MRI during radiotherapy of glioblastoma : Does MRI allow for prognostic stratification?
OBJECTIVE
To evaluate the role of magnetic resonance imaging (MRI) as a predictor for the clinical course in patients with glioblastoma.


METHODS
In 64 patients with glioblastoma undergoing (chemo)radiotherapy MRI studies were obtained before radiation, after 30 gray (Gy), after 60 Gy and during follow-up. MRI findings were assigned to categories: definite progression, questionable progression, no change. Patients were followed clinically.


RESULTS
At 30 Gy, 23 of 64 patients (36 %) demonstrated definite (dp; n = 15) or questionable (qp; n = 8) progression; in 41/64 (64 %) no change was found compared with preradiation MRI. After radiotherapy at 60 Gy, 26 of 64 (41 %) patients showed dp (n = 18) or qp (n = 8). In 2 cases with qp at the 30 Gy MRI, progress was unquestionable in the 60 Gy MRI study. In the 64 patients, 5 of the 60 Gy MRIs showed dp/qp after being classified as no change at the 30 Gy MRI, 2 of the 30 Gy MRIs showed qp, while the 60 Gy MRI showed tumour regression and 3 fulfilled the criteria for pseudoprogression during ongoing radiotherapy. The 30 Gy study allowed for prognostic stratification: dp/qp compared to stable patients showed median survival of 10.5 versus 20 months.


CONCLUSIONS
MR follow-up after 30 Gy in patients undergoing (chemo)radiotherapy for glioblastoma allows prognostic appraisal. Pseudoprogression has to be taken into account, though rare in our setting. Based on these findings, early discussion of treatment modification is possible.
Radiologische Klinik, FE Strahlentherapie, Universitätsklinik Bonn, Sigmund-Freud-Str. 25, 53105, Bonn, Germany. christina.leitzen@ukb.uni-bonn.de.
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Leitzen
Radiologische Klinik, FE Strahlentherapie, Universitätsklinik Bonn, Sigmund-Freud-Str. 25, 53105, Bonn, Germany.
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Wilhelm-Buchstab
Radiologische Klinik, FE Strahlentherapie, Universitätsklinik Bonn, Sigmund-Freud-Str. 25, 53105, Bonn, Germany.
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Schmeel
Radiologische Klinik, FE Strahlentherapie, Universitätsklinik Bonn, Sigmund-Freud-Str. 25, 53105, Bonn, Germany.
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Garbe
Radiologische Klinik, Universitätsklinik Bonn, Bonn, Germany.
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Greschus
Radiologische Klinik, FE Strahlentherapie, Universitätsklinik Bonn, Sigmund-Freud-Str. 25, 53105, Bonn, Germany.
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Müdder
Radiologische Klinik, FE Strahlentherapie, Universitätsklinik Bonn, Sigmund-Freud-Str. 25, 53105, Bonn, Germany.
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Oberste-Beulmann
Radiologische Klinik, FE Strahlentherapie, Universitätsklinik Bonn, Sigmund-Freud-Str. 25, 53105, Bonn, Germany.
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Simon
Radiologische Klinik, Universitätsklinik Bonn, Bonn, Germany.
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Schild
Radiologische Klinik, FE Strahlentherapie, Universitätsklinik Bonn, Sigmund-Freud-Str. 25, 53105, Bonn, Germany.
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Schüller
D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000000981:diagnostic imaging / Q000401:mortality* / Q000532:radiotherapy*; D005260:Female; D005858:Germany / Q000453:epidemiology; D005909:Glioblastoma / Q000000981:diagnostic imaging / Q000401:mortality* / Q000532:radiotherapy*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011379:Prognosis; D011879:Radiotherapy Dosage; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D015996:Survival Rate; D016896:Treatment Outcome
Chemoradiotherapy; Magnetic resonance imaging; Prognosis; Radiotherapy; Survival analysis