학술논문
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
Document Type
Original Paper
Author
Barry, Nathaniel; Francis, Roslyn J.; Ebert, Martin A.; Koh, Eng-Siew; Rowshanfarzad, Pejman; Hassan, Ghulam Mubashar; Kendrick, Jake; Gan, Hui K.; Lee, Sze T.; Lau, Eddie; Moffat, Bradford A.; Fitt, Greg; Moore, Alisha; Thomas, Paul; Pattison, David A.; Akhurst, Tim; Alipour, Ramin; Thomas, Elizabeth L.; Hsiao, Edward; Schembri, Geoffrey P.; Lin, Peter; Ly, Tam; Yap, June; Kirkwood, Ian; Vallat, Wilson; Khan, Shahroz; Krishna, Dayanethee; Ngai, Stanley; Yu, Chris; Beuzeville, Scott; Yeow, Tow C.; Bailey, Dale; Cook, Olivia; Whitehead, Angela; Dykyj, Rachael; Rossi, Alana; Grose, Andrew; Scott, Andrew M.
Source
European Journal of Nuclear Medicine and Molecular Imaging. 50(13):3970-3981
Subject
Language
English
ISSN
1619-7070
1619-7089
1619-7089
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 PET for glioblastoma patient management. FET PET 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 FET PET delineation and image interpretation.Methods: Sites were required to complete contouring and dynamic analysis by ≥ 2 NMPs on benchmarking cases (n = 6) assessing biological tumour volume (BTV) delineation (3 × FET1) and image interpretation (3 × FET3). Data was reviewed by experts and violations noted. BTV definition includes tumour-to-background ratio (TBR) threshold of 1.6 with crescent-shaped background contour in the contralateral normal brain. Recurrence/pseudoprogression interpretation (FET3) required assessment of maximum TBR (TBRmax ), dynamic analysis (time activity curve [TAC] type, time to peak), and qualitative assessment. Intraclass correlation coefficient (ICC) assessed volume agreement, coefficient of variation (CoV) compared maximum/mean TBR (TBRmax /TBRmean ) across cases, and pairwise analysis assessed spatial (Dice similarity coefficient [DSC]) and boundary agreement (Hausdorff distance [HD], mean absolute surface distance [MASD]).Results: Data was accrued from 21 NMPs (10 centres, n ≥ 2 each) and 20 underwent review. The initial pass rate was 93/119 (78.2%) and 27/30 requested resubmissions were completed. Violations were found in 25/72 (34.7%; 13/12 minor/major) of FET1 and 22/74 (29.7%; 14/8 minor/major) of FET3 reports. The primary reasons for resubmission were as follows: BTV over-contour (15/30, 50.0%), background placement (8/30, 26.7%), TAC classification (9/30, 30.0%), and image interpretation (7/30, 23.3%). CoV median and range for BTV, TBRmax , and TBRmean were 21.53% (12.00–30.10%), 5.89% (5.01–6.68%), and 5.01% (3.37–6.34%), respectively. BTV agreement was moderate to excellent (ICC = 0.82; 95% CI, 0.63–0.97) with good spatial (DSC = 0.84 ± 0.09) and boundary (HD = 15.78 ± 8.30 mm; MASD = 1.47 ± 1.36 mm) agreement.Conclusion: The FIG study credentialing program has increased expertise across study sites. TBRmax and TBRmean were robust, with considerable variability in BTV delineation and image interpretation observed.