Hippocampal avoidance techniques have demonstrable advantages in preservation of short-term memory when delivering whole brain radiation. As with many novel radiation treatments, however, HA-WBRT planning is labor intensive and quite variable across practices. But it’s 2022 so auto-planning is coming to the rescue. Here is a dosimetric evaluation of version 2 of Varian’s RapidPlan for HA-WBRT (now publicly available). It uses four full coplanar arcs with collimator positions set at 0, 45, 90 and 315 degrees. The program runs without any input after “single-click” initiation and takes an average of 76 minutes to complete planning. When compared to Version 1 based on the NRG-CC001 protocol, Version 2 notably improved homogeneity, target conformation, and hippocampal sparing. Re: homogeneity, the target volume receiving ≥ 105% of prescription was decreased from 35% to 6%. While coverage was maintained—minimum dose to 98% of target was 28.1-28.3 Gy with both—the minimum dose to the hottest 2% of the target was decreased from 32.7 Gy to 31.8 Gy. Finally, mean hippocampal dose was decreased from 8.1 Gy to 7.5 Gy. | Liu, Med Dosim 2022
