Initial clinical experience using 68Ga-FAPI-46 PET/CT for detecting various cancer types.

OBJECTIVE: Numerous studies have shown that gallium-68-labeled fibroblast activation protein inhibitor (68Ga-FAPI) positron emission tomography/computed tomography (PET/CT) scans would yield high intra-tumoral tracer uptake and low uptake in normal tissues as background, thus allowing for excellent visualization of lesions in the cancer microenvironment. This study set out to compare the suitability of novel 68Ga-FAPI-46 PET versus routine fluorine-18-fluorodeoxyglucose (18F-FDG) PET and other few cases of 68Ga-DOTATATE/68Ga-Pentixafor PET/CT for the assessment of different types of cancer. SUBJECTS AND METHODS: A retrospective analysis of 11 patients (6 males, 5 females; average age: 53 years, range: 10-58 years) with histopathologically confirmed, well-differentiated adenocarcinoma, medullar thyroid cancer (MTC), papillary thyroid carcinoma (PTC), cervical, gastric, glioblastoma multiform (GBM), colon, Ewing's sarcoma, and breast cancer was performed. These patients underwent PET/CT scans using four different radiotracers (9 18F-FDG, 11 68Ga- FAPI, 3 68Ga-DOTATATE, and 1 68Ga-Pentixafor). The patients' PET/CT images were visually evaluated for cancer detection, and analyzed semi-quantitatively through image- derived metrics, such as target-to-background ratio (TBR) and maximum standardized uptake value (SUVmax), for recurrence and metastasis. RESULTS: The study of 11 patients revealed that 68Ga-FAPI-46 was more effective than other tracers for detecting metastases, with 55 vs. 49 metastases in the lymph nodes, 4 vs. 3 in the liver, and 4 vs. 3 in the bones detected in comparison to 18F-FDG. No significant differences were observed in 68Ga-DOTATATE and 68Ga-Pentixafor PET images. In addition, in five patients, the SUVmax and TBR values in 68Ga-FAPI-46 PET images were significantly higher than those in 18F-FDG PET images for lymph nodes and bone metastases. Although the SUVmax in 68Ga-FAPI-46 and 18F-FDG PET images for liver metastases was comparable, 68Ga-FAPI- 46 had a significantly higher TBR than 18F-FDG. CONCLUSION: Our findings suggest that FAPI PET/CT is not suitable for evaluating GBM and Ewing sarcoma but generally outperforms 18F-FDG PET/CT in various types of breast cancer, gastrointestinal, gynecological, PTC and MTC. However, larger trials are needed to validate these preliminary findings.

An Overview of Appropriate Medical Practice and Preparedness in Radiation Emergency Response.

Radiation emergencies involving high doses of nuclear radiation pose significant risks from exposure to ionizing radiation in various scenarios. These situations include transportation accidents involving radioactive materials, occupational exposure, nuclear detonations, dirty bombs, and nuclear power plant accidents. In addition to the immediate risks of acute radiation syndrome (ARS) and related diseases, long-term exposure can increase the risk of other health issues such as cardiovascular disease and cancer. Vulnerable populations, including pregnant women and children, face particular concern due to potential impacts on their health and the health of unborn babies. The severity of ARS depends on several factors such as radiation dose, quality, dose rate, exposure uniformity, and individual biological responses. Bioindicators are biological responses or markers that help assess the severity and effects of radiation exposure on an individual. Bioindicators can include physical symptoms such as nausea, vomiting, and diarrhea, or laboratory tests such as changes in blood cell counts and gene expression that can help in assessing and treating exposed individuals. Additionally, early prodromal symptoms such as vomiting, diarrhea, and erythema can provide important clues for diagnosis and treatment. Developing a comprehensive plan for radiation emergencies is vital for safeguarding public health, infrastructure, and the environment. First responders play a critical role in establishing safety perimeters, triage, and coordination with various stakeholders. Education and training are essential for medical personnel and the public. This article provides general recommendations and identifies challenges to effective radiation emergency preparedness and response.

A rare presentation of thyroid malignant peripheral nerve sheath tumor in neurofibromatosis type 1 delineated by FDG PET/CT: A case report and literature review.

Malignant peripheral nerve sheath tumors (MPNST) are rare, aggressive soft tissue sarcomas that arise from peripheral nerves and often present a diagnostic and therapeutic challenge. They can occur sporadically or in association with neurofibromatosis type 1 (NF1), a genetic disorder caused by mutations in the NF1 gene. This report presents the unique case of a 33-year-old male with progressive dry cough, hoarseness, and neck swelling who underwent a total thyroidectomy, revealing a high-grade malignant peripheral nerve sheath tumor invading the thyroid. FDG PET/CT led to the additional diagnosis of NF1. This case stands out due to the rarity of finding an MPNST within the thyroid and the simultaneous identification of NF1. It underscores the importance of screening MPNST patients for NF1 and vice versa, spotlighting the expanding role of FDG PET/CT in comprehensive evaluations. To our knowledge, this report presents the first case of NF1-associated MPNST with thyroid involvement worldwide.

From Despair to Hope: First Arabic Experience of 177Lu-PSMA and 161Tb-PSMA Therapy for Metastatic Castration-Resistant Prostate Cancer.

The objective of this retrospective study is to assess the effectiveness and safety of two beta-emitting prostate-specific membrane antigen (PSMA) radioligands, [177Lu]Lu and [161Tb]Tb, in heavily treated patients with metastatic castration-resistant prostate cancer (mCRPC). A total of 148 cycles of beta-emitting PSMA radioligand therapy were given to 53 patients at a specialized cancer care center in Amman, Jordan. This treatment was offered following the exhaustion of all prior treatment modalities. Approximately half of the cases (n = 26) demonstrated an initial partial response to PSMA radioligand therapy. Moreover, roughly one-fourth of the patients (n = 13) exhibited a sustained satisfactory biochemical response, which qualified them to receive a total of six PSMA radioligand therapy cycles and maintain continued follow-up for additional treatment cycles. This was reflected by an adequate prostate-specific antigen (PSA) decline and a concomitant partial response evident on [68Ga]Ga-PSMA positron emission tomography/computed tomography imaging. A minority of patients (n= 18; 34%) experienced side effects. Generally, these were low-grade and self-limiting toxicities. This study endorses previous research evidence about PSMA radioligand therapy's safety and efficacy. It also provides the first clinical insight from patients of Arab ethnicity. This should facilitate and promote further evidence, both regionally and internationally.

Comparative analysis through propensity score matching in thyroid cancer: unveiling the impact of multiple malignancies.

Background: The incidence of thyroid cancer is on the rise worldwide, with childhood exposure to radiation being the sole acknowledged catalyst for its emergence. Nonetheless, numerous other factors that may pose risks are awaiting thorough examination and validation. This retrospective study aims to explore the malignancies linked to thyroid cancer and contrast the survival rates of those afflicted with a solitary tumor versus those with multiple primary neoplasms (MPN). Methods: This retrospective study examined data from King Hussein Cancer Center (KHCC), Jordan. Among 563 patients diagnosed with thyroid cancer, 30 patients had thyroid malignancy as part of MPN. For a 1:3 propensity score-matched analysis, 90 patients with only a primary thyroid malignancy were also enrolled. Results: Hematologic and breast malignancies were among the most frequent observed cancers alongside thyroid neoplasm. Patients who had MPN were diagnosed at older age, had higher body mass index and presented with higher thyroglobulin antibody levels (p < 0.05 for each). Additionally, MPN patient displayed a stronger family history for cancers (p= 0.002). A median follow-up duration of 135 months unveiled that MPN patients faced a worse 5-year survival compared to their counterparts with a singular neoplasm (87% vs 100% respectively; p < 0.01). However, no distinction emerged in the 5-year event-free survival between these two groups. Conclusion: MPN correlates with a significantly altered survival outcome of thyroid cancer patients. The diagnosis of thyroid carcinoma at an older age, accompanied by elevated initial thyroglobulin antibody levels and a notable familial predisposition, may raise concerns about the potential occurrence of synchronous or metachronous tumors.

[18F]F-Poly(ADP-Ribose) Polymerase Inhibitor Radiotracers for Imaging PARP Expression and Their Potential Clinical Applications in Oncology.

Including poly(ADP-ribose) polymerase (PARP) inhibitors in managing patients with inoperable tumors has significantly improved outcomes. The PARP inhibitors hamper single-strand deoxyribonucleic acid (DNA) repair by trapping poly(ADP-ribose)polymerase (PARP) at sites of DNA damage, forming a non-functional "PARP enzyme-inhibitor complex" leading to cell cytotoxicity. The effect is more pronounced in the presence of PARP upregulation and homologous recombination (HR) deficiencies such as breast cancer-associated gene (BRCA1/2). Hence, identifying HR-deficiencies by genomic analysis-for instance, BRCA1/2 used in triple-negative breast cancer-should be a part of the selection process for PARP inhibitor therapy. Published data suggest BRCA1/2 germline mutations do not consistently predict favorable responses to PARP inhibitors, suggesting that other factors beyond tumor mutation status may be at play. A variety of factors, including tumor heterogeneity in PARP expression and intrinsic and/or acquired resistance to PARP inhibitors, may be contributing factors. This justifies the use of an additional tool for appropriate patient selection, which is noninvasive, and capable of assessing whole-body in vivo PARP expression and evaluating PARP inhibitor pharmacokinetics as complementary to the currently available BRCA1/2 analysis. In this review, we discuss [18F]Fluorine PARP inhibitor radiotracers and their potential in the imaging of PARP expression and PARP inhibitor pharmacokinetics. To provide context we also briefly discuss possible causes of PARP inhibitor resistance or ineffectiveness. The discussion focuses on TNBC, which is a tumor type where PARP inhibitors are used as part of the standard-of-care treatment strategy.

Clinical Characteristics and Outcomes of CML in Adolescents and Young Adults.

BACKGROUND: While Chronic Myeloid Leukemia (CML) is a disease of older adults, there is a growing population of adolescent and young adults (AYAs) with CML. This study evaluated the clinical characteristics and outcomes of CML in AYAs. PATIENTS AND METHODS: Data from medical records of adults with chronic phase CML diagnosed and treated at our center from 2011until 2021were retrospectively analyzed. Age between 18 and 29 years was used to define AYAs. Response to tyrosine kinase inhibitors (TKIs), progression to accelerated phase (AP) or blast crisis (BC), event-free survival (EFS) and overall survival (OS) were compared between AYAs and older adults. RESULTS: Among 163 patients included, 41 (25.1%) were AYAs. AYAs were more likely to be males (P = .02), to present with symptoms (P = .004), had a higher median white blood cell count (P = .007), neutrophil count (P = .029), eosinophil count (P = 0.01), low-risk Sokal (P = .033) and Hasford (P = .005) groups. TKI-sensitivity as well as median times for achievement of complete cytogenetic and major molecular response were comparable between both groups. After a median follow-up of 76 (range: 11-235) months, there was no difference in OS (P = .528), or cumulative incidence of transformation to accelerated phase or blast crisis (P = .11). On the other hand, AYA had an inferior EFS (P = .034). CONCLUSION: A quarter of the patients diagnosed with CML in our population were AYAs. Despite being characterized as "lower-risk," they presented with a greater disease burden, had a shorter EFS but comparable OS. Further studies are needed to better understand the disease biology of this group.

18 F-FDG PET/CT Unveils Coexistent Myelomatous Hepatosplenic and Thyroid Cartilage Involvement : A Rare Presentation in Multiple Myeloma.

ABSTRACT: Extramedullary myelomatous disease is an aggressive condition where clonal plasma cells proliferate outside the bone marrow, allowing independent survival. This state is generally associated with negative outcomes. A 65-year-old woman presented with progressive bilateral hypochondrial pain, was initially misattributed to an inflammatory etiology, and was consequently managed with corticosteroid therapy. A bone marrow biopsy was offered after further deterioration confirming plasma cell myeloma. Afterward, 18 F-FDG PET/CT revealed medullary and extramedullary hepatosplenic and thyroid cartilage involvement, concluding an overall picture of an atypical and extensive extramedullary myelomatous disease.

Incidental Intense Fibroblast Activation Protein Inhibitor (FAPI) Uptake in Bilateral Gluteal Myositis Ossificans: A Case Report.

Positron emission tomography/computed tomography (PET/CT) using 18F-fluorodeoxyglucose ([18F]-FDG) is a widely adopted imaging modality for detecting hypermetabolic lesions. However, emerging positron-emitting tracers, such as radiopharmaceuticals featuring fibroblast activation protein (FAP) inhibitors (FAPI) labeled with [18F] or [68Ga], have opened new avenues in nuclear medicine. This case report focuses on the unique behavior of [68Ga]-FAPI in bilateral gluteal myositis ossificans, an infrequent condition characterized by soft tissue ossification. A 45-year-old woman with gastric adenocarcinoma underwent subtotal gastrectomy and received neoadjuvant and adjuvant chemotherapy; [68Ga]-FAPI PET revealed metastatic processes and unexpected [68Ga]-FAPI avid intramuscular ossifications in the pelvic and bilateral thigh muscles. Even though there was no history of trauma, the patient was diagnosed with myositis ossificans, a condition marked by non-cancerous ectopic ossifications. Diagnosis relies on history, radiology, and/or histology. FAPI imaging, increasingly used for inflammatory and infectious diseases, can exhibit uptake in benign conditions, including those involving bones and joints. This case report is the first to document incidental bilateral [68Ga]-FAPI uptake in bilateral gluteal myositis ossificans. The robust [68Ga]-FAPI activity in myositis ossificans highlights the importance of considering myositis ossificans in the context of soft tissue calcifications with intense [68Ga]-FAPI uptake.

False-Negative 68 Ga-FAPI PET/CT in Pediatric Thyroid Medullary Carcinoma Seen With 68 Ga-DOTATOC PET/CT and 18 F-FDG PET/CT.

ABSTRACT: In adults, 68 Ga-FAP inhibitor ( 68 Ga-FAPI) PET/CT outperforms 68 Ga-radiolabeled somatostatin analog peptides ( 68 Ga PET/CT) and 18 F-FDG PET/CT in detecting thyroid lesions. This is the case of a 13-year-old boy newly diagnosed with medullary thyroid cancer with high calcitonin level. 68 Ga PET/CT revealed the presence of only a primary thyroid lesion. Proven to be superior in detecting metastasis, 68 Ga-FAPI PET/CT was performed. The results came out negative for primary and potential metastatic lesions. This case sheds shed light on false-negatives reported in 68 Ga-FAPI PET/CT scans in pediatric patients, emphasizing the need for alternate radiotracers when a negative study is met.

FDG-PET in Chimeric Antigen Receptor T-Cell (CAR T-Cell) Therapy Toxicity: A Systematic Review.

The utilization of chimeric antigen receptor (CAR) T-cell therapy to target cluster of differentiation (CD)19 in cancer immunotherapy has been a recent and significant advancement. Although this approach is highly specific and selective, it is not without complications. Therefore, a systematic review was conducted to assess the current state of positron emission tomography (PET) in evaluating the adverse effects induced by CAR T-cell therapy. A thorough search of relevant articles was performed in databases such as PubMed, Scopus, and Web of Science up until March 2024. Two reviewers independently selected articles and extracted data, which was then organized and categorized using Microsoft Excel. The risk of bias and methodological quality was assessed. In total, 18 articles were examined, involving a total of 753 patients, in this study. A wide range of utilities were analyzed, including predictive, correlative, and diagnostic utilities. While positive outcomes were observed in all the mentioned areas, quantitative analysis of the included studies was hindered by their heterogeneity and use of varying PET-derived parameters. This study offers a pioneering exploration of this promising field, with the goal of encouraging further and more focused research in upcoming clinical trials.

Investigating knowledge of DRLs, image quality and radiation dose in PET/CT and CT imaging among medical imaging professionals.

Objective: To investigate the knowledge of diagnostic reference levels (DRLs), image quality, radiation dose and protocol parameters among Jordanian medical imaging professionals (MIPs) involved in PET/CT and CT scan procedures. Materials and methods: A questionnaire was designed and distributed to MIPs in Jordan. The survey comprised four sections: demographic data, MIP knowledge on dose/protocol parameters, image quality, and DRLs. Statistical analyses were performed utilizing Pearson's correlation, t-tests, ANOVA, and linear regression, with a significance level of 95 % and a p-value threshold of <0.05. Results: The study involved 147 participants. Most respondents were male (76.2 %), and most were aged 26-35 years (44.2 %). Approximately 51 % held a bachelor's degree, and the most common range of experience was 3-5 years (28.6 %). Participants showed a moderate level of knowledge regarding dose and protocol parameters, with a mean score of 61.8 %. The mean scores for knowledge of image quality and DRLs were 45.2 % and 44.8 %, respectively. The age group of the MIPs and the total experience were found to have a significant impact on the knowledge of the dose and protocol parameters, as well as the DRLs. Additionally, experience was found to have a significant influence on knowledge of the dose and protocol parameters. The study revealed a positive and significant effect of MIPs' knowledge of dose/protocol parameters and image quality on their knowledge of DRLs. Conclusions: This study indicates that professionals across five specialties who are engaged in PET/CT and CT imaging possess a moderate understanding of dosage and protocol parameters. However, there is a notable gap in knowledge regarding DRLs and image quality. To address this issue, it is recommended that MIPs actively engage in educational programs emphasizing exposure parameters and their impact on image quality. Additionally, access to comprehensive education and training programs will enable MIPs to grasp the complexities of DRLs and their implications, facilitating their implementation in clinical practice.

Navigating The Prostate Cancer Frontier: A Bibliometric and Altmetric Analysis of [225Ac]Ac-PSMA Therapy.

The main aim of this study was to evaluate the current state of bibliometric and altmetric research output of [225Ac]Ac-Prostate specific membrane antigen (PSMA) and its implications for prostate cancer (PC). Both PubMed and Scopus digital libraries were systematically explored to retrieve relevant data on the topic of interest. The study of various bibliometric and altmetric indices was facilitated through the use of Microsoft Excel, Stata (Version 17.0), and VOSviewer (Version 1.6) Softwares. The parameters included in this study comprised the examination of published articles, annual trends, countries, institutions, authors, journals, and co-occurring keywords. From 2014 to 2024, our study examined a total of 100 publications within the given domain. The studies that received the highest citations primarily centered on the crucial topic of metastatic castration-resistant prostate cancer, with a particular emphasis on evaluating the safety and effectiveness of [225Ac]Ac-PSMA therapy. Moreover, much scholarly inquiry has been devoted to examining the [225Ac]Ac-PSMA adverse effects. Three high prolific countries (namely, Germany, United States, and South Africa) dominated the research render in terms of publications and citations. Finally, A strong correlation was observed between altmetric score and citation number (P < 0.001). The observed surge in scholarly research output and altmetric indicators associated with [225Ac]Ac-PSMA signifies a shift in emphasis towards embracing alpha targeted therapy in PC.

Intense prostate-specific membrane antigen receptor expression in coronary artery pypass graft scar tissue: A potential molecular imaging pitfall.

68Gallium-PSMA positron emission tomography/computer tomography has been utilized recently for the diagnosis and staging of prostate cancer. PSMA is a transmembrane protein that is expressed not only in the prostate gland but also in other tissues. While some pitfalls have been addressed, there are still uncertainties. Herein, we report a 79-year-old male with prostate cancer who underwent a PSMA scan after coronary artery bypass graft surgery, revealing disease progression and PSMA-avid foci at the surgical stitch sites. This report discusses the immunohistochemical and molecular imaging mechanisms underlying PSMA expression in surgical scar tissues, providing critical insights for optimizing radiologic reporting in such situations.

Gallium-68-Labeled Fibroblast Activation Protein Inhibitor as an Alternative Radiotracer to Fluorine 18-Fluorodeoxyglucose: A Case Report of Rare Pulmonary Colloid Adenocarcinoma Diagnosed by PET/CT.

Colloid pulmonary adenocarcinoma represents a seldom encountered neoplasm in clinical practice. The diagnostic process for this rare neoplasm is complicated by its infrequency and the limited understanding of its specific molecular imaging characteristics. We report a 65-year-old male who was diagnosed with pulmonary colloid mucinous cystadenocarcinoma. Fluorine 18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) was conducted for initial evaluation. The scan showed mild 18F-FDG expression at the primary tumor site, and several non-18F-FDG-avid mediastinal and paraesophageal lymph nodes exhibited suspicious morphologic features. Owing to the ongoing atrial fibrillation, initial histopathological confirmation of the primary tumor mass carries a sense of risk, prompting the imperative for cardiological assessment before proceeding. Instead, Gallium-68-labeled fibroblast activation protein inhibitor (68Ga-FAPI) PET/CT was performed, expecting this to be more informative in terms of malignancy potential than 18F-FDG PET in colloid mucinous histology. A scan revealed moderate 68Ga-FAPI expression at the primary tumor site but unremarkable 68Ga-FAPI expression at the questionable lymph node. Subsequently, a biopsy from a mediastinal node (left para-aortic) lymph node via endobronchial ultrasound (EUS) showed benign findings. The patient was treated with concurrent chemoradiation. This case underscores the vital role that 68Ga-FAPI PET/CT can play in specific cases of rare cancers, especially when invasive testing for tissue biopsy is not feasible.