Gross Total Resection Of Atypical Meningioma Research Articles

Adjuvant radiotherapy in grossly total resected grade II atypical meningiomas: a protective effect on recurrence?

Management of grade II atypical meningiomas (AM) remains controversial. Conflicting evidence exist on the possible protective effect of adjuvant radiotherapy (ART) on recurrence in grossly resected AMs. The aim of this meta-analysis is to evaluate the role of ART in grossly resected (Simpson grades 1-3) AMs on the recurrence and survival. Literature review was performed by the study investigators who handily queried the MEDLINE database using keywords and MeSH terms in different combinations using the Boolean operators "AND" or "OR," and database-related filters to maximize the chance to identify articles focusing on role of radiotherapy in atypical (WHO grade II) meningiomas. Data were retrieved from comparative studies of AMs undergone surgical resection alone vs. surgery + ART. Only grossly total resected AMs (Simpson grades 1-3) were included. The individual and pooled odds ratio (OR) for the crude recurrence, progression free survival (PFS) at 1, 3 and 5-years, as well as for the overall survival (OS) at 5-years were calculated by using the Mantel-Haenszel model in surgery alone vs. surgery + ART. Eleven studies were considered eligible. 8 were included for the outcome "crude recurrence;" 6 for PFS at 1-3 years, 7 for PFS at 5-years; 6 for the OS at 5-years. Results suggest that surgery + ART might have a protective role on recurrence in gross-totally resected AMs (OR:1.66). Specifically, surgery + ART slightly improved PFS at 1-year (OR:0.92) and more consistently at 3- and 5-years (OR:0.31 and 0.35 respectively) hence favoring a combined approach. Current literature on the impact of ART after gross total resection of AM are still heterogeneous and not systematically reported. The present meta-analysis suggests a possible protective role of postoperative RT against long-term recurrence as compared to surgical resection alone.

RADT-41. ASSESSING THE ROLE OF ADJUVANT RADIATION THERAPY AND RISK FACTORS FOR RECURRENCE FOLLOWING GROSS TOTAL RESECTION OF ATYPICAL MENINGIOMAS

Abstract While meningiomas are commonly benign brain tumors, as many as 30% may be classified as atypical, or WHO Grade 2. Patients are at risk of recurrence following resection and often are prescribed adjuvant radiation therapy (RT)-although most data on this treatment is retrospective and has shown mixed RESULTS: In this study we assessed the influence of adjuvant RT following gross total resection (GTR) in patients with newly diagnosed atypical meningiomas at our institution and sought to determine predictors of tumor recurrence. All patients who underwent GTR (Simpson Grade I and II) at their index operation from 1994-2014 were retrospectively reviewed. Patients then either underwent observation or adjuvant RT (Intensity-Modulated Radiation Therapy (IMRT) or stereotactic radiosurgery (SRS)). A total of 145 patients had documented GTR at the time of initial resection, including 88 females (61%) and 57 males (39%), with a mean age of 58 +/- 15.7 years. 118 patients were followed with observation after surgery while 27 (18.6%) patients received adjuvant RT prior to known recurrence (IMRT for 15 patients (55.5%) and SRS in 12 patients (44.4%)). Patients receiving adjuvant RT had significantly larger tumors, as well as a higher incidence of spontaneous necrosis and small cell phenotype on histopathology. Overall 5-year PFS in our cohort was 71.6% (CI 60.6%-84.7%) and was unchanged by adjuvant RT (p = 0.52). 23 patients (15.8%) had a recurrence with a mean follow up of 42.9 months (17.1-53.5 months). Male gender (HR=1.02, p=0.019), tumor size (HR=1.17, p= 0.002) and MIB-1 > 4 (HR=8.50, p=0.04) were associated with increased recurrence risk. There was no association between radiation type (SRS vs. IMRT) and risk of recurrence (p= 0.154). In our patients, adjuvant RT following GTR of atypical meningiomas did not improve PFS. Risk factors for recurrence included male gender, larger tumor size, and MIB-1 > 4.

Revisiting Adjuvant Radiotherapy After Gross Total Resection of World Health Organization Grade II Meningioma.

Atypical meningioma is a World Health Organization grade II tumor with intermediate prognosis and risk of recurrence. Optimal management after gross total resection (GTR) is controversial, with observation versus adjuvant radiotherapy (RT) contentiously debated. Pathologic review was performed of all atypical meningiomas diagnosed at our institution from 1988 to 2011. Retrospective chart review documented patient demographics, extent of surgical resection, history of radiation therapy, progression-free survival (PFS), and overall survival (OS). A supplemental systematic literature review was completed in which English-language articles published since 1979 comparing observation and RT after GTR of atypical meningioma were surveyed. Sixty-nine patients met inclusion criteria. Sixty-one underwent observation, and 8 received RT. Overall, 15 observation and 3 patients undergoing RT experienced tumor recurrence (5-year PFS 79% vs. 88%; P= 0.67); 19 observation and 2 patients undergoing RT died (5-year OS 89% vs. 83%; P= 0.68). Systematic review identified 9 preceding studies reporting extractable data comparing observation and RT outcomes after GTR. Recurrence was 18% and 19% after observation and RT (P= 0.9); total survival was 84% and 93% (P= 0.2). At 5 years, PFS was 81% after observation and 88% after RT (P= 0.2), whereas survival was 87% after observation and 96% after RT (P= 0.4). Observation alone after GTR of atypical meningioma was not associated with increased risk of tumor recurrence or mortality. Although some preceding authors advocate for RT based on empiric experience, a systematic review also suggests that observation may provide equivalent PFS and OS to RT. Taken together, these findings indicate that observation after GTR may be a safe alternative to RT.

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

The management of WHO Grade II "atypical" meningiomas (AMs) and Grade III "malignant" meningiomas (MMs) remains controversial and under-investigated in prospective studies. The roles of surgery, radiation therapy, radiosurgery, and chemotherapy have been incompletely delineated. This has left physicians to decipher how they should treat patients on a case-by-case basis. In this study, the authors review the English-language literature on the management and clinical outcomes associated with AMs and MMs diagnosed using the WHO 2000/2007 grading criteria. Twenty-two studies for AMs and 7 studies for MMs were examined in detail. The authors examined clinical decision points using the literature and concepts from evidence-based medicine. Acknowledging the retrospective nature of the studies concerning AM and MM, the authors did find evidence for the following clinical strategies: 1) maximal safe resection of AM and MM; 2) active surveillance after gross-total resection of AM; 3) adjuvant radiation therapy after subtotal resection of AM, especially in the absence of putative radioresistant features; and 4) adjuvant radiation therapy after resection of MM.

Management of atypical cranial meningiomas, part 1: predictors of recurrence and the role of adjuvant radiation after gross total resection.

Indications for external beam radiation therapy (EBRT) for atypical meningiomas (AMs) remain unclear. To analyze features associated with recurrence in AM patients after gross total resection (GTR) and to assess the relative benefit of EBRT in a retrospective cohort study. One hundred fifty-one primary AMs after GTR (88 female patients; median follow-up, 45.0 months) were examined for possible predictors of recurrence (age, sex, location, volume, bone involvement, brain invasion). The Fisher exact and Wilcoxon rank-sum tests were used to analyze the association between these predictors and use of EBRT. The impact on recurrence for these predictors and EBRT was analyzed with Kaplan-Meier and Cox regression. Of 151 patients, 13 (8.6%) experienced recurrence after GTR (median, 47.0 months). Multivariate analysis identified elevated mitotic index (P = .007) and brain invasion (P = .002) as predictors of recurrence. Larger volume (P = .96) was not associated with recurrence but was more likely to prompt EBRT (P = .001). Recurrences occurred in 11 of 112 with GTR (9.8%; median, 44 months) and 2 of 39 with GTR/EBRT (5.1%; median, 133 months). The 2-, 5-, and 10-year progression-free survival rates after GTR vs GTR/EBRT were 97%, 86%, and 68% vs 100%, 100%, and 78%. Kaplan-Meier analysis demonstrated no difference in progression-free survival or overall survival after GTR vs GTR/EBRT (P = .8, P > .99). Brain invasion and high mitotic rates may predict recurrence. After GTR of AMs, EBRT appears not to affect progression-free survival and overall survival, suggesting that observation rather than EBRT may be indicated after GTR.

The role of radiotherapy following gross-total resection of atypical meningiomas

Atypical (WHO Grade II) meningiomas comprise a heterogeneous group of tumors, with histopathology delineated under the guidance of the WHO and a spectrum of clinical outcomes. The role of postoperative radiotherapy for patients with atypical meningiomas who have undergone gross-total resection (GTR) remains unclear. In this paper, the authors sought to clarify this role by reviewing their experience over the past 2 decades. The authors retrospectively analyzed all patients at their institution who underwent GTR between 1992 and 2011 with a final histology demonstrating atypical meningioma. Information regarding patients, tumor characteristics, and postoperative adjuvant therapy was gleaned from medical records. Time to recurrence and overall survival were analyzed using univariate, multivariate, and Kaplan-Meier survival analyses. Forty-five patients who met the inclusion criteria underwent GTR for atypical meningiomas. By a median follow-up of 44.1 months, 22% of atypical meningiomas had recurred. There was no recurrence in 12 (92%) of 13 patients who received postoperative radiotherapy or in 19 (59%) of 32 patients who did not undergo postoperative radiotherapy (p = 0.085), demonstrating a strong trend toward improved local control with postoperative radiotherapy. No other factors were significantly associated with recurrence in univariate or multivariate analyses. This retrospective series supports the observation that postoperative radiotherapy likely results in lower recurrence rates of gross totally resected atypical meningiomas. Although a multicenter prospective trial will ultimately be needed to fully define the role of radiotherapy in managing gross totally resected atypical meningiomas, the authors' results contribute to a growing number of series that support routine postoperative radiotherapy as an adjuvant treatment for these lesions.