ERRATUM

In 1, there was a mistake in the expressions in the top row of Figure 4. The wording of the figure caption has also been clarified. The corrected figure is shown below.

Figure 4.

Types of molecular exams performed. Numbers outside circles correspond to total centers participating from each country. Numbers inside circles correspond to total estimated annual cases of brain tumor concerned by the survey in each country. HDI = human development index. Plots are given for individual countries and for all countries and grouped countries according to IDH.

The Publisher apologizes for the errors.