Intensity inhomogeneities often occur in medical images, especially when using magnetic resonance imaging. In these images, the standard Chan-and-Vese levelset segmentation method may not work properly, as it assumes constant intensity distributions for foreground and background. Recently, a novel method was published that models the intensities as piece-wise smooth, and thus is more suitable to segment images with intensity homogeneities. However, this method was not yet implemented in ITK. This submission introduces our implementation of the region-scalable-fitting levelset segmentation method within the ITKv4 levelset framework.