Target-volume-based prescription selection for specified adverse-effect levels in automated stereotactic radiosurgery.

Automated stereotactic radiosurgery (SRS) planning produced consistent dose falloff, enabling adverse-effect-relevant isodose volumes ( IDV ) to be estimated before plan generation. We derived a direct isoeffect prescription dose ( D RX ) model from previously validated target-volume ( V target ) power laws for single-isocenter automated SRS. IDV coefficients and exponents were modelled as continuous functions of relative isodose level ( RIL ), allowing D RX to be solved from V target , desired IDV , and HyTEC brain adverse-effect dose thresholds. Across held-out levels, target-level IDV residuals had a median of 0.2%, an interquartile range of [-5.2%, +7.0%], and a 95% interval of [-12.8%, +27.0%].