Predictors of salvage therapy for parasagittal meningiomas treated with primary surgery, radiosurgery, or surgery plus adjuvant radiotherapy

OBJECTIVE

Parasagittal meningiomas (PM) are treated with primary microsurgery, radiosurgery (SRS), or surgery with adjuvant radiation. We investigated predictors of tumor progression requiring salvage surgery or radiation treatment. We sought to determine whether primary treatment modality, or radiologic, histologic, and clinical variables were associated with tumor progression requiring salvage treatment.

METHODS

Retrospective study of 109 consecutive patients with PMs treated with primary surgery, radiation (RT), or surgery plus adjuvant RT (2000-2017) and minimum 5 years follow-up. Patient, radiologic, histologic, and treatment data were analyzed using standard statistical methods.

RESULTS

Median follow up was 8.5 years. Primary treatment for PM was surgery in 76 patients, radiation in 16 patients, and surgery plus adjuvant radiation in 17 patients. Forty percent of parasagittal meningiomas in our cohort required some form of salvage treatment. On univariate analysis, brain invasion (OR: 6.93, p < 0.01), WHO grade 2/3 (OR: 4.54, p < 0.01), peritumoral edema (OR: 2.81, p = 0.01), sagittal sinus invasion (OR: 6.36, p < 0.01), sagittal sinus occlusion (OR: 4.86, p < 0.01), and non-spherical shape (OR: 3.89, p < 0.01) were significantly associated with receiving salvage treatment. On multivariate analysis, superior sagittal sinus invasion (OR: 8.22, p = 0.01) and WHO grade 2&3 (OR: 7.58, p < 0.01) were independently associated with receiving salvage treatment. There was no difference in time to salvage therapy (p = 0.11) or time to progression (p = 0.43) between patients receiving primary surgery alone, RT alone, or surgery plus adjuvant RT. Patients who had initial surgery were more likely to have peritumoral edema on preoperative imaging (p = 0.01). Median tumor volume was 19.0 cm3 in patients receiving primary surgery, 5.3 cm3 for RT, and 24.4 cm3 for surgery plus adjuvant RT (p < 0.01).

CONCLUSION

Superior sagittal sinus invasion and WHO grade 2/3 are independently associated with PM progression requiring salvage therapy regardless of extent of resection or primary treatment modality. Parasagittal meningiomas have a high rate of recurrence with 80.0% of patients with WHO grade 2/3 tumors with sinus invasion requiring salvage treatment whereas only 13.6% of the WHO grade 1 tumors without sinus invasion required salvage treatment. This information is useful when counseling patients about disease management and setting expectations.

The Evolving Classification of Meningiomas: Integration of Molecular Discoveries to Inform Patient Care

Meningioma classification and treatment have evolved over the past eight decades. Since Bailey, Cushing, and Eisenhart's description of meningiomas in the 1920s and 1930s, there have been continual advances in clinical stratification by histopathology, radiography and, most recently, molecular profiling, to improve prognostication and predict response to therapy. Precise and accurate classification is essential to optimizing management for patients with meningioma, which involves surveillance imaging, surgery, primary or adjuvant radiotherapy, and consideration for clinical trials. Currently, the World Health Organization (WHO) grade, extent of resection (EOR), and patient characteristics are used to guide management. While these have demonstrated reliability, a substantial number of seemingly benign lesions recur, suggesting opportunities for improvement of risk stratification. Furthermore, the role of adjuvant radiotherapy for grade 1 and 2 meningioma remains controversial. Over the last decade, numerous studies investigating the molecular drivers of clinical aggressiveness have been reported, with the identification of molecular markers that carry clinical implications as well as biomarkers of radiotherapy response. Here, we review the historical context of current practices, highlight recent molecular discoveries, and discuss the challenges of translating these findings into clinical practice.

A Systematic Review of Outpatient Telemedicine Use in Neurosurgery Since the Start of Coronavirus Disease 2019

OBJECTIVE

The coronavirus disease 2019 (COVID-19) pandemic has sparked interest in telemedicine, resulting in an increase in neurosurgical publications focused on it. We summarize this new literature to evaluate telemedicine applications to neurosurgery.

METHODS

A systematic literature review was performed in accordance with the PRISMA guidelines by searching PubMed, Embase, and Scopus for journal articles published after January 1, 2020. All journal articles that included data after the start of COVID-19 and evaluated any aspect of telemedicine relevant to outpatient neurosurgical visits were included. The premise and key findings of each included study were extracted, as well as patient and provider satisfaction with and preference for telemedicine.

RESULTS

Thirty-seven articles met the inclusion criteria. Four studies proposed and evaluated a remote neurologic examination. Two studies reported similar postvisit outcomes between remote and in-person visits. Twenty-four studies reported a combination of patient and provider opinions toward telemedicine. Of 9834 patients and 116 providers, 82.4% and 65.2% were satisfied overall with telemedicine, respectively. Of 3526 patients and 168 providers, 57.0% and 66.5% preferred telemedicine to in-person visits, respectively.

CONCLUSIONS

Overall, most patients and providers have a high opinion of telemedicine for outpatient visits, and increasing evidence suggests that remote visits yield favorable clinical outcomes. The high rates of patient and provider satisfaction and preference may be considered for further adoption of remote neurosurgical visits beyond the COVID-19 era.

Outcomes following stereotactic radiosurgery for foramen magnum meningiomas: a single-center experience and systematic review of the literature

OBJECTIVE

Foramen magnum meningiomas (FMMs) pose a unique challenge given their intimate anatomical relationship with the craniovertebral junction. While resection has been studied extensively, much less has been reported about the use of stereotactic radiosurgery (SRS) for FMMs. This study includes what is to the authors’ knowledge the first systematic review in the literature that summarizes patient and treatment characteristics and synthesizes outcomes following SRS for FMMs.

METHODS

A retrospective chart review was conducted at a single major academic institution, and a systematic review was performed according to PRISMA guidelines. The initial search on the PubMed and Scopus databases yielded 530 results. Key data extracted from both databases included Karnofsky Performance Status (KPS) score and neurological deficits at presentation, tumor location, treatment indication, target volume, single versus multiple fractions, marginal and maximum doses, isodose line, clinical and radiographic follow-up times, and primary (clinical stability and local control at last follow-up) and secondary (mortality, adverse radiation events, time to regression, progression-free survival) outcomes.

RESULTS

The study patients included 9 patients from the authors’ institution and 165 patients across 4 studies who received SRS for FMMs. The weighted median age at treatment was 60.2 years, and 73.9% of patients were female. Common presenting symptoms included headache (33.9%), dizziness/ataxia (29.7%), cranial nerve deficit(s) (27.9%), numbness (22.4%), weakness (15.2%), and hydrocephalus (4.2%). Lateral/ventrolateral (64.2%) was the most common tumor location. SRS was utilized as the primary therapy in 63.6% of patients and as salvage (21.8%) or adjuvant (14.5%) therapy for the rest of the patients. Most patients (91.5%) were treated with a single fraction. A tumor with a weighted median target volume of 2.9 cm3 was treated with a weighted median marginal dose, maximum dose, and isodose line of 12.9 Gy, 22.8 Gy, and 58%, respectively. Clinical stability and local control at last follow-up were achieved in 98.8% and 97.0% of patients, respectively. Only one possible adverse radiation event occurred, and no mortality directly related to the tumor or SRS was reported.

CONCLUSIONS

In this retrospective analysis and systematic review, the authors demonstrate SRS to be an effective and safe treatment option for carefully selected patients with FMMs.

Meningeal defects and focal cortical dysplasia: an unrecognized relationship? Illustrative case

BACKGROUND

Focal cortical dysplasias (FCDs) are a heterogenous cluster of histopathologic entities classically associated with medically refractory epilepsy. Because there is substantial histopathologic variation among different types of FCD, there are likely multiple pathogenic mechanisms leading to these disorders. The meninges are known to play a role in cortical development, and disruption of meningeal-derived signaling pathways has been shown to impact neurodevelopment. To our knowledge, there has not yet been an investigation into whether genetic pathways regulating meningeal development may be involved in the development of FCD.

OBSERVATIONS

The authors reported a patient with refractory epilepsy and evidence of FCD on imaging who received surgical intervention and was found to have an unusual dural anomaly overlying a region of type Ic FCD. To the authors’ knowledge, this was the first report describing a lesion of this nature in the context of FCD.

LESSONS

The dural anomaly exhibited by the patient presented what could be a potentially novel pathogenic mechanism of FCD. Resection of the cortical tissue underlying the dural anomaly resulted in improvement in seizure control. Although the pathogenesis is unclear, this case highlighted the importance of further investigation into the developmental origins of FCD, which may help elucidate whether a connection between meningeal development and FCD exists.

The role of neurosurgery in the management of tuberous sclerosis complex–associated epilepsy: a systematic review

OBJECTIVE

Tuberous sclerosis complex (TSC) is an autosomal dominant, multisystem neurocutaneous disorder associated with cortical tubers, brain lesions seen in nearly all patients with TSC, which are frequently epileptogenic. Seizures are often the earliest clinical manifestation of TSC, leading to epilepsy in over 70% of patients. Medical management with antiepileptic drugs constitutes early therapy, but over 50% develop medically refractory epilepsy, necessitating surgical evaluation and treatment. The objective of this study was to summarize the literature and report seizure outcomes following surgical treatment for TSC-associated epilepsy.

METHODS

A systematic literature review was performed in accordance with the PRISMA guidelines. The PubMed and Embase databases were searched for journal articles reporting seizure outcomes following epilepsy surgery in TSC patients. Included studies were placed into one of two groups based on the surgical technique used. Excellent and worthwhile seizure reductions were defined for each group as outcomes and extracted from each study.

RESULTS

A total of 46 studies were included. Forty of these studies reported seizure outcomes following any combination of resection, disconnection, and ablation on a collective 1157 patients. Excellent and worthwhile seizure reductions were achieved in 59% (683/1157) and 85% (450/528) of patients, respectively. Six of these studies reported seizure outcomes following treatment with neuromodulation. Excellent and worthwhile seizure reductions were achieved in 34% (24/70) and 76% (53/70) of patients, respectively.

CONCLUSIONS

Surgery effectively controls seizures in select patients with TSC-associated epilepsy, but outcomes vary. Further understanding of TSC-associated epilepsy, improving localization strategies, and emerging surgical techniques represent promising avenues for improving surgical outcomes.

Upper extremity nerve transfers for acute flaccid myelitis: a systematic literature review

BACKGROUND

Acute flaccid myelitis (AFM) is a rare disease that commonly affects young children. AFM's pathophysiology involves loss of lower motor neurons following a viral infection and induces acute asymmetric flaccid paralysis most commonly in the upper extremities. Nerve transfers have emerged as a treatment option for these patients with permanent motor deficits.

OBJECTIVE

To summarize the literature and report safety and efficacy outcomes following nerve transfers for recovery of shoulder abduction and external rotation, and elbow flexion and extension in pediatric patients with AFM. Recovery of at least antigravity function was defined as a successful outcome. This systematic review was performed according to the PRISMA guidelines. The PubMed, Embase and Cochrane databases were utilized.

RESULTS

Five studies comprising 44 patients (median age 2.95 years; 71% male), and 93 upper extremity nerve transfers were included. Thirty-eight patients received 65 nerve transfer procedures aiming for recovery of shoulder abduction and/or external rotation with a transfer to the axillary and/or suprascapular nerve. The recovery of shoulder abduction and external rotation was achieved in 40.7% (n = 11/27) and 60% (n = 6/10) of patients, respectively. Time from injury to surgery showed an inverse relationship with the odds for successful recovery (OR: 0.81; 95% CI: 0.64-1.02; p = 0.07); however, statistical significance was not reached. Successful recovery of elbow flexion with a transfer to the musculocutaneous was reported at a rate of 92.3% (n = 12/13). Successful re-innervation of the radial nerve with recovery of elbow extension was found in 75% (n = 6/8) of patients. No complications were reported.

CONCLUSIONS

Upper extremity nerve transfers appear to be promising and safe for AFM patients. Shoulder abduction is the most challenging upper extremity function to recover. Further studies are warranted to identify whether nerve transfers are associated with superior outcomes when performed earlier.

Pediatric spinal intramedullary anaplastic myxopapillary ependymoma: a case report

A 6-year-old girl presented with a 1-week history of progressive upper and lower extremity weakness and bilateral upper extremity dysesthesia. Imaging demonstrated a 4.7 × 1.2-cm enhancing intramedullary lesion in the cervical spine from level C2 to C5 with associated cystic components and syringomyelia. The patient underwent a C2-C5 laminoplasty, with gross total resection of the intramedullary lesion. Histological analysis showed small to medium-sized epithelioid cells, with predominantly a solid architecture focally infiltrating into the adjacent spinal cord tissue. Focal papillary differentiation was present along with peri-vascular pseudorosettes, mucin microcysts, and globules of dense collagen. Focal anaplasia was noted with mitosis (5/10 HPF), focal necrosis, and elevated Ki67 10-15%. These findings were consistent with a myxopapillary ependymoma with anaplastic features. CSF cytology was negative for tumor cells. MYCN amplification was not present. She was treated with targeted proton-beam radiation therapy. This is the fourth case of an intramedullary anaplastic myxopapillary ependymoma to date, and the first case in the cervical spine reported in the literature.

Radiation Induced Cavernomas in the Treatment of Pediatric Medulloblastoma: Comparative Study Between Proton and Photon Radiation Therapy

Radiation induced cavernomas among children with medulloblastoma are common following external beam radiation (XRT) treatment with either photon or proton beams. However, with the increased utilization of proton beam therapy over the last decade we sought to determine if there was any difference in the development or natural history of these cavernous malformations (CM) or CM-like lesions. We performed a retrospective analysis of 79 patients from 2003 to 2019 who had undergone resection of medulloblastoma and subsequent XRT (30 photon or 49 proton beam therapy). The average age of patients at radiation treatment was 8.7 years old. Average follow up for patients who received photon beam therapy was 105 months compared to 56.8 months for proton beam therapy. A total of 68 patients (86.1%) developed post-radiation CMs, including 26 photon and 42 proton patients (86.7% and 85.7% respectively). The time to cavernoma development was significantly different, with a mean of 40.2 months for photon patients and 18.2 months for proton patients (p = 1.98 x 10^-4). Three patients, one who received photon and two who received proton beam radiation, required surgical resection of a cavernoma. Although CM or CM-like lesions are detected significantly earlier in patients after receiving proton beam therapy, there appears to be no significant difference between the two radiation therapy modalities in the development of significant CM requiring surgical resection or intervention other than continued follow up and surveillance.

Infratentorial choroid plexus tumors in children

OBJECTIVE

Choroid plexus tumors (CPTs) are rare pediatric intracranial neoplasms, and mostly occur in the lateral ventricle. CPTs located in the infratentorial location are considered to be rare in the pediatric population. We present a series of eight patients treated in the last decade at our institution focusing on clinical presentations and their outcome after excision.

METHODS

We performed an institutional retrospective review of patients who underwent surgical resection of infratentorial CPTs during the period from 2008 to 2017. Patients' charts were reviewed for demographic data, clinical presentation, surgical treatment, and follow-up.

RESULTS

There were eight patients (6 females and 2 males), with mean age for the cohort at presentation was 9.0 years. They represent 75% of 12 CPTs of all locations treated at the same period in our institution. These 8 infratentorial CPTs were in the fourth ventricle in seven, and in the cerebellopontine angle (CPA) in one. Seven patients had choroid plexus papillomas (WHO grade I) and 1 had an atypical choroid plexus papilloma (WHO grade II). Gross total resection was attempted in all patients. However, two of 3 patients with fourth ventricle floor invasion had subtotal resection with a thin layer of tumor left on the floor. The remaining 6 had a gross total resection. Six patients with preoperative hydrocephalus had a perioperative external ventricular drainage but none required permanent shunting after tumor resection. None showed recurrence/tumor progression without adjuvant therapy during the follow-up period of 20 months to 11 years.

CONCLUSION

Infratentorial dominance among pediatric CPTs in this series contradicts previous reports. Infratentorial CPTs are amenable to surgical resection. Unresected small residuals due to invasion to the fourth ventricle floor showed no regrowth during 2 to 3 years follow-up without adjuvant therapy. However, these patients with incomplete resection need watchful observations.