TY - JOUR
T1 - Final results of the prospective biomarker trial PETra
T2 - [11C]-MET-accumulation in postoperative PET/MRI predicts outcome after radiochemotherapy in glioblastoma
AU - Seidlitz, Annekatrin
AU - Beuthien-Baumann, Bettina
AU - Löck, Steffen
AU - Jentsch, Christina
AU - Platzek, Ivan
AU - Zöphel, Klaus
AU - Linge, Annett
AU - Kötzerke, J. rg
AU - Petr, Jan
AU - van den Hoff, J. rg
AU - Steinbach, J. rg
AU - Krex, Dietmar
AU - Schmitz-Schackert, Gabriele
AU - Falk, Monique
AU - Baumann, Michael
AU - Krause, Mechthild
PY - 2021/3/1
Y1 - 2021/3/1
N2 - Purpose: This prospective trial investigates the association of time to recurrence (TTR) in glioblastoma with [11C]methionine (MET) tracer uptake before postoperative radiochemotherapy (RCT) aiming to guide radiotherapy boost regions. Experimental Design: Between 2013 and 2016, 102 patients with glioblastoma were recruited. RCT was performed with concurrent and adjuvant temozolomide to a total dose of 60 Gy. Tumor residues in postresection PET and MRI were together defined as gross tumor volumes for radiotherapy treatment planning. [11C]methionine (MET)-PET/MRI was performed before RCT and at each follow-up. Results: The primary hypothesis of a longer TTR for patients without increased tracer accumulation in postoperative MET-PET was confirmed in 89 patients. With 18.9 months (95% confidence interval, 9.3-28.5 months), median TTR was significantly (P < 0.001) longer for patients without (n ¼ 29, 32.6%) as compared with 6.3 months (3.6-8.9) for patients with MET accumulation (n ¼ 60, 67.4%) in pre-RCT PET. Although MRI often did not detect all PET-positive regions, an unfavorable impact of residual tumor in postsurgical MRI (n ¼ 38, 42.7%) on TTR was observed [4.6 (4.2-5.1) vs. 15.5 months (6.0-24.9), P < 0.001]. Significant multivariable predictors for TTR were MRI positivity, PET-positive volume, and O6-methylguanine DNA methyltransferase (MGMT) hypermethylation. Conclusions: Postsurgical amino acid PET has prognostic value for TTR after RCT in glioblastoma. Because of the added value of the metabolic beyond the pure structural information, it should complement MRI in radiotherapy planning if available with reasonable effort, at least in the context of maximal therapy. Furthermore, the spatial correlation of regions of recurrence with PET-positive volumes could provide a bioimaging basis for further trials, for example, testing local radiation dose escalation.
AB - Purpose: This prospective trial investigates the association of time to recurrence (TTR) in glioblastoma with [11C]methionine (MET) tracer uptake before postoperative radiochemotherapy (RCT) aiming to guide radiotherapy boost regions. Experimental Design: Between 2013 and 2016, 102 patients with glioblastoma were recruited. RCT was performed with concurrent and adjuvant temozolomide to a total dose of 60 Gy. Tumor residues in postresection PET and MRI were together defined as gross tumor volumes for radiotherapy treatment planning. [11C]methionine (MET)-PET/MRI was performed before RCT and at each follow-up. Results: The primary hypothesis of a longer TTR for patients without increased tracer accumulation in postoperative MET-PET was confirmed in 89 patients. With 18.9 months (95% confidence interval, 9.3-28.5 months), median TTR was significantly (P < 0.001) longer for patients without (n ¼ 29, 32.6%) as compared with 6.3 months (3.6-8.9) for patients with MET accumulation (n ¼ 60, 67.4%) in pre-RCT PET. Although MRI often did not detect all PET-positive regions, an unfavorable impact of residual tumor in postsurgical MRI (n ¼ 38, 42.7%) on TTR was observed [4.6 (4.2-5.1) vs. 15.5 months (6.0-24.9), P < 0.001]. Significant multivariable predictors for TTR were MRI positivity, PET-positive volume, and O6-methylguanine DNA methyltransferase (MGMT) hypermethylation. Conclusions: Postsurgical amino acid PET has prognostic value for TTR after RCT in glioblastoma. Because of the added value of the metabolic beyond the pure structural information, it should complement MRI in radiotherapy planning if available with reasonable effort, at least in the context of maximal therapy. Furthermore, the spatial correlation of regions of recurrence with PET-positive volumes could provide a bioimaging basis for further trials, for example, testing local radiation dose escalation.
UR - https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85102533006&origin=inward
UR - https://www.ncbi.nlm.nih.gov/pubmed/33376095
U2 - https://doi.org/10.1158/1078-0432.CCR-20-1775
DO - https://doi.org/10.1158/1078-0432.CCR-20-1775
M3 - Review article
C2 - 33376095
SN - 1078-0432
VL - 27
SP - 1351
EP - 1360
JO - Clinical Cancer Research
JF - Clinical Cancer Research
IS - 5
ER -