Faculty Bibliography

Object Pituitary adenomas are fairly common intracranial neoplasms, and nonfunctioning ones constitute a large subgroup of these adenomas. Complete resection is often difficult and may pose undue risk to neurological and endocrine function. Stereotactic radiosurgery has come to play an important role in the management of patients with nonfunctioning pituitary adenomas. This study examines the outcomes after radiosurgery in a large, multicenter patient population. Methods Under the auspices of the North American Gamma Knife Consortium, 9 Gamma Knife surgery (GKS) centers retrospectively combined their outcome data obtained in 512 patients with nonfunctional pituitary adenomas. Prior resection was performed in 479 patients (93.6%) and prior fractionated external-beam radiotherapy was performed in 34 patients (6.6%). The median age at the time of radiosurgery was 53 years. Fifty-eight percent of patients had some degree of hypopituitarism prior to radiosurgery. Patients received a median dose of 16 Gy to the tumor margin. The median follow-up was 36 months (range 1-223 months). Results Overall tumor control was achieved in 93.4% of patients at last follow-up; actuarial tumor control was 98%, 95%, 91%, and 85% at 3, 5, 8, and 10 years postradiosurgery, respectively. Smaller adenoma volume (OR 1.08 [95% CI 1.02-1.13], p = 0.006) and absence of suprasellar extension (OR 2.10 [95% CI 0.96-4.61], p = 0.064) were associated with progression-free tumor survival. New or worsened hypopituitarism after radiosurgery was noted in 21% of patients, with thyroid and cortisol deficiencies reported as the most common postradiosurgery endocrinopathies. History of prior radiation therapy and greater tumor margin doses were predictive of new or worsening endocrinopathy after GKS. New or progressive cranial nerve deficits were noted in 9% of patients; 6.6% had worsening or new onset optic nerve dysfunction. In multivariate analysis, decreasing age, increasing volume, history of prior radiation therapy, and history of prior pituitary axis deficiency were predictive of new or worsening cranial nerve dysfunction. No patient died as a result of tumor progression. Favorable outcomes of tumor control and neurological preservation were reflected in a 4-point radiosurgical pituitary score. Conclusions Gamma Knife surgery is an effective and well-tolerated management strategy for the vast majority of patients with recurrent or residual nonfunctional pituitary adenomas. Delayed hypopituitarism is the most common complication after radiosurgery. Neurological and cranial nerve function were preserved in more than 90% of patients after radiosurgery. The radiosurgical pituitary score may predict outcomes for future patients who undergo GKS for a nonfunctioning adenoma.

The anti-cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) monoclonal antibody ipilimumab has been shown to improve survival in patients with metastatic non-CNS melanoma. The purpose of this study was to investigate the efficacy of CTLA-4 inhibitors in the treatment of metastatic melanoma with limited brain metastases treated with stereotactic radiosurgery (SRS). Between January 2008 and June 2011, 58 patients with limited brain metastases from melanoma were treated with SRS with a median dose of 20 Gy delivered to the 50% isodose line (range, 15-20 Gy). In 25 patients, ipilimumab was administered intravenously at a dose of 3 mg/kg over 90 min every 3 weeks for a median of four doses (range, 1-8). Local control (LC), freedom from new brain metastases, and overall survival (OS) were assessed from the date of the SRS procedure. The median LC, freedom from new brain metastases, and OS for the entire group were 8.7, 4.3, and 5.9 months, respectively. The cause of death was CNS progression in all but eight patients. Six-month LC, freedom from new brain metastases, and OS were 65, 35, and 56%, respectively, for those who received ipilimumab and 63, 47, and 46% for those who did not (P=NS). Intracranial hemorrhage was noted in seven patients who received ipilimumab compared with 10 patients who received SRS alone (P=NS). In this retrospective study, administration of ipilimumab neither increased toxicity nor improved intracerebral disease control in patients with limited brain metastases who received SRS.

A philosophical approach to tactical and remote medicine should be reflected in the gear (e.g., equipment and technology) chosen as well as the protocols used. The gear needs to be lightweight and small volume. Asmuch as possible, it should have multiple uses, and there should be no redundancy with other items. When modern technology (e.g., hemostatic gauze, pulse oximeters, etc.) allows it to have unique applications, it should be used. Otherwise, if simple basic gear works, it should remain a staple (e.g., cravats). Protocols should reflect the goal to provide thorough care in an efficient manner. They should be straightforward and scaleable and be capable of being trained in a fashion that will allow them to become automatic under duress. These guiding principles establish a basis from which the Special Operations Forces/Tactical Medic or PJ can operate to maximal effectiveness. This article will describe current thinking in Pararescue as it relates to gear and protocols.

BACKGROUND: : Stereotactic radiosurgery is an effective treatment modality for small arteriovenous malformations (AVMs) of the brain. For larger AVMs, the treatment dose is often lowered to reduce potential complications, but this decreases the likelihood of cure. One strategy is to divide large AVMs into smaller anatomic volumes and treat each volume separately. OBJECTIVE: : To prospectively assess the long-term efficacy and complications associated with staged-volume radiosurgical treatment of large, symptomatic AVMs. METHODS: : Eighteen patients with AVMs larger than 15 mL underwent prospective staged-volume radiosurgery over a 13-year period. The median AVM volume was 22.9 mL (range, 15.7-50 mL). Separate anatomic volumes were irradiated at 3- to 9-month intervals (median volume, 10.9 mL; range, 5.3-13.4 mL; median marginal dose, 15 Gy; range, 15-17 Gy). The AVM was divided into 2 volumes in 10 patients, 3 volumes in 5 patients, and 4 volumes in 3 patients. Seven patients underwent retreatment for residual disease. RESULTS: : Actuarial rates of complete angiographic occlusion were 29% and 89% at 5 and 10 years. Five patients (27.8%) had a hemorrhage after radiosurgery. Kaplan-Meier analysis of cumulative hemorrhage rates after treatment were 12%, 18%, 31%, and 31% at 2, 3, 5, and 10 years, respectively. One patient died after a hemorrhage (5.6%). CONCLUSION: : Staged-volume radiosurgery for AVMs larger than 15 mL is a viable treatment strategy. The long-term occlusion rate is high, whereas the radiation-related complication rate is low. Hemorrhage during the lag period remains the greatest source of morbidity and mortality. ABBREVIATION:: AVM, arteriovenous malformation.

Introduction: Intraosseous (IO) devices have gained popularity because of TCCC. The ability to gain access to the vascular system when intra venous access is not possible, and techniques such as central lines or cut-downs are beyond the scope of battlefield providers and tactically not feasible, has lead to the increased use of IO access. Since tibias are often not available sites in blast injury patients, the sternum was often used. Recently the humeral head has gained popularity because of ease of access and placement. The optimal needle length has not been defined or studied. Methods and Materials: Fifty consecutive shoulder MRIs among 18?40 year old patients were reviewed. Distances from the skin surface to the cortex from anterior and lateral trajectories were simulated and measured. Two different lateral trajectories were studied described as lateral minimum and lateral maximum trajectories, correlating with seemingly less and greater soft tissue. The cortical thickness was also recorded. Mean values and ranges for the measurements were determined. Results: The anterior trajectory represented the shortest distance. Mean anterior, mean lateral minimum and mean lateral maximum distances were 2.3, 3.0 and 4.7cm with corresponding ranges of 1.1?4.1, 1.6?5.7 and 2.8?7.4cm respectively. The cortical thickness was 4mm in all cases. Conclusions: Although this information was gathered amongst civilians, and many military members may have more soft tissue, these results indicate that needle length generally in the 40?50mm range should be used via the anterior approach. Use of a standard 25mm needle often used in the tibia would be inadequate in over half the cases, and may result in undue tissue compression or distortion.

Progressive injury prevention and physical preparation programs are needed in military special operations to optimize mission success and Operator quality of life and longevity. While physical risk is inherent in Special Operations, non-traumatic injuries resulting from overuse, poor biomechanics, and arbitrary exercise selection can be alleviated with proper medical care and patient education. An integrated approach to physical readiness that recognizes the continuity between rehabilitation and performance training is advocated to ensure that physiological adaptations do not come at the expense of orthopedic health or movement proficiency. Movement quality should be regularly evaluated and enforced throughout the training process to minimize preventable injuries and avoid undermining previous rehabilitative care. While fitness and proper movement are not substitutes for Operator specific tasks, they are foundational to many tactically-relevant skills. In light of how much is at stake, sports medicine care in the military, especially special operations, should parallel that which is practiced in professional and collegiate athletics.