PET/CT and Conventional Imaging for the Assessment of Neuroendocrine Prostate Cancer: A Systematic Review

SIMPLE SUMMARY: Neuroendocrine prostate cancer is a rare neoplasm with aggressive behavior and poor prognosis. Its diagnostic approach is challenging since no specific features are present when using conventional imaging or positron emission tomography (PET). The aim of this systematic review was, therefore, to evaluate the role of these imaging modalities for the assessment of neuroendocrine prostate cancer. At present, it is still uncertain which tracer performs best, and although [(18)F]FDG has been evaluated and seems to offer some advantages in availability and clinical staging, other tracers may be more useful to understand tumor biology or identify targets for subsequent radioligand therapy. Further research is therefore desirable. In contrast, data are still limited to draw a final conclusion on the role and the specific characteristics of CI in this rare form of neoplasm, and therefore, more studies are needed in this setting. ABSTRACT: Background: Neuroendocrine prostate cancer (NEPC) is a rare neoplasm, and the role of both conventional imaging (CI) and positron emission tomography/computed tomography (PET/CT) for its assessment has not been clearly evaluated and demonstrated. The aim of this systematic review was to analyze the diagnostic performances of these imaging modalities in this setting. Methods: A wide literature search of the PubMed/MEDLINE, Scopus, and Web of Science databases was made to find relevant published articles about the role of CI and PET/CT for the evaluation of NEPC. Results: 13 studies were included in the systematic review. PET/CT imaging with different radiopharmaceuticals has been evaluated in many studies (10) compared to CI (3 studies), which has only a limited role in NEPC. Focusing on PET/CT, a study used [(18)F]FDG, labeled somatostatin analogs were used in 5 cases, a study used [(68)Ga]Ga-FAPI-04, [(68)Ga]Ga-PSMA-11 was evaluated in a single case, and two works used different tracers. Conclusion: Published data on the role of PET/CT for the assessment of NEPC are limited. At present, it is still uncertain which tracer performs best, and although [(18)F]FDG has been evaluated and seems to offer some advantages in availability and clinical staging, other tracers may be more useful to understand tumor biology or identify targets for subsequent radioligand therapy. Further research is therefore desirable. In contrast, data are still limited to draw a final conclusion on the role and the specific characteristics of CI in this rare form of neoplasm, and therefore, more studies are needed in this setting.