A tri-modal tissue-equivalent anthropomorphic phantom for PET, CT and multi-parametric MRI radiomics.

PURPOSE: Radiomics has emerged as an advanced image processing methodology to define quantitative imaging biomarkers for prognosis and prediction of treatment response and outcome. The development of quantitative imaging biomarkers requires careful analysis to define their accuracy, stability and reproducibility through phantom measurements. Few efforts were devoted to develop realistic anthropomorphic phantoms. In this work, we developed a multimodality image phantom suitable for PET, CT and multiparametric MRI imaging. METHODS: A tissue-equivalent gel-based mixture was designed and tested for compatibility with different imaging modalities. Calibration measurements allowed to assess gel composition to simulate PET, CT and MRI contrasts of oncological lesions. The characterized gel mixture was used to create realistic synthetic lesions (e.g. lesions with irregular shape and non-uniform image contrast), to be inserted in a standard anthropomorphic phantom. In order to show phantom usefulness, issues related to accuracy, stability and reproducibility of radiomic biomarkers were addressed as proofs-of-concept. RESULTS: The procedure for gel preparation was straightforward and the characterized gel mixture allowed to mime simultaneously oncological lesion contrast in CT, PET and MRI imaging. Proofs-of-concept studies suggested that phantom measurements can be customized for specific clinical situations and radiomic protocols. CONCLUSIONS: We developed a strategy to manufacture an anthropomorphic, tissue-equivalent, multimodal phantom to be customized on specific radiomics protocols, for addressing specific methodological issues both in mono and multicentric studies.

Could radiotherapy play a major role in misidentification of sentinel lymph node in breast cancer recurrence?

Misidentification of sentinel lymph node via lymphoscintigraphy for breast cancer is an infrequent event. We analysed 35.022 consecutive procedures from a single institution and tried to find a correlation between failures of sentinel node identification and previous oncologic treatments received by the patients.

Early and Delayed 18F-FCH PET/CT Imaging in Parathyroid Adenomas.

Preoperative localization with Tc-sestaMIBI or ultrasound is a common prerequisite for successful minimally invasive parathyroid adenoma (PA) surgery. SPECT/CT with Tc-sestaMIBI and PET/CT with F-FCH offer the possibility of attenuation correction and coregistration of functional and anatomical images providing more accurate PA localization. F-FCH PET/CT is used predominantly in patients with prostate cancer and is under investigation in PA. We report the case of a 43-year-old man with early FCH uptake in a cystic PA with delayed washout at 60 minutes.