Poster Presentation Australasian Melanoma Conference 2026

Assessing the relationship between FDG‑PET/CT parameters and tumour glucose metabolism in melanoma (#412)

Daniel S Gu 1 2 , Ramin Alipour 2 3 , Jessica Van Zuylekom 1 , David E Gyorki 2 4 , Louise Jackett 5 , SueJin Shim 6 , Xantine Garrido 6 , Thomas Breakell 1 2 7 , Jessica Sudderth 8 , Kai Jhuang 1 , Stephanie Jansen 1 , Danni Norman 1 , Hayden Snow 4 , Avinash Sharma 4 , Bryce Jackson 4 , John Spillane 4 , David Speakman 4 , Michael A Henderson 4 , Adam Miller 6 , Lavinia Spain 2 9 , Friyana Bhabha 4 , Christopher Angel 5 , Kristin K Brown 1 2 , Bernhard Riedel 2 6 , Shaneen Sandhu 2 9 , Benjamin Blyth 1 2 , Jennifer G Gill 10 , Grant A McArthur 1 2 9 , Ralph J Deberardinis 8 11 12 , Aparna D Rao 1 2 9
  1. Division of Cancer Research, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
  2. Sir Peter MacCallum Department of Oncology, The University of Melbourne, Melbourne, Victoria, Australia
  3. Department of Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
  4. Department of Surgical Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
  5. Department of Anatomical Pathology, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
  6. Department of Anaesthesia, Perioperative Medicine and Pain Medicine, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
  7. Department of Dermatology, Uniklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Germany
  8. Children's Medical Center Research Institute, University of Texas Southwestern Medical Center, Dallas, Texas, USA
  9. Department of Medical Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
  10. Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
  11. Department of Paediatrics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
  12. Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, USA

Background/Aim

[18F]Fluoro-2-deoxyglucose positron emission tomography computed tomography (FDG-PET/CT) is routinely used in the diagnosis and monitoring of patients with melanoma. However, it remains unclear how FDG-PET/CT parameters relate to the utilisation of glucose in vivo. In the MetaMel Study (NCT05570227), 13C-glucose is infused in patients undergoing surgical resection, enabling the assessment of glucose utilisation in vivo in melanoma. This project aims to explore whether FDG-PET/CT parameters correlate with metabolic features of melanoma.

Methods

Patients received intravenous 13C-glucose, first as an 8g bolus followed by infusion of 4g/hour for 2-3 hours prior to surgical resection. Blood and tumour samples were obtained to analyse enrichment of 13C-labelled metabolites via gas-chromatography mass spectrometry (GC-MS). Baseline FDG-PET/CT and clinical parameters were obtained for each patient. Tumour samples were also processed to develop parallel patient-derived xenografts (PDXs), which subsequently underwent 13C-glucose infusion and FDG-PET/CT imaging. The FDG-PET/CT parameters extracted were: maximum and mean standardised uptake values (SUVmax/mean); metabolic tumour volume (MTV); total lesion glycolysis (TLG). These parameters were correlated with tumour metabolic parameters, including the following ratios: tumour/serum glucose [M+6]; citrate [M+2]/pyruvate [M+3]; lactate [M+3]/pyruvate [M+3]. FDG-PET parameters between patients and PDXs were also correlated.

Results

Fourteen patients have received a [13C]-glucose infusion (with sampling from 2 primary lesions, 10 lymph nodes, 3 in-transits, 3 distant metastasis). MS data is currently available for 8 patients, with analyses ongoing. We have also successfully established and imaged 20 PDXs (derived from 5 patient samples). Preliminary analyses show no correlation between FDG-PET/CT and mass spectrometry parameters, including between SUVmax and tumour/serum glucose [M+6], which may be surrogates of tumour glucose uptake. We observed a similar trend of SUVmax in patients and their matched PDXs, comparison with mass spectrometry parameters in these models is underway.

Conclusion

In this initial exploratory analysis, it appears that FDG-PET/CT parameters do not correlate with metabolic features of melanoma assessed by mass spectrometry, illustrating the potential for 13C-glucose tracing to provide additional insights into melanoma metabolism in vivo.