We propose the modulation of dispersion to prevent collapse of planar pulsed beams which propagate in Ken-type selffocusing optical media. As a result, we find a new type of two-dimensional spatio-temporal solitons stabilized by dispersion management. We have studied the existence and properties of these solitary waves both analytically and numerically. We show that the adequate choice ofthe modulation parameters optimizes the stabilization ofthe pulse.