Impact of [18F]FET-PET on MRI-Based Radiotherapy Target Volumes in Newly Diagnosed Glioblastoma:Results from the FET-PET in Glioblastoma (FIG) Study TROG 18.06
- Author(s)
- Koh, ES; Francis, RJ; Ninatti, G; Ruisi, I; Ebert, MA; Lau, E; Whitehead, A; Descallar, J; Barnes, EH; Lee, ST; Thomas, EL; Pinkham, MB; Back, M; Ng, SP; Bucknell, N; Gan, HK; Cook, O; Dykyj, R; Moore, A; Porter, S; Banyer, P; Scott, FE; Bailey, DL; Barry, N; Akhurst, T; Alipour, R; Bece, A; Bettingdon, C; Beuzeville, S; Chang, JH; Chua, B; Clark, C; Croker, J; Gill, S; Gorayski, P; Hsiao, E; Jung, K; Khan, S; Krishna, D; Kirkwood, I; Le, H; Lin, P; Ly, T; McGuiness, M; Ngai, S; Pattison, DA; Phillips, C; Pullar, AP; Schembri, G; Sia, J; Syed, F; Thomas, P; Vallat, W; Wada, M; Wong, D; Yap, J; Yeow, TC; Nowak, AK; Foroudi, F; Rosenthal, M; Roach, P; Adda, L; De Abreu Lourenco, R; Moffat, BA; Brighi, C; Lasocki, A; Holloway, L; Fay, M; Scott, AM;
- Journal Title
- Neuro-Oncology
- Publication Type
- Online publication before print
- Abstract
- BACKGROUND: The FET-PET in Glioblastoma (FIG) study (TROG 18.06) assessed the impact of adding FET-PET to MRI on radiotherapy gross tumor volume delineation in newly diagnosed glioblastoma. METHODS: This multicenter prospective phase 2 study evaluated participants with newly diagnosed glioblastoma IDH-wildtype undergoing post-operative MRI and FET-PET imaging before adjuvant radiotherapy, delivered according to standard MRI-based planning. The FET-PET-positive biological tumor volume (BTV) was used to derive the Hybrid (FET-PET+MRI) gross tumor volume (Hybrid-GTV). Primary outcomes were: 1) BTV excluded from the GTV defined on MRI alone (MR-GTV); 2) Hybrid-GTV excluded from the MR-GTV with both comparisons analyzed by non-overlap volume (cm3 and %), dosimetry (D98 and V95) and spatial similarity metrics; 3) clinically meaningful change in GTV non-overlap percentage volume with the addition of FET-PET. RESULTS: There were 172 participants recruited, n = 140 evaluable. Median BTV was 23.1 cm3, median MR-GTV was 32.1 cm3, and median Hybrid-GTV was 46.0 cm3. Hybrid-GTV was significantly larger than the MR-GTV (p < 0.001), with a larger Hybrid-GTV observed in 83% of cases. Comparing BTV to MR-GTV, median non-overlap volume was 10.1 cm3 and non-overlap percentage volume 53.5%. Comparing Hybrid-GTV to MR-GTV, median non-overlap volume was 14.9 cm3 and non-overlap percentage volume 33.9%. D98 and V95 were lower for the Hybrid-GTV than for the MR-GTV, suggesting lower dose coverage. Applying a > 20% non-overlap percentage volume threshold, 76% of participants had a meaningful change in GTV with the addition of FET-PET. CONCLUSION: FET-PET differed significantly from MRI-based GTV delineation, with its incorporation leading to a clinically meaningful change in GTV in the majority of participants.; We investigated whether an advanced brain scan called FET-PET could help plan radiotherapy after surgery for newly diagnosed glioblastoma, the most aggressive brain cancer. We found that adding FET-PET to standard magnetic resonance imaging (MRI) scans showed more clearly where the tumour may remain and how far it extended. FET-PET could help oncologists better target the abnormal areas with radiotherapy. Our findings suggest that adding FET-PET to MRI scans led to changes in the radiotherapy treatment volume. In future, adding FET-PET may help make treatment more effective by better coverage and thus control of the brain cancer, leading to improved outcomes.; eng
- Keywords
- Fet pet; glioblastoma; radiotherapy planning
- Department(s)
- Cancer Imaging; Radiation Oncology; Medical Oncology
- Publisher's Version
- https://doi.org/10.1093/neuonc/noag229
- Open Access at Publisher's Site
https://doi.org/10.1093/neuonc/noag229- Terms of Use/Rights Notice
- Refer to copyright notice on published article.
Creation Date: 2026-10-12 05:40:46
Last Modified: 2026-10-12 05:41:16