Adjuvant radiotherapy for atypical meningiomas

Abstract

OBJECTIVE The aim of this paper was to evaluate outcomes in patients with atypical meningiomas (AMs) treated with surgery alone compared with surgery and radiotherapy at initial diagnosis, or at the time of first recurrence. METHODS Patients with pathologically confirmed AMs treated at the University of Utah from 1991 to 2014 were retrospectively reviewed. Local control (LC), overall survival (OS), Karnofsky Performance Status (KPS), and toxicity were assessed. Outcomes for patients receiving adjuvant radiotherapy were compared with those for patients treated with surgery alone. Kaplan-Meier and the log-rank test for significance were used for LC and OS analyses. RESULTS Fifty-nine patients with 63 tumors were reviewed. Fifty-two patients were alive at the time of analysis with a median follow-up of 42 months. LC for all tumors was 57% with a median time to local failure (TTLF) of 48 months. The median TTLF following surgery and radiotherapy was 180 months, compared with 46 months following surgery alone (p = 0.02). Excluding Simpson Grade IV (subtotal) resections, there remained an LC benefit with the addition of radiotherapy for Simpson Grade I, II, and III resected tumors (median TTLF 180 months after surgery and radiotherapy compared with 46 months with surgery alone [p = 0.002]). Patients treated at first recurrence following any initial therapy (either surgery alone or surgery and adjuvant radiotherapy) had a median TTLF of 26 months compared with 48 months for tumors treated at first diagnosis (p = 0.007). There were 2 Grade 3 toxicities and 1 Grade 4 toxicity associated with radiotherapy. CONCLUSIONS Adjuvant radiotherapy improves LC for AMs. The addition of adjuvant radiotherapy following even a Simpson Grade I, II, or III resection was found to confer an LC benefit. Recurrent disease is difficult to control, underscoring the importance of aggressive initial treatment.

Early or late radiotherapy following gross or subtotal resection for atypical meningiomas: Clinical outcomes and local control

“…A recent retrospective review showed a significant improvement in local control for patients receiving early adjuvant radiotherapy, irrespective of EOR. They found time to local failure to be 180 months after surgery and radiotherapy, compared to 46 months for surgery alone (p = 0.002) [7]. Our data confirm these findings, but only with the modality of EBRT, with a cumulative incidence of local failure of only 20.0% for those receiving early EBRT versus 51.4% for surgery alone (p = 0.02).…”

“…Managing these patients requires evaluating the role of adjuvant therapy in both patients receiving GTR and STR. A growing body of literature suggests that early adjuvant radiotherapy improves local control [7–9]; however, the effect on OS is more disputed with some recent studies finding no benefit [7,27]. Some of the inconsistencies reported in the literature could be a result of the variability in the administration of radiotherapy.…”

“…While gross total resection (GTR) (Simpson grade I, II, or III) or subtotal resection (Simpson grade IV or V) alone are standard treatment options for benign meningiomas, it is unclear if surgery alone is adequate for atypical meningiomas. Several series have demonstrated improved local control with immediate postoperative radiotherapy following surgery [7–9]; however, there is less evidence to support a benefit in overall survival (OS). Moreover, the cognitive toxicities of radiotherapy need to be considered when treating patients with relatively long life expectancy [10,11].…”

“…Some retrospective studies support the role of adjuvant radiotherapy [7,12–15] while others do not [16,17] and most of these studies are limited by being retrospective series with a limited number of patients [14,18]. Further, these series have discrepancies in the extent of resection (EOR), timing of treatment, and criteria for atypical meningioma (AM) classification in the evaluated patient populations.…”

Long-Term Clinical Outcome of First Recurrence Skull Base Meningiomas

“…Recently, several studies 17] and SBMs [18,19] after initial surgical resection. Various forms of adjuvant radiotherapy, including fractionated radiotherapy and stereotactic radiosurgery, have been found to improve local control [16,17,19]. However, the efficacy of adjuvant radiotherapy for the recurrent stage of SBMs remains unclear [16,17].…”