Brendan McShane

Stereotactic Radiosurgery for Cushing Disease: Results of an International, Multicenter Study

Context: Cushing disease (CD) due to adrenocorticotropic hormone‐secreting pituitary tumors can be a management challenge. Objective: To better understand the outcomes of stereotactic radiosurgery (SRS) for CD and define its role in management. Design: International, multicenter, retrospective cohort analysis. Setting: Ten medical centers participating in the International Gamma Knife Research Foundation. Patients: Patients with CD with >6 months endocrine follow‐up. Intervention: SRS using Gamma Knife radiosurgery. Main Outcome Measures: The primary outcome was control of hypercortisolism (defined as normalization of free urinary cortisol). Radiologic response and adverse radiation effects (AREs) were recorded. Results: In total, 278 patients met inclusion criteria, with a mean follow‐up of 5.6 years (0.5 to 20.5 years). Twenty‐two patients received SRS as a primary treatment of CD. Mean margin dose was 23.7 Gy. Cumulative initial control of hypercortisolism was 80% at 10 years. Mean time to cortisol normalization was 14.5 months. Recurrences occurred in 18% with initial cortisol normalization. Overall, the rate of durable control of hypercortisolism was 64% at 10 years and 68% among patients who received SRS as a primary treatment. AREs included hypopituitarism (25%) and cranial neuropathy (3%). Visual deficits were related to treatment of tumor within the suprasellar cistern (P = 0.01), whereas both visual (P < 0.0001) and nonvisual cranial neuropathy (P = 0.02) were related to prior pituitary irradiation. Conclusions: SRS for CD is well tolerated and frequently results in control of hypercortisolism. However, recurrences can occur. SRS should be considered for patients with persistent hypercortisolism after pituitary surgery and as a primary treatment in those unfit for surgery. Long‐term endocrine follow‐up is essential after SRS.

Technique of Whole-Sellar Stereotactic Radiosurgery for Cushing Disease: Results from a Multicenter, International Cohort Study

BACKGROUNDnStereotactic radiosurgery (SRS) is used to manage patients with Cushing disease (CD) who have failed surgical/medical management. Because many patients with recurrent/persistent CD lack an identifiable adenoma on neuroimaging, whole-sellar SRS has been increasingly used. Thus, we sought to define the outcomes of patients undergoing whole-sellar SRS.nnnMETHODSnAn international, multicenter, retrospective cohort design was used to define clinical/endocrine outcomes for patients undergoing whole-sellar SRS for CD. Propensity-score matching was used to compare patients undergoing whole-sellar SRS and patients who underwent discreet adenoma-targeted SRS.nnnRESULTSnA total of 68 patients underwent whole-sellar SRS, with a mean endocrine follow-up of 5.3 years. The mean treatment volume was 2.6 cm3, and the mean margin dose was 22.4 Gy. The 5-year actuarial remission rate was 75.9%, and the median time to remission was 12-months. Treatment volumes >1.6 cm3 were associated with shorter times to remission (P < 0.05). The 5-year recurrence-free survival rate was 86.0%. Decreased margin and maximum treatment doses were associated with recurrence (P < 0.05). New pituitary hormone deficiency occurred in 15 patients (22.7%). An additional 210 patients were identified who underwent adenoma-targeted SRS. There was no difference in remission rate, time to remission, recurrence-free survival or new endocrinopathy development between patients who underwent whole-sellar SRS and those who underwent discreet adenoma-targeted SRS.nnnCONCLUSIONSnWhole-sellar GKRS is effective in controlling CD when an adenoma is not clearly defined on imaging or when an invasive adenoma is suspected at the time of initial surgery. Patients who undergo whole-sellar SRS have outcomes and rates of new pituitary hormone deficiency similar to those of patients who undergo discrete adenoma-targeted GKRS.

A Prospective Detailed Time Analysis Study of 18 Patients Undergoing Elective Single-Level Open Lumbar Microdiscectomy Spinal Surgery Compared with Centers for Medicare and Medicaid Services Reimbursement Guidelines

BACKGROUNDnSingle-level open lumbar microdiscectomy surgery is one of the most straightforward and effective spinal surgeries performed by spinal surgeons today to treat disk herniation. Although a common operation, little in the literature is reported on the exact overall time, cost, and effort associated with the performance of this surgery. The consistency of this operation across institutions and disciplines makes it a good starting point to accurately track the total time and effort of all phases of the surgical intervention.nnnMETHODSnEighteen patients undergoing elective single-level open lumbar microdiscectomy surgery were prospectively enrolled in this study. The time spent interacting with each patient by every member of the surgical team was tracked and recorded along will every phone call and e-mail. All perioperative times associated with the surgery were tracked and analyzed. Each patient was followed from their first interaction through surgery and for the first 3 months postoperatively.nnnRESULTSnThe advanced practice providers spent the most time with the patient both pre- and postoperatively followed by the surgeon and resident. A total of 2.98 hours was spent with the patient preoperatively in clinic and 1.69 hours postoperatively. The total time commitment of an institution treating this condition was 12.56 hours.nnnCONCLUSIONSnComparing our results with the Centers for Medicare and Medicaid Services data, a significant discrepancy and underestimation was observed. As such, we hope our results enable health care providers to more accurately allocate resources for the provision of high-quality medical care to patients with this increasingly common condition.

Neurologic Status on Presentation as Predictive Measurement in Success of Closed Reduction in Traumatic Cervical Facet Fractures

BACKGROUNDnDislocations to cervical facets resulting from traumatic injury often lead to neurologic impairment and can be treated both surgically and in a closed manner.nnnOBJECTIVEnWe sought to evaluate the utilization of closed reduction in the initial management of bilateral facet dislocations over the past 10 years at our institution.nnnMETHODSnWe retrospectively reviewed the charts of patients who experienced subaxial cervical facet injury within the Penn Health System between 1 June 2006 and 1 June 2016 to identify patients with bilateral jumped/perched facets. The neurologic injury was identified on the basis of the American Spinal Injury Association (ASIA) spinal cord injury score. Analysis of variance and 2-sample t-tests were used to compare continuous distributions, and chi-square tests were used to compare categorical distributions.nnnRESULTSnWe focused our analyses on patients who presented with bilateral jumped/perched facets with (ASIA A and B) or without (ASIA C, D, E) complete voluntary motor deficit and underwent attempted closed reduction. We found that the rate of successful closed reduction was significantly higher in incomplete motor deficits (5/5, Pxa0=xa00.04, chi-square test) as compared with complete motor deficits (nxa0= 2/11).nnnCONCLUSIONnOur results demonstrate a significant difference in the success rate of closed reduction in patients with good neurologic status on presentation (ASIA A or B), compared with those with poor neurologic status (ASIA C, D, and E). These results suggest that closed reduction should be attempted in patients with good motor examinations on presentation, whereas those with significant deficits may benefit from earlier surgical intervention.

Growth of a Sacral Perineural (Tarlov) Cyst: Clinical Images

Although Tarlov cysts (TC) were first described in 1938, our understanding of these common spinal lesions remains poor. As TCs represent incidental findings in the vast majority of cases, evidence to guide their management is limited to small case series. When they are symptomatic, the presentation can have significant overlap with degenerative spine disease. This is the first report demonstrating growth of TCs. The patient underwent open surgical reduction of the symptomatic TCs, leading to improvement in her symptoms.

Stereotactic Radiosurgery for Acromegaly: An International Multicenter Retrospective Cohort Study

BACKGROUNDnStereotactic radiosurgery (SRS) is a treatment option for persistent or recurrent acromegaly secondary to a growth hormone secreting pituitary adenoma, but its efficacy is inadequately defined.nnnOBJECTIVEnTo assess, in a multicenter, retrospective cohort study, the outcomes of SRS for acromegaly and determine predictors.nnnMETHODSnWe pooled and analyzed data from 10 participating institutions of the International Gamma Knife Research Foundation for patients with acromegaly who underwent SRS with endocrine follow-up of ≥6 mo.nnnRESULTSnThe study cohort comprised 371 patients with a mean endocrine follow-up of 79 mo. IGF-1 lowering medications were held in 56% of patients who were on pre-SRS medical therapy. The mean SRS treatment volume and margin dose were 3.0 cm3 and 24.2 Gy, respectively. The actuarial rates of initial and durable endocrine remission at 10 yr were 69% and 59%, respectively. The mean time to durable remission after SRS was 38 mo. Biochemical relapse after initial remission occurred in 9%, with a mean time to recurrence of 17 mo. Cessation of IGF-1 lowering medication prior to SRS was the only independent predictor of durable remission (P = .01). Adverse radiation effects included the development of ≥1 new endocrinopathy in 26% and ≥1 cranial neuropathy in 4%.nnnCONCLUSIONnSRS is a definitive treatment option for patients with persistent or recurrent acromegaly after surgical resection. There appears to be a statistical association between the cessation of IGF-1 lowering medications prior to SRS and durable remission.

Upfront Gamma Knife radiosurgery for Cushing’s disease and acromegaly: a multicenter, international study

OBJECTIVEGamma Knife radiosurgery (GKS) is typically used after failed resection in patients with Cushings disease (CD) and acromegaly. Little is known about the upfront role of GKS for patients with CD and acromegaly. In this study, the authors examine the outcome of upfront GKS for patients with these functioning adenomas.METHODSAn international group of 7 Gamma Knife centers sent pooled data from 46 patients (21 with CD and 25 with acromegaly) undergoing upfront GKS to the coordinating center of the study for analysis. Diagnosis was established on the basis of clinical, endocrine, and radiological studies. All patients were treated on a common radiosurgical platform and longitudinally followed for tumor control, endocrine remission, and hypopituitarism. Patients received a tumor median margin dose of 25 Gy (range 12-40.0 Gy) at a median isodose of 50%.RESULTSThe median endocrine follow-up was 69.5 months (range 9-246 months). Endocrine remission was achieved in 51% of the entire cohort, with 28% remission in acromegaly and 81% remission for those with CD at the 5-year interval. Patients with CD achieved remission earlier as compared to those with acromegaly (p = 0.0005). In patients post-GKS, the pituitary adenoma remained stable (39%) or reduced (61%) in size. Hypopituitarism occurred in 9 patients (19.6%), and 1 (2.2%) developed third cranial nerve (CN III) palsy. Eight patients needed further intervention, including repeat GKS in 6 and transsphenoidal surgery in 2.CONCLUSIONSUpfront GKS resulted in good tumor control as well as a low rate of adverse radiation effects in the whole group. Patients with CD achieved a faster and far better remission rate after upfront GKS in comparison to patients with acromegaly. GKS can be considered as an upfront treatment in carefully selected patients with CD who are unwilling or unable to undergo resection, but it has a more limited role in acromegaly.

Posterior Cervical Laminectomy Results in Better Radiographic Decompression of Spinal Cord Compared with Anterior Cervical Discectomy and Fusion

BACKGROUNDnCervical spondylitic myelopathy is a degenerative condition resulting from chronic spinal cord compression and a leading cause of nontraumatic spinal cord dysfunction. The chief surgical goal in the management of cervical spondylitic myelopathy is adequate spinal cord decompression with or without fusion to slow or prevent further neurologic decline. We conducted a radiographic analysis of canal parameters preoperatively and postoperatively for patients undergoing either anterior or posterior cervical decompression.nnnMETHODSnPreoperative and postoperative radiographic analysis was performed using midsagittal and axial magnetic resonance imaging at the level of the disc space for 37 patients who underwent anterior or posterior cervical decompression. Statistical comparisons between anterior and posterior groups were performed using independent t test and Mann-Whitney U test where appropriate.nnnRESULTSnBoth postoperative anteroposterior canal diameter and posterior cerebrospinal fluid (CSF) space were greater in patients undergoing posterior decompression (Pxa0= 0.011 and P < 0.001, respectively), although postoperative anterior CSF space was comparable between both groups. Both anterior and posterior approaches to decompression resulted in a statistically significant improvement in anteroposterior diameter, anterior CSF space, and posterior CSF space (P < 0.001). Posterior decompression yielded significantly greater change in anteroposterior diameter and posterior CSF space compared with the anterior approach (P < 0.001).nnnCONCLUSIONSnIn this quantitative radiographic study, we found that although both posterior cervical laminectomy and anterior cervical discectomy yielded significant decompression, laminectomy yielded a greater degree of decompression of the posterior CSF space.

Outcomes of stereotactic radiosurgery for foramen magnum meningiomas: an international multicenter study

OBJECTIVE Meningiomas are the most common benign extramedullary lesions of the foramen magnum; however, their optimal management remains undefined. Given their location, foramen magnum meningiomas (FMMs) can cause significant morbidity, and complete microsurgical removal can be challenging. Anterior and anterolateral FMMs carry greater risks with surgery, but they comprise the majority of these lesions. As an alternative to resection, stereotactic radiosurgery (SRS) has been used to treat FMMs in small case series. To more clearly define the outcomes of SRS and to delineate a rational management paradigm for these lesions, the authors analyzed the safety and efficacy of SRS for FMM in an international multicenter trial. METHODS Seven medical centers participating in the International Gamma Knife Research Foundation (IGKRF) provided data for this retrospective cohort study. Patients who were treated with Gamma Knife radiosurgery and whose clinical and radiological follow-up was longer than 6 months were eligible for study inclusion. Data from pre- and post-SRS radiological and clinical evaluations were analyzed. Stereotactic radiosurgery treatment variables were recorded. RESULTS Fifty-seven patients (39 females and 18 males, with a median age of 64 years) met the study inclusion criteria. Thirty-two percent had undergone prior microsurgical resection. Patients most frequently presented with cranial neuropathy (39%), headache (35%), numbness (32%), and ataxia (30%). Median pre-SRS tumor volume was 2.9 cm3. Median SRS margin dose was 12.5 Gy (range 10-16 Gy). At the last follow-up after SRS, 49% of tumors were stable, 44% had regressed, and 7% had progressed. Progression-free survival rates at 5 and 10 years were each 92%. A greater margin dose was associated with a significantly increased likelihood of tumor regression, with 53% of tumors treated with > 12 Gy regressing. Fifty-two percent of symptomatic patients noted some clinical improvement. Adverse radiation effects were limited to hearing loss and numbness in 1 patient (2%). CONCLUSIONS Stereotactic radiosurgery for FMM frequently results in tumor control or tumor regression, as well as symptom improvement. Margin doses > 12 Gy were associated with increased rates of tumor regression. Stereotactic radiosurgery was generally safe and well tolerated. Given its risk-benefit profile, SRS may be particularly useful in the management of small- to moderate-volume anterior and anterolateral FMMs.