**6. Management**

The management of multicentric-diffuse recurrences of intracranial meningiomas is often difficult to be defined; there are not studies defining the guidelines. The management options include a second surgery, external radiotherapy, stereotactic radiosurgery, medical therapy.

The decision is based on several factors, including tumor location (non-skull base versus skull base; critical versus not critical), significant intradural mass versus prevalent dural infiltration (**Figures 4** and **5**), entity of bone extension, time to recurrence, WHO grade of the initial tumor, patient age and KPS, neurological symptoms and signs.

#### **Figure 4.**

*Post-contrast MRI of a 58 years old man with history of previous surgery (5 years before) of gross-total resection of a bilateral meningioma of the anterior third of the falx (WHO grade II). Sagittal (a-b) and coronal (c-d) T1 sequences: distant and diffuse recurrence at the right fronto-temporal bone and suprasellar regions, with no recurrence at the initial tumor site. Reoperation and resection of the recurrent tumor (WHO grade II). Postoperative death for respiratory failure.*

*Topographic Distribution of Intracranial Meningioma's Recurrences: Localized Versus Diffuse… DOI: http://dx.doi.org/10.5772/intechopen.97120*

#### **Figure 5.**

*Post-contrast MRI of a 70 years old woman with history of previous (7 year before) surgical resection (Simpson 3) of a WHO grade II meningioma of the posterior parasagittal region: sagittal (a) and coronal (b-c) sequences: diffuse recurrence with extensive dural and superior sagittal sinus involvement and tumor nodules at the posterior fossa. No reoperation was decided.*

#### **6.1 Surgery**

The indication to reoperation is mainly posed for younger and middle-aged patients with symptomatic recurrences. According to the location and pattern of regrowth, surgery should be reserved to cases with prevalent intradural tumor growth, tumor nodules ≥3 cm and not extensive dural infiltration (**Figures 1**). Non skull-base meningiomas, mainly if limited to the brain convexity, are usually more favorable to surgery, because of the chance of more wide resection of the involved dura mater. For skull-base meningiomas a more wide resection is possible at the anterior cranial fossa and external sphenoid wing; on the other hand, diffuse recurrences at the suprasellar, parasellar and spheno-orbital regions (**Figure 3**), as well as clival and petroclival regions, are difficult to treat, because of the involvement of the cranial nerves and vessels; for such locations a second surgery is only justified for the resection of a large symptomatic intradural mass.

Elderly patients with comorbidities, particularly if with no or trivial neurological symptoms, must be treated conservatively with periodical radiological follow-up.

The WHO grade at initial diagnosis is obviously important. Only WHO grades I and II meningiomas are suitable for reoperation. On the other hand, anaplastic WHO grade III tumors at initial diagnosis must not be reoperated on.

In selected patients according to the above discussed criteria the reoperation results is satisfactory resection of the intradural tumor and involved dura. However, a really complete resection with no residual contrast enhancement on MRI (Simpson grades 1 and 2) is obtained only in some cases (20% in our series versus 76% of local-peripheral recurrences) [28].

Further recurrences may be reoperated on following the same criteria, if they occur after several years and if the tumor does not progress to anaplastic WHO III form.

#### **6.2 Radiotherapy**

All studies focusing on the irradiation of recurrent meningiomas include all recurrences; thus guidelines of radiotherapy management of diffuse recurrences are not available.

The external radiotherapy of multicentric-diffuse recurrences of meningiomas is in our opinion mandatory, independently from the entity of resection and the WHO grade, but mainly in subtotally or partially resected WHO grade II recurrences [55, 56].

The stereotactic radiosurgery is scarcely indicated, because of the extensive and diffuse tumor growth. It may sometimes be performed in association to the external radiotherapy to increase the control of smaller nodules and to treat the not infrequent second recurrences outside the radiotherapic field [57]. Besides, re-radiosurgery for recurrent meningiomas is advisable if the previous radiosurgical treatment was unsatisfactory [58].
