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Effect of dural detachment on long-term tumor control for meningiomas treated using Simpson grade IV resection
Yuta Fukushima1, Soichi Oya, Hirofumi Nakatomi
1Departments of Neurosurgery and.
Object:
Meningiomas treated by subtotal or partial resection are associated with significantly shorter recurrence-free survival than those treated by gross-total resection. The Simpson grading system classifies incomplete resections into a single category, namely Simpson Grade IV, with wide variations in the volume and location of residual tumors, making it complicated to evaluate the achievement of surgical goals and predict the prognosis of these tumors. Authors of the present study investigated the factors related to necessity of retreatment and tried to identify any surgical nuances achievable with the aid of modern neurosurgical techniques for meningiomas treated using Simpson Grade IV resection.
Methods:
This retrospective analysis included patients with WHO Grade I meningiomas treated using Simpson Grade IV resection as the initial therapy at the University of Tokyo Hospital between January 1995 and April 2010. Retreatment was defined as reresection or stereotactic radiosurgery due to postoperative tumor growth.
Results:
A total of 38 patients were included in this study. Regrowth of residual tumor was observed in 22 patients with a mean follow-up period of 6.1 years. Retreatment was performed for 20 of these 22 tumors with regrowth. Risk factors related to significantly shorter retreatment-free survival were age younger than 50 years (p = 0.006), postresection tumor volume of 4 cm(3) or more (p = 0.016), no dural detachment (p = 0.001), and skull base location (p = 0.016). Multivariate analysis revealed that no dural detachment (hazard ratio [HR] 6.42, 95% CI 1.41-45.0; p = 0.02) and skull base location (HR 11.6, 95% CI 2.18-218; p = 0.002) were independent risk factors for the necessity of early retreatment, whereas postresection tumor volume of 4 cm(3) or more was not a statistically significant risk factor.
Conclusions:
Compared with Simpson Grade I, II, and III resections, Simpson Grade IV resection includes highly heterogeneous tumors in terms of resection rate and location of the residual mass. Despite the difficulty in analyzing such diverse data, these results draw attention to the favorable effect of dural detachment (instead of maximizing the resection rate) on long-term tumor control. Surgical strategy with an emphasis on detaching the tumor from the affected dura might be another important option in resection of high-risk meningiomas not amenable to gross-total resection.
Insights
For incomplete meningioma resections (Simpson Grade IV), avoiding dural detachment and skull base location are key factors predicting the need for retreatment. Focusing on dural detachment may improve long-term tumor control.
Area of Science:
- Neurosurgery
- Oncology
- Pathology
Background:
- Subtotal or partial meningioma resection (Simpson Grade IV) is linked to poorer outcomes than gross-total resection.
- Simpson Grade IV encompasses diverse residual tumor volumes and locations, complicating prognostic evaluation.
- Identifying factors influencing retreatment necessity is crucial for optimizing surgical strategies.
Purpose of the Study:
- To investigate factors associated with retreatment necessity in meningiomas treated with Simpson Grade IV resection.
- To identify surgical nuances for improving outcomes in incomplete meningioma resections using modern techniques.
Main Methods:
- Retrospective analysis of WHO Grade I meningioma patients undergoing Simpson Grade IV resection.
- Data collected from the University of Tokyo Hospital between January 1995 and April 2010.
- Retreatment defined as re-resection or stereotactic radiosurgery for tumor regrowth.
Main Results:
- Twenty-two of 38 patients experienced tumor regrowth over a mean 6.1-year follow-up.
- No dural detachment (HR 6.42) and skull base location (HR 11.6) were independent risk factors for retreatment.
- Postresection tumor volume ≥ 4 cm³ was not a significant predictor of retreatment.
Conclusions:
- Simpson Grade IV resections are heterogeneous, challenging standard prognostic models.
- Dural detachment, rather than maximizing resection rate, shows a favorable effect on long-term meningioma control.
- Prioritizing dural detachment in high-risk meningiomas may be a valuable surgical strategy when gross-total resection is not feasible.
