title: Impact of the activity calculation method used in transarterial radioembolization: a dosimetric comparison between 90Y-SIRSphere and 90Y-TheraSphere therapy.
abstract: OBJECTIVE
  Transarterial radioembolization is used to treat primary and secondary liver malignancies. Two commercially available drugs are utilized for the purpose. The aim of our study is to compare the radiation dose delivered to the tumor by these drugs.
  
  
  METHODS
  This study included 86 patients (M : F - 7.6 : 1, median age=50.5 years), 46 patients were treated by Y-TheraSphere and 42 patients were treated by Y-SIRSphere. Activity administered in Y-TheraSphere and Y-SIRSphere was calculated using a modified partition model and a modified body surface area model, respectively. The radiation dose delivered by two drugs was calculated and compared in our study.
  
  
  RESULTS
  Activity administered in Y-TheraSphere was significantly higher than that of Y-SIRSphere. Hence, the radiation dose delivered to the tumor by Y-SIRSphere was significantly lower (58.4%) than that of Y-TheraSphere (P=0.000).
  
  
  CONCLUSIONS
  As the radiation dose delivered by Y-SIRSphere was lower than Y-TheraSphere, we believe that the formula for Y-SIRSphere activity calculation needs to be modified so that the optimal dose can be delivered to the tumor.
authors.affiliation: Departments of aNuclear Medicine and Molecular Imaging bRadiodiagnosis, Tata Memorial Hospital, HBNI Deemed University, Mumbai, Maharashtra, India.
authors.forename: Ashish K
authors.initials: AK
authors.lastname: Jha
authors.forename: Sneha
authors.initials: S
authors.lastname: Mithun
authors.forename: Nilendu C
authors.initials: NC
authors.lastname: Purandare
authors.forename: Sneha A
authors.initials: SA
authors.lastname: Shah
authors.forename: Archi
authors.initials: A
authors.lastname: Agrawal
authors.forename: Suyash S
authors.initials: SS
authors.lastname: Kulkarni
authors.forename: Nitin
authors.initials: N
authors.lastname: Shetty
authors.forename: Venkatesh
authors.initials: V
authors.lastname: Rangarajan
mesh_terms: D001830:Body Surface Area; D004621:Embolization, Therapeutic / Q000379:methods*; D005260:Female; D006499:Hepatic Artery; D006801:Humans; D008113:Liver Neoplasms / Q000098:blood supply / Q000532:radiotherapy*; D008297:Male; D008863:Microspheres; D008875:Middle Aged; D008954:Models, Biological; D011879:Radiotherapy Dosage; D015021:Yttrium Radioisotopes / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D015021:Yttrium Radioisotopes