Multi-organ dose evaluations and the effects of heterogeneous tissue dose calculations have been retrospectively evaluated following irradiation to the whole thorax and lung in non-human primates (NHP). A clinical-based approach was established to evaluate actual doses received in the heart and lungs during whole thorax lung irradiation. Anatomical structure and organ densities have been introduced in the calculations to show the effects of dose distribution through heterogeneous tissue. Mean organ doses received by non-human primates undergoing whole thorax lung irradiations were calculated using a treatment planning system that is routinely used in clinical radiation oncology. The doses received by non-human primates irradiated following conventional dose calculations have been retrospectively reconstructed using computerized tomography-based, heterogeneity-corrected dose calculations. The use of dose volume descriptors for irradiation to organs at risk and tissue exposed to radiation is introduced. Mean and partial-volume doses to lung and heart are presented and contrasted. The importance of exact dose definitions is highlighted, and the relevance of precise dosimetry to establish organ-specific dose response relationships in NHP models of acute and delayed effects of acute radiation exposure is emphasized.