Global Neurosurgery: A Retrospective Cohort Study to Compare the Effectiveness of Two Training Methods in Resource-Poor Settings.

BACKGROUND AND OBJECTIVES: Many low- and middle-income countries are experiencing profound health care workforce shortages. Surgical subspecialists generally practice in large urban centers but are in high demand in rural areas. These subspecialists must be trained through sustainable programs to address this disparity. We quantitatively compared the relative effectiveness of 2 unique training models to advance neurosurgical skills in resource-poor settings where formally trained neurosurgeons are unavailable. METHODS: Neurosurgical procedure data were collected from 2 hospitals in Tanzania (Haydom Lutheran Hospital [HLH] and Bugando Medical Centre [BMC]), where 2 distinct training models ("Train Forward" and "Back-to-Back," respectively) were incorporated between 2005 and 2012. RESULTS: The most common procedures performed were ventriculoperitoneal shunt (BMC: 559, HLH: 72), spina bifida repair (BMC: 187, HLH: 54), craniotomy (BMC: 61, HLH: 19), bone elevation (BMC: 42, HLH: 32), and craniotomy and evacuation (BMC: 18, HLH: 34). The number of annual procedures at BMC increased from 148 in 2008 to 357 in 2012; at HLH, they increased from 18 in 2005 to 80 in 2010. Postoperative complications over time decreased or did not significantly change at both sites as the diversity of procedures increased. CONCLUSION: The Train Forward and Back-to-Back training models were associated with increased surgical volume and complexity without increased complications. However, only the Train Forward model resulted in local, autonomous training of surgical subspecialists after completion of the initial training period. Incorporating the Train Forward method into existing training programs in low- and middle-income countries may provide unique benefits over historic training practices.

ZAP-X Gyroscopic Radiosurgery System: A Preliminary Analysis of Clinical Applications within a Retrospective Case Series.

INTRODUCTION: The ZAP-X Gyroscopic Radiosurgery system (ZAP Surgical Systems, Inc., San Carlos, CA, USA) is a novel high-dose targeted stereotactic radiosurgery platform for outpatient use that includes self-shielding, X-ray image guidance, and the capacity to aim the radiation beam gyroscopically at an intracranial lesion using 5 independent degrees of freedom. The ZAP-X Gyroscopic Radiosurgery system accomplishes these actions while meeting widely accepted standards for dose gradient and accuracy. This retrospective study examined data of patients treated with gyroscopic radiosurgery (GRS) to document clinical outcomes. METHODS: Medical records of all outpatients treated with GRS over a 20-month period from January 2019 to August 2020 were searched to extract relevant details, including follow-up data until August 2021 (32-month study interval). Patients with <6 months of radiographical follow-up data were excluded unless death occurred. Data collection included pretreatment clinical history, pathological diagnosis, radiographical features, treatment parameters, and long-term clinical and radiographical follow-up. RESULTS: Sixty-eight patients received outpatient treatment with GRS during the 20-month treatment interval, with 59 patients remaining after exclusion for the minimum follow-up threshold, with a mean (standard deviation [SD]) fractionation of 1.85 (1.63). Eighty-two lesions were treated across a very heterogeneous patient population, including meningiomas (42.4%), metastases (39.0%), gliomas (6.8%), schwannomas (1.7%), and pituitary tumor (1.7%). Mean (SD) radiographical follow-up data (14.7 [6.60] months) were available for 56 patients. During that interval, 13 treated lesions in 13 patients (15.9%) demonstrated progression, 9 of which were stable during the initial posttreatment imaging surveillance period. Mean lesion volume was stable from pretreatment (2.54 cm3 [4.37 cm3]) to most recent follow-up (2.80 cm3 [8.20 cm3]) (t [79] = -0.310; p = 0.76). Minor adverse clinical events were noted in 3 (5.1%) of the 59 patients during the posttreatment phase that may have been related to the treatment. Ten (16.9%) patients died within the 32-month study interval. DISCUSSION/CONCLUSION: This preliminary assessment of the first series of patients treated with the Zap-X Gyroscopic Radiosurgery system documents its overall feasibility in clinical applications. Although the duration of follow-up was brief, GRS appeared to be both safe and effective. Additional analysis, with an ongoing prospective registry, is underway.

Treatment planning system and beam data validation for the ZAP-X: A novel self-shielded stereotactic radiosurgery system.

PURPOSE: To evaluate the treatment planning system (TPS) performance of the ZAP-X stereotactic radiosurgery (SRS) system through nondosimetric, dosimetric, and end-to-end (E2E) tests. METHODS: A comprehensive set of TPS commissioning and validation tests was developed using published guidelines. Nondosimetric validation tests included information transfer, computed tomography-magnetic resonance (CT-MR) image registration, structure/contouring, geometry, dose tools, and CT density. Dosimetric validation included comparisons between TPS and water tank/Solid Water measurements for various geometries and beam arrangements and end-to-end (E2E) tests. Patient-specific quality assurance was performed with an ion chamber in the Lucy phantom and with Gafchromic EBT3 film in the CyberKnife head phantom. RadCalc was used for independent verification of monitor units. Additional E2E tests were performed using the RPC Gamma Knife thermoluminescent dosimeter (TLD) phantom, MD Anderson SRS head phantom, and PseudoPatient gel phantom for independent absolute dose verification. RESULTS: CT-MR image registrations with known translational and rotational offsets were within tolerance (<0.5 × maximum voxel dimension). Slice thickness and distance accuracy were within 0.1 mm, and volume accuracy was within 0 to 0.11 cm3 . Treatment planning system volume measurement uncertainty was within 0.1 to 0.4 cm3 . Ion chamber point-dose measurements for a single beam in a water phantom agreed to TPS-calculated values within ±4% for collimator diameters 10 to 25 mm, and ±6% for 7.5 mm, for all measured depths (7, 50, 100, 150, and 200 mm). In homogeneous Solid Water, point-dose measurements agreed to within ±4% for cones sizes 7.5 to 25 mm. With 1-cm high/low density inserts, measurements were within ±4.2% for cone sizes 10 to 25 mm. Film-based E2E using 4/5-mm cones resulted in a gamma passing rate (%GP) of 99.8% (2%/1.5 mm). Point-dose measurements in a Lucy phantom with an ion chamber using 36 beams distributed along three noncoplanar arcs agreed to within ±4% for cone sizes 10 to 25 mm. The RPC Gamma Knife TLD phantom yielded passing results with a measured-to-expected TLD dose ratio of 1.02. The MD Anderson SRS head phantom yielded passing results, with 4% TLD agreement and %GP of 95%/93% (5%/3 mm) for coronal/sagittal film planes. The RTsafe gel phantom gave %GP of >95% (5%/2 mm) for all four targets. For our first 58 patients, film-based patient-specific quality assurance has resulted in an average %GP of 98.7% (range, 94-100%) at 2%/2 mm. CONCLUSIONS: Core ZAP-X features were found to be functional. On the basis of our results, point-dose and planar measurements were in agreement with TPS calculations using multiple phantoms and setup geometries, validating the ZAP-X TPS beam model for clinical use.

Rare Thyroid Transcription Factor 1-Positive Tumors of the Sellar Region: Barrow Neurological Institute Retrospective Case Series.

OBJECTIVE: Granular cell tumors (GCTs), pituicytomas, and spindle cell oncocytomas are rare, nonfunctioning pituitary tumors sharing positive staining of thyroid transcription factor 1. We present our series, the first single-institutional report with long-term surgical follow-up of all 3 tumor types. METHODS: Our institutional pathology database was queried for these 3 pathologic diagnoses. Clinical records were assessed for clinical presentation, preoperative and postoperative endocrine status, tumor location on imaging, surgical characteristics, pathology results, and tumor recurrence. RESULTS: Data were analyzed for 4 patients with GCTs, 4 with pituicytomas, and 3 with spindle cell oncocytomas. The most common symptoms at presentation were vision changes (64%), headache (55%), endocrine abnormalities (55%), and fatigue (46%). GCTs were the only subtype to present exclusively in the infundibulum and the only subtype in our series to be treated with a transcranial transsylvian approach to resection (n = 2). In our study, in contrast to other reports, estimated blood loss was less than 300 mL in all patients. Imaging confirmed gross total resection in all 11 cases with no known recurrences at a mean (standard deviation) follow-up of 4.7 (3.7) years. CONCLUSIONS: We present a single-institution series of rare thyroid transcription factor 1-staining posterior pituitary tumors of the sellar region. Key novel findings include gross total resection with no tumor recurrence at nearly 5 years of mean follow-up and no cases of excess or uncontrolled blood loss. Our findings reinforce the observation that GCTs present in the suprasellar space.

Cost Transparency in Neurosurgery: A Single-Institution Analysis of Patient Out-of-Pocket Spending in 13 673 Consecutive Neurosurgery Cases.

BACKGROUND: Patient out-of-pocket (OOP) spending is an increasingly discussed topic; however, there is minimal data available on the patient financial burden of surgical procedures. OBJECTIVE: To analyze hospital and surgeon expected payment data and patient OOP spending in neurosurgery. METHODS: This is a retrospective cohort study of neurosurgical patients at a tertiary-referral center from 2013 to 2016. Expected payments, reflecting negotiated costs-of-care, as well as actual patient OOP payments for hospital care and surgeon professional fees were analyzed. A 4-tiered model of patient OOP cost sharing and a multivariate model of patient expected payments were created. RESULTS: A total of 13 673 consecutive neurosurgical cases were analyzed. Patient age, insurance type, case category, severity of illness, length of stay (LOS), and elective case status were significant predictors of increased expected payments (P < .05). Craniotomy ($53 397 ± 811) and posterior spinal fusion ($48 329 ± 864) were associated with the highest expected payments. In a model of patient OOP cost sharing, nearly all neurosurgical procedures exceeded yearly OOP maximums for Healthcare Marketplace plans. Mean patient payments for hospital care and surgeon professional fees were the highest for anterior/lateral spinal fusion cases for commercially insured patients ($1662 ± 165). Mean expected payments and mean patient payments for commercially insured patients increased significantly from 2013 to 2016 (P < .05). CONCLUSION: Expected payments and patient OOP spending for commercially insured patients significantly increased from 2013 to 2016, representing increased healthcare costs and patient cost sharing in an evolving healthcare environment. Patients and providers can consider this information prior to surgery to better anticipate the individual financial burden for neurosurgical care.