Delineation and agreement of FET PET biological volumes in glioblastoma: results of the nuclear medicine credentialing program from the prospective, multi-centre trial evaluating FET PET In Glioblastoma (FIG) study—TROG 18.06

• DOI: 10.1007/s00259-023-06371-5
• Publication Date: 2023-08-11T01:01:56Z
• Authors: Nathaniel Barry; Roslyn J. Francis; Martin A. Ebert; Eng-Siew Koh; Pejman Rowshanfarzad; Ghulam Mubashar H...; Jake Kendrick; Hui K. Gan; Sze T. Lee; Eddie Lau; Bradford A. Moffat; Greg Fitt; Alisha Moore; Paul Thomas; David A. Pattison; Tim Akhurst; Ramin Alipour; Elizabeth L. Thomas; Edward Hsiao; Geoffrey P. Schembri; Peter Lin; Tam Ly; June Yap; Ian Kirkwood; Wilson Vallat; Shahroz Khan; Dayanethee Krishna; Stanley Ngai; Chris Yu; Scott Beuzeville; Tow C. Yeow; Dale Bailey; Olivia Cook; Angela Whitehead; Rachael Dykyj; Alana Rossi; Andrew Grose; Andrew M. Scott
• Keywords: Credentialing

Abstract Purpose The O-(2-[ 18 F]-fluoroethyl)- l -tyrosine (FET) PET in Glioblastoma (FIG) trial is an Australian prospective, multi-centre study evaluating FET for glioblastoma patient management. imaging timepoints are pre-chemoradiotherapy (FET1), 1-month post-chemoradiotherapy (FET2), and at suspected progression (FET3). Before participant recruitment, site nuclear medicine physicians (NMPs) underwent credentialing of delineation image interpretation. Methods Sites were required to complete contouring dynamic analysis by ≥ 2 NMPs on benchmarking cases ( n = 6) assessing biological tumour volume (BTV) (3 × FET1) interpretation FET3). Data was reviewed experts violations noted. BTV definition includes tumour-to-background ratio (TBR) threshold 1.6 with crescent-shaped background contour the contralateral normal brain. Recurrence/pseudoprogression (FET3) assessment maximum TBR (TBR max ), (time activity curve [TAC] type, time peak), qualitative assessment. Intraclass correlation coefficient (ICC) assessed agreement, variation (CoV) compared maximum/mean /TBR mean ) across cases, pairwise spatial (Dice similarity [DSC]) boundary agreement (Hausdorff distance [HD], absolute surface [MASD]). Results accrued from 21 (10 centres, each) 20 review. initial pass rate 93/119 (78.2%) 27/30 requested resubmissions completed. Violations found 25/72 (34.7%; 13/12 minor/major) FET1 22/74 (29.7%; 14/8 FET3 reports. primary reasons resubmission as follows: over-contour (15/30, 50.0%), placement (8/30, 26.7%), TAC classification (9/30, 30.0%), (7/30, 23.3%). CoV median range BTV, , 21.53% (12.00–30.10%), 5.89% (5.01–6.68%), 5.01% (3.37–6.34%), respectively. moderate excellent (ICC 0.82; 95% CI, 0.63–0.97) good (DSC 0.84 ± 0.09) (HD 15.78 8.30 mm; MASD 1.47 1.36 mm) agreement. Conclusion FIG program has increased expertise sites. robust, considerable variability observed.