Diagnosis of Pseudoprogression Following Lomustine-Temozolomide Chemoradiation in Newly Diagnosed Glioblastoma Patients Using FET-PET.
Clin Cancer Res
; 27(13): 3704-3713, 2021 07 01.
Article
in En
| MEDLINE
| ID: mdl-33947699
ABSTRACT
PURPOSE:
The CeTeG/NOA-09 phase III trial demonstrated a significant survival benefit of lomustine-temozolomide chemoradiation in patients with newly diagnosed glioblastoma with methylated O6-methylguanine-DNA methyltransferase (MGMT) promoter. Following lomustine-temozolomide chemoradiation, late and prolonged pseudoprogression may occur. We here evaluated the value of amino acid PET using O-(2-[18F]fluoroethyl)-l-tyrosine (FET) for differentiating pseudoprogression from tumor progression. EXPERIMENTALDESIGN:
We retrospectively identified patients (i) who were treated off-study according to the CeTeG/NOA-09 protocol, (ii) had equivocal MRI findings after radiotherapy, and (iii) underwent additional FET-PET imaging for diagnostic evaluation (number of scans, 1-3). Maximum and mean tumor-to-brain ratios (TBRmax, TBRmean) and dynamic FET uptake parameters (e.g., time-to-peak) were calculated. In patients with more than one FET-PET scan, relative changes of TBR values were evaluated, that is, an increase or decrease of >10% compared with the reference scan was considered as tumor progression or pseudoprogression. Diagnostic performances were evaluated using ROC curve analyses and Fisher exact test. Diagnoses were confirmed histologically or clinicoradiologically.RESULTS:
We identified 23 patients with 32 FET-PET scans. Within 5-25 weeks after radiotherapy (median time, 9 weeks), pseudoprogression occurred in 11 patients (48%). The parameter TBRmean calculated from the FET-PET performed 10 ± 7 days after the equivocal MRI showed the highest accuracy (87%) to identify pseudoprogression (threshold, <1.95; P = 0.029). The integration of relative changes of TBRmean further improved the accuracy (91%; P < 0.001). Moreover, the combination of static and dynamic parameters increased the specificity to 100% (P = 0.005).CONCLUSIONS:
The data suggest that FET-PET parameters are of significant clinical value to diagnose pseudoprogression related to lomustine-temozolomide chemoradiation.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Tyrosine
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Brain Neoplasms
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Antineoplastic Combined Chemotherapy Protocols
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Glioblastoma
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Antineoplastic Agents, Alkylating
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Positron-Emission Tomography
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Chemoradiotherapy
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Temozolomide
/
Lomustine
Type of study:
Diagnostic_studies
/
Guideline
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Observational_studies
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Prognostic_studies
/
Risk_factors_studies
Limits:
Adult
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Aged
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Female
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Humans
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Male
/
Middle aged
Language:
En
Journal:
Clin Cancer Res
Journal subject:
NEOPLASIAS
Year:
2021
Document type:
Article
Affiliation country:
Alemania