Staged image guided robotic radiosurgery for optic nerve sheath meningiomas

Effectiveness and Safety of Robotic Radiosurgery for Optic Nerve Sheath Meningiomas: A Single Institution Series

Simple Summary

Optic nerve sheath meningiomas (ONSM) are a rare subtype of meningioma. Only four retrospective studies with 3–21 patients have been published on the treatment of ONSM by radiosurgery. This study represents the largest published series on robotic radiosurgery to date, treating 25 patients with 27 ONSM lesions. Furthermore, hypofractionated radiosurgical treatment proves to be a safe alternative to surgery and fractionated stereotactic radiation with an overall local tumor control rate of 96.0% and stable or improved visual acuity in 90.0% and 10.0% of patients, respectively. We believe that our study makes a significant contribution to the literature, as our results indicate that robotic radiosurgery is a safe and effective treatment for the management of ONSM and offers a potential treatment option that would improve patient care and clinical outcomes.

Abstract

The role of robotic radiosurgery (RRS) in the treatment of optic nerve sheath meningiomas (ONSM) remains controversial and it is only performed in specialized institutions due to tight dose constraints. We evaluated the effectiveness and safety of RRS in the management of ONSM. Twenty-five patients with 27 ONSM lesions who underwent RRS using the Cyberknife (CK) system were retrospectively analyzed (median age, 47.9 years; 84.0% women). Multisession RRS was used with 4–5 fractions with a cumulative dose of 20.0–25.0 Gy in 84.0% of patients and a single fraction at a dose of 14.0–15.0 Gy in 16% of patients. Prior to RRS, seven (28%) patients experienced blindness on the lesion side. In those patients with preserved vision prior to radiosurgery, the visual acuity remained the same in 90.0% and improved in 10.0% of the patients. Overall local tumor control was 96.0% (mean follow-up period; 37.4 ± 27.2 months). Neither patient age, previous surgery, or the period from the initial diagnosis to RRS showed a dependency on visual acuity before or after radiosurgery. RRS is a safe and effective treatment for the management of ONSM. Hypofractionation of radiosurgery in patients with preserved vision before CK treatment results in stable or improved vision.

The rationale and development of a CyberKnife© registry for pediatric patients with CNS lesions

BACKGROUND

CyberKnife© Radiosurgery (CKRS) is a recognized treatment concept for CNS lesions in adults due to its high precision and efficacy beside a high patient comfort. However, scientific evidence for this treatment modality in pediatric patients is scarce. A dedicated registry was designed to document CyberKnife© procedures in children, aiming to test the hypothesis that it is safe and efficient for the treatment of CNS lesions.

METHODS

The CyberKnife© registry is designed as a retrospective and prospective multicenter observational study (German Clinical Trials Register ( https://www.drks.de ), DRKS-ID 00016973). Patient recruitment will be ongoing throughout a 5-year period and includes collection of demographic, treatment, clinical, and imaging data. Follow-up results will be monitored for 10 years. All data will be registered in a centralized electronic database at the Charité-Universitätsmedizin. The primary endpoint is stable disease for benign and vascular lesions at 5 years of follow-up and local tumor control for malign lesions at 1- and 2-year follow-up. Secondary endpoints are radiation toxicity, side effects, and neurocognitive development.

CONCLUSION

The CyberKnife© registry intends to generate scientific evidence for all treatment- and outcome-related aspects in pediatric patients with treated CNS lesions. The registry may define safety and efficacy of CKRS in children and serve as a basis for future clinical trials, inter-methodological comparisons and changes of treatment algorithms.

Primary and Secondary Optic Nerve Sheath Meningioma

Objective  This study was aimed to review issues relating to the recognition, radiographic diagnosis, monitoring, and management of primary and secondary optic nerve sheath meningioma (ONSM). Design  This study is a review of peer-reviewed literature combined with illustrative case studies. Participants and Methods  A literature search was conducted via the PubMed database using pertinent search terms. Selected articles were limited to those written or translated into English. Additional works cited within articles were also included. Individual cases were drawn from the experience of a tertiary academic neuroophthalmic and orbital practice. Tables summarize radiotherapeutic and surgical studies, excluding single case reports and studies focusing on meningioma of intracranial origin. Main Outcome Measurements  Review of reported surgical and radiotherapeutic series is the primary measurement. Results  The natural history of optic nerve sheath meningiomas is primarily characterized by progressive ipsilateral vision loss. Diagnosis is typically based on radiographic imaging findings, with biopsy remaining indicated in some patients. Management strategies may include observation, radiation, and/or surgical intervention, or a combination of these approaches. The role of surgery, especially with respect to primary ONSM (pONSM), remains controversial. Advancement of radiotherapy techniques has shifted modern treatment paradigms in pONSM toward radiation as primary treatment, as surgical outcomes are inferior in major studies. Although radiation remains the treatment of choice in many cases, selected patients may benefit from surgery, especially in the setting of secondary ONSM (sONSM). Conclusion  A wide variety of radiotherapeutic and surgical treatment modalities for ONSM exist. The specific indications for each management strategy continue to be redefined.

Prognostic Factors for Functional Outcome of Patients with Optic Nerve Sheath Meningiomas Treated with Stereotactic Radiotherapy-Evaluation of Own and Meta-Analysis of Published Data

Simple Summary

This article highlights the fractionated stereotactic radiotherapy in the treatment of optic nerve sheath meningioma (ONSM). ONSM, a slow-growing tumor next to the optic nerve, causes over a long period partial or complete blindness. As visual impairments appear and progress slowly in the disease history, the need for treatment and treatment starting time are controversial. We restate in our article that fractionated stereotactic radiotherapy improves visual function. We further search for prognostic factors which might provide valuable additional and independent information on when to start treatment. We reveal that the visual acuity is a prognostic factor for the outcome of stereotactic therapy for ONSM and promote it as a biomarker for the decision for treatment initiation.

Abstract

Objective: To evaluate prognostic factors for a favorable outcome (improvement of the visual acuity or visual fields) after fractionated stereotactic radiotherapy (fSRT) of optic nerve sheath meningioma (ONSM). Methods: We performed a database search for ONSM treatments during the period from April 2008 to September 2019 in the prospective database for stereotactic radiosurgery/radiotherapy (SRS/SRT) of the Robert Janker Clinic Bonn (Department of Radiotherapy) and performed a literature review and meta-analysis of published data on ONSM between 2010 and 2019. Ophthalmic status before and after treatment was evaluated and the collective was dichotomized into two groups: functional improvement (FI; improvement of either visual acuity or visual fields) and non functional improvement (NFI; with stable or deteriorating visual acuity or visual fields). The two groups were compared regarding different variables: pretreatment visual acuity, age, gender, gross tumor volume (GTV), follow up (FU) time, tumor localization, and maximal retina dose. Results: Overall, 13 stereotactic radiotherapies were performed for ONSM (12 × fSRT, 1 × SRS). Mean follow up was 3 years (range: 1–5 years). The total dose was 50.4 Gy (5 × 1.8 Gy/week) in 12 patients treated with fSRT and 1 × 14 Gy in one SRS case. Mean GTV was 1.13 ccm (range: 0.44–2.20 ccm). During follow up, all tumors were stable or showed shrinkage of tumor volume (100% tumor control), no adverse events were observed, 53% of the patients achieved either better visual acuity or visual fields. Pretreatment visual acuity was significantly different between the FI and the NFI group (0.17 vs. 0.63, p = 0.03) in our series and in the meta analysis (p < 0.01). Moreover, shorter FU time and lower retinal dose were significantly linked (p < 0.05 and p < 0.01, respectively) with a better outcome in the meta-analysis but not in our patient cohort. Intracranial tumor localization, gender, and age were not significantly different between the two outcome groups. Conclusion: FSRT for ONSM achieves in over 50% of cases an improvement of the ophthalmic status with low morbidity and excellent tumor control in our series and the meta analysis. Patients with a favorable outcome had in all analysis a significantly higher visual acuity before treatment start. Therefore, we advocate using fSRT as early as possible before vision deterioration occurs.

Image-Guided Multisession Radiosurgery of Skull Base Meningiomas

Simple Summary

Stereotactic radiosurgery has changed the landscape of treatment for skull base meningiomas. Lesions encasing or compressing radiosensitive structures are considered not suitable for single session stereotactic radiosurgery because of the high risk of side effects. Multisession stereotactic radiosurgery can reduce these risks, allowing for normal tissue repair between fractions, while delivering a high dose per fraction. The aim of this study is to validate the role of multi-session stereotactic radiosurgery in the treatment of skull base meningiomas, through a retrospective analysis of 156 patients affected by skull base meningioma, treated at the University of Messina between 2008 and 2018. Our study suggests that multisession stereotactic radiosurgery represents a safe and effective profile in the treatment of skull base meningioma, providing a satisfactory local control and a low toxicity rate, together with patient comfort from a frameless procedure.

Abstract

Background: The efficacy of single-session stereotactic radiosurgery (sSRS) for the treatment of intracranial meningioma is widely recognized. However, sSRS is not always feasible in cases of large tumors and those lying close to critically radiation-sensitive structures. When surgery is not recommended, multi-session stereotactic radiosurgery (mSRS) can be applied. Even so, the efficacy and best treatment schedule of mSRS are not yet established. The aim of this study is to validate the role of mSRS in the treatment of skull base meningiomas. Methods: A retrospective analysis of patients with skull base meningiomas treated with mSRS (two to five fractions) at the University of Messina, Italy, from 2008 to 2018, was conducted. Results: 156 patients met the inclusion criteria. The median follow-up period was 36.2 ± 29.3 months. Progression-free survival at 2-, 5-, and 10- years was 95%, 90%, and 80.8%, respectively. There were no new visual or motor deficits, nor cranial nerves impairments, excluding trigeminal neuralgia, which was reported by 5.7% of patients. One patient reported carotid occlusion and one developed brain edema. Conclusion: Multisession radiosurgery is an effective approach for skull base meningiomas. The long-term control is comparable to that obtained with conventionally-fractionated radiotherapy, while the toxicity rate is very limited.

Normofractionated stereotactic radiotherapy versus CyberKnife-based hypofractionation in skull base meningioma: a German and Italian pooled cohort analysis

Background

This retrospective German and Italian multicenter analysis aimed to compare the role of normofractionated stereotactic radiotherapy (nFSRT) to CyberKnife-based hypofractionated stereotactic radiotherapy (CK-hFSRT) for skull base meningiomas.

Methods

Overall, 341 patients across three centers were treated with either nFSRT or CK-hFSRT for skull base meningioma. Treatment planning was based on computed tomography (CT) and magnetic resonance imaging (MRI) following institutional guidelines. Most nFSRT patients received 33 × 1.8 Gy, and most CK-hFSRT patients received 5 × 5 Gy. The median follow-up time was 36 months (range: 1–232 months).

Results

In the CK-hFSRT group, the 1-, 3-, and 10-year local control (LC) rates were 99.4, 96.8, and 80.3%, respectively. In the nFSRT group, the 1-, 3-, and 10-year LC rates were 100, 99, and 79.1%, respectively. There were no significant differences in LC rates between the nFSRT and CK-hFSRT groups (p = 0.56, hazard ratio = 0.76, 95% confidence interval, 0.3–1.9). In the CK-hFSRT group, only one case (0.49%) of severe toxicity (CTCAE 4.0 ≥ 3) was observed. In the nFSRT group, three cases (2.1%) of grade III toxicity were observed.

Conclusion

This analysis of pooled data from three centers showed excellent LC and low side effect rates for patients treated with CK-hFSRT or nFSRT. The efficacy, safety, and convenience of a shortened treatment period provide a compelling case for the use of CK-hFSRT in patients with moderate size skull base meningioma and provided that OAR constraints are met.

Benefits of image-guided stereotactic hypofractionated radiation therapy as adjuvant treatment of craniopharyngiomas. A review

PURPOSE

Craniopharyngiomas account for 5.6-13% of intracranial tumors in children. Despite being histologically benign, these tumors remain a major neurosurgical challenge because of the typical tight adherence to adjacent critical structures. The optimal therapeutic approach for this disease is controversial. Large cystic size and adherence to neurovascular, neuroendocrine, and optic structures without a clear line of cleavage make complete resection problematic and often hazardous. For these reasons, partial resection and adjuvant treatment play an important role. Post-operative radiation therapy (RT) following either complete or incomplete tumor removal is associated with significantly decreased recurrence rates. The aim of this review is to analyze the potential advantage of the most modern technical advancements for RT of craniopharyngiomas.

METHODS

This narrative review on the topic of craniopharyngiomas was based on published data available on PUBMED/Medline. All data concerning adjuvant or upfront radiation therapy treatment of craniopharyngioma were reviewed and summarized. A more detailed analysis of fractionated frameless steretactic radiosurgery of these tumors is provided as well.

RESULTS

We reviewed the possible improvement provided by intensity modulated beams, arc therapy, image guidance, proton radiation, and fractionated stereotactic radiosurgery. Many published findings on outcome and toxicity after RT involve the use of relatively outdated RT techniques. Technologic improvements in imaging, radiation planning, and delivery have improved the distribution of radiation doses to desired target volumes and reduced the dose to nearby critical normal tissues. Currently available techniques, providing image guidance and improved radiation doses distribution profile, have shown to maintain the efficacy of conventional techniques while significantly reducing the toxicity.

CONCLUSIONS

Image-guided radiosurgery holds the dose distributions and precision of frame-based techniques with the remarkable advantage of multiple-session treatments that are better tolerated by sensitive peritumoral structures, such as the optic pathway and hypothalamus. This, together with the comfort of a frameless technique, candidates frameless image-guided radiosurgery to be the first option for the adjuvant post-operative treatment of craniopharyngiomas in children and young adults when total resection cannot be achieved, in particular those with hypothalamic involvement, and when the residual tumor is mostly solid.

Optic nerve sheath meningiomas: prevalence, impact, and management strategies

Optic nerve sheath meningiomas are rare benign neoplasms of the meninges surrounding the optic nerve. They are a significant cause of morbidity. While the mortality rate is practically zero, these tumors can blind or disfigure patients. Given that the clinical course can be variable, and treatment has the capacity to cause morbidity itself, the management of these patients can be difficult. We review the literature to discuss the prevalence of optic nerve sheath meningiomas, the association with neurofibromatosis type 2, natural history, and management options and strategies.

Multicriteria optimization of the spatial dose distribution

PURPOSE

Treatment planning for radiation therapy involves trade-offs with respect to different clinical goals. Typically, the dose distribution is evaluated based on few statistics and dose-volume histograms. Particularly for stereotactic treatments, the spatial dose distribution represents further criteria, e.g., when considering the gradient between subregions of volumes of interest. The authors have studied how to consider the spatial dose distribution using a multicriteria optimization approach.

METHODS

The authors have extended a stepwise multicriteria optimization approach to include criteria with respect to the local dose distribution. Based on a three-dimensional visualization of the dose the authors use a software tool allowing interaction with the dose distribution to map objectives with respect to its shape to a constrained optimization problem. Similarly, conflicting criteria are highlighted and the planner decides if and where to relax the shape of the dose distribution.

RESULTS

To demonstrate the potential of spatial multicriteria optimization, the tool was applied to a prostate and meningioma case. For the prostate case, local sparing of the rectal wall and shaping of a boost volume are achieved through local relaxations and while maintaining the remaining dose distribution. For the meningioma, target coverage is improved by compromising low dose conformality toward noncritical structures. A comparison of dose-volume histograms illustrates the importance of spatial information for achieving the trade-offs.

CONCLUSIONS

The results show that it is possible to consider the location of conflicting criteria during treatment planning. Particularly, it is possible to conserve already achieved goals with respect to the dose distribution, to visualize potential trade-offs, and to relax constraints locally. Hence, the proposed approach facilitates a systematic exploration of the optimal shape of the dose distribution.

Optic nerve sheath meningioma: a case report with 15-year follow-up

Meningiomas are benign neoplastic lesions of arachnoidal cells of the meninges. These tumors may arise wherever meninges exists, such as in the nasal cavity, paranasal sinuses, middle ear, and mediastinum. Optic nerve sheath meningiomas (ONSMs) are usually unilateral and occur predominantly in middle-aged females, although they may be present at any age. We present a case of a 55-year-old female with ONSM diagnosed when she was 40 years old. Diagnosis and follow-up was based on the clinical picture, CT orbit scan, and magnetic resonance imaging.