18F-FDG-PET evaluation of treatment response to neo-adjuvant therapy in patients with locally advanced rectal cancer: A meta-analysis

Authors

  • Chenpeng Zhang,

    1. Department of Nuclear Medicine, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China
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    • C.Z. and J.T. contributed equally to this work.

  • Jinlu Tong,

    1. Department of Gastroenterology, Shanghai Institute of Gastrointestinal Diseases; Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China
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    • C.Z. and J.T. contributed equally to this work.

  • Xiaoguang Sun,

    1. Department of Nuclear Medicine, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China
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  • Jianjun Liu,

    1. Department of Nuclear Medicine, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China
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  • Yuting Wang,

    1. Department of Nuclear Medicine, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China
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  • Gang Huang

    Corresponding author
    1. Department of Nuclear Medicine, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China
    2. Institute of Health Sciences, Shanghai Jiao Tong University School of Medicine (SJTUSM) & Shanghai Institutes for Biological Sciences (SIBS), Chinese Academy of Sciences (CAS), Shanghai, People's Republic of China
    • Department of Nuclear Medicine, Renji hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People's Republic of China
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Abstract

The purpose of this meta-analysis was to evaluate the utility of positron emission tomography (PET) using fluor-18-deoxyglucose (FDG) to predict the response of rectal cancer to neo-adjuvant therapy. All previously published studies on the role of FDG-PET in predicting the response of rectal cancer to neo-adjuvant therapy were collected. Pooled sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated using statistical software. A total of 28 studies, comprising 1,204 patients with rectal cancer, were included in the meta-analysis. Pooled sensitivity, specificity, PPV and NPV for FDG-PET predicting the response to therapy was 78% [95% confidence interval (CI): 75–82%], 66% (95% CI: 62–69%), 70% (95% CI; 66–73%) and 75% (95% CI: 71–0.79%), respectively. The included studies were of a relatively high methodological quality according to the QUADAS (quality assessment of studies of diagnostic accuracy included in systematic reviews) criteria. Based on the subgroup analyses, there was no significant difference between the response index, the standardized uptake value and the visual response score in predicting the therapy response. However, the accuracy of the group that underwent PET scanning during therapy showed significantly higher values (sensitivity 86% and specificity 80%) than the group that was scanned after completion of the therapy. Therefore, FDG-PET is valuable for predicting the response of rectal carcinoma to neo-adjuvant therapy, and early evaluation of response during the therapy may be more promising. However, additional studies using prospective clinical trials will be required to assess the clinical benefit of this strategy.

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