Physics and Imaging in Radiation Oncology (Apr 2024)

[18]F-fluoroethyl-l-tyrosine positron emission tomography for radiotherapy target delineation: Results from a Radiation Oncology credentialing program

  • Nathaniel Barry,
  • Eng-Siew Koh,
  • Martin A. Ebert,
  • Alisha Moore,
  • Roslyn J. Francis,
  • Pejman Rowshanfarzad,
  • Ghulam Mubashar Hassan,
  • Sweet P. Ng,
  • Michael Back,
  • Benjamin Chua,
  • Mark B. Pinkham,
  • Andrew Pullar,
  • Claire Phillips,
  • Joseph Sia,
  • Peter Gorayski,
  • Hien Le,
  • Suki Gill,
  • Jeremy Croker,
  • Nicholas Bucknell,
  • Catherine Bettington,
  • Farhan Syed,
  • Kylie Jung,
  • Joe Chang,
  • Andrej Bece,
  • Catherine Clark,
  • Mori Wada,
  • Olivia Cook,
  • Angela Whitehead,
  • Alana Rossi,
  • Andrew Grose,
  • Andrew M. Scott

Journal volume & issue
Vol. 30
p. 100568

Abstract

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Background and purpose: The [18]F-fluoroethyl-l-tyrosine (FET) PET in Glioblastoma (FIG) study is an Australian prospective, multi-centre trial evaluating FET PET for newly diagnosed glioblastoma management. The Radiation Oncology credentialing program aimed to assess the feasibility in Radiation Oncologist (RO) derivation of standard-of-care target volumes (TVMR) and hybrid target volumes (TVMR+FET) incorporating pre-defined FET PET biological tumour volumes (BTVs). Materials and methods: Central review and analysis of TVMR and TVMR+FET was undertaken across three benchmarking cases. BTVs were pre-defined by a sole nuclear medicine expert. Intraclass correlation coefficient (ICC) confidence intervals (CIs) evaluated volume agreement. RO contour spatial and boundary agreement were evaluated (Dice similarity coefficient [DSC], Jaccard index [JAC], overlap volume [OV], Hausdorff distance [HD] and mean absolute surface distance [MASD]). Dose plan generation (one case per site) was assessed. Results: Data from 19 ROs across 10 trial sites (54 initial submissions, 8 resubmissions requested, 4 conditional passes) was assessed with an initial pass rate of 77.8 %; all resubmissions passed. TVMR+FET were significantly larger than TVMR (p < 0.001) for all cases. RO gross tumour volume (GTV) agreement was moderate-to-excellent for GTVMR (ICC = 0.910; 95 % CI, 0.708–0.997) and good-to-excellent for GTVMR+FET (ICC = 0.965; 95 % CI, 0.871–0.999). GTVMR+FET showed greater spatial overlap and boundary agreement compared to GTVMR. For the clinical target volume (CTV), CTVMR+FET showed lower average boundary agreement versus CTVMR (MASD: 1.73 mm vs. 1.61 mm, p = 0.042). All sites passed the planning exercise. Conclusions: The credentialing program demonstrated feasibility in successful credentialing of 19 ROs across 10 sites, increasing national expertise in TVMR+FET delineation.

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