title: Technical Note: Determination of individual thyroid clearance effective half-life with a common handheld electronic dosimeter.
abstract: OBJECTIVE
  To determine the thyroid clearance effective half-life T with a common handheld electronic dosimeter (ED) in patients undergoing radioiodine treatment for hyperthyroidism.
  
  
  METHODS
  Dose rates from 12 inpatients were measured daily with an ED and with a clinical uptake counter. The ED was attached to the patient with two different setups, one using a cervical collar and another employing a neck strap. Estimation of T was performed by linear regression analysis of the log of both the ED and the uptake counter measurements versus time. The latter provided the reference data.
  
  
  RESULTS
  Based on repeated neck strap dose rate measurements, individual Ts were determined with clinically required accuracy. The mean difference from the reference method equaled to -0.09 ± 0.35 days.
  
  
  CONCLUSIONS
  Determination of individual T is feasible with a common handheld ED using the simple and easy to instruct neck strap measurement setup. This simple method complements stationary uptake counter measurements and thus may improve the accuracy of radioiodine treatment planning by adding an individual T for dose calculation.
authors.affiliation: Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
authors.forename: Markus
authors.initials: M
authors.lastname: Fürstner
authors.affiliation: Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
authors.forename: Michael
authors.initials: M
authors.lastname: Hentschel
authors.affiliation: Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
authors.forename: Petar-Marko
authors.initials: PM
authors.lastname: Spanjol
authors.affiliation: Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
authors.forename: George A
authors.initials: GA
authors.lastname: Prenosil
authors.affiliation: Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
authors.forename: Sabine
authors.initials: S
authors.lastname: Weidner
authors.affiliation: Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Krause
authors.affiliation: Department of Nuclear Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
authors.forename: Bernd
authors.initials: B
authors.lastname: Klaeser
mesh_terms: D055615:Electrical Equipment and Supplies; D006207:Half-Life; D006801:Humans; D006980:Hyperthyroidism / Q000378:metabolism / Q000532:radiotherapy; D007457:Iodine Radioisotopes / Q000378:metabolism / Q000627:therapeutic use; D011874:Radiometry / Q000295:instrumentation*; D013961:Thyroid Gland / Q000378:metabolism* / Q000528:radiation effects
chemical_list: D007457:Iodine Radioisotopes
keywords: effective half-life; electronic dosimeter; hyperthyroidism; radioiodine; thyroid