Optimizing Stereotactic Intracranial Neoplasm Treatment: A Systematic Review of PET Integration with Gamma Knife Radiosurgery

OBJECTIVE: Traditional imaging modalities for the planning of Gamma Knife radiosurgery (GKRS) are non-specific and do not accurately delineate intracranial neoplasms. This study aimed to evaluate the utility of positron emission tomography (PET) for the planning of GKRS for intracranial neoplasms (ICNs) and the post-GKRS applications of PET for patient care. METHODS: PubMed, Scopus, and ScienceDirect were searched in order to assemble relevant studies regarding the uses of PET in conjunction with GKRS for ICN treatment. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed to identify relevant studies on the use of PET in conjunction with GKRS. Particular emphasis was placed on review articles and medical research investigating tumor delineation and post-operative care. Relevant studies were selected and assessed based on quality measures, including study design, sample size, and significance. Inclusion and exclusion criteria were used to examine the yield of the initial search (n = 105). After a secondary review, the included results were identified (n = 50). RESULTS: This study revealed that PET imaging is highly accurate for the planning of GKRS. In fact, many cases indicate that it is more specific than traditional imaging modalities. PET is also capable of complementing traditional imaging techniques through combination imaging. This showed significant efficacy for the planning of GKRS for ICNs. CONCLUSIONS: While PET shows a multitude of applications for the treatment of ICNs with GKRS, further research is necessary to assemble a complete set of clinical guidelines for treatment specifications. Importantly, future studies need a greater standardization of methods and expanded trials with a multitude of radiotracers

Aging and Cerebral Glucose Metabolism: 18F-FDG-PET/CT Reveals Distinct Global and Regional Metabolic Changes in Healthy Patients

Alterations in cerebral glucose metabolism can be indicative of both normal and pathological aging processes. In this retrospective study, we evaluated global and regional neurological glucose metabolism in 73 healthy individuals (mean age: 35.8 ± 13.1 years; 82.5% female) using 18F-Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT). This population exhibited a low prevalence of comorbidities associated with cerebrovascular risk factors. We utilized 18F-FDG-PET/CT imaging and quantitative regional analysis to assess cerebral glucose metabolism. A statistically significant negative correlation was found between age and the global standardized uptake value mean (SUVmean) of FDG uptake (p = 0.000795), indicating a decrease in whole-brain glucose metabolism with aging. Furthermore, region-specific analysis identified significant correlations in four cerebral regions, with positive correlations in the basis pontis, cerebellar hemisphere, and cerebellum and a negative correlation in the lateral orbital gyrus. These results were further confirmed via linear regression analysis. Our findings reveal a nuanced understanding of how aging affects glucose metabolism in the brain, providing insight into normal neurology. The study underscores the utility of 18F-FDG-PET/CT as a sensitive tool in monitoring these metabolic changes, highlighting its potential for the early detection of neurological diseases and disorders related to aging

Optimizing Stereotactic Intracranial Neoplasm Treatment: A Systematic Review of PET Integration with Gamma Knife Radiosurgery

Objective: Traditional imaging modalities for the planning of Gamma Knife radiosurgery (GKRS) are non-specific and do not accurately delineate intracranial neoplasms. This study aimed to evaluate the utility of positron emission tomography (PET) for the planning of GKRS for intracranial neoplasms (ICNs) and the post-GKRS applications of PET for patient care. Methods: PubMed, Scopus, and ScienceDirect were searched in order to assemble relevant studies regarding the uses of PET in conjunction with GKRS for ICN treatment. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed to identify relevant studies on the use of PET in conjunction with GKRS. Particular emphasis was placed on review articles and medical research investigating tumor delineation and post-operative care. Relevant studies were selected and assessed based on quality measures, including study design, sample size, and significance. Inclusion and exclusion criteria were used to examine the yield of the initial search (n = 105). After a secondary review, the included results were identified (n = 50). Results: This study revealed that PET imaging is highly accurate for the planning of GKRS. In fact, many cases indicate that it is more specific than traditional imaging modalities. PET is also capable of complementing traditional imaging techniques through combination imaging. This showed significant efficacy for the planning of GKRS for ICNs. Conclusions: While PET shows a multitude of applications for the treatment of ICNs with GKRS, further research is necessary to assemble a complete set of clinical guidelines for treatment specifications. Importantly, future studies need a greater standardization of methods and expanded trials with a multitude of radiotracers

The Emerging Role of NaF-PET/CT in Detecting Vascular Microcalcification in the Pathogenesis of Neurological Dysfunction

Cerebrovascular disease (CVD) is a global health concern, and early detection is crucial for effective intervention. This case report presents a 31-year-old male patient with multiple cardiac risk factors who underwent positron emission tomography/computed tomography (PET/CT) with 18F-sodium fluoride (NaF) and 18F-fluorodeoxyglucose (FDG) to evaluate for the presence and degree of atherosclerosis in the aorta, carotid arteries, coronary arteries, iliac arteries, and the femoral arteries. Elevated NaF uptake within the bilateral carotid arteries signified substantial ongoing vascular microcalcification. Reduced global brain metabolism and region-specific hypometabolism measured with FDG PET indicated potential cerebrovascular mechanisms that may be influencing neurological function. The findings highlight the potential of emerging PET tracers, such as NaF, to improve the diagnostic accuracy and therapeutic management of CVD. This case emphasizes the importance of a comprehensive diagnostic approach as well as continued investigation into CVD pathophysiology using PET-based techniques, which may guide the development of innovative therapeutic strategies

Abstract 015: Pioneering NaF‐PET/CT Imaging for Early Detection of Atherosclerosis: Potential Implications for Neurointerventional Surgery

Introduction Cerebrovascular disease (CVD), particularly carotid artery atherosclerosis, contributes substantially to global morbidity and mortality. The ability to precisely detect atherosclerosis is crucial, as it directly influences patient management, including decisions regarding surgical interventions. Given the high prevalence and severe outcomes of CVD, there is an urgent need for improved early detection methods. Utilizing a novel approach, this study pioneers the use of 18F‐sodium fluoride (NaF) PET/CT imaging for the early identification of microcalcification, a key marker of atherosclerosis. A nuanced understanding of vascular calcification's temporal progression may aid in optimally timing surgical interventions, such as carotid endarterectomy or carotid artery stenting, thereby reducing stroke risk. Methods Our study participant is a 31‐year‐old male with atrial fibrillation, multiple cardiovascular risk factors, and class 2 obesity, enrolled in the Cardiovascular Molecular Calcification Assessed by 18F‐NaF PET/CT (CAMONA) study. The patient underwent both FDG‐PET/CT and NaF‐PET/CT imaging. We utilized OsiriX MD software v.13.0.1 (Pixmeo SARL, Bernex, Switzerland), to compute the standardized uptake value (SUVmean), serving as a measure of disease progression in both the global brain and the bilateral carotid arteries. Subsequently, we employed MIMneuro version 7.1.5 (MIM Software, Inc., Cleveland, OH, USA) to conduct a comprehensive regional brain metabolism analysis, harnessing the power of an integrated anatomical atlas. Results NaF‐PET/CT imaging revealed elevated NaF uptake in the bilateral carotid arteries (z‐score = 0.012), suggesting notable microcalcification. Conversely, FDG‐PET/CT imaging revealed low FDG uptake in the carotid arteries, with an average SUVmean of 0.66 for both right and left carotids and a z‐score of −2.32. Analysis of global brain metabolism demonstrated decreased FDG uptake detected by FDG‐PET/CT (z‐score = ‐2.32). Concurrently, we identified a decline in regional brain metabolism, with prominent decreases observed in regions including the brainstem (z score = −1.95), medial temporal lobe (z‐score = −1.81), cerebellum (z–score = −2.13), hippocampus (z‐score = −2.13), inferior frontal gyrus (z‐score = −3.53), lateral orbital gyrus (z‐score = −3.24), and putamen (z‐score = −2.47) (Figure 1). Conclusion Our findings highlight the potential of NaF‐PET/CT imaging to enhance early detection of carotid artery atherosclerosis and cerebral hypometabolism. These results highlight the subtle, yet potent, potential of NaF‐PET/CT scans to detect active, asymptomatic cases where FDG‐PET/CT scans may not indicate high activity. The findings suggest that NaF‐PET could play a pivotal role in diagnosing and managing CVD where traditional tracers encounter limitations. Early recognition of these alterations facilitates clinical decision‐making, including determining the necessity and timing of surgical intervention. This advanced diagnostic tool presents an opportunity to improve pre‐operative assessments by providing insights into disease progression prior to macrocalcification development, a clear advantage over existing imaging modalities. The correlation between vascular calcification and decreased cerebral metabolism enhances our understanding of CVD pathophysiology, thereby paving the way for transformative therapeutic interventions. While these findings provide preliminary insight, further research is crucial to corroborate our results and delineate their potentially transformative implications on patient care, particularly in the context of surgical interventions