The HEATMAP Project stands for Hematologic Effects and Toxicity Modeling to Aid Pelvic Radiotherapy. The focus of this research is to study the impact of variations in locoregional bone marrow irradiation on peripheral blood counts and hematologic toxicity. The goal is to develop bone marrow-sparing radiotherapy techniques to facilitate better delivery of concurrent and adjuvant systemic therapy. The figure above shows a HEATMAP of radiation dose distributions for patients matched to a common template using deformable image registration. The figure below is an axial cross-section of a population-based functional HEATMAP of active pelvic bone marrow, showing regions of higher proliferation (red/orange) vs. lower proliferation (blue/green), averaged over multiple patients. To the right is a schematic mathematical representation of the space-preserving NTCP model used in our research.