Mismatch areas. T2-w image showing segmented irradiation effect and 16.2Gy isodose encompassing the corresponding tolerance dose volume. A very pronounced shift of the irradiation effect with respect to the isodoses is shown to illus-trate the likely maximum inaccuracy of catheter positioning. Mismatch areas in which we observed a dose response at doses smaller than the tolerance dose of the total irradiation effect are indexed with "MA+" and mismatch areas in which we did not observe a dose response at doses higher than the tolerance dose of the total irradiation effect are indexed with "MA- ".