Radiological evaluation of low-grade glioma: time to embrace quantitative data?

Excerpt

The imaging modality that most of us rely upon in the management of the diffuse low-grade glioma (LGG) is MRI, with T1, T1 contrast enhanced, T2/FLAIR, perfusion and diffusion weighted imaging being the minimum core [4]. In addition to assess image appearance at a time point using different MRI sequences, the longitudinal information may also provide relevant information. The typical LGG is characterized by continuous slow and infiltrative growth [10, 12]. In cases where the diagnosis is unclear the radiological demonstration of growth may guide treatment decisions. In addition, some centers still want to establish growth of a suspected LGG prior to referral to neurosurgery or before surgical resection, even though the traditional “wait-and-scan” until malignant transformation should clearly be avoided [8]. For these purposes, reliable measurement of growth is key. However, the routine assessment of lesion volume or even lesion diameter is lacking in many institutions. This may lead to underestimation of growth dynamics, as demonstrated by Gui and colleagues in this issue of Acta Neurochirurgica [5]. The radiologists reported “growth” when there was more than 20% increase of the volume. So called “stable lesions” were associated with approximately 10% increase in volume. This disturbing finding is in line with our previous report [7]. …