title: (44g)Sc production using a water target on a 13MeV cyclotron.
abstract: BACKGROUND
  Access to promising radiometals as isotopes for novel molecular imaging agents requires that they are routinely available and inexpensive to obtain. Proximity to a cyclotron center outfitted with solid target hardware, or to an isotope generator for the metal of interest is necessary, both of which can introduce significant hurdles in development of less common isotopes. Herein, we describe the production of ⁴⁴Sc (t1/2=3.97 h, Eavg,β⁺=1.47MeV, branching ratio=94.27%) in a solution target and an automated loading system which allows a quick turn-around between different radiometallic isotopes and therefore greatly improves their availability for tracer development. Experimental yields are compared to theoretical calculations.
  
  
  METHODS
  Solutions containing a high concentration (1.44-1.55g/mL) of natural-abundance calcium nitrate tetrahydrate (Ca(NO₃)2·4 H₂O) were irradiated on a 13MeV proton-beam cyclotron using a standard liquid target. (44g)Sc was produced via the ⁴⁴Ca(p,n)(44g)Sc reaction.
  
  
  RESULTS
  (44g)Sc was produced for the first time in a solution target with yields sufficient for early radiochemical studies. Saturation yields of up to 4.6 ± 0.3 MBq/μA were achieved using 7.6 ± 0.3 μA proton beams for 60.0 ± 0.2 minutes (number of runs n=3). Experimental data and calculation results are in fair agreement. Scandium was isolated from the target mixture via solid-phase extraction with 88 ± 6% (n=5) efficiency and successfully used for radiolabelling experiments. The demonstration of the production of ⁴⁴Sc in a liquid target greatly improves its availability for tracer development.
authors: TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada.
authors: Cornelia
authors: C
authors: Hoehr
authors: TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada.
authors: Elisabeth
authors: E
authors: Oehlke
authors: British Columbia Cancer Agency, 675 West 10th Avenue, Vancouver, BC, V5Z 1L3, Canada; University of British Columbia, 3350-950 W. 10th Avenue, Vancouver, BC, V5Z 4E3, Canada. Electronic address: fbenard@bccrc.ca.
authors: Francois
authors: F
authors: Benard
authors: TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada.
authors: Chris Jaeil
authors: CJ
authors: Lee
authors: University of British Columbia, 3350-950 W. 10th Avenue, Vancouver, BC, V5Z 4E3, Canada.
authors: Xinchi
authors: X
authors: Hou
authors: TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada.
authors: Brian
authors: B
authors: Badesso
authors: TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada.
authors: Simon
authors: S
authors: Ferguson
authors: TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada.
authors: Qing
authors: Q
authors: Miao
authors: TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada.
authors: Hua
authors: H
authors: Yang
authors: TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada.
authors: Ken
authors: K
authors: Buckley
authors: TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada.
authors: Victoire
authors: V
authors: Hanemaayer
authors: TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada.
authors: Stefan
authors: S
authors: Zeisler
authors: TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada; British Columbia Cancer Agency, 675 West 10th Avenue, Vancouver, BC, V5Z 1L3, Canada.
authors: Thomas
authors: T
authors: Ruth
authors: University of British Columbia, 3350-950 W. 10th Avenue, Vancouver, BC, V5Z 4E3, Canada.
authors: Anna
authors: A
authors: Celler
authors: TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada; University of British Columbia, 3350-950 W. 10th Avenue, Vancouver, BC, V5Z 4E3, Canada.
authors: Paul
authors: P
authors: Schaffer
mesh_terms: D017357:Cyclotrons; D011854:Radiochemistry / Q000295:instrumentation*; D011868:Radioisotopes / Q000737:chemistry*; D012538:Scandium / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D011868:Radioisotopes; D014867:Water; D012538:Scandium
keywords: (44)Sc; PET; Radioisotope production; Radiometal; Scandium-44; Targetry