Postoperative radiotherapy for meningiomas – a decision-making analysis

Abstract

Background The management of meningiomas is challenging, and the role of postoperative radiotherapy is not standardized. Methods Radiation oncology experts in Swiss centres were asked to participate in this decision-making analysis on the use of postoperative radiotherapy (RT) for meningiomas. Experts from ten Swiss centres agreed to participate and provided their treatment algorithms. Their input was converted into decision trees based on the objective consensus methodology. The decision trees were used as a basis to identify consensus and discrepancies in clinical routine. Results Several criteria used for decision-making in postoperative RT in meningiomas were identified: histological grading, resection status, recurrence, location of the tumour, zugzwang (therapeutic need to treat and/or severity of symptoms), size, and cell division rate. Postoperative RT is recommended by all experts for WHO grade III tumours as well as for incompletely resected WHO grade II tumours. While most centres do not recommend adjuvant irradiation for WHO grade I meningiomas, some offer this treatment in recurrent situations or routinely for symptomatic tumours in critical locations. The recommendations for postoperative RT for recurrent or incompletely resected WHO grade I and II meningiomas were surprisingly heterogeneous. Conclusions Due to limited evidence on the utility of postoperative RT for meningiomas, treatment strategies vary considerably among clinical experts depending on the clinical setting, even in a small country like Switzerland. Clear majorities were identified for postoperative RT in WHO grade III meningiomas and against RT for hemispheric grade I meningiomas outside critical locations. The limited data and variations in clinical recommendations are in contrast with the high prevalence of meningiomas, especially in elderly individuals.

Recurrence of Resected Skull Base Meningiomas during Long-term Follow-up: Incidence and Predisposing Factors

“…51 At present, postoperative radiotherapy is typically reserved for when there is evidence of tumor regrowth on follow-up imaging and there remains uncertainty regarding the efficacy of immediate adjuvant radiotherapy for WHO grade II tumors. 49,52,53 This question is currently the subject of two ongoing randomized control trials which will be instructive in guiding the future management of such patients. 54,55 In summary, our data demonstrate that 46% of SBM in this cohort demonstrated recurrence during a median period of follow-up of 11.25 years.…”

Surveillance, Epidemiology, and End Results database and propensity score matching analysis of postoperative radiotherapy for non‐malignant meningioma: A retrospective cohort study

“…Different organizations have different views on how to treat atypical meningiomas, with some preferring treatment with radiation therapy after GTR, while others preferring radiation therapy alone 23 . NCCN and EANO guidelines recommend PORT for incompletely resected Grade II tumors 8,26 . The randomized trial ROAM/EORTC demonstrated a clinical benefit of PORT for recurrent atypical meningiomas after complete surgery 27 .…”

“…23 NCCN and EANO guidelines recommend PORT for incompletely resected Grade II tumors. 8,26 The randomized trial ROAM/EORTC demonstrated a clinical benefit of PORT for recurrent atypical meningiomas after complete surgery. 27 Prospective clinical trials are still needed to overcome this uncertainty.…”

“…For WHO Grade I, the National Comprehensive Cancer Network and EZNO guidelines recommend PORT in incompletely resected tumors or symptomatic patients. Although PORT is unsuitable for patients with completely resected WHO Grade I meningioma, radiation therapy (with or without surgery) can be considered for those with WHO Grade II meningioma 8,9 . A recent study reported that atypical meningiomas (non‐malignant, classified according to the CBTRUS report ICD‐O‐3 code 10 ) receiving PORT had worse survival outcomes or no survival difference with PORT 11,12 …”

“…Although PORT is unsuitable for patients with completely resected WHO Grade I meningioma, radiation therapy (with or without surgery) can be considered for those with WHO Grade II meningioma. 8,9 A recent study reported that atypical meningiomas (non-malignant, classified according to the CBTRUS report ICD-O-3 code 10 ) receiving PORT had worse survival outcomes or no survival difference with PORT. 11,12 We performed a large population-based study to determine the effect of PORT on NMMs using propensity score matching (PSM) to eliminate baseline differences between samples.…”