Abstract for presentation at 38th Annual Scientific Meeting of the Australian and New Zealand Society of Nuclear Medicine 2008

Non-Invasive Evaluation of Hypoxia Using 18F-FMISO PET in Liver Metastasis from Colorectal Carcinoma*

  • Dr Sze Ting Lee, Austin Health, Melbourne, Australia
  • Dr Peter Wong, Austin Health, Melbourne, Australia
  • Dr V Muraliharan, Austin Health, Melbourne, Australia
  • Dr Rebecca Herbertson, Austin Health, Melbourne, Australia
  • Mrs Kunthi Pathmaraj, Austin Health, Melbourne, Australia
  • Dr Graeme O'Keefe, Austin Health, Melbourne, Australia
  • Dr John Sachinidis, Austin Health, Melbourne, Australia
  • Dr Niall Tebbutt, Austin Health, Melbourne, Australia
  • C Christophi, University of Melbourne, Australia
  • Prof Andrew Scott, Centre for P.E.T., Austin Health, Australia

    • Objective
    Hypoxia in liver metastasis from colorectal carcinoma (mCRC) may be a cause of treatment resistance, but it is not currently known whether these tumours are hypoxic. We aim to assess FMISO uptake in liver metastases and compare it with FDG uptake, and assess the influence of hypoxia on angiogenesis.
    Methods
    Fourteen patients with mCRC in the liver had 18F-FDG and 18F-FMISO PET/CT scans performed. Maximum standardised uptake value (SUVmax) was measured for the metabolically active liver lesions identified on concurrent low dose CT for both PET scans, as well as the calculation of tumour to normal liver ratio (TNR). Tissue and plasma samples was obtained to assess hypoxia and angiogenesis.
    Results
    For the FMISO scan, mean tumour SUVmax was 2.5 (range 1.3-3.8) and mean normal liver SUVmax was 2.2 (range 1.3-2.7). There was a statistically significant difference in SUVmax between the tumour and normal liver (p-value <0.05; 95%CI 0.07-0.54). For the FDG scan, mean tumour SUVmax was 6.8 (range 4.3-10.6) and mean normal liver SUVmax was 2.6 (range 1.7-3.6), which also showed a statistically significant difference (p-value <0.05; 95% CI 3.0-5.4). The TNR was 1.13 for FMISO and 2.72 for FDG, with a statistically significant difference between the two radiotracers (p-value <0.05; 95% CI 1.0-2.18).
    Conclusions
    The study shows that hypoxia is present in liver metastases in colorectal carcinoma, as assessed by 18F-FMISO. Further analysis of tissue and plasma markers of hypoxia and angiogenesis are ongoing.

    Conference Organiser - ICMS Pty Ltd