Applying PET/MR in Rectal Cancer.

The use of the novel recently introduced PET/MR scanner is believed to be promising in RC management, providing great anatomical details and detailed metabolic characterization. Preliminary data indicate it may become a strong imaging modality for staging of RC and has the potential to be used as a predictive tool guiding individualized therapy in patients receiving nT, but confirmation on prospective studies is mandatory. The use of radiomics as analysis approach may assist in achieving a better understanding of the obtained image data, and thus a more accurate disease assessment. Objectives To preliminary assess the potential diagnostic value of single PET/MR scan in RC staging and compare it to that of MRI alone, PET/CT alone, and combined MRI and PET/CT. To preliminary assess the potential value of PET/MR in predicting pMR to nT. To use radiomics analysis of PET/MR data to develop a quantification clinical tools that allow a more accurate and comprehensive assessment of RC patients.

whole-body PET/CT scan and pelvic PET/MR scan (MR protocol will include three plane fast spin echo T2 weighted, DWI and dynamic contrast enhanced imaging). The ad interim assessment will use a pelvic PET/MR scan only (without PET/CT), to avoid the radiation associated with whole body CT. In the staging and post-nT assessment, the addition of PET/MR to the standard use of PET/CT adds no radiation exposure.

Number of patient that shown the different between diagnostic value of single PET/MR scan in RC staging and compare it to that of MRI alone, PET/CT alone, and combined MRI and PET/CT

Inclusion Criteria: 1.Patients with newly diagnosed RC; histopathological confirmation of adenocarcinoma of colorectal origin. Exclusion Criteria: Patients younger than 18 years; pregnancy; other known active malignancy; previous chemotherapy or radiotherapy; previous pelvic operation; patient that no intent / not suited for neoadjuvant therapy (including metastatic disease at presentation); contraindication to intravenous contrast agents.