The symposium focused on the proposed mechanisms of action and strategies for clinical translation of the novel, unconventional spatial-fractionated and dose-rate modification modalities of GRID, LATTICE and FLASH radiotherapy. Clinical translation sections focused on developing a consensus approach to clinical utilization and for clinical trial design. A practical planning workshop walked both inexperienced and experienced users of these modalities through the clinical and physics considerations of delivering these modalities. Mechanisms for synergism of these techniques with other modalities such as immunotherapy, conventionally fractionated radiotherapy, and proton therapy were also discussed.