Objectives: To assess the diagnostic accuracy of computed tomographic (CT) perfusion technique in discriminating recurrent nasopharyngeal carcinoma (NPC) after radiation therapy.
Methods: Forty-eight patients with a pathologic finding as reference standards were divided into 2 groups, recurrent and nonrecurrent NPCs. Perfusion parameters blood flow (BF), blood volume (BV), permeability surface (PS), and mean transit time were statistically analyzed. A receiver operating characteristic curve was used to study whether CT perfusion parameters could aid in detecting recurrent NPC.
Results: Blood flow, BV, and PS values between recurrent NPC (n = 27) and nonrecurrent NPC (n = 21) were 526.8 (168.1) versus 312.1 (214.4) mL/100 g per minute, 35.1 (23.6) versus 9.2 (8.0) (ml/100 g), and 53.4 (34.3) versus 17.6 (14.7) mL/100 g per minute, respectively. There was a significant difference between these 2 groups (P < 0.01). Mean transit time values in these 2 groups were 3.5 (2.0) versus 4.3 (2.7) seconds; there was no statistical difference. To optimize sensitivity and specificity, BF, BV, and PS threshold values for differentiating between recurrent and nonrecurrent NPCs were 537.20 mL/100 g per minute, 37.18 (ml/100 g), and 57.34 mL/100 g per minute, respectively. According to threshold values of BF, BV, and PS, sensitivity and specificity for distinguishing recurrent and nonrecurrent NPCs were 92.6% and 76.2%, 96.3% and 81%, and 81.5% and 61.9%, respectively.
Conclusions: The CT perfusion technique may be helpful to find patients with recurrent NPC after radiation therapy.