Cerebral staging of lung cancer: is one single contrast-enhanced T1-weighted three-dimensional gradient-echo sequence sufficient?
BACKGROUND
Gadolinium-enhanced magnetic resonance imaging (MRI) is the gold standard for cerebral staging in thoracic oncology. We hypothesize that a minimalist examination, consisting of a single contrast-enhanced T1-weighted three-dimensional gradient-echo sequence (CE 3D-GRE), would be sufficient for the cerebral staging of nonsymptomatic lung cancer patients.


METHODS
Seventy nonsymptomatic patients (50 % men; 62 years ± 10.2) referred for cerebral staging of a lung cancer were retrospectively included. All underwent a standard 3 T MRI examination with T1, FLAIR, T2* GRE, diffusion, and CE 3D-GRE sequences, for a total examination time of 20 min. The sole CE 3D-GRE (acquisition time: 6 min) was extracted and blindly interpreted by two radiologists in search of brain metastases. Hemorrhagic features of potential lesions and relevant incidental findings were also noted. Discrepant cases were reviewed by a third reader. The full MRI examination and follow-up studies were used as a reference to calculate sensitivity and specificity of the sole CE 3D-GRE.


RESULTS
Thirty-eight point six percent (27 out of 70) of the patients had brain metastases. Performances and reader's agreement with the sole CE 3D-GRE sequence were excellent for the diagnosis of brain metastases (sensitivity=96.3 %, specificity=100 %, κ=0.91) and incidental findings (sensitivity=85.7 %, specificity=100 %, κ=0.62) but insufficient for the identification of hemorrhages within the metastases (sensitivity=33.3 %, specificity=85.7 %, κ=0.47).


CONCLUSIONS
In the specific case of lung cancer, cerebral staging in nonsymptomatic patients can be efficiently achieved with a minimalistic protocol consisting of a single CE 3D-GRE sequence, completed if positive with a T2* sequence for hemorrhagic assessment, thus halving appointment delays.
Service de Radiologie B/Radiology Department, Nouvel Hôpital Civil-Hôpitaux Universitaires de Strasbourg, 1 place de l'hôpital, 67000, Strasbourg, France, mickael.ohana@gmail.com.
Mickaël
M
Ohana
Mi-Young
MY
Jeung
Gauthier
G
Bazille
Catherine
C
Roy
D000368:Aged; D058070:Asymptomatic Diseases; D001932:Brain Neoplasms / Q000556:secondary*; D002277:Carcinoma / Q000556:secondary*; D003287:Contrast Media; D017352:Echo-Planar Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008175:Lung Neoplasms / Q000473:pathology*; D008297:Male; D008536:Meglumine; D008875:Middle Aged; D009367:Neoplasm Staging; D018358:Neuroendocrine Tumors / Q000556:secondary*; D009942:Organometallic Compounds; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
D003287:Contrast Media; D009942:Organometallic Compounds; D008536:Meglumine; C072417:gadoterate meglumine