Fig. 3From: A retrospective dosimetry study of intensity-modulated radiotherapy for nasopharyngeal carcinoma: radiation-induced brainstem injury and dose-volume analysisReceiver operating characteristic (ROC) curve for D2% of gross tumor volume of nasopharyngeal primary lesions and their direct extensions (GTVnx D2%) (a) and Dmax (b), D1% (c), D0.1 cc (d), and D1cc (e) of the brainstem, respectively. The cutoff points for the five parameters (as the brainstem dose tolerance) were determined to be 77.26 Gy, 67.85 Gy, 60.13 Gy, 60.75 Gy, and 54.58 Gy for NPC patients treated with IMRT. D2%, near the maximum absorbed dose of GTVnx; Dmax, the maximum point dose of brainstem; D1%, the dose of 1% of the brainstem volume; D0.1 cc, the maximum dose of brainstem delivered to a volume of 0.1 ml; D1cc, the maximum dose of brainstem delivered to a volume of 1.0 mlBack to article page