FAPI-based radiopharmaceuticals are a novel class of tracers, mainly used for PET imaging, which have demonstrated several advantages over [¹⁸F]FDG, especially in the case of low-grade or well-differentiated tumors. We conducted this systematic review to evaluate all the studies where a head-to-head comparison had been performed to explore the potential utility of FAPI tracers in clinical practice. FAPI-based radiopharmaceuticals have shown promising results globally, in particular in detecting peritoneal carcinomatosis, but studies with wider populations are needed to better understand all the advantages of these new radiopharmaceuticals.

(1) Background: Thyroid cancer (TC) is often treated with surgery followed by iodine-131. Up to 50% of the instances of TC lose their avidity to ¹³¹I, becoming more aggressive. In this scenario, [¹⁸F]FDG PET/CT imaging is used for evaluating the widespread nature of the disease, despite its low sensitivity and a false negative rate of 8–21.1%. A novel class of PET agents targeting the fibroblast activation protein inhibitor (FAPi) has emerged, studied particularly for their potential application to theranostics. (2) Methods: A search of the literature was performed by two independent authors (P.G. and L.E.) using the PubMed, Scopus, Web of Science, Cochrane Library, and EMBASE databases. The following terms were used: “FAP” or “FAPi” or “Fibroblast activating protein” and “thyroid” or “thyroid cancer”, in different combinations. The included papers were original articles, clinical studies, and case reports in the English language. No time limits were used. Editorials, conference papers, reviews, and preclinical studies were excluded. (3) Results: There were 31 papers that were selected. Some studies reported a low or absent FAPi uptake in TC lesions; others reported promising findings for the detection of metastases. (4) Conclusions: The preliminary results are encouraging. FAPI agents are an alternative to [¹⁸F]FDG and a promising theranostic tool. However, further studies with a larger population are needed.

In the last decades, the development of PET/CT radiopharmaceuticals, targeting the Prostate-Specific Membrane Antigen (PSMA), changed the management of prostate cancer (PCa) patients thanks to its higher diagnostic accuracy in comparison with conventional imaging both in staging and in recurrence. Alongside molecular imaging, PSMA was studied as a therapeutic agent targeted with various isotopes. In 2021, results from the VISION trial led to the Food and Drug Administration (FDA) approval of [¹⁷⁷Lu]Lu-PSMA-617 as a novel therapy for metastatic castration-resistant prostate cancer (mCRPC) and set the basis for a radical change in the future perspectives of PCa treatment and the history of Nuclear Medicine. Despite these promising results, primary resistance in patients treated with single-agent [¹⁷⁷Lu]Lu-PSMA-617 remains a real issue. Emerging trials are investigating the use of [¹⁷⁷Lu]Lu-PSMA-617 in combination with other PCa therapies in order to cover the multiple oncologic resistance pathways and to overcome tumor heterogeneity. In this review, our aim is to retrace the history of PSMA-targeted therapy from the first preclinical studies to its future applications in PCa.

Objective: to evaluate the feasibility of the intra-operative application of a specimen PET/CT imager in a clinical setting. Materials and methods: this is a pilot analysis performed in three patients who received an intra-operative administration of ⁶⁸Ga-PSMA-11 (n = 2) and ⁶⁸Ga-DOTA-TOC (n = 1), respectively. Patients were administrated with PET radiopharmaceuticals to perform radio-guided surgery with a beta-probe detector during radical prostatectomy for prostate cancer (PCa) and salvage lymphadenectomy for recurrent neuroendocrine tumor (NET) of the ileum, respectively. All procedures have been performed within two ongoing clinical trials in our Institute (NCT05596851 and NCT05448157). Pathologic assessment with immunohistochemistry (PSMA-staining and SSA immunoreactivity) was considered as standard of truth. Specimen images were compared with baseline PET/CT images and histopathological analysis. Results: Patients received 1 MBq/Kg of ⁶⁸Ga-PSMA-11 (PCa) or 1.2 MBq/Kg of ⁶⁸Ga-DOTA-TOC (NET) prior to surgery. Specimens were collected, positioned in the dedicated specimen container, and scanned to obtain high-resolution PET/CT images. In all cases, a perfect match was observed between the findings detected by the specimen imager and histopathology. Overall, the PET spatial resolution was sensibly higher for the specimen images compared to the baseline whole-body PET/CT images. Furthermore, the use of the PET/CT specimen imager did not significantly interfere with any procedures, and the overall length of the surgery was not affected using the PET/CT specimen imager. Finally, the radiation exposure of the operating theater staff was lower than 40 µSv per procedure (range 26–40 μSv). Conclusions: the image acquisition of specimens obtained by patients who received intra-surgery injections of ⁶⁸Ga-PSMA-11 and ⁶⁸Ga-DOTA-TOC was feasible and reliable also in a live-experience session and has been easily adapted to surgery daily practice. The high sensitivity, together with the evaluation of intra-lesion tumor heterogeneity, were the most relevant results since the data derived from specimen PET/CT imaging matched perfectly with the histopathological analysis.

Tin‐based perovskites offer one of the most viable sustainable alternatives to their lead counterparts, combining comparable band structures with strong visible‐light absorption and favorable charge transport. Most studies have focused on thin films, where grain boundaries dominate charge transport, and the large surface area accelerates the oxidation of tin, obscuring the intrinsic properties of the material. Here, single crystals of phenethylammonium tin iodide (PEA ₂ SnI ₄ ) are investigated, isolating their fundamental optoelectronic response from film‐related artefacts. It is found that air and light exposure primarily affect surface layers, with partial recovery achievable through exfoliation. Photodetectors fabricated from single crystals exhibit a photoresponsivity of ≈60 A W ⁻¹ under low‐intensity 650 nm illumination, with photocurrent scaling quadratically with bias in a space charge‐limited current regime, and transport displaying a transition from thermal excitation to phonon scattering at 225 K. Time‐resolved photocurrent measurements further reveal prolonged decay dynamics and cumulative pulse responses, characteristic of short‐term synaptic plasticity such as temporal integration and voltage‐modulated persistence. These findings establish PEA ₂ SnI ₄ single crystals as a benchmark for understanding degradation and transport in lead‐free perovskites, while positioning them as a viable materials platform for neuromorphic vision and adaptive optoelectronics.