Segmentation of peritumoral oedema offers a valuable radiological feature of cerebral metastasis.
OBJECTIVE
Peritumoral oedema (PTO) is commonly observed on MRI in malignant brain tumours including brain metastasis (bMET) and glioblastoma multiforme (GBM). This study aimed to differentiate bMET from GBM by comparing the volume ratio of PTO to tumour lesion (Rvol).


METHODS
56 patients with solitary bMET or GBM were enrolled, and MRI was analyzed by a semi-automatic methodology based on MATLAB (Mathworks, Natick, MA). The PTO volume (Voedema) was segmented for quantification using T2 fluid-attenuated inversion-recovery images, while the tumour volume was quantified with enhanced T1 images. The quantitative volume of the tumour, PTO and the ratio of PTO to tumour were interpreted using SPSS(®) (IBM Corp., New York, NY; formerly SPSS Inc., Chicago, IL) by considering different locations and pathologies.


RESULTS
The tumour volumes of supratentorial GBM, supratentorial bMET (supra-bMET) and infratentorial bMET were 32.22 ± 21.9, 18.45 ± 17.28 and 11.40 ± 5.63 ml, respectively. The corresponding Voedema were 44.08 ± 25.84, 73.20 ± 40.35 and 23.74 ± 7.78 ml, respectively. The Voedema difference between supratentorial and infratentorial lesions is significant (p-value = 0.002). Supra-bMET has a smaller tumour volume (p-value = 0.032), but a larger PTO (p-value = 0.007). The ratio of Voedema to the tumour volume in bMET is statistically higher than that in GBM (p-value = 0.015). The cut-off ratio for identifying bMET from GBM is 3.9, with a specificity and sensitivity of 90.0% and 68.8%, respectively.


CONCLUSIONS
Segmentation is an efficient method to quantify irregular PTO. bMET possesses more extensive oedema with smaller tumour volume than does GBM. The Rvol is a valuable index to distinguish bMET from GBM.


CONCLUSIONS
This study presents a new method for the quantitation of PTO to differentiate bMET from GBM.
Department of Neurosurgery, Huashan Hospital, Shanghai, China.
Chengcheng
C
Zhou
Department of Neurosurgery, Huashan Hospital, Shanghai, China.
Zixiao
Z
Yang
Department of Radiology, Huashan Hospital, Shanghai, China.
Zhengwei
Z
Yao
Department of Radiology, Huashan Hospital, Shanghai, China.
Bo
B
Yin
Department of Radiology, Huashan Hospital, Shanghai, China.
Jiawei
J
Pan
Department of Radiology, Huashan Hospital, Shanghai, China.
Yang
Y
Yu
Department of Neurosurgery, Huashan Hospital, Shanghai, China.
Wei
W
Zhu
Department of Neurosurgery, Huashan Hospital, Shanghai, China.
Wei
W
Hua
Department of Neurosurgery, Huashan Hospital, Shanghai, China.|State Key Laboratory of Medical Neurobiology, Institute of Brain Science, Fudan University, Shanghai, China.|Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China.
Ying
Y
Mao
D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology; D001932:Brain Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000556:secondary; D004487:Edema / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D005909:Glioblastoma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000556:secondary; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity