Faculty Bibliography

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.

OBJECT: In this paper, the authors' goal was to analyze the incidence, timing, and treatment of new metastases following initial treatment with 20-Gy Gamma Knife surgery (GKS) alone in patients with limited brain metastases without whole-brain radiation therapy (WBRT). METHODS: A retrospective analysis of 114 consecutive adults (75 women and 34 men; median age 61 years) with KPS scores of 60 or higher who received GKS for 1-3 brain metastases </= 2 cm was performed (median lesion volume 0.35 cm(3)). Five patients lacking follow-up data were excluded from analysis. After treatment, patients underwent MR imaging at 6 weeks and every 3 months thereafter. New metastases were preferentially treated with additional GKS. Indications for WBRT included development of numerous metastases, leptomeningeal disease, or diffuse surgical-site recurrence. RESULTS: The median overall survival from GKS was 13.8 months. Excluding the 3 patients who died before follow-up imaging, 12 patients (11.3%) experienced local failure at a median of 7.4 months. Fifty-three patients (50%) developed new metastases at a median of 5 months. Six (7%) of 86 instances of new lesions were symptomatic. Most patients (67%) with distant failures were successfully treated using salvage GKS alone. Whole-brain radiotherapy was indicated in 20 patients (18.3%). Thirteen patients (11.9%) died of neurological disease. CONCLUSIONS: For patients with limited brain metastases and functional independence, 20-Gy GKS provides excellent disease control and high-functioning survival with minimal morbidity. New metastases developed in almost 50% of patients, but additional GKS was extremely effective in controlling disease. Using our algorithm, fewer than 20% of patients required WBRT, and only 12% died of progressive intracranial disease

OBJECTIVE: To review the authors' experience with Gamma Knife radiosurgery (GKR) for small recurrent high-grade gliomas (HGGs) following prior radical resection, external-beam radiation therapy (EBRT), and chemotherapy with temozolomide (TMZ). METHODS: The authors retrospectively analyzed 26 consecutive adults (9 women and 17 men; median age 60.4 years; Karnofsky Performance Status [KPS] >/=70) who underwent GKR for recurrent HGGs from 2004-2009. Median lesion volume was 1.22 cc, and median treatment dose was 15 Gy. Pathology included glioblastoma multiforme (GBM; n = 16), anaplastic astrocytoma (AA; n = 5), and anaplastic mixed oligoastrocytoma (AMOA; n = 5). Two patients lost to follow-up were excluded from radiographic outcome analyses. RESULTS: Median overall survival (OS) for the entire cohort from the time of GKR was 13.5 months. Values for 12-month actuarial survival from time of GKR for GBM, AMOA, and AA were 37%, 20% and 80%. Local failure occurred in 9 patients (37.5%) at a median time of 5.8 months, and 18 patients (75%) experienced distant progression at a median of 4.8 months. Complications included radiation necrosis in two patients and transient worsening of hemiparesis in one patient. Multivariate hazard ratio (HR) analysis showed KPS 90 or greater, smaller tumor volumes, and increased time to recurrence after resection to be associated with longer OS following GKR. CONCLUSIONS: GKR provided good local tumor control in this group of clinically stable and predominantly high-functioning patients with small recurrent HGGs after radical resection. Meaningful survival times after GKR were seen. GKR can be considered for selected patients with recurrent HGGs