Amide proton transfer imaging to predict tumor response to neoadjuvant chemotherapy in locally advanced rectal cancer. Nishie Akihiro,Asayama Yoshiki,Ishigami Kousei,Ushijima Yasuhiro,Takayama Yukihisa,Okamoto Daisuke,Fujita Nobuhiro,Tsurumaru Daisuke,Togao Osamu,Sagiyama Koji,Manabe Tatsuya,Oki Eiji,Kubo Yuichiro,Hida Tomoyuki,Hirahashi-Fujiwara Minako,Keupp Jochen,Honda Hiroshi Journal of gastroenterology and hepatology BACKGROUND AND AIM:The amount of proteins and peptides can be estimated with amide proton transfer (APT) imaging. Previous studies demonstrated the usefulness of APT imaging to predict tumor malignancy. We determined whether APT imaging can predict the tumor response to neoadjuvant chemotherapy (NAC) in patients with locally advanced rectal cancer (LARC). METHODS:Seventeen patients with LARC who underwent a pretherapeutic magnetic resonance examination including APT imaging and NAC (at least two courses) were enrolled. The APT-weighted imaging (WI) signal intensity (SI) (%) was defined as magnetization transfer ratio asymmetry (MTR ) at the offset of 3.5 ppm. Each tumor was histologically evaluated for the degree of degeneration and necrosis and then classified as one of five histological Grades (0, none; 1a, less than 1/3; 1b, 1/3 to 2/3; 2, more than 2/3; 3, all). We compared the mean APTWI SIs of the tumors between the Grade 0/1a/1b (low-response group) and Grade 2/3 (high-response group) by Student's t-test. We used receiver operating characteristics curves to determine the diagnostic performance of the APTWI SI for predicting the tumor response. RESULTS:The mean APTWI SI of the low-response group (n = 12; 3.05 ± 1.61%) was significantly higher than that of the high-response group (n = 5; 1.14 ± 1.13%) (P = 0.029). The area under the curve for predicting the tumor response using the APTWI SI was 0.87. When ≥2.75% was used as an indicator of low-response status, 75% sensitivity and 100% specificity of the APTWI SI were obtained. CONCLUSION:Pretherapeutic APT imaging can predict the tumor response to NAC in patients with LARC. 10.1111/jgh.14315

Differentiation of Malignant and Benign Head and Neck Tumors with Amide Proton Transfer-Weighted MR Imaging. Yu Lu,Li Chunmei,Luo Xiaojie,Zhou Jinyuan,Zhang Chen,Zhang Yi,Chen Min Molecular imaging and biology PURPOSE:To prospectively evaluate the feasibility and capability of amide proton transfer-weighted (APTw) imaging for the characterization of head and neck tumors. PROCEDURES:Twenty-nine consecutive patients with suspected head and neck tumors were enrolled in this study and underwent APTw magnetic resonance imaging (MRI) on a 3.0-T MRI scanner. The patients were divided into malignant (n = 16) and benign (n = 13) groups, based on pathological results. A map of magnetization transfer ratio asymmetry at 3.5 ppm [MTR (3.5 ppm)] was generated for each patient. Interobserver agreement was evaluated and comparisons of MTR (3.5 ppm) were made between the malignant and benign groups. Receiver operating characteristic analysis was used to determine the appropriate threshold value of MTR (3.5 ppm) for the differentiation of malignant from benign tumors. RESULTS:The intraclass correlation coefficients of the malignant and benign groups were 0.96 and 0.90, respectively, which indicated a good interobserver agreement. MTR (3.5 ppm) was significantly higher for the malignant group (3.66 ± 1.15 %) than for the benign group (1.94 ± 0.93 %, P < 0.001). APTw MRI revealed an area under the curve of 0.904 in discriminating these two groups, with a sensitivity of 81.3 %, a specificity of 92.3 %, and an accuracy of 86.2 %, at the threshold of 2.62 % of MTR (3.5 ppm). CONCLUSIONS:APTw MRI is feasible for use in the head and neck tumors and is a valuable imaging biomarker for distinguishing malignant from benign lesions. 10.1007/s11307-018-1248-1

Amide proton transfer imaging can predict tumor grade in rectal cancer. Nishie Akihiro,Takayama Yukihisa,Asayama Yoshiki,Ishigami Kousei,Ushijima Yasuhiro,Okamoto Daisuke,Fujita Nobuhiro,Tsurumaru Daisuke,Togao Osamu,Manabe Tatsuya,Oki Eiji,Kubo Yuichiro,Hida Tomoyuki,Hirahashi-Fujiwara Minako,Keupp Jochen,Honda Hiroshi Magnetic resonance imaging PURPOSE:To prospectively investigate the ability of amide proton transfer (APT) imaging, in comparison with that of diffusion-weighted imaging (DWI), to predict pathological factors in rectal cancer. MATERIALS AND METHODS:Twenty-two patients who underwent MR examination including APT imaging and DWI for evaluation of rectal cancer were enrolled. APT signal intensity (SI) was defined as the magnetization transfer asymmetry at 3.5 ppm and was mapped. An apparent diffusion coefficient (ADC) map was generated using b-values of 0, 500 and 1000 s/mm. APT SI and ADC were calculated by placing regions-of-interest in the tumors on these maps. Pathological factors including tumor size and tumor grade were also evaluated. Average APT SIs or ADCs were compared between the two groups classified based on each pathological factor using Student's t-test. RESULTS:The average APT SI of tumors with diameters of 5 cm or more (3.09 ± 1.41%) was significantly higher than that of tumors with diameters < 5 cm (1.83 ± 1.38%). In addition, the average APT SI of moderately differentiated adenocarcinoma (2.82 ± 1.51%) was significantly higher than that of well-differentiated adenocarcinoma (1.24 ± 0.57%). There was no difference in ADC between groups classified based on any pathological factor. CONCLUSION:Amide proton transfer imaging can predict tumor grade in rectal cancer. 10.1016/j.mri.2018.04.017

Can amide proton transfer-weighted imaging differentiate tumor grade and predict Ki-67 proliferation status of meningioma? Yu Hao,Wen Xinrui,Wu Pingping,Chen Yueqin,Zou Tianyu,Wang Xianlong,Jiang Shanshan,Zhou Jinyuan,Wen Zhibo European radiology OBJECTIVES:To determine the utility of the amide proton transfer-weighted MR imaging in differentiating the WHO grade and predict proliferative activity of meningioma. METHODS:Fifty-three patients with WHO grade I meningiomas and 26 patients with WHO grade II meningiomas underwent conventional and APT-weighted sequences on a 3.0 Tesla MR before clinical intervention. The APT-weighted (APTw) parameters in the solid tumor region were obtained and compared between two grades using the t test; the receiver operating characteristic (ROC) curve was used to assess the best parameter for predicting the grade of meningiomas. Pearson's correlation coefficient was calculated between the APTw and Ki-67 labeling index in meningiomas. RESULTS:The APTw and APTw values were not significantly different between WHO grade I and grade II meningiomas (p = 0.103 and p = 0.318). The APTw value was higher and the APTw value was lower in WHO grade II meningiomas than in WHO grade I tumors (p = 0.027 and p = 0.019). But the APTw was higher and the APTw was lower in microcystic meningiomas than in WHO grade II meningiomas (p = 0.001 and p = 0.006). The APTw combined with APTw showed the best diagnostic performance in predicting the grade of meningiomas with an AUC of 0.772. The APTw value was positively correlated with Ki-67 labeling index (r = 0.817, p < 0.001) in meningiomas; the regression equation for the Ki-67 labeling index (%) (Y) and APTw (%) (X) was Y = 4.9 × X - 12.4 (R = 0.667, p < 0.001). CONCLUSION:As a noninvasive imaging method, the ability of APTw-MR imaging in differentiating the grade of meningiomas is limited, but the technology can be used to predict the proliferative activity of meningioma. KEY POINTS:• The APTw value was higher and the APTw value was lower in WHO grade II meningioma than in grade I tumors. • The APTw value was higher and the APTw value was lower in microcystic meningiomas than in WHO grade II meningiomas. • The APTw value was positively correlated with meningioma proliferation index. 10.1007/s00330-019-06115-w