What does enhancement mean

in low grade gliomas?

B. Bison, M. Warmuth-Metz, M. Schneckenburger

Reference Center for Neuroradiology for the HIT-Studies of the GPOH

Departement of NeuroradiologyUniversity Hospital Würzburg, Germany

Rationale• In high grade gliomas an

intensification or new contrast enhancement (CE) is considered a sign of malignisation and therefore progression

• CE in low grade gliomas is variable and without prognostic significance

• Pilocytic astrocytomas showing a spontaneous regression (+/-NF1) always show a reduction of CE

Rationale• New or intensified CE in low grade

gliomas is frequently diagnosed as progression by outside (neuro)radiologists in the German patients of the LGG-study.

6/09 vs. 9/09

Patients• 303 pairs of MRIs of consecutive time

points• 73 patients• up to 9 pairs of MRIs per patient• patients with multifocal tumors

(n=79)• 3 categories of CE

Change of CE• increase: 35

• no change: 234– without CE: 75

• decrease: 34

Increase of CE• n = 35• 9 x size reduction (-39 bis -

2%)• 3 x same size• 23 x size increase (2-1664%)• median 14.95%• mean 125.32%

No change of CE• n = 234• 109 x size reduction (-84 to -0.02%)• 21 x no change of size• 104 x size increase (0.4 to

503.6%)• median 0%• mean 5.8%

Decrease of CE• n = 34• 12 x size increase (0.2 to

81%)• 22 x size reduction (-2 to -72%)• median -10.4%• mean -14.5%

New enhancement• n = 14 (n=3 no further MRI)

• 1 x progression next follow up• 2 x in progression• 1 x in regression• 1 x regression next follow up• 6 x stabile tumor

Conclusion• There is a statistical correlation

between CE in low grade gliomas and a change of tumor size.

• But, discrepant behaviour can be found in all groups

• No conclusion must be drawn from a change of CE alone.

• The primary staging criteria is the evolution of tumor size.

Thank you

The Reference Center for Neuroradiology for the HIT-studies and the HIT LGG-study are supported by: