Surgery for convexity meningioma: Simpson Grade I resection as the goal

Abstract

Object Recently the relevance of Simpson resection grade as a prognostic factor for recurrence of WHO Grade I meningiomas was challenged, contradicting many previous scientific reports and traditional neurosurgical teaching. The objective of this study was to determine whether the predictive value of Simpson resection grade is outdated or remains valid with respect to meningioma recurrence and overall survival. Methods All patients at least 16 years old who underwent primary craniotomies for convexity meningiomas at Oslo University–affiliated hospitals (Rikshospitalet and Ullevål University Hospitals) in the period between January 1, 1990, and January 27, 2011, were included. Overall survival and retreatment-free survival rates were correlated with patient- and surgery-specific factors. Results Three hundred ninety-one consecutive patients were included in the study. The median patient age was 60.1 years (range 19–92 years). The female-to-male ratio was 2.1:1. The WHO grades were Grade I in 353 (90.3%), Grade II in 22 (5.6%), and Grade III in 16 (4.1%). The follow-up rate was 100%. Median follow-up time was 7.1 years (range 0.0–20.9 years) and total observation time was 3147 patient-years. The 1-, 5-, and 10-year overall survival rates were 96%, 89%, and 78%, respectively. Age, sex, WHO grade, and Simpson grade were significantly associated with overall survival. The 1-, 5-, and 10-year retreatment-free survival rates were 99%, 94%, and 90%, respectively. Simpson resection grade and WHO grade were significantly associated with retreatment-free survival. The hazard ratios for retreatment after combined Simpson resection Grades II+III and IV+V were 4.9- and 13.2-times higher than after Simpson Grade I resection, respectively. Conclusions Simpson Grade I resection should continue to be the goal for convexity meningiomas.

Effect of dural detachment on long-term tumor control for meningiomas treated using Simpson Grade IV resection

“…10 In fact, postresection tumor volume in our series ranged widely. Recent studies appear to converge on the view that meningioma resections classified as Simpson Grade I, II, and III imply good tumor control over the long term, 7,21,32 but also underline the persistent difficulty found in the treatment of meningiomas treated with a Simpson Grade IV resection. Efforts to obtain long-term tumor control in meningioma surgery have been directed mainly at maximizing the resection rate.…”

“…Since then, surgery for meningiomas has been conducted on the principle that achievement of better Simpson grade would lead to better surgical outcome. 3,7,10,32 Recent patient series evaluating the significance of Simpson grades in modern neurosurgery have tended to find statistically significant differences in recurrence-or regrowth-free survival between Simpson Grade IV resection and Simpson Grade I-III resections, but have failed to find significant differences between Simpson Grade I, II, and III resections. 20,21,32 Such findings prompted us to separately review our outcomes of Simpson Grade IV resection from those of gross-total resection because the treatment goals are different from those of Simpson Grade I, II, and III resections.…”

An evidence-based treatment algorithm for the management of WHO Grade II and III meningiomas

“…For benign meningiomas, some authors reported that Simpson Grade I-III resection yielded equivalent results, 31,58,74 while others have advocated for Simpson Grade I or even more radical resection. 28,42,79 This issue becomes even more ambiguous for AMs. Hammouche et al reported a 5-year PFS of 74% after Simpson Grade I resection of AMs but only 34% after Simpson Grade II resection.…”

“…72,75 Hence, while GTR is the goal, STR may be considered in select patients through traditional open surgery or minimally invasive techniques. 28,36 It is unknown whether STR improves outcomes compared with biopsy alone.…”

Current standing and frontiers of gene therapy for meningiomas

“…8,16,26,36 Meningiomas are more commonly sporadic, yet they can be hereditary in patients with neurofibromatosis Type 2, multiple endocrine neoplasia Type 1, or Li-Fraumeni, Turcot, Gardener, von Hippel-Lindau, Cowden, or Gorlin syndrome. 38 The current standard of care for patients with meningiomas is gross-total resection of the tumor, 37 a feat that is sometimes difficult to achieve due its location and/or surgical morbidities. Hence, complete resection is achieved in less than 50% of patients, 27 and recurrence rates in macroscopically complete tumor removal (Simpson Grades 1-3) are up to 32% after 15 years of follow-up.…”