Molecular imaging phenotyping for selecting and monitoring radioligand therapy of neuroendocrine neoplasms

Neuroendocrine neoplasia (NEN) is an umbrella term that includes a widely heterogeneous disease group including well-differentiated neuroendocrine tumours (NETs), and aggressive neuroendocrine carcinomas (NECs). The site of origin of the NENs is linked to the intrinsic tumour biology and is predictive of the disease course. It is understood that NENs demonstrate significant biologic heterogeneity which ultimately translates to widely varying clinical presentations, disease course and prognosis. Thus, significant emphasis is laid on the pre-therapy evaluation of markers that can help predict tumour behavior and dynamically monitors the response during and after treatment. Most well-differentiated NENs express somatostatin receptors (SSTRs) which make them appropriate for peptide receptor radionuclide therapy (PRRT). However, the treatment outcomes of PRRT depend heavily on the adequacy of patient selection by molecular imaging phenotyping not only utilizing pre-treatment SSTR PET bu

Aberrant vascular anatomy associated with artifactual focal avidity in the liver on PSMA PET

68Ga–prostate-specific membrane antigen (PSMA) PET/CT is a valuable tool for staging and restaging of prostate cancer. Prostate-specific membrane antigen expression is not specific to prostate cancer, as it is expressed in normal tissues as well as in neoplastic and nonneoplastic processes. Awareness of the broad possibility of lesions with PSMA avidity is necessary to recognize normal variants and avoid potential pitfalls in image interpretation. We present a series of cases showing physiologic focal PSMA avidity in hepatic segment IVb. We correlate this uptake with aberrant hepatic vasculature. The awareness of this variant is important for accurate image interpretation to prevent additional invasive procedures, undue treatment escalation, and denial of curative treatment to patients.https://journals.lww.com/nuclearmed/pages/default.aspxhj2023Nuclear Medicin

Somatostatin Receptor Imaging and Theranostics: Current Practice and Future Prospects

A new era of precision diagnostics and therapy for patients with neuroendocrine neoplasms began with the approval of somatostatin receptor (SSTR) radiopharmaceuticals for PET imaging followed by peptide receptor radionuclide therapy (PRRT). With the transition from SSTR-based γ-scintigraphy to PET, the higher sensitivity of the latter raised questions regarding the direct application of the planar scintigraphy-based Krenning score for PRRT eligibility. Also, to date, the role of SSTR PET in response assessment and predicting outcome remains under evaluation. In this comprehensive review article, we discuss the current role of SSTR PET in all aspects of neuroendocrine neoplasms, including its relation to conventional imaging, selection of patients for PRRT, and the current understanding of SSTR PET-based response assessment. We also provide a standardized reporting template for SSTR PET with a brief discussion