FET-PET assessed recurrence pattern after radio-chemotherapy in newly diagnosed patients with glioblastoma is influenced by MGMT methylation status.
OBJECTIVE
The aim of the present study was to evaluate factors predicting the recurrence pattern determined by [(18)F]FET-PET imaging in patients with newly diagnosed glioblastoma after combined radio-chemotherapy treated according to the EORTC/NCIC trial.


METHODS
Seventy-nine patients with newly diagnosed GBM treated with radiotherapy plus temozolomide (75 mg/m(2)/d) followed by adjuvant cyclic (5/28 days) temozolomide (150-200 mg/m(2)) were retrospectively analysed. Recurrence patterns were assessed by means of positron-emission-tomography with [(18)F]FET and additional MRI; in 54 patients MGMT methylation status was evaluated.


RESULTS
Whilst 49.4% of the patients had an in-field recurrence, 12.6% an ex-field recurrence and 3.8% a recurrence at the field margin, 34.2% of the patients did not relapse during follow-up (median 595 days). Considering all patients included in this study, 41.5% (12/29) of the MGMT methylated population had no relapse, 37.9% (11/29) had an in-field-recurrence and 20.7% (6/29) an ex-field/marginal recurrence, whilst 28.0% (7/25) of the MGMT unmethylated population had no relapse, 64.0% (16/25) had an in-field-recurrence and 8.0% (2/25) an ex-field/marginal recurrence (p=0.15).


CONCLUSIONS
After the administration of temozolomide concomitant with and adjuvant to radiotherapy in patients with glioblastoma, the pattern determined by [(18)F]FET-PET seems to be associated with MGMT methylation status.
Department of Radiation Oncology, Ludwig-Maximilians-University Munich, Germany.
Maximilian
M
Niyazi
Oliver
O
Schnell
Bogdana
B
Suchorska
Silke Birgit
SB
Schwarz
Ute
U
Ganswindt
Julia
J
Geisler
Peter
P
Bartenstein
Friedrich-Wilhelm
FW
Kreth
Jörg-Christian
JC
Tonn
Sabina
S
Eigenbrod
Claus
C
Belka
Christian
C
la Fougère
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001932:Brain Neoplasms / Q000235:genetics / Q000401:mortality / Q000628:therapy*; D059248:Chemoradiotherapy; D019175:DNA Methylation; D015254:DNA Modification Methylases / Q000235:genetics*; D045643:DNA Repair Enzymes / Q000235:genetics*; D005260:Female; D005909:Glioblastoma / Q000235:genetics / Q000401:mortality / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography; D025521:Tumor Suppressor Proteins / Q000235:genetics*; D014443:Tyrosine / Q000031:analogs & derivatives*
D025521:Tumor Suppressor Proteins; C545932:(18F)fluoroethyltyrosine; D014443:Tyrosine; D015254:DNA Modification Methylases; C515491:MGMT protein, human; D045643:DNA Repair Enzymes