title: Predictive value of T2 relative signal intensity for response to somatostatin analogs in newly diagnosed acromegaly.
abstract: BACKGROUND
  The difficulty of predicting the efficacy of somatostatin analogs (SSA) is not fully resolved. Here, we quantitatively evaluated the predictive value of relative signal intensity (rSI) on T1- and T2-weighted magnetic resonance imaging (MRI) for the short-term efficacy (3 months) of SSA therapy in patients with active acromegaly and assessed the correlation between MRI rSI and expression of somatostatin receptors (SSTR).
  
  
  METHODS
  This was a retrospective review of prospectively recorded data. Ninety-two newly diagnosed patients (37 males and 55 females) with active acromegaly were recruited. All patients were treated with pre-surgical SSA, followed by reassessment and transspenoidal surgery. rSI values were generated by calculating the ratio of SI in the tumor to the SI of normal frontal white matter. The Youden indices were calculated to determine the optimal cutoff of rSI to determine the efficacy of SSA. The correlation between rSI and expression of SSTR2/5 was analyzed by the Spearman rank correlation coefficient.
  
  
  RESULTS
  T2 rSI was strongly correlated with biochemical sensitivity to SSA. The cutoff value of T2 rSI to distinguish biochemical sensitivity was 1.205, with a positive predictive value (PPV) of 81.5 % and a negative predictive value (NPV) of 77.3 %. No correlation was found between MRI and tumor size sensitivity. Moreover, T2 rSI was negatively correlated with the expression of SSTR5.
  
  
  CONCLUSIONS
  T2 rSI correlates with the expression of SSTR5 and quantitatively predicts the biochemical efficacy of SSA in acromegaly.
authors: Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Fudan University, 12 Wulumuqi Zhong Road, Shanghai, 200040, China.|Shanghai Pituitary Tumor Center, Shanghai, China.
authors: Ming
authors: M
authors: Shen
authors: Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Fudan University, 12 Wulumuqi Zhong Road, Shanghai, 200040, China.|Shanghai Pituitary Tumor Center, Shanghai, China.
authors: Qilin
authors: Q
authors: Zhang
authors: Shanghai Pituitary Tumor Center, Shanghai, China.|Department of Endocrinology and Metabolism, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors: Wenjuan
authors: W
authors: Liu
authors: Department of Endocrinology and Metabolism, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.|Division of Endocrinology, the Second Affiliated Hospital, Soochow University, Suzhou, China.
authors: Meng
authors: M
authors: Wang
authors: Shanghai Pituitary Tumor Center, Shanghai, China.|Department of Neuropathology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors: Jingjing
authors: J
authors: Zhu
authors: Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Fudan University, 12 Wulumuqi Zhong Road, Shanghai, 200040, China.|Shanghai Pituitary Tumor Center, Shanghai, China.
authors: Zengyi
authors: Z
authors: Ma
authors: Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Fudan University, 12 Wulumuqi Zhong Road, Shanghai, 200040, China.|Shanghai Pituitary Tumor Center, Shanghai, China.
authors: Wenqiang
authors: W
authors: He
authors: Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Fudan University, 12 Wulumuqi Zhong Road, Shanghai, 200040, China.|Shanghai Pituitary Tumor Center, Shanghai, China.
authors: Shiqi
authors: S
authors: Li
authors: Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Fudan University, 12 Wulumuqi Zhong Road, Shanghai, 200040, China.|Shanghai Pituitary Tumor Center, Shanghai, China.
authors: Xuefei
authors: X
authors: Shou
authors: Shanghai Pituitary Tumor Center, Shanghai, China.|Department of Endocrinology and Metabolism, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors: Yiming
authors: Y
authors: Li
authors: Shanghai Pituitary Tumor Center, Shanghai, China.|Department of Endocrinology and Metabolism, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors: Zhaoyun
authors: Z
authors: Zhang
authors: Shanghai Pituitary Tumor Center, Shanghai, China.|Department of Endocrinology and Metabolism, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors: Hongying
authors: H
authors: Ye
authors: Shanghai Pituitary Tumor Center, Shanghai, China.|Department of Endocrinology and Metabolism, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors: Min
authors: M
authors: He
authors: Shanghai Pituitary Tumor Center, Shanghai, China.|Department of Endocrinology and Metabolism, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors: Bin
authors: B
authors: Lu
authors: Shanghai Pituitary Tumor Center, Shanghai, China.|Department of Radiology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors: Zhenwei
authors: Z
authors: Yao
authors: Department of Nuclear Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors: Yun
authors: Y
authors: Lu
authors: Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Fudan University, 12 Wulumuqi Zhong Road, Shanghai, 200040, China.|Shanghai Pituitary Tumor Center, Shanghai, China.
authors: Nidan
authors: N
authors: Qiao
authors: Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Fudan University, 12 Wulumuqi Zhong Road, Shanghai, 200040, China.|Shanghai Pituitary Tumor Center, Shanghai, China.
authors: Zhao
authors: Z
authors: Ye
authors: Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Fudan University, 12 Wulumuqi Zhong Road, Shanghai, 200040, China.|Shanghai Pituitary Tumor Center, Shanghai, China.
authors: Yichao
authors: Y
authors: Zhang
authors: Shanghai Pituitary Tumor Center, Shanghai, China.|Department of Endocrinology and Metabolism, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors: Yeping
authors: Y
authors: Yang
authors: Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Fudan University, 12 Wulumuqi Zhong Road, Shanghai, 200040, China. zhaoyaohs@vip.sina.com.|Shanghai Pituitary Tumor Center, Shanghai, China. zhaoyaohs@vip.sina.com.
authors: Yao
authors: Y
authors: Zhao
authors: Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Fudan University, 12 Wulumuqi Zhong Road, Shanghai, 200040, China. eamns@hotmail.com.|Shanghai Pituitary Tumor Center, Shanghai, China. eamns@hotmail.com.
authors: Yongfei
authors: Y
authors: Wang
mesh_terms: D000172:Acromegaly / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000601:surgery; D000328:Adult; D016903:Drug Monitoring / Q000379:methods*; D005260:Female; D049912:Growth Hormone-Secreting Pituitary Adenoma / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013004:Somatostatin / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D013004:Somatostatin
keywords: Acromegaly; Magnetic resonance imaging; Relative signal intensity; Somatostatin analog; Somatostatin receptor