An apparatus for ablating tissue in an organ inside a body of a subject includes bringing a probe inside the body into a position in contact with the tissue to be ablated, and measuring one or more local parameters at the position using the probe prior to ablating the tissue (62). A map of the organ is displayed, showing, based on the one or more local parameters, a predicted extent of ablation of the tissue to be achieved for a given dosage of energy (64) applied at the position using the probe. The given dosage of energy is applied to ablate the tissue using the probe, and an actual extent of the ablation at the position is measured using the probe subsequent to ablating the tissue. The measured actual extent of the ablation is displayed on the map for comparison with the predicted extent (70).
