68Ga-DOTATOC PET/CT-Based Radiomic Analysis and PRRT Outcome: A Preliminary Evaluation Based on an Exploratory Radiomic Analysis on Two Patients

Virginia Liberini; Osvaldo Rampado; Elena Gallio; Bruno De Santi; Francesco Ceci; Beatrice Dionisi; Philippe Thuillier; Libero Ciuffreda; Alessandro Piovesan; Federica Fioroni; Annibale Versari; Filippo Molinari; Désirée Deandreis

doi:10.3389/fmed.2020.601853

⁶⁸Ga-DOTATOC PET/CT-Based Radiomic Analysis and PRRT Outcome: A Preliminary Evaluation Based on an Exploratory Radiomic Analysis on Two Patients

Front Med (Lausanne). 2021 Jan 26:7:601853. doi: 10.3389/fmed.2020.601853. eCollection 2020.

Affiliations

¹ Nuclear Medicine Unit, Department of Medical Sciences, University of Turin, Turin, Italy.
² Medical Physics Unit, Azienda Ospedaliero-Universitaria Città della Salute e della Scienza, Turin, Italy.
³ Biolab, Department of Electronics and Telecommunications, Politecnico di Torino, Turin, Italy.
⁴ Department of Endocrinology, University Hospital of Brest, Brest, France.
⁵ Medical Oncology Division 1, Azienda Ospedaliero-Universitaria Città della Salute e della Scienza, University of Turin, Turin, Italy.
⁶ Division of Oncological Endocrinology, Department of Medical Sciences, University of Turin, Turin, Italy.
⁷ Medical Physics Unit, Azienda Unit Sanitaria Locale di Reggio Emilia - Istituto di Ricovero e Cura a Carattere Scientifico of Reggio Emilia, Reggio Emilia, Italy.
⁸ Nuclear Medicine Unit, Azienda Unit Sanitaria Locale di Reggio Emilia - Istituto di Ricovero e Cura a Carattere Scientifico of Reggio Emilia, Reggio Emilia, Italy.

Abstract

Aim: This work aims to evaluate whether the radiomic features extracted by 68Ga-DOTATOC-PET/CT of two patients are associated with the response to peptide receptor radionuclide therapy (PRRT) in patients affected by neuroendocrine tumor (NET). Methods: This is a pilot report in two NET patients who experienced a discordant response to PRRT (responder vs. non-responder) according to RECIST1.1. The patients presented with liver metastasis from the rectum and pancreas G3-NET, respectively. Whole-body total-lesion somatostatin receptor-expression (TLSREwb-50) and somatostatin receptor-expressing tumor volume (SRETV wb-50) were obtained in pre- and post-PRRT PET/CT. Radiomic analysis was performed, extracting 38 radiomic features (RFs) from the patients' lesions. The Mann-Whitney test was used to compare RFs in the responder patient vs. the non-responder patient. Pearson correlation and principal component analysis (PCA) were used to evaluate the correlation and independence of the different RFs. Results: TLSREwb-50 and SRETVwb-50 modifications correlate with RECIST1.1 response. A total of 28 RFs extracted on pre-therapy PET/CT showed significant differences between the two patients in the Mann-Whitney test (p < 0.05). A total of seven second-order features, with poor correlation with SUVmax and PET volume, were identified by the Pearson correlation matrix. Finally, the first two PCA principal components explain 83.8% of total variance. Conclusion: TLSREwb-50 and SRETVwb-50 are parameters that might be used to predict and to assess the PET response to PRRT. RFs might have a role in defining inter-patient heterogeneity and in the prediction of therapy response. It is important to implement future studies with larger and more homogeneous patient populations to confirm the efficacy of these biomarkers.

Keywords: 68Ga-DOTATOC PET/CT; NET; peptide receptor radionuclide therapy; radiomic analysis; somatostatin receptor expressing tumor volume; total lesion somatostatin receptor expression.