery set is reproducibly low and between reported values for glass and resin microspheres. The majority of microspheres is transferred to the patient during the second and third injection cycle. An estimated residual waste of 3% to 4% may be included in the treatment activity calculation. For planning procedures, a modified injection technique should be used to avoid high residual activities.
References17
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Abstract Purpose To evaluate the microsphere flow dynamics and residual yttrium-90 (90Y) activity during and after transarterial radioembolization with glass microspheres and to assess the distribution and predilection sites of residual activity in the administration devices. Materials and Methods In this laboratory investigation, after 18 consecutive clinical transarterial radioembolization and 4 ex vivo experimental procedures with 90Y glass microspheres, the distribution of residual activity ...
1 CitationsSource
#1Maarten L. J. Smits (UU: Utrecht University)H-Index: 16
#2Mathijs G Dassen (UU: Utrecht University)H-Index: 1
Last. Marnix G.E.H. Lam (UU: Utrecht University)H-Index: 30
view all 8 authors...
Purpose As an alternative to technetium-99m-macroaggregated albumin (99mTc-MAA), a scout dose of holmium-166 (166Ho) microspheres can be used prior to 166Ho-radioembolization. The use of identical particles for pre-treatment and treatment procedures may improve the predictive value of pre-treatment analysis of distribution. The aim of this study was to analyze the agreement between 166Ho-scout and 166Ho-therapeutic dose in comparison with the agreement between 99mTc-MAA and 166Ho-therapeutic dos...
20 CitationsSource
Abstract Purpose To evaluate the infusion dynamics and residual yttrium-90 activity during and after resin microsphere radioembolization with different injection techniques and initial activities. To assess the distribution of residual activity in the administration systems to allow optimization of the procedure and the equipment. Materials and Methods In a setup similar to that in standard clinical practice, radioembolization procedures were performed ex vivo. The influence of different injecti...
2 CitationsSource
#1Nienke J. M. Klaassen (Radboud University Nijmegen)H-Index: 1
#2Mark J. Arntz (Radboud University Nijmegen)H-Index: 6
Last. J. Frank W. Nijsen (Radboud University Nijmegen)H-Index: 2
view all 5 authors...
Over the years, a broad spectrum of applications of the radionuclide holmium-166 as a medical isotope has been established. The isotope holmium-166 is attractive as it emits high-energy beta radiation which can be used for a therapeutic effect and gamma radiation which can be used for nuclear imaging purposes. Furthermore, holmium-165 can be visualized by MRI because of its paramagnetic properties and by CT because of its high density. Since holmium-165 has a natural abundance of 100%, the only ...
14 CitationsSource
#1Robbert C. Bakker (UU: Utrecht University)H-Index: 3
#2Remmert de Roos (UU: Utrecht University)H-Index: 6
Last. Gerard C. Krijger (UU: Utrecht University)H-Index: 18
view all 7 authors...
Abstract Background [ 166 Ho]Ho-acetylacetonate-poly(L-lactic acid) microspheres were used in radioembolization of liver malignancies by intra-arterial administration. The primary aim of this study was to assess the stability and biodistribution of these microspheres. Materials and methods Peripheral blood and urine samples were obtained from two clinical studies. Patient and in vitro experiment samples were analyzed using inductively coupled plasma mass spectrometry (ICP-MS), gamma-ray spectros...
3 CitationsSource
#1Margot T. M. Reinders (UU: Utrecht University)H-Index: 4
#2Maarten L. J. Smits (UU: Utrecht University)H-Index: 16
Last. Arthur J. A. T. Braat (UU: Utrecht University)H-Index: 13
view all 4 authors...
Holmium microspheres have recently become available in the European market as the third type of microspheres for radioembolization of unresectable liver malignancies. Holmium microspheres come with a dedicated administration system, and since these microspheres contain holmium-166 (166Ho) instead of yttrium-90, unique dosing and imaging possibilities have become available as well. In addition, a scout dose of 166Ho microspheres (Conformite Europeenne mark is now granted and not pending anymore) ...
19 CitationsSource
#1Jip F. Prince (UU: Utrecht University)H-Index: 12
#2Maurice A. A. J. van den Bosch (UU: Utrecht University)H-Index: 42
Last. Marnix G.E.H. Lam (UU: Utrecht University)H-Index: 30
view all 11 authors...
Rationale: Radioembolization of liver malignancies with holmium-166 (166Ho) microspheres has been shown safe in a phase 1 dose-escalation study. The purpose of this study was to investigate the efficacy of 166Ho radioembolization. Methods: In this prospective single-arm study, 56 patients were enrolled, all with liver metastases refractory to systemic therapy and ineligible for surgical resection. Radioembolization was performed with a projected average absorbed dose of 60 Gy to the liver (equal...
40 CitationsSource
#1Arthur J. A. T. Braat (UU: Utrecht University)H-Index: 13
#2Jip F. Prince (UU: Utrecht University)H-Index: 12
Last. Marnix G.E.H. Lam (UU: Utrecht University)H-Index: 30
view all 6 authors...
Objective Radioembolisation is generally preceded by a scout dose of technetium-99m-macroaggregated albumin to estimate extrahepatic shunting of activity. Holmium-166 microspheres can be used as a scout dose (±250 MBq) and as a therapeutic dose. The general toxicity of a holmium-166 scout dose (166Ho-SD) and safety concerns of an accidental extrahepatic deposition of 166Ho-SD were investigated.
24 CitationsSource
#1Hojjat Ahmadzadehfar (University Hospital Bonn)H-Index: 36
#2Carsten H. Meyer (University Hospital Bonn)H-Index: 50
Last. Markus Essler (University Hospital Bonn)H-Index: 37
view all 8 authors...
Background The purpose of this study is to evaluate the impact of switching from sterile water to 5 % glucose (G5W) for the administration of yttrium-90 (90Y)-resin microspheres on the total activity of 90Y administered (expressed as a proportion of the prescribed/calculated activity), as well as the number of cases of stasis and the reported incidence of discomfort during the selective internal radiation therapy (SIRT) procedure.
20 CitationsSource
#1Jip F. Prince (UU: Utrecht University)H-Index: 12
#2Rob van Rooij (UU: Utrecht University)H-Index: 5
Last. Marnix G.E.H. Lam (UU: Utrecht University)H-Index: 30
view all 6 authors...
UNLABELLED: Before (166)Ho radioembolization, a small batch of the same type of microspheres is administered as a scout dose instead of the conventional (99m)Tc-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 β-emitting scout dose could inflict radiation damage, the extent of which we aimed to quantify in this study. METHODS: All patients el...
25 CitationsSource
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