===== Sindou Grading System for Cavernous Sinus Meningiomas =====

The **Sindou Grade** is a classification system used to assess the **extent of resection** and **postoperative outcomes** in patients undergoing surgery for **cavernous sinus meningiomas (CSMs)**. It was developed by **Marc Sindou** to provide a standardized way to evaluate surgical results.

=== **Sindou Grades (I-VI)** ===

^ **Grade** ^ **Extent of Resection** ^ **Description** ^
| **Grade I** | **Total Resection (100%)** | Complete tumor removal, including dural attachment and invaded bone. |
| **Grade II** | **Subtotal Resection (>90%)** | Small residual tumor in non-critical areas. |
| **Grade III** | **Partial Resection (50-90%)** | Significant tumor removal, but residual tumor remains in critical structures. |
| **Grade IV** | **Limited Resection (<50%)** | Only a portion of the tumor is removed due to high surgical risk. |
| **Grade V** | **Biopsy or Decompression** | Minimal resection, only for symptom relief. |
| **Grade VI** | **No Resection** | Tumor is deemed inoperable. |

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=== **Clinical Implications** ===
- **Higher grades (I-II)** are associated with **better prognosis** but may carry a higher risk of **cranial nerve deficits**.
- **Lower grades (IV-VI)** suggest **incomplete resection**, often due to **tumor invasion into critical neurovascular structures**.
- **Adjunctive treatments**, such as **radiosurgery (Gamma Knife, CyberKnife)**, are often considered for **residual or inoperable tumors** (Grade III-VI).

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**Example Interpretation:**
- A patient with **Grade I resection** has a **complete tumor removal** and a **lower risk of recurrence**.
- A patient with **Grade IV resection** has a **high residual tumor burden**, requiring **adjuvant therapy**.

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**References:**  
- **Sindou M. et al.** "Resection of cavernous sinus meningiomas: A grading system and evaluation of surgical results." *Neurosurgery*, 2002.