Head-to-head comparison of Ga-FAPI-46 PET/CT, F-FDG PET/CT, and contrast-enhanced CT for the detection of various tumors.

Objective: FAPI-PET/CT exhibits high tumor uptake and low background accumulation, enabling high-sensitivity tumor detection. We compared the diagnostic performance of  Ga-FAPI-46 PET/CT plus contrast-enhanced CT (CE-CT), F-FDG PET/CT plus CE-CT, and standalone CE-CT in patients with various malignancies.

Methods: 232 patients underwent  Ga-FAPI-46 PET/CT,F-FDG PET/CT, and CE-CT each within 4 weeks.

Detection of tumour heterogeneity in patients with advanced, metastatic castration-resistant prostate cancer on [Ga]Ga-/[F]F-PSMA-11/-1007, [Ga]Ga-FAPI-46 and 2-[F]FDG PET/CT: a pilot study.

Purpose: In metastatic castration-resistant prostate cancer (mCRPC), some patients show low/absent PSMA expression in tumour lesions on positron emission tomography (PET) scans, indicating heterogeneity and heightened risk of non-response to PSMA-RLT (radioligand therapy). Imaging cancer-associated fibroblasts and glucose uptake may further characterise tumour heterogeneity in mCRPC patients. Here, we aimed to evaluate tumour heterogeneity and its potential implications for management in mCRPC patients assessed for PSMA-RLT using [Ga]Ga-FAPI-46, 2-[F]FDG and [Ga]Ga-/[F]F-PSMA-11/-1007 PET.

Fibroblast Activation Protein-Directed Imaging Outperforms F-FDG PET/CT in Malignant Mesothelioma: A Prospective, Single-Center, Observational Trial.

The fibroblast activation protein (FAP) is highly expressed in tumor and stromal cells of mesothelioma and thus is an interesting imaging and therapeutic target. Previous data on PET imaging with radiolabeled FAP inhibitors (FAPIs) suggest high potential for superior tumor detection. Here, we report the data of a large malignant pleural mesothelioma cohort within a Ga-FAPI46 PET observational trial (NCT04571086).

The Role of Fibroblast Activation Protein in Glioblastoma and Gliosarcoma: A Comparison of Tissue, Ga-FAPI-46 PET Data, and Survival Data.

Despite their unique histologic features, gliosarcomas belong to the group of glioblastomas and are treated according to the same standards. Fibroblast activation protein (FAP) is a component of a tumor-specific subpopulation of fibroblasts that plays a critical role in tumor growth and invasion. Some case studies suggest an elevated expression of FAP in glioblastoma and a particularly strong expression in gliosarcoma attributed to traits of predominant mesenchymal differentiation.

Prognostic Implications of Ga-FAPI-46 PET/CT-Derived Parameters on Overall Survival in Various Types of Solid Tumors.

Tumoral fibroblast activation protein expression is associated with proliferation and angiogenesis and can be visualized by PET/CT. We examined the prognostic value of [Ga]Ga-fibroblast activation protein inhibitor (FAPI) (Ga-FAPI)-46 PET/CT for different tumor entities in patients enrolled in 2 prospective imaging studies (NCT05160051, = 30; NCT04571086, = 115). Within 4 wk, 145 patients underwent Ga-FAPI-46 and [F]FDG (F-FDG) PET/CT.

Ga-Fibroblast Activation Protein Inhibitor PET/CT Improves Detection of Intermediate and Low-Grade Sarcomas and Identifies Candidates for Radiopharmaceutical Therapy.

Fibroblast activation protein-α (FAP) is often highly expressed by sarcoma cells and by sarcoma-associated fibroblasts in the tumor microenvironment. This makes it a promising target for imaging and therapy. The level of FAP expression and the diagnostic value of Ga-FAP inhibitor (FAPI) PET for sarcoma subtypes are unknown.

Thyroglobulin measurement is the most powerful outcome predictor in differentiated thyroid cancer: a decision tree analysis in a European multicenter series.

Objectives: An accurate prognostic assessment is pivotal to adequately inform and individualize follow-up and management of patients with differentiated thyroid cancer (DTC). We aimed to develop a predictive model for recurrent disease in DTC patients treated by surgery and I by adopting a decision tree model.

Methods: Age, sex, histology, T stage, N stage, risk classes, remnant estimation, thyroid-stimulating hormone (TSH), thyroglobulin (Tg), administered I activities and post-therapy whole body scintigraphy (PT-WBS) were identified as potential predictors and put into regression algorithm (conditional inference tree, c-tree) to develop a risk stratification model for predicting persistent/recurrent disease over time.

Fibroblast Activation Protein α-Directed Imaging and Therapy of Solitary Fibrous Tumor.

Fibroblast activation protein α (FAPα) is expressed at high levels in several types of tumors. Here, we report the expression pattern of FAPα in solitary fibrous tumor (SFT) and its potential use as a radiotheranostic target. We analyzed FAPα messenger RNA and protein expression in biopsy samples from SFT patients using immunohistochemistry and multiplexed immunofluorescence.

Ga-Labeled Fibroblast Activation Protein Inhibitor (Ga-FAPI) PET for Pancreatic Adenocarcinoma: Data from the Ga-FAPI PET Observational Trial.

The fibroblast activation protein (FAP) is highly expressed on carcinoma-associated fibroblasts in the stroma of pancreatic cancer and thus is a promising target for imaging and therapy. Preliminary data on PET imaging with radiolabeled FAP inhibitors (FAPIs) demonstrate superior tumor detection. Here we assess the accuracy of FAP-directed PET in patients with pancreatic cancer.

Lu-Prostate-Specific Membrane Antigen Therapy in Patients with Metastatic Castration-Resistant Prostate Cancer and Prior Ra (RALU Study).

Ra-dichloride (Ra) and Lu-prostate-specific membrane antigen (PSMA) are approved treatments for metastatic castration-resistant prostate cancer (mCRPC). The safety and effectiveness of sequential use of Ra and Lu-PSMA in patients with mCRPC are not well described. This study aimed to evaluate Lu-PSMA safety and efficacy in patients with mCRPC previously treated with Ra.

Bilobar Radioembolization Carries the Risk of Radioembolization-Induced Liver Disease in the Treatment of Advanced Hepatocellular Carcinoma: Safety and Efficacy Comparison to Systemic Therapy with Atezolizumab/Bevacizumab.

Recommended treatment options for advanced-stage hepatocellular carcinoma (HCC) include systemic therapy (ST) and trans-arterial radioembolization (TARE) with Yttrium-90 (Y90). Before the approval of immune-checkpoint inhibitors, a similar safety profile was reported for TARE and ST with tyrosine kinase inhibitors (TKI). However, whole-liver treatment and underlying cirrhosis were identified as risk factors for potentially lethal radioembolization-induced liver disease (REILD).

Ga-FAPI PET/CT Interobserver Agreement on Tumor Assessment: An International Multicenter Prospective Study.

Ga-fibroblast activation protein inhibitors (FAPIs) are promising radiotracers for cancer imaging, with emerging data in the recent years. Nonetheless, the interobserver agreement on Ga-FAPI PET/CT study interpretations in cancer patients remains poorly understood. Ga-FAPI PET/CT was performed on 50 patients with various tumor entities (sarcoma [ = 10], colorectal cancer [ = 10], pancreatic adenocarcinoma [ = 10], genitourinary cancer [ = 10], and other types of cancer [ = 10]).

Postoperative thyroglobulin as a yard-stick for radioiodine therapy: decision tree analysis in a European multicenter series of 1317 patients with differentiated thyroid cancer.

Purpose: An accurate postoperative assessment is pivotal to inform postoperative I treatment in patients with differentiated thyroid cancer (DTC). We developed a predictive model for post-treatment whole-body scintigraphy (PT-WBS) results (as a proxy for persistent disease) by adopting a decision tree model.

Methods: Age, sex, histology, T stage, N stage, risk classes, remnant estimation, TSH, and Tg were identified as potential predictors and were put into regression algorithm (conditional inference tree, ctree) to develop a risk stratification model for predicting the presence of metastases in PT-WBS.

Superior Tumor Detection for Ga-FAPI-46 Versus F-FDG PET/CT and Conventional CT in Patients with Cholangiocarcinoma.

Management of cholangiocarcinoma is among other factors critically determined by accurate staging. Here, we aimed to assess the accuracy of PET/CT with the novel cancer fibroblast-directed Ga-fibroblast activation protein (FAP) inhibitor (FAPI)-46 tracer for cholangiocarcinoma staging and management guidance. Patients with cholangiocarcinoma from a prospective observational trial were analyzed.

Fibroblast-Activation Protein PET and Histopathology in a Single-Center Database of 324 Patients and 21 Tumor Entities.

We present an overview of our prospective fibroblast-activation protein inhibitor (FAPI) registry study across a 3-y period, with head-to-head comparison of tumor uptake in Ga-FAPI and F-FDG PET, as well as FAP immunohistochemistry. This is an interim analysis of the ongoing Ga-FAPI PET prospective observational trial at our department. Patients who underwent clinical imaging with Ga-FAPI PET between October 2018 and October 2021 were included.

Predictive value of highly sensitive basal versus stimulated thyroglobulin measurement in long-term follow-up of thyroid cancer.

Objective: Recurrence of differentiated thyroid cancer (DTC) is associated with reduced quality of life, and therefore, early identification of patients at risk is urgently needed.Here we investigated the predictive power of various cut-off values of single stimulated thyroglobulin (s-Tg) and single highly sensitive measured, unstimulated thyroglobulin (u-hsTg) measurements close to the end of primary therapy for recurrence-free survival (RFS) in long-term follow-up (>10 years) of patients with DTC.

Methods: In DTC patients with adjuvant radioiodine therapy, we assessed retrospectively u-hsTg (6 ± 3 months before s-Tg measurement) and s-Tg measurements (≤24 months after last radioiodine therapy).

Safety and Survival Outcomes of Lu-Prostate-Specific Membrane Antigen Therapy in Patients with Metastatic Castration-Resistant Prostate Cancer with Prior Ra treatment: The RALU Study.

The radium lutetium (RALU) study evaluated the feasibility of sequential α- and β-emitter use in patients with bone-predominant metastatic castration-resistant prostate cancer. This preplanned interim retrospective analysis investigated safety and survival outcomes with Lu-PSMA in patients treated with prior Ra. Forty-nine patients were evaluated.

Safety and Efficacy of 90Y-FAPI-46 Radioligand Therapy in Patients with Advanced Sarcoma and Other Cancer Entities.

Purpose: We report efficacy and safety of 90Y-labeled FAPI-46 (90Y-FAPI-46-RLT) in patients with advanced sarcoma, pancreatic cancer, and other cancer entities.

Experimental Design: Up to four cycles of radioligand therapy (RLT) were offered to patients with (i) progressive metastatic malignancy, (ii) exhaustion of approved therapies, and (iii) high fibroblast activation protein (FAP) expression, defined as SUVmax ≥ 10 in more than 50% of tumor. Primary endpoint was RECIST response after RLT.

Clinical Use of PET/MR in Oncology: An Update.

The combination of PET and MRI is one of the recent advances of hybrid imaging. Yet to date, the adoption rate of PET/MRI systems has been rather slow. This seems to be partially caused by the high costs of PET/MRI systems and the need to verify an incremental benefit over PET/CT or sequential PET/CT and MRI.

The Future Role of PET Imaging in Metastatic Breast Cancer.

Background: A variety of therapeutic approaches are employed to treat patients suffering from breast cancer. Likewise, a broad spectrum of imaging ligands has been introduced for noninvasive positron emission tomography/computed tomography (PET/CT) imaging to enable comprehensive tumor characterization and more accurate response evaluation.

Summary: In recent years, novel radioactively labeled ligands have been developed for PET/CT imaging in metastatic breast cancer.

Diagnostic Performance of I-Metaiodobenzylguanidine PET/CT in Patients with Pheochromocytoma.

I-metaiodobenzylguanidine (MIBG) scintigraphy has shown a high specificity for imaging pheochromocytoma and paraganglioma, but with low sensitivity because of low spatial resolution. I-MIBG PET may be able to overcome this limitation and improve the staging of patients with (suspected) pheochromocytoma. We analyzed the sensitivity, specificity, and positive and negative predictive values of I-MIBG PET in 43 consecutive patients with suspected (recurrence of) pheochromocytoma using histopathologic ( = 25) and clinical validation ( = 18) as the standard of truth.