In:
EJNMMI Research, Springer Science and Business Media LLC, Vol. 5, No. 1 ( 2015-12)
Kurzfassung:
High-grade gliomas (HGGs) express somatostatin receptors (SSTR), rendering them candidates for peptide receptor radionuclide therapy (PRRT). Our purpose was to evaluate the potential of 68 Ga-DOTA-1-Nal 3 -octreotide ( 68 Ga-DOTANOC) or 68 Ga-DOTA-Tyr 3 -octreotide ( 68 Ga-DOTATOC) to target SSTR subtype 2 (SSTR 2 ) in HGGs, and to study the association between SSTR 2 expression and established biomarkers. Methods Twenty-seven patients (mean age 52 years) with primary or recurrent HGG prospectively underwent 68 Ga-DOTA-peptide positron emission tomography/computed tomography (PET/CT) before resection. Maximum standardized uptake values (SUVmax) and receptor binding potential (BP) were calculated on PET/CT and disruption of blood–brain barrier (BBB) from contrast-enhanced T1-weighted magnetic resonance imaging (MRI-T1-Gad). Tumor volume concordance between PET and MRI-T1-Gad was assessed by Dice similarity coefficient (DC) and correlation by Spearman’s rank. Immunohistochemically determined SSTR 2 status was compared to receptor imaging findings, prognostic biomarkers, and survival with Kruskal-Wallis, Pearson chi-square, and multivariate Cox regression, respectively. Results All 19 HGGs with disrupted BBB demonstrated tracer uptake. Tumor SUVmax (2.25 ± 1.33) correlated with MRI-T1-Gad ( r = 0.713, P = 0.001) although DC 0.41 ± 0.19 suggested limited concordance. SSTR 2 immunohistochemistry was regarded as positive in nine HGGs (32%) but no correlation with SUVmax or BP was found. By contrast, SSTR 2 expression was associated with IDH1 mutation ( P = 0.007), oligodendroglioma component ( P = 0.010), lower grade ( P = 0.005), absence of EGFR amplification ( P = 0.021), and longer progression-free survival (HR 0.161, CI 0.037 to 0.704, P = 0.015). Conclusions In HGGs, uptake of 68 Ga-DOTA-peptides is associated with disrupted BBB and cannot be predicted by SSTR 2 immunohistochemistry. Thus, PET/CT shows limited value to detect HGGs suitable for PRRT. However, high SSTR 2 expression portends favorable outcome along with established biomarkers such as IDH1 mutation. Trial registration ClinicalTrials.gov NCT01460706
Materialart:
Online-Ressource
ISSN:
2191-219X
DOI:
10.1186/s13550-015-0106-2
Sprache:
Englisch
Verlag:
Springer Science and Business Media LLC
Publikationsdatum:
2015
ZDB Id:
2619892-7
