Figure 2From: 3D Variation in delineation of head and neck organs at riskVariation in the definition of organ at risk volume. Volumes of the organs at risk according to observer 1(○), 2(□), 3(×), 4(Δ) and 5 (+). CTplan is planning CT and CTrep is repeat CT scan. The right parotid gland data contains 5 patients instead of 6 because of the exclusion of one gland (of patient 4) due to tumour infiltration.Back to article page