NRG-CC001 protocol — A Randomized Phase III Trial of Memantine and Whole-Brain Radiotherapy With or Without Hippocampal Avoidance in Patients With Brain Metastases

The NRG CC001 trial protocol (version date 26 September 2017, copy posted on ClinicalTrials.gov for NCT02360215). Arm 1 was standard whole-brain radiotherapy with 3D conformal fields; arm 2 was IMRT-based hippocampal avoidance, both 30 Gy in 10 fractions with memantine. Sections 5.2.4–5.2.8 define the CTV and PTV, the required structures (hippocampi, the hippocampal avoidance region, lenses, optic nerves and chiasm), the normalization, the per-protocol and variation-acceptable limits for the PTV, hippocampi and optic structures, and the planning priority order. DoseLab's hippocampal avoidance table quotes section 5.2.7 directly.

The planning rules behind most hippocampal avoidance plans in the US: structure names, normalization, hippocampal and optic limits, target goals and planning priorities.