The Challenge of Evaluating Response to Peptide Receptor Radionuclide Therapy in Gastroenteropancreatic Neuroendocrine Tumors: The Present and the Future
Virginia Liberini,
Martin W. Huellner,
Serena Grimaldi,
Monica Finessi,
Philippe Thuillier,
Alfredo Muni,
Riccardo E. Pellerito,
Mauro G. Papotti,
Alessandro Piovesan,
Emanuela Arvat,
Désirée Deandreis
Affiliations
Virginia Liberini
Nuclear Medicine Unit, Department of Medical Sciences, University of Turin, 10126 Turin, Italy
Martin W. Huellner
Department of Nuclear Medicine, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland
Serena Grimaldi
Nuclear Medicine Unit, Department of Medical Sciences, University of Turin, 10126 Turin, Italy
Monica Finessi
Nuclear Medicine Unit, Department of Medical Sciences, University of Turin, 10126 Turin, Italy
Philippe Thuillier
Nuclear Medicine Unit, Department of Medical Sciences, University of Turin, 10126 Turin, Italy
Alfredo Muni
Department of Nuclear Medicine, S.S. Biagio e Antonio e C. Arrigo Hospital, 15121 Alessandria, Italy
Riccardo E. Pellerito
Department of Nuclear Medicine, AO Ordine Mauriziano di Torino, 10128 Turin, Italy
Mauro G. Papotti
Pathology Unit, City of Health and Science University Hospital, 10126 Turin, Italy
Alessandro Piovesan
Department of Endocrinology, A. O. U. Città della Salute della Scienza of Turin, 10126 Turin, Italy
Emanuela Arvat
Oncological Endocrinology, Department of Medical Sciences, University of Turin, 10126 Turin, Italy
Désirée Deandreis
Nuclear Medicine Unit, Department of Medical Sciences, University of Turin, 10126 Turin, Italy
The NETTER-1 study has proven peptide receptor radionuclide therapy (PRRT) to be one of the most effective therapeutic options for metastatic neuroendocrine tumors (NETs), improving progression-free survival and overall survival. However, PRRT response assessment is challenging and no consensus on methods and timing has yet been reached among experts in the field. This issue is owed to the suboptimal sensitivity and specificity of clinical biomarkers, limitations of morphological response criteria in slowly growing tumors and necrotic changes after therapy, a lack of standardized parameters and timing of functional imaging and the heterogeneity of PRRT protocols in the literature. The aim of this article is to review the most relevant current approaches for PRRT efficacy prediction and response assessment criteria in order to provide an overview of suitable tools for safe and efficacious PRRT.
