From bench to bedside, blade, and back: FAP expression in juvenile angiofibroma. Potential implications for FAPI-PET/CT imaging and targeted therapy?

Purpose: Juvenile angiofibroma (JA) is a rare, benign fibrovascular tumor that predominantly affects adolescent males. The underlying biological mechanisms remain poorly understood. Fibroblast activation protein (FAP), known for its involvement in tumor invasion, matrix remodeling, and angiogenesis, has been implicated in various malignancies but has not been studied in JA so far.

Tolerability of PSMA radioligand therapy in metastatic prostate cancer patients with baseline mild to moderate leukopenia.

Background: Aim of this study was to analyze the safety of prostate-specific membrane antigen radioligand therapy (PSMA-RLT) in patients with metastatic castration-resistant prostate cancer (mCRPC) with preexisting mild to moderate leukopenia (CTCAE ≥ 1).

Results: Thirty-seven mCRPC patients with preexisting leukopenia (leukocyte count < 3.8 × 10/L) were included in this study.

Tumor sink effect in PSMA-targeted theranostics: intra-patient evaluation of a cohort receiving 225Ac/177Lu-PSMA tandem radioligand therapy.

Background: This study aims to further strengthen the evidence of tumor sink effect (TSE) and to confirm this phenomenon in patients undergoing Ac/Lu-PSMA tandem radioligand therapy.

Methods: The study included a total of N.=31 mCRPC patients who undergone two cycles of [Lu]Lu-PSMA-617 RLT, with at least one cycle being augmented by [Ac]Ac-PSMA-617.

Novel 64Cu-labeled Trimeric PSMA Ligand Unequivocally Identifies Local Recurrence of Prostate Cancer Ambiguously Imaged by 18F-DCFPyL PSMA PET/CT.

A 72-year-old man underwent 18F-DCFPyL PSMA PET/CT imaging for the localization of biochemical recurrence (BCR) of prostate cancer. The scan revealed no definite findings, with only a vague uptake of uncertain significance in the bladder neck region. An additional PET/CT scan using a 64Cu-labeled trimeric PSMA ligand demonstrated astonishing distinct uptake in the former prostate bed, unequivocally confirming the presence of a small local recurrence and allowing for targeted local therapy.

Expanding the scope of PSMA-RLT: evaluating treatment in challenging mCRPC patients with poor performance status (ECOG 3).

Purpose: Given the increasing inclusion of ECOG 3 patients in oncology practice, data on this subgroup in the context of prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (RLT) remain limited. This study evaluates the safety and outcome of PSMA-RLT in metastatic castration-resistant prostate cancer (mCRPC) patients with ECOG performance status 3.

Methods: In this analysis, a cohort of 18 mCRPC patients with ECOG performance status 3 who received PSMA-RLT was examined.

PSMA Radioligand Therapy in Advanced Age: Insights From an 85y+ mCRPC Patient Cohort.

Purpose: With increasing life expectancy, the number of older patients with metastatic castration-resistant prostate cancer (mCRPC) continues to rise, but this group is currently underrepresented in clinical trials. This study aims to assess the efficacy and safety of prostate-specific membrane antigen (PSMA) targeted radioligand therapy (RLT) in patients over 85 years old with mCRPC.

Materials And Methods: A retrospective analysis was conducted on 21 mCRPC patients aged 85 years or older receiving PSMA-RLT (range: 85-96 y).

PSMA PET/CT in biochemical recurrence of prostate cancer with PSA levels ≤ 0.2 ng/mL: a German multicenter analysis of conventional PSMA tracers, including [Ga]Ga-PSMA-11, [Ga]Ga-PSMA I&T, and [F]PSMA-1007.

Background: Prostate-specific membrane antigen (PSMA)-directed positron emission tomography/computed tomography (PET/CT) has emerged as a highly accurate imaging modality for detecting tumor lesions in patients with biochemical recurrence (BCR) of prostate cancer (PC). While detection rates of lesions suspicious for PC relapse are known to increase with rising prostate-specific antigen (PSA) levels, data on the efficacy of PSMA PET/CT at very low PSA values (≤ 0.2 ng/mL) remain limited.

Superior Response of CAP-PRRT of G3 NET When Switching to the Somatostatin Receptor Antagonist LM3: Intraindividual Proof-of-concept.

We present a 67-year-old man with inoperable metastatic G3 NET of the pancreas. The lesions were intensely positive in [ 68 Ga]Ga-DOTATOC PET/CT and only weakly positive in the supplementary [ 18 F]-FDG PET/CT. Peptide receptor radionuclide therapy (PRRT) with [ 177 Lu]Lu-DOTA-octreotate, after longstanding efficacy with repetitive retreatments over 7 years, eventually resulted only in disease stabilization without partial regression of lesions.

Superior NET Targeting by Switch From Agonist to Antagonist-mediated Somatostatin Receptor Theranostics Allowing Successful (LM3-based) PRRT of Otherwise Precluded mNET: Intraindividual Proof-of-concept.

We present a case of a 69-year-old woman with metastasized small bowel NET G2 initially treated with somatostatin analogs (SSA). Disease progression was observed under SSA, and poor tracer uptake on [68Ga]Ga-DOTATOC PET/CT precluded peptide receptor radionuclide therapy (PRRT). Subsequently, evaluation with [68Ga]Ga-NODAGA-LM3 PET/CT was performed, which showed markedly better and treatment-sufficient uptake, enabling initiation of PRRT with [177Lu]Lu-DOTA-LM3.

[F]FDG PET/CT of Langerhans Cell Histiocytosis with Vertebra Plana.

We present an F-fluorodeoxyglucose ([F]FDG) positron emission tomography/computed tomography (PET/CT) scan of a 27 y/o patient with long-standing significant B symptoms, diffuse bone pain, increased inflammation parameters, and polydipsia revealing multiple FDG-avid osteolytic lesions of the axial skeleton including a vertebra plana of T7 and paraosseous soft tissue lesions. A CT-guided biopsy confirmed the diagnosis of Langerhans cell histiocytosis (LCH). This case highlights the importance of considering LCH in young patients with vertebral collapse and underscores the role of PET/CT imaging in establishing an accurate diagnosis.

Prediction of lesion-based response to PRRT using baseline somatostatin receptor PET.

Aim: The heterogeneous expression of somatostatin receptors in gastroenteropancreatic neuroendocrine tumors (GEP-NET) leads to significant intra-individual variability in tracer uptake during pre-therapeutic [Ga]Ga-DOTATOC PET/CT for patients receiving peptide receptor radionuclide therapy (PRRT). This study aims to evaluate the lesion-based relationship between receptor-mediated tracer uptake and the functional response to PRRT.

Methods: A retrospective analysis was conducted on 32 patients with metastatic GEP-NET (12 pancreatic and 20 non-pancreatic), all treated with [Lu]Lu-octreotate (4 cycles, with a mean of 7.

225 Ac-PSMA-617 Augmentation After Insufficient Response Under 177 Lu-PSMA-617 Radioligand Therapy in mCRPC: Evaluation of Outcome and Safety From a Prospective Registry (REALITY Study).

Background: Even though the introduction of 177 Lu-PSMA-617 RLT represents a major milestone in the treatment of mCRPC, there are still patients who do not respond adequately to this therapy and for whom there are only limited options left. Augmenting 177 Lu-PSMA-617 RLT with the alpha-emitter 225 Ac-PSMA-617 may present an escalating treatment option to increase efficacy. In this study, we aim to evaluate outcome and safety of 225 Ac-PSMA-617 augmentation to 177 Lu-PSMA-617 RLT in patients who present insufficient response to monotherapy with 177 Lu-PSMA-617 RLT.

Diffuse Peritoneal Carcinomatosis of Prostate Cancer Unveiled by [89Zr]Zr-PSMA-617 PET/CT.

We report an interesting case of a 64-year-old man with a history of radical prostatectomy for prostate cancer. The patient presented with steady increasing prostate-specific antigen levels, but with negative findings on previous multiple conventional prostate-specific membrane antigen (PSMA) PET/CT (with [68Ga]Ga-PSMA-11) and [18F]FDG PET/CT. A recently introduced PSMA tracer using long-lived 89Zr (half-life 3.

Development of a homotrimeric PSMA radioligand based on the NOTI chelating platform.

Background: The NOTI chelating scaffold can readily be derivatized for bioconjugation without impacting its metal complexation/radiolabeling properties making it an attractive building block for the development of multimeric/-valent radiopharmaceuticals. The objective of the study was to further explore the potential of the NOTI chelating platform by preparing and characterizing homotrimeric PSMA radioconjugates in order to identify a suitable candidate for clinical translation.

Results: Altogether, three PSMA conjugates based on the NOTI-TVA scaffold with different spacer entities between the chelating unit and the Glu-CO-Lys PSMA binding motif were readily prepared by solid phase-peptide chemistry.

Safety of PSMA radioligand therapy in mCRPC patients with preexisting moderate to severe thrombocytopenia.

Purpose: Aim of this study was to analyze the safety of prostate-specific membrane antigen radioligand therapy (PSMA-RLT) in patients with metastatic castration-resistant prostate cancer (mCRPC) with preexisting moderate to severe thrombocytopenia (CTCAE ≥ 2).

Materials And Methods: Seventeen mCRPC patients with preexisting thrombocytopenia (platelet count < 75 × 10/L) were included in this study. Patients received a median of 3 cycles of [Lu]Lu-PSMA-617 (range 1-6).

Outcome and Renal Safety of PSMA-Targeted Radioligand Therapy in mCRPC Patients With Preexisting Impaired Renal Function.

Purpose: This study aims to evaluate the outcome and renal safety of prostate-specific membrane antigen (PSMA)-radioligand therapy (RLT) in patients with metastatic castration-resistant prostate carcinoma (mCRPC) and preexisting renal impairment.

Methods: Ninety-four patients with preexisting renal impairment were included in this retrospective analysis. Inclusion criterion was a glomerular filtration rate (GFR) of ≤60 mL/min (equivalent to Common Terminology Criteria of Adverse Events [CTCAE] ≥2).

Analysis of Molecular Imaging Biomarkers Derived from [F]FDG PET/CT in mCRPC: Whole-Body Total Lesion Glycolysis (TLG) Predicts Overall Survival in Patients Undergoing [Ac]Ac-PSMA-617-Augmented [Lu]Lu-PSMA-617 Radioligand Therapy.

The augmentation of [Lu]Lu-PSMA-617 radioligand therapy by alpha emitting [Ac]Ac-PSMA-617, known as the tandem therapy concept, is a promising escalating treatment option in advanced mCRPC. In this study, we evaluated the value of [F]FDG PET/CT-derived molecular imaging biomarkers for predicting response and outcome to PSMA tandem RLT in = 33 patients with insufficient response on [Lu]Lu-PSMA-617 monotherapy. Six different molecular imaging parameters at baseline, i.

[Zr]Zr-PSMA-617 PET/CT in a Patient with Biochemical Recurrence of Prostate Cancer and Prior Indetermined Findings on [F]PSMA-1007 Imaging.

We report a case of a 79-year-old male patient with a history of radical prostatectomy for prostate cancer. The patient presented with biochemical reoccurrence; however, previous conventional PSMA PET/CT using [F]PSMA-1007 showed two indetermined findings with low uptake in the right iliac lymph nodes. Further MRI evaluation provided no additional information.

Cutting the Gordian Knot: Rare Presentation of Nodular Fasciitis as Supraclavicular Swelling with Muscular Involvement in Ga-FAPI-PET/CT.

Nodular fasciitis is a benign, singularly occurring nodular fibroblastic/myofibroblastic neoplasia. Due to the rapid growth and cellular atypia, this rare differential diagnosis in the head and neck region can be mistaken for malignant sarcomas. We present a 40-year-old female patient with an unclear, rough, and poorly displaceable supraclavicular swelling on the right as part of a medical check-up.

Ectopic Cushing Syndrome Localized by 68 Ga-DOTA-LM3 PET/CT.

A 53-year-old woman presented with signs of Cushing syndrome with challenges in diagnosis and localization. A novel somatostatin receptor (SSTR)-targeted PET/CT with 68 Ga-DOTA-LM3, an SSTR antagonist, revealed a suspicious focal finding in the pancreatic head, proven to be ectopic Cushing syndrome after surgical resection. This interesting image clearly shows the potential of PET imaging with SSTR antagonists as 68 Ga-DOTA-LM3 in the diagnosis of ectopic Cushing syndrome.

Analysis of Molecular Imaging and Laboratory Baseline Biomarkers in PSMA-RLT: Whole-Body Total Lesion PSMA (TLP) Predicts Overall Survival.

The aim of this retrospective study was to identify pre-therapeutic predictive laboratory and molecular imaging biomarkers for response and overall survival (OS) in patients with metastatic castration-resistant prostate cancer (mCRPC) treated with prostate-specific membrane antigen (PSMA)-targeted radioligand therapy (RLT). Pre-therapeutic laboratory and [Ga]Ga-PSMA-11 PET/CT data of = 102 mCRPC patients receiving [Lu]Lu-PSMA-617 RLT within a prospective registry (REALITY Study, NCT04833517) were analyzed including laboratory parameters such as alkaline phosphatase (ALP), prostate-specific antigen (PSA), gamma glutamyl transferase (GGT), glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), neuron specific enolase (NSE), hemoglobin (Hb), and imaging parameters such as maximum standardized uptake value of the tumor lesions (SUV), the mean standardized uptake value of all tumor lesions (SUV), the whole-body molecular tumor volume (MTV), and the whole-body total lesion PSMA (TLP). Mann-Whitney U test, univariate and multivariable Cox-regression were performed to test for association of the parameters with response and OS.

Efficacy and safety of rechallenge [Lu]Lu-PSMA-617 RLT after initial partial remission in patients with mCRPC: evaluation of a prospective registry (REALITY study).

Aim: Rechallenge of [Lu]Lu-PSMA-617 radioligand therapy (RLT) was proposed for patients who initially responded to PSMA-RLT experiencing partial remission, but relapsed into progression after a certain period of remission. However, only limited data is available regarding this approach. In this study, we analyzed the efficacy and safety profile of one or more series of [Lu]Lu-PSMA-617 RLT rechallenge in patients from a prospective registry (REALITY Study, NCT04833517) after they initially benefited from PSMA-RLT.