Redefining the Role of Medical Affairs Professionals as Innovators and Leaders in Industry-Led Medical Education.

Medical affairs professionals are pivotal players at the intersection of medical innovation and practice in the pharmaceutical industry. They are uniquely positioned to translate complex medical knowledge into actionable insights for internal and external stakeholders. Industry-led continuing medical education (CME) programs, guided by these professionals, hold the potential to markedly improve clinicians' application of evidence-based medicine (EBM) in clinical settings, thereby elevating patient care outcomes. However, current CME techniques often overlook the integration of diverse disciplines such as educational theories, cognitive psychology, information mastery, and implementation science, which are important for effective real-time decision-making in patient care. This gap in integrating implementation science is vital, as it is key in ensuring that medical innovations are not just developed but also effectively implemented and efficiently utilized in clinical settings. In this opinion article, we aim to highlight the crucial yet often underrecognized role of medical affairs professionals in shaping robust and practical CME programs within the industry. We explore emerging trends and approaches in medical education and CME based on the principles of adult education. Additionally, we explore how medical affairs professionals can effectively drive the adoption of EBM in clinical practice. This exploration aims to provide insights into enhancing CME programs, with medical affairs professionals at the forefront of innovation and leadership in bridging gaps in clinical practice.

Disruption of Fuz in mouse embryos generates hypoplastic hindbrain development and reduced cranial nerve ganglia.

BACKGROUND: The brain and spinal cord formation is initiated in the earliest stages of mammalian pregnancy in a highly organized process known as neurulation. Environmental or genetic interferences can impair neurulation, resulting in clinically significant birth defects known collectively as neural tube defects. The Fuz gene encodes a subunit of the CPLANE complex, a macromolecular planar polarity effector required for ciliogenesis. Ablation of Fuz in mouse embryos results in exencephaly and spina bifida, including dysmorphic craniofacial structures due to defective cilia formation and impaired Sonic Hedgehog signaling. RESULTS: We demonstrate that knocking Fuz out during embryonic mouse development results in a hypoplastic hindbrain phenotype, displaying abnormal rhombomeres with reduced length and width. This phenotype is associated with persistent reduction of ventral neuroepithelial stiffness in a notochord adjacent area at the level of the rhombomere 5. The formation of cranial and paravertebral ganglia is also impaired in these embryos. CONCLUSIONS: This study reveals that hypoplastic hindbrain development, identified by abnormal rhombomere morphology and persistent loss of ventral neuroepithelial stiffness, precedes exencephaly in Fuz ablated murine mutants, indicating that the gene Fuz has a critical function sustaining normal neural tube development and neuronal differentiation.

The role of susceptibility-weighted imaging & contrast-enhanced MRI in the diagnosis of primary CNS vasculitis: a large case series.

Primary CNS Vasculitis (PCNSV) is a rare, diverse, and polymorphic CNS blood vessel inflammatory condition. Due to its rarity, clinical variability, heterogeneous imaging results, and lack of definitive laboratory markers, PCNSV diagnosis is challenging. This retrospective cohort analysis identified patients with histological diagnosis of PCNSV. Demographic data, clinical presentation, neuroimaging studies, and histopathologic findings were recorded. We enrolled 56 patients with a positive biopsy of CNS vasculitis. Most patients had cerebral hemisphere or brainstem symptoms. Most brain MRI lesions were bilateral, diffuse discrete to confluent white matter lesions. Frontal lobe lesions predominated, followed by inferior cerebellar lesions. Susceptibility-weighted imaging (SWI) hemorrhages in 96.4% (54/56) of patients, either solitary microhemorrhages or a combination of micro and macrohemorrhages. Contrast-enhanced T1-WIs revealed parenchymal enhancement in 96.3% (52/54 patients). The most prevalent pattern of enhancement observed was dot-linear (87%), followed by nodular (61.1%), perivascular (25.9%), and patchy (16.7%). Venulitis was found in 19 of 20 individuals in cerebral DSA. Hemorrhages in SWI and dot-linear enhancement pattern should be incorporated as MINOR diagnostic criteria to diagnose PCNSV accurately within an appropriate clinical context. Microhemorrhages in SWI and venulitis in DSA, should be regarded as a potential marker for PCNSV.

Tunable Macroscopic Alignment of Self-Assembling Peptide Nanofibers.

Fibrous proteins that comprise the extracellular matrix (ECM) guide cellular growth and tissue organization. A lack of synthetic strategies able to generate aligned, ECM-mimetic biomaterials has hampered bottom-up tissue engineering of anisotropic tissues and led to a limited understanding of cell-matrix interactions. Here, we present a facile extrusion-based fabrication method to produce anisotropic, nanofibrous hydrogels using self-assembling peptides. The application of shear force coinciding with ion-triggered gelation is used to kinetically trap supramolecular nanofibers into aligned, hierarchical structures. We establish how modest changes in phosphate buffer concentration during peptide self-assembly can be used to tune their alignment and packing. In addition, increases in the nanostructural anisotropy of fabricated hydrogels are found to enhance their strength and stiffness under hydrated conditions. To demonstrate their utility as an ECM-mimetic biomaterial, aligned nanofibrous hydrogels are used to guide directional spreading of multiple cell types, but strikingly, increased matrix alignment is not always correlated with increased cellular alignment. Nanoscale observations reveal differences in cell-matrix interactions between variably aligned scaffolds and implicate the need for mechanical coupling for cells to understand nanofibrous alignment cues. In total, innovations in the supramolecular engineering of self-assembling peptides allow us to generate a gradient of anisotropic nanofibrous hydrogels, which are used to better understand directed cell growth.

Optical coherence elastography measures the biomechanical properties of the ex vivo porcine cornea after LASIK.

Significance: The biomechanical impact of refractive surgery has long been an area of investigation. Changes to the cornea structure cause alterations to its mechanical integrity, but few studies have examined its specific mechanical impact. Aim: To quantify how the biomechanical properties of the cornea are altered by laser assisted in situ keratomileusis (LASIK) using optical coherence elastography (OCE) in ex vivo porcine corneas. Approach: Three OCE techniques, wave-based air-coupled ultrasound (ACUS) OCE, heartbeat (Hb) OCE, and compression OCE were used to measure the mechanical properties of paired porcine corneas, where one eye of the pair was left untreated, and the fellow eye underwent LASIK. Changes in stiffness as a function of intraocular pressure (IOP) before and after LASIK were measured using each technique. Results: ACUS-OCE showed that corneal stiffness changed as a function of IOP for both the untreated and the treated groups. The elastic wave speed after LASIK was lower than before LASIK. Hb-OCE and compression OCE showed regional changes in corneal strain after LASIK, where the absolute strain difference between the cornea anterior and posterior increased after LASIK. Conclusions: The results of this study suggest that LASIK may soften the cornea and that these changes are largely localized to the region where the surgery was performed.

Developments in pancreatic cancer surgery.

Pancreatic cancer surgery, with one of the worst prognoses in oncology, is a challenge to the surgical community. Centralization of pancreatic surgery has led to the foundation of high-volume centers, thereby greatly facilitating the successful performance of more radical approaches. This review spotlights on recent advances in surgical approaches to pancreatic cancer and the risks and benefits of vascular reconstruction to improve resectability. Surgery being the only modality to achieve cure, multivisceral and vascular resections are being incorporated to improve dismal operability rates of < 10%. Great leaps have been made in neoadjuvant and adjuvant treatment, as targeted and specific chemotherapeutic agents are being continually added. The concept of borderline and locally advanced pancreatic tumors and the use of neoadjuvant chemorad has extended the indications of oncological resection in such tumors. Venous resections are being routinely performed so as to facilitate en bloc removal of tumors, while arterial resections, owing to the increased morbidity and mortality, are offered to highly selective cases. New techniques like the triangle operation and periarterial divestment have opened new viable surgical options. Although laparoscopic approach is time consuming, it offers reduced operative blood loss and a shortened hospital stay at specialized centers. Robotic surgery may produce better results in patients needing vascular resection and reconstruction, but the expenses involved and limited availability are major deterrents. Advanced techniques of surgical resection and vessel reconstruction provide a repository for curative-intent surgery in borderline resectable and locally advanced pancreatic cancer.

Diversity in Oncology Clinical Trials: Current Landscape for Industry-Sponsored Clinical Trials in Asia.

INTRODUCTION: There has been a growing recognition on the importance of diversity in clinical trials. Existing research has highlighted a significant demographic imbalance. Amidst this renewed focus on diversity, it is crucial to acknowledge that Asia comprises over half of the world's population. Given the region's demographic significance, we sought to compare various characteristics and growth rates for trials with sites in Asia against those without any sites in Asia. METHODS: We performed comprehensive analyses of industry-sponsored phase 2 and 3 oncology trials registered at Clinicaltrials.gov, using drugs or biologics as investigational agents and executed between 1 January 2018 and 31 December 2022. We applied the compound annual growth rate (CAGR) as an analytical tool to track the trial growth rates over this 5-year period. RESULTS: We identified 894 industry-sponsored phase 2 and 3 cancer studies with available study location data. Out of these, 415 trials (46.42%) had study sites in Asia. Notably, these trials with sites in Asia were also more likely to be phase 3 trials (39.76% vs 6.47%, p < 0.001), include female and paediatric populations, and be randomised trials. Interestingly, lung and stomach cancers were more commonly studied in these trials, while myeloma was less commonly studied. The number of trial sites for liver cancer was not significantly higher for Asia, even though the incidence of the disease is much higher in this region. Despite an overall declining trend in the number of clinical trials in the last 5 years, we observed a transitional positive increase in the CAGR from 2020 to 2021 for trials with sites in Asia. However, East Asia, specifically China, exhibited a disproportionate overrepresentation in these trials. CONCLUSIONS: There are notable characteristics of clinical trials with sites in Asia. Comprehending these disparities may aid in the strategic planning to enhance a balanced representation of ethnicities in trials.

Metabolic imaging in recurrent gliomas: comparative performance of 18F-FDOPA, 18F-fluorocholine and 18F-FDG PET/CT.

PURPOSE: The aim of this study was to directly evaluate glucose, amino-acid and membrane metabolism in tumor cells for diagnosis and prognostication of recurrent gliomas. METHODS: Fifty-five patients (median age = 36 years; 33 men) with histologically proven gliomas and suspected recurrence were prospectively recruited and underwent 18F-FDG (Fluorodeoxyglucose), 18F-FDOPA (fluorodopa) and 18F-Fluorocholine-PET/CT. Images were evaluated by two physicians visually and quantitatively [lesion-SUVmax, tumor (T) to gray-matter (G) and metabolically-active tumor volumes (MTV)]. After median follow-up of 51.5 months, recurrence was diagnosed in 49 patients. Thirty-one patients died with a median survival of 14 months. RESULTS: Diagnostic-accuracies for 18F-FDOPA, 18F-Fluorocholine,18F-FDG and contrast-enhanced-MRI were 92.7% (95% CI 82.7-97.1), 81.8% (69.7-89.8), 45.5% (33.0-58.5) and 44.7% (30.2-60.3), respectively. Among the 20 lesions, missed by MRI; 18F-FDOPA, 18F-Fluorocholine and 18F-FDG were able to detect 19, 14 and 4 lesions. Corresponding area-under-the-curves (T/G ratios) were 0.817 (0.615-1.000), 0.850 (0.736-0.963) and 0.814 (0.658-0.969), when differentiating recurrence from treatment-induced changes. In univariate-survival-analysis, 18F-FDOPA-T/G, visually detectable recurrence in 18F-FDG, 18F-FDOPA-MTV, cell-lineage and treatment-type were significant parameters. In Multivariate-Cox-regression analysis, 18F-FDOPA-MTV [HR = 1.009 (1.001-1.017); P  = 0.024 (~0.9% increase in hazard for every mL increase of MTV)] and cell-lineage [3.578 (1.447-8.846); P  = 0.006] remained significant. 18F-FDOPA-MTV cutoff <29.59 mL predicted survival higher than 2 years. At cutoff ≥29.59 mL, HR at 2 years was 2.759 (1.310-5.810). CONCLUSION: 18F-FDOPA-PET/CT can diagnose recurrence with high accuracy and MTV predicts survival. 18F-Fluorocholine is a good alternative. Higher 18F-FDG uptake is an adverse prognostic indicator.

Topical Vancomycin for Prevention of Surgical Site Infection in Cranial Surgeries: Results of an Updated Systematic Review, Meta-Analysis and Meta-Regression.

Background: Surgical site infection (SSI) rates (1-9%) remain high despite the widespread adoption of infection control bundles. Topical vancomycin has emerged as an effective strategy to reduce the rate of SSI in patients undergoing spinal surgery including instrumentation. However, its use and efficiency in cranial neurosurgery is not well established. The aim of this study is to study the efficacy of topical vancomycin in cranial neurosurgery. Methods: A systematic search was performed according to Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. Data regarding type of surgery, use of implants, the dose of vancomycin, technique of administration in each study, outcomes, rate of SSI, and the interval between surgery and SSI; possible complications related to antibiotic use were collected. Results: A total of 12 studies were included in the qualitative analysis with 3,446 patients. SSI developed in 1.6% of the patients in the vancomycin group as compared to 5.28% in the control group. The pooled risk ratio was 0.24 with 95% CI: 0.12-0.51 (P-value: <0.00001). The difference between the subgroups was significant (P-value: < 0.00001). The number needed to treat (NNT) was 27.2. The studies showed low heterogeneity with an I2 of 24%. Meta-regression analysis showed that the number of patients in a study, duration of follow-up, and year of publication did not contribute significantly to effect size. Conclusion: The limited systemic absorption of vancomycin and broad-spectrum led to its widespread applicability in the prevention of SSI in all types of cranial neurosurgery. Cases with implantable pulse generators, cranioplasty, and cerebrospinal fluid (CSF) diversion procedures have all demonstrated their unequivocal effectiveness.

Nanobomb optical coherence elastography in multilayered phantoms.

Many tissues are composed of layered structures, and a better understanding of the changes in the layered tissue biomechanics can enable advanced guidance and monitoring of therapy. The advent of elastography using longitudinally propagating shear waves (LSWs) has created the prospect of a high-resolution assessment of depth-dependent tissue elasticity. Laser activation of liquid-to-gas phase transition of dye-loaded perfluorocarbon (PFC) nanodroplets (a.k.a., nanobombs) can produce highly localized LSWs. This study aims to leverage the potential of photoactivation of nanobombs to incudce LSWs with very high-frequency content in wave-based optical coherence elastography (OCE) to estimate the elasticity gradient with high resolution. In this work, we used multilayered tissue-mimicking phantoms to demonstrate that highly localized nanobomb (NB)-induced LSWs can discriminate depth-wise tissue elasticity gradients. The results show that the NB-induced LSWs rapidly change speed when transitioning between layers with different mechanical properties, resulting in an elasticity resolution of ∼65 µm. These results show promise for characterizing the elasticity of multilayer tissue with a fine resolution.

An assessment of the variation in the practice of lumbar discectomy and its role in axial back pain.

Background: Lumbar discectomy is performed for symptomatic lumbar disc herniation and is one of the most widely performed spinal surgical procedures worldwide in a variety of ways. This survey aimed at providing an overview/perspective of different practice patterns and the impact of lumbar discectomy on axial back pain with or without sciatica. Methods: An online survey was performed using the application "Google Forms." The link to the questionnaire was distributed to neurosurgeons through personal E-mail and social media platforms. Results: We received 333 responses. The largest percentage of responses across five continents was from Asia (66.97%, n = 223). The mean age of the respondents was 40.08 ± 10.5 years. A total of 66 respondents (20%) had a spine practice of 7%-90%, and 28 respondents had a spine practice of 90%-100% (8.4%). The number of respondents who practiced microscopic discectomy using a tubular retractor (n = 143 respondents, 42.9%) was nearly equal to the number of respondents who practiced open discectomy (n = 142 respondents, 42.6%). An almost equal proportion of respondents believed discectomy does not help in relieving axial back pain. Only 20.4% (n = 68) of respondents recommend bed rest for a longer duration postoperatively. Conclusions: Our survey revealed that only 22.2% of spine surgeons recommended discectomy in patients with radiological disc herniation with axial back pain alone and preferred a minimally invasive method of discectomy. Almost half of them believed discectomy to be ineffective for axial low back pain and only a few recommended prolonged bed rest postoperatively.

Multifocal acoustic radiation force-based reverberant optical coherence elastography for evaluation of ocular globe biomechanical properties.

Significance: Quantifying the biomechanical properties of the whole eye globe can provide a comprehensive understanding of the interactions among interconnected ocular components during dynamic physiological processes. By doing so, clinicians and researchers can gain valuable insights into the mechanisms underlying ocular diseases, such as glaucoma, and design interventions tailored to each patient's unique needs. Aim: The aim of this study was to evaluate the feasibility and effectiveness of a multifocal acoustic radiation force (ARF) based reverberant optical coherence elastography (RevOCE) technique for quantifying shear wave speeds in different ocular components simultaneously. Approach: We implemented a multifocal ARF technique to generate reverberant shear wave fields, which were then detected using phase-sensitive optical coherence tomography. A 3D-printed acoustic lens array was employed to manipulate a collimated ARF beam generated by an ultrasound transducer, producing multiple focused ARF beams on mouse eye globes ex vivo. RevOCE measurements were conducted using an excitation pulse train consisting of 10 cycles at 3 kHz, followed by data processing to produce a volumetric map of the shear wave speed. Results: The results show that the system can successfully generate reverberant shear wave fields in the eye globe, allowing for simultaneous estimation of shear wave speeds in various ocular components, including cornea, iris, lens, sclera, and retina. A comparative analysis revealed notable differences in wave speeds between different parts of the eye, for example, between the apical region of the cornea and the pupillary zone of the iris (p=0.003). Moreover, the study also revealed regional variations in the biomechanical properties of ocular components as evidenced by greater wave speeds near the apex of the cornea compared to its periphery. Conclusions: The study demonstrated the effectiveness of RevOCE based on a non-invasive multifocal ARF for assessing the biomechanical properties of the whole eyeball. The findings indicate the potential to provide a comprehensive understanding of the mechanical behavior of the whole eye, which could lead to improved diagnosis and treatment of ocular diseases.

Disruption of Fuz in mouse embryos generates hypoplastic hindbrain development and reduced cranial nerve ganglia.

The formation of the brain and spinal cord is initiated in the earliest stages of mammalian pregnancy in a highly organized process known as neurulation. Convergent and extension movements transforms a flat sheet of ectodermal cells into a narrow and elongated line of neuroepithelia, while a major source of Sonic Hedgehog signaling from the notochord induces the overlying neuroepithelial cells to form two apposed neural folds. Afterward, neural tube closure occurs by synchronized coordination of the surface ectoderm and adjacent neuroepithelial walls at specific axial regions known as neuropores. Environmental or genetic interferences can impair neurulation resulting in neural tube defects. The Fuz gene encodes a subunit of the CPLANE complex, which is a macromolecular planar polarity effector required for ciliogenesis. Ablation of Fuz in mouse embryos results in exencephaly and spina bifida, including dysmorphic craniofacial structures due to defective cilia formation and impaired Sonic Hedgehog signaling. In this work, we demonstrate that knocking Fuz out during embryonic mouse development results in a hypoplastic hindbrain phenotype, displaying abnormal rhombomeres with reduced length and width. This phenotype is associated with persistent loss of ventral neuroepithelial stiffness, in a notochord adjacent area at the level of the rhombomere 5, preceding the development of exencephaly in Fuz ablated mutants. The formation of cranial and paravertebral ganglia is also impaired in these embryos, indicating that Fuz has a critical function sustaining normal neural tube development and neuronal differentiation. SIGNIFICANCE STATEMENT: Neural tube defects (NTDs) are a common cause of disability in children, representing the second most common congenital structural malformation in humans following only congenital cardiovascular malformations. NTDs affect approximately 1 to 2 pregnancies per 1000 births every year worldwide, when the mechanical forces folding the neural plate fails to close at specific neuropores located anteriorly (cranial) or posteriorly (caudal) along the neural tube, in a process known as neurulation, which happens throughout the third and fourth weeks of human pregnancy.

Cancer incidence and mortality trends in Asia based on regions and human development index levels: an analyses from GLOBOCAN 2020.

OBJECTIVE: As Asian countries transition socially and economically to higher Human Development Index (HDI) levels, cancer trends are expected to shift to those seen in the Western World. A strong correlation also exists between HDI levels and age-standardized rates (ASR) for the incidence and mortality of cancer. However, there are very few reports on the trends in Asian countries, particularly in Low and Middle-Income Countries (LMICs). In this study, we have investigated the relationship between socioeconomic developments in Asia (determined using HDI levels of countries) and cancer incidence and mortality in these nations. METHODS: The GLOBOCAN 2020 database was used to study the cancer incidence and mortality data for all cancers combined and those most commonly diagnosed in Asia. The difference in data was analyzed based on region and HDI level. Further, the predictions for cancer incidence and mortality in 2040 according to the GLOBOCAN 2020 were analyzed using the updated HDI stratification described in the UNDP 2020 report. RESULTS: Asia has the highest cancer burden compared to the other regions worldwide. Lung cancer carries the highest cancer incidence and mortality rates in the region. Inequitable distribution of cancer incidence and mortality is seen across regions and HDI levels in Asia. CONCLUSIONS: Inequalities in cancer incidence and mortality can only be expected to increase unless innovative and cost-effective interventions are urgently implemented. An effective cancer management plan is needed in Asia, particularly in LMICs, prioritizing effective cancer prevention and control measures for health systems.

Assessing the effects of prenatal poly-drug exposure on fetal brain vasculature using optical coherence angiography.

Significance: Maternal exposure to drugs during pregnancy is known to have detrimental effects on the fetus. Alcohol (ethanol) and nicotine are two of the most commonly co-abused substances during pregnancy, and prenatal poly-drug exposure is common due, in part, to the prevalence of unplanned pregnancies. The second trimester is a critical period for fetal neurogenesis and angiogenesis. When drug exposure occurs during this time, fetal brain development is affected. Several behavioral, morphological, and functional studies have evaluated the changes in fetal brain development due to exposure to these drugs individually. However, research on the combined effects of ethanol and nicotine is far more limited, specifically on fetal vasculature changes and development. Aim: We use correlation mapping optical coherence angiography (cm-OCA) to evaluate acute changes in fetal brain vasculature caused by maternal exposure to a combination of ethanol and nicotine. Approach: Ethanol (16.6% v/v, at a dose of 0.75g/kg) and nicotine (at a dose of 0.1 mg/kg) were administered to pregnant mice after initial cm-OCA measurements in utero. Subsequent measurements were taken at 5-min intervals for a total period of 45 min. Results from these experiments were compared to results from our previous studies in which the mother was exposed to only ethanol (dose: 0.75 g/kg) or nicotine (dose: 0.1 mg/kg). Results: While results from exposure to ethanol or nicotine independently showed vasoconstriction, no significant change in vasculature was observed with combined exposure. Conclusion: Results suggested antagonistic effects of ethanol and nicotine on fetal brain vasculature.

Reverberant optical coherence elastography using multifocal acoustic radiation force.

In this study, we introduce a multifocal acoustic radiation force source that combines an ultrasound transducer and a 3D-printed acoustic lens for application in reverberant optical coherence elastography (Rev-OCE). An array of plano-concave acoustic lenses, each with an 11.8 mm aperture diameter, were used to spatially distribute the acoustic energy generated by a 1 MHz planar ultrasound transducer, producing multiple focal spots on a target plane. These focal spots generate reverberant shear wave fields detected by the optical coherence tomography (OCT) system. The effectiveness of the multifocal Rev-OCE system in probing mechanical properties with high resolution is demonstrated in layered gelatin phantoms.

Role of Stereotactic Radiosurgery for Cavernous Sinus Hemangiomas - An Individual Patient Data-Based Meta-Analysis.

Context: Cavernous sinus haemangiomas (CSHs) are rare vascular malformations arising from the micro-circulation of the cavernous sinus. The current treatment options are micro-surgical excision of CSH, stereotactic radiosurgery (SRS), and fractionated radiation therapy (FRT). Aims: We conducted a meta-analysis assessing the effect and complications of SRS in CSH and compared the pooled results after surgical excision of CSH. The aim of the study is to provide valuable insight into the role of SRS in the treatment of CSHs. Materials and Methods: The literature search revealed a total of 21 articles with 199 patients who met our inclusion criteria, and these were analyzed for this study. Results: There were 138 (69.3%) female and 61 (30.7%) male patients. The mean age at the time of radiosurgery was 48.4 ± 14.9 years. The mean tumor volume at the time of SRS was 17.4 cm3 (range 0.3-138 cm3). Fifty (25%) patients had undergone surgery before SRS, whereas 149 (75%) patients received standalone SRS. A total of 186 (93.5%) patients were treated by gamma knife radiosurgery (GKRS), whereas 13 got treated by Cyberknife. The mean tumor volume in CK-F, GKRS, and GKRS-F groups was 36.6 ± 26.3, 15.4 ± 18.4, and 86.0 ± 19.5 cm3, respectively. The mean marginal dose was 21.8 ± 2.9 Gy, 14.0 ± 1.9 Gy, and 25 ± 0.0 Gy in CK-F, GKRS, and GKRS-F groups, respectively. The mean marginal dose of SRS was 14.6 ± 2.9 Gy. The mean follow-up period after SRS was 35.8 ± 31.6 months. Significant clinical improvement was seen in 106 patients out of 116 (91.4%) after SRS with remarkable shrinkage, 22 patients out of 27 (81.5%) with minimal shrinkage, and nine patients out of 13 (69.2%) with stationary tumor shrinkage. The sixth cranial nerve (CN6) was the most commonly involved nerve in 73 patients (36.7%). 30/65 (89%) experienced an improvement in the abducent nerve function following SRS. 115/120 (95.8%) patients primary treated with SRS experienced clinical improvement, whereas the rest of the five patients remained clinically stable. Conclusion: Radiosurgery SRS is a safe and effective option in patients with CSHs and resulted in more than 50% decrease in tumor volume in 72.4% of the patients.