Figure 2From: Accuracy of methionine-PET in predicting the efficacy of heavy-particle therapy on primary adenoid cystic carcinomas of the head and neckA comparison of the tumor to normal tissue ratio (TNR) prior to and following CIRT. The average values of the TNR prior to treatment and after treatment were 4.8 ± 1.5 (2.6-9.0) and 3.0 ± 1.3 (1.0-7.0), respectively, and the difference between them was significant (paired-t test, p < 0.0001).Back to article page