Biodistribution analysis

Blood, muscle, lung, liver, tumour, bone and tail were collected for biodistribution analysis. Samples were weighed and weights were recorded. Tissue samples were counted in a gamma counter (Perkin Elmer, 1480, Wizard 3) for 20s per sample. The gamma counter provides a “counts per minute” parameter. These data were imported into an Excel spreadsheet where the counts per minute were converted into activity by conversions into disintegrations per minute; by multiplying the efficiency of the gamma counter for ¹⁸F. Activity was decay corrected to the time of injection and converted into a concentration using the ex-vivo tissue weight (in kilobecquerel per gram). Tissue weights were imported into the Excel spreadsheet. All mice in which ¹⁸F-FDG radioactivity in the tail exceeded 10% of the injected dose were excluded from analysis.