This study was performed to synthesize multimodal radiopharmaceutical designed for the diagnosis and treatment of prostate cancer. To achieve this goal, Super Paramagnetic Iron Oxide (SPIO) nanoparticles were used as a platform for targeting molecule (PSMA-617) and for complexation of two scandium radionuclides, 44Sc for PET imaging and 47Sc for radionuclide therapy. TEM and XPS images showed that the Fe3O4 NPs have a uniform cubic shape and a diameter from 38 to 50 nm. The Fe3O4 core are surrounded by SiO2 and an organic layer. The saturation magnetization of the SPION core was 60 emu/g. However, coating the SPIONs with silica and polyglycerol reduces the magnetization significantly. The obtained bioconjugates were labeled with 44Sc and 47Sc, with a yield higher than 97%. The radiobioconjugate exhibited high affinity and cytotoxicity towards the human prostate cancer LNCaP (PSMA+) cell line, much higher than for PC-3 (PSMA-) cells. High cytotoxicity of the radiobioconjugate was confirmed by radiotoxicity studies on LNCaP 3D-spheroids. In addition, the magnetic properties of the radiobioconjugate should allow for its use in guide drug delivery driven by magnetic field gradient.

Radiolabelled tracers targeting the prostate-specific membrane antigen (PSMA) have become important radiopharmaceuticals for the PET-imaging of prostate cancer. In this connection we recently developed the fluorine-18 labelled PSMA-ligand [¹⁸F]PSMA-1007 as next generation radiofluorinated Glu-ureido PSMA inhibitor after [¹⁸F]DCFPyL and [¹⁸F]DCFBC. Since radiosynthesis so far was suffering for rather poor yields novel procedures for the automated radiosyntheses of [¹⁸F]PSMA-1007 have been developed. We herein report on both the two-step and the novel one-step procedures, which have been performed on different commonly used radiosynthesisers. Using the novel one-step procedure the [¹⁸F]PSMA-1007 was produced in good radiochemical yields ranging from 30-70 % and synthesis times less than 55 minutes. Furthermore, upscaling to product activities up to 50 GBq per batch was successfully conducted. All batches passed quality control according to European Pharmacopoeia standards. Therefore, we were able to disclose a new, simple and at the same time high yielding production pathway for the next generation PSMA radioligand [¹⁸F]PSMA-1007. Actually it turned out that the radiosynthesis is as easily realised as the well-known [¹⁸F]FDG synthesis and thus transferable onto all currently available radiosynthesisers. Using the new procedures, clinical daily routine can be sustainably supported in-house even in larger hospitals by a single production batch.

Despite advances in the understanding of its molecular pathophysiology, prostate cancer remains largely incurable, highlighting the need for novel therapies. We developed a chimeric antigen receptor (CAR) specific for prostate specific membrane antigen (PSMA), a glycoprotein that is overexpressed in prostate cancer, which expression involves neovasculature of several tumor entities, thus envisaging an additional antiangiogenic effect. To optimize the CAR design, we compared two CARs with signaling domains containing one or two T cell costimulatory elements, in addition to CD3ζ. Conversely, what has been described for other CARs, a third-generation CAR (containing CD28 and 41BB co-signaling domains) induced a potent antitumor effect similar to a second-generation CAR (containing CD28 co-signaling domain), though we observed a detrimental effect of the additional costimulatory domain that was attributed to increased activation-induced cell death (AICD). This “super-stimulation” resulted in exhaustion of cells, higher frequencies of cell death and, more importantly, the impossibility of sufficiently expanding the CAR cells to obtain the minimum number of cells requested for in vivo therapies. While the superiority of 2nd and 3rd generation over 1st generation CAR T cells has been clearly shown in both preclinical and clinical studies, the optimal combination of costimulatory domains for 3rd generation CAR-T cells must still be defined and should be evaluated case-by-case in order to fine-tune immunotherapy approaches.

Radiotheranostics refers to pairing of radioactive imaging biomarkers with radioactive therapeutic compounds that deliver ionizing radiation. Given the introduction of very promising radio-pharmaceuticals, the radiotheranostics approach is creating a novel paradigm in personalized, targeted radionuclide therapies (TRTs), also known as radiopharmaceuticals (RPTs). Radiother-apeutic pairs targeting somatostatin receptors (SSTR) and prostate-specific membrane antigens (PSMA) are increasingly used to diagnose and treat patients with metastatic neuroendocrine tumors (NETs) and prostate cancer. In parallel, radiomics and artificial intelligence (AI) as important areas in quantitative image analysis are paving the way for significantly enhanced workflows in diagnostic and theranostic fields, from data and image processing to clinical decision support, improving patient selection, personalized treatment strategies, response prediction, and prognostication. Furthermore, AI has the potential for tremendous effectiveness in patient dosimetry which copes with complex and time-consuming tasks in the RPT workflow. The present work provides a comprehensive overview of radiomics and AI application in radio-theranostics, focusing on pairs of SSTR- or PSMA‑targeting radioligands, describing the funda-mental concepts and specific imaging/treatment features. Our review includes ligands radio-labeled by 68Ga, 18F, 177Lu, 64Cu, 90Y, and 225Ac. Specifically, contributions by radiomics and AI towards improved image acquisition, reconstruction, treatment response, segmentation, restag-ing, lesion classification, dose prediction, and estimation as well as ongoing developments and future directions are discussed.

The recent approval of 177Lu PSMA-617 (Pluvicto®) by the United States Food and Drug Administration (FDA) is the culmination of decades of work in advancing the field of targeted radionuclide therapy for metastatic prostate cancer. 177Lu PSMA-617, along with the bone specific radiotherapeutic agent, 223RaCl2, are now commonly used in routine clinical care as a tertiary line of therapy for men with metastatic castrate resistant prostate cancer and for osseus metastatic disease respectively. While these radiopharmaceuticals are changing how metastatic prostate cancer is classified and treated, there is relatively little guidance to the practitioner and patient as to how best utilize these therapies, especially in conjunction with other more well-established regimens including hormonal, immunologic, and chemotherapeutic agents. This review article will go into detail about the mechanism and effectiveness of these radiopharmaceuticals and less well known classes of targeted radionuclide radiopharmaceuticals including alpha emitting prostate specific membrane antigen (PSMA) -, gastrin-releasing peptide receptor (GRPR) -, and somatostatin targeted radionuclide therapeutics. Additionally, a thorough discussion of the clinical approach of these agents is included and required futures studies.

Some bispecific radiotracers have been developed to overcome the limitations of monospecific tracers and improve detection sensitivity for heterogeneous tumor lesions. Here we aim to synthesize two bispecific tracers targeting prostate-specific membrane antigen (PSMA) and fibroblast activation protein (FAP), which are key markers expressed in prostate cancer. A pyridine-based FAP-targeted ligand was synthesized through multi-step organic synthesis, and then connected to the 2-Nal-containing PSMA-targeted motif. Ki(PSMA) values of Ga-complexed bispecific ligands, Ga-AV01084 and Ga-AV01088, were 11.6 ± 3.25 and 28.7 ± 6.05 nM, respectively, and the IC50(FAP) values of Ga-AV01084 and Ga-AV01088 were 10.9 ± 0.67 and 16.7 ± 1.53 nM, respectively. The uptake values for PSMA-expressing LNCaP tumor xenografts were 9.05 ± 1.54 and 8.85 ± 1.25 %ID/g for [68Ga]Ga-AV010184 and [68Ga]Ga-AV01088, respectively, which were lower than the monospecific PSMA-targeted tracer [68Ga]Ga-PSMA-617 (16.7 ± 2.30 %ID/g). The uptake values for FAP-expressing HEK293T:hFAP tumor xenografts were 1.90 ± 0.41 and 1.20 ± 0.25 %ID/g for [68Ga]Ga-AV01084 and [68Ga]Ga-AV01088, respectively, which were also lower than the monospecific FAP-targeted tracer, [68Ga]Ga-AV02070 (7.93 ± 1.88 %ID/g). Further investigations are needed to optimize the selection of linkers and targeted pharmacophores to improve the tumor uptake of PSMA/FAP bispecific tracers for prostate cancer imaging.

Prostate cancer (PCa) has become the most common tumor among males in Europe and the USA. Adoptive immunotherapy appears as a promising strategy to control the advanced stages of the disease by specific targeting the tumor, in particular through chimeric antigen receptor T (CAR-T) cell therapy. Despite the advancements of CAR-T technology in the treatment of hematological malignancies, solid tumors still represent a challenge. To overcome current limits, other cellular effectors than T lymphocytes are under study as possible candidates for CAR-engineered cancer immunotherapy. A novel approach involves the NK-92 cell line, which mediates strong cytotoxic responses against a variety of tumor cells but has no effect on non-malignant healthy counterparts. Here, we report a therapeutic approach against PCa based on engineering of NK-92 cells with a CAR recognizing the human prostate-specific membrane antigen (PSMA), which is overexpressed in prostatic neoplastic cells. Upon CAR transduction, NK-92/CAR cells acquired high and specific lytic activity against PSMA-expressing prostate cancer cells in vitro, and also underwent degranulation and produced high levels of IFN-γ in response to antigen recognition. Lethal irradiation of the effectors, a safety measure requested for the clinical application of retargeted NK-92 cells, fully abrogated replication but did not impact on phenotype and short-term functionality. PSMA-specific recognition and antitumor activity were retained in vivo, as adoptive transfer of irradiated NK-92/CAR cells in prostate cancer-bearing mice restrained tumor growth and improved survival. Anti-PSMA CAR-modified NK-92 cells represent a universal, off-the-shelf, renewable and cost-effective product endowed with relevant potentialities as a therapeutic approach for PCa immunotherapy.

Aim of the study: To draw inferences from a retrospective evaluation of PSMA PET CT scans performed for the evaluation of biochemical recurrence. Material and Methods: Retrospective analysis of 295 PSMA PET CT scans spanning 3 years between 2020 and 2022 was undertaken. Results: Of 295 PET CT scans, 179 were positive, 66 negative and 50 had indeterminate findings. In positive group, 67 had radical prostatectomy and PSMA avid lesions were seen most commonly in pelvic lymph nodes. Remaining 112 positive scans, in non-radical prostatectomy group; 25 had recurrence only in prostate, 17 had recurrence involving prostate bed; 28 had no recurrence in prostate gland, while 42 had recurrence in prostate as well as extra prostatic sites. Overall, in non-prostatectomy group, 75 % population was harbouring a PSMA avid lesion in prostate gland while in remaining 25% population recurrence did not involve prostate gland. Majority of indeterminate findings were seen in small pelvic or retroperitoneal lymph nodes or skeletal regions (ribs/others) and in 9 patients indeterminate focus was seen in the prostate bed only. Follow up PSMA PET CT was helpful in prior indeterminate findings and unexplained PSA rise. Conclusion: A higher recurrence in prostate bed while evaluating biochemical recurrence prompts us to think; whether prostatectomy should be offered more proactively? Follow up PSMA PET CT is helpful for indeterminate findings; a PSA rise of 0.7 ng/ml in 6 months can result in positive PSMA PET CT while negative scan can be seen upto 2ng/ml PSA rise in 6 months.

Purpose: Prostate cancer is the most common male prevalent malignancy in Europe. Biological recurrence occurs in 20-40% of patients within 10 years following treatment. [18F]F-Choline PET/CT is the most used technique for detecting recurrent disease but is rarely positive for low PSA levels. [18F]PSMA-1007 PET/CT allows early detection of recurrence sites. Methods: We conducted a prospective multicenter study. Each patient had access to a [18F]F-Choline and [18F]PSMA PET/CT. The primary endpoint was to determine the therapeutic impact of the [18F]PSMA comparative to [18F]F-Choline PET/CT. Secondary endpoints were the diagnostic performance and the correlation between PET/CT parameters and prognostic factors of prostate disease. Results: 47 patients were included. A therapeutic modification was observed in 36% of them between what the clinicians expected after the [18F]F-Choline PET/CT and what they finally decided after the [18F]PSMA PET/CT. Diagnostic performance of [18F]F-Choline was 28% versus 70% for [18F]PSMA with a significant difference. With [18F]PSMA PET/CT, there was a significative correlation between PSA level of biological recurrence and SUVmax but not between ISUP score and SUVmax of the selected lesion. Conclusion: This study found a modification in therapeutic management following [18F]PSMA PET/CT in one third of patients. This change could result in earlier and better management with detection of lesions at a lower PSA level than is possible with [18F]F-Choline.

Prostate-specific membrane antigen (PSMA) is a well validated prostate cancer marker, but reported PSMA-targeted tracers derived from the Lys-urea-Glu pharmacophore including the clinically validated [99mTc]Tc-EDDA/HYNIC-iPSMA have high off-target uptake in kidneys, spleen and salivary glands. In this study, we synthesized and evaluated three novel 99mTc-labeled PSMA-targeted tracers and investigated if the tracers derived from the Lys-urea-Aad pharmacophore could have minimized uptake in off-target organs/tissues. In vitro competition binding assays showed that compared with HYNIC-iPSMA, the three novel ligands had slightly weaker PSMA binding affinity (average Ki = 3.11 vs 8.96 - 11.6 nM). Imaging and ex vivo biodistribution studies in LNCaP tumor-bearing mice showed that [99mTc]Tc-EDDA/HYNIC-iPSMA and the three novel tracers successfully visualized LNCaP tumor xenografts in SPECT images and were excreted mainly via the renal pathway. The average tumor uptake at 1 h post-injection varied from 5.40 to 18.8 %ID/g, and the tracers derived from the Lys-urea-Aad pharmacophore had much lower uptake in spleen and salivary glands. Compared with the clinical tracer [99mTc]Tc-EDDA/HYNIC-iPSMA, the Lys-urea-Aad derived [99mTc]Tc-EDDA-KL01127 had lower background uptake and superior tumor-to-background contrast ratios, and is therefore promising for clinical translation to detect prostate cancer lesions with SPECT.

Within the oligometastatic state, oligo-recurrent lymph node disease in prostate cancer represents an interesting clinical entity characterized by a relatively indolent biology that makes it unique: it can be treated radically, and its treatment is usually associated with a long period of control and excellent survival. Additionally it is an emergent situation that we are facing more frequently, mainly due to: a) the incorporation into clinical practice of the PSMA PET that provides strikingly increase superior images in comparison to conventional imaging, with higher sensitivity and specificity; b) the higher detection rates of bone and node disease with extremely low levels of PSA; and c) the availability of high-precision technology in radiotherapy treatments with the incorporation of stereotaxic body radiotherapy (SBRT) or stereotaxic ablative radiotherapy (SABR) technology that allows the safe administration of high doses of radiation in a very limited number of fractions with low toxicity and excellent tolerance. This approach of new image-guided patient management is compelling for doctors and patients since it can potentially contribute to improve the clinical outcome. In this work we discuss the available evidence, areas of debate, and potential future directions concerning the utilization of new imaging guided SBRT for the treatment of nodal recurrence in prostate cancer.

Prostate cancer (PC) is the second most diagnosed cancer among men. It was observed that early diagnosis of disease is highly beneficial for survival of cancer patients. Therefore, extension and increasing quality of life of PC patients can be achieved by broadening the Cancer Screening programs that are aimed at the identification of cancer manifestation in patients at earlier stages before they demonstrate well-understood signs of the disease. Therefore, there is an urgent need in standard, sensitive, robust, and commonly available screening and diagnosis tools for identification of early signs of cancer pathologies. In this respect, “Holy Grail” of cancer researchers and bioengineers for decades have been molecular sensing probes that would allow diagnosis, prognosis, and monitoring of cancer diseases by their interaction with cell-secreted and cellassociated PC biomarkers, e.g. PSA and PSMA correspondinly. At present, most PSA tests are performed at centralized laboratories using high throughput Total PSA immune analyzers which are suitable for dedicated laboratories and are not readily available for the broad health screening. Therefore, the current trend in detection of PC is developments of the portable biosensors for mobile laboratories and individual use. Phage display since its conception by George Smith in 1985 has emerged as a premier tool in molecular biology with widespread applications. This review describes how the paradigm of molecular evolution and phage display revolutionized the methods of early diagnosis and monitoring of PC.