Radiotherapy for World health organization grade 2 meningioma treatment
While World health organization grade 1 meningioma can be treated with either surgery or External beam radiotherapy, World health organization grade 2 meningioma and World health organization grade 3 meningioma often require a combination of the two modalities. For these high-grade lesions, conventional external beam radiation is delivered to either the residual tumor or the surgical resection margin. The optimal timing of radiation, either immediately following surgical resection or at the time of recurrence, is yet to be determined. Additionally, another method of radiation delivery, brachytherapy, can be administered locally at the time of surgery for recurrent lesions. Altogether, the complex nature of WHO grade II and III meningiomas require careful treatment planning and delivery by a multidisciplinary team 1).
Stereotactic Radiosurgery should be considered in carefully selected patients with atypical meningiomas 2).
Meningioma Radiomics significantly contribute added value in predicting recurrence when integrated with the clinicopathological features in patients with grade 2 meningiomas. Furthermore, the combined model can be applied to identify high-risk patients who require adjuvant radiotherapy 3).
Results are still suboptimal with high rates of local progression. A dose escalation using high-conformal RT techniques needs to be evaluated in terms of efficacy and safety. A dose escalation for hRG2 meningiomas, using a Combo-RT approach, is safe and particularly effective in the subgroup of patients with STR 4).
In a large retrospective cohort, Rebchuk et al. from the UBC Hospital, found no survival or local recurrence benefit to adjuvant radiotherapy in the treatment of grade 2 meningiomas. Sensitivity analysis limited to initial GTR and STR also failed to demonstrate any OS or LR benefit with adjuvant radiotherapy. There is a limited utility to upfront adjuvant radiotherapy following initial surgical resection in the treatment of grade 2 meningiomas 5).