UNLABELLED: Selective internal radiation treatment (SIRT) via intrahepatic arterial administration of (90)Y microspheres is an effective therapeutic modality. The conventional and generally applied MIRD schema is based on the premise that the distribution of microspheres in the liver parenchyma is uniform. In reality, however, the distribution of the microspheres follows a distinct pattern, requiring that a model be developed to more appropriately estimate radiation absorbed doses to the different structural/functional elements of the hepatic microanatomy. METHODS: A systematic investigation was performed encompassing a conventional average absorbed dose assessment, a compartmental macrodosimetric approach that accounts for the anticipated higher tumor-to-normal liver activity concentration ratio, dose point-kernel convolution-derived estimates, and Monte Carlo dose estimates employing a spherical and 3-dimensional hexagonal liver model, including various subunits of the hepatic anatomy, down to the micrometer level. RESULTS: Detailed specifics of the radiation dose deposition of (90)Y microspheres demonstrated a rapid decrease in absorbed dose in and around the portal tracts where the microspheres are deposited. The model also demonstrated that the hepatocellular parenchymal and central vein doses could be at significant levels because of a cross-fire effect. CONCLUSION: The reported microstructural dosimetry models can help in the detailed assessment of the dose distributions in the hepatic functional subunits and in relating these doses to their effects. These models have also revealed that the there is a consistent relationship between the average liver dose as calculated by MIRD macrodosimetry and the structural dosimetry estimates in support of the clinical utility of the MIRD methodology. This relationship could be used to more realistically assess patterns of hepatic toxicity associated with the (90)Y SIRT treatment.
UNLABELLED: Selective internal radiation treatment (SIRT) via intrahepatic arterial administration of (90)Y microspheres is an effective therapeutic modality. The conventional and generally applied MIRD schema is based on the premise that the distribution of microspheres in the liver parenchyma is uniform. In reality, however, the distribution of the microspheres follows a distinct pattern, requiring that a model be developed to more appropriately estimate radiation absorbed doses to the different structural/functional elements of the hepatic microanatomy. METHODS: A systematic investigation was performed encompassing a conventional average absorbed dose assessment, a compartmental macrodosimetric approach that accounts for the anticipated higher tumor-to-normal liver activity concentration ratio, dose point-kernel convolution-derived estimates, and Monte Carlo dose estimates employing a spherical and 3-dimensional hexagonal liver model, including various subunits of the hepatic anatomy, down to the micrometer level. RESULTS: Detailed specifics of the radiation dose deposition of (90)Y microspheres demonstrated a rapid decrease in absorbed dose in and around the portal tracts where the microspheres are deposited. The model also demonstrated that the hepatocellular parenchymal and central vein doses could be at significant levels because of a cross-fire effect. CONCLUSION: The reported microstructural dosimetry models can help in the detailed assessment of the dose distributions in the hepatic functional subunits and in relating these doses to their effects. These models have also revealed that the there is a consistent relationship between the average liver dose as calculated by MIRD macrodosimetry and the structural dosimetry estimates in support of the clinical utility of the MIRD methodology. This relationship could be used to more realistically assess patterns of hepatic toxicity associated with the (90)Y SIRT treatment.
Authors: Riad Salem; Robert J Lewandowski; Vanessa L Gates; Charles W Nutting; Ravi Murthy; Steven C Rose; Michael C Soulen; Jean-Francois H Geschwind; Laura Kulik; Yun Hwan Kim; Carlo Spreafico; Marco Maccauro; Lourens Bester; Daniel B Brown; Robert K W Ryu; Daniel Y Sze; William S Rilling; Kent T Sato; Bruno Sangro; Jose Ignacio Bilbao; Tobias F Jakobs; Samer Ezziddin; Suyash Kulkarni; Aniruddha Kulkarni; David M Liu; David Valenti; Philip Hilgard; Gerald Antoch; Stefan P Muller; Hamad Alsuhaibani; Mary F Mulcahy; Marta Burrel; Maria Isabel Real; Stewart Spies; Abdulredha A Esmail; Jean-Luc Raoul; Etienne Garin; Mathew S Johnson; Al B Benson; Ricky A Sharma; Harpreet Wasan; Bieke Lambert; Khairuddin Memon; Andrew S Kennedy; Ahsun Riaz Journal: J Vasc Interv Radiol Date: 2011-03 Impact factor: 3.464
Authors: Kathy P Willowson; Geoffrey P Schembri; Elizabeth J Bernard; David Lh Chan; Dale L Bailey Journal: Eur J Nucl Med Mol Imaging Date: 2020-01-20 Impact factor: 9.236
Authors: Alexander S Pasciak; Godwin Abiola; Robert P Liddell; Nathan Crookston; Sepideh Besharati; Danielle Donahue; Richard E Thompson; Eric Frey; Robert A Anders; Matthew R Dreher; Clifford R Weiss Journal: Eur J Nucl Med Mol Imaging Date: 2019-11-18 Impact factor: 9.236