TY - JOUR T1 - <strong>Comparison of visual and semiquantitative analysis of C-11 Methionine PET/CT for the differentiation of recurrent brain tumors from radiation necrosis after radiotherapy.</strong> JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1503 LP - 1503 VL - 60 IS - supplement 1 AU - Shingo Baba AU - Takuro Isoda AU - Yoshiyuki Kitamura AU - Ryo Somehara AU - Akio Hiwatashi AU - Saiji Ohga AU - Nobuhiro Hata AU - Masayuki Sasaki AU - Hiroshi Honda Y1 - 2019/05/01 UR - http://jnm.snmjournals.org/content/60/supplement_1/1503.abstract N2 - 1503Background: C-11Methionine positron emission tomography has reported to be useful to distinguish brain tumor recurrence from radiation necrosis. We undertook this study to directly compare visual and semiquantitative analysis for the evaluation of recurrence in brain tumors. Methods: Thirty-nine patients with a history of treated brain tumors (32 primary brain tumor and 7 metastatic tumor) referred for evaluation of recurrent disease were initially included in the study. There were 24 males and 15 females (mean age: 39.1. ± 15.4 years; range: 15 to 69 years). All patients are suspected recurrence, persistence, or necrotic post-therapeutic changes and underwent the MET PET/CT study. Visual image interpretation was performed independently by 2 PET physicians using the fused PET/CT images. Images were also analyzed semiquantitatively using ratio of SUVmax of tumor and normal contralateral white matter (T/Nw) and grey matter (T/Ng). Imaging results were compared with histopathology on tumor excision or biopsy in 12 patients and with clinical follow-up in 27 patients. Results: The final diagnosis was tumor recurrence in 28 patients and no recurrence/stable disease in 11 patients. Visual analyses were positive in 25 (64.1%) and negative in 9 (35.9%). The sensitivity, specificity and accuracy were 82.1%, 81.8% and 82.1% respectively. For the semiquantitative analysis, positive cases were seen in 26 (66.7%) (TNw) and 25 (64.1%) (TNg). The sensitivity, specificity and accuracy were [89.3(TNw); 85.7(TNg)], [90.9(TNw); 90.9(TNg)] and [89.7(TNw); 87.2(TNg)] respectively. Highest AUC of 0.93 was seen in TNw using the cut-off value of 1.95. There was no statistically significant differences among three methods. Conclusions: Although, it was a slight difference, diagnostic performance using semiquantitative analysis using T/Nw was the best among the three method used in this study. MET-PET/CT was a useful technique to differentiate post-therapeutic changes from tumor presence in treated patients with brain tumor in whom diagnosis was nonconclusive, ER -