**4. Case illustrations**

**Case 1.** 25 years old male presented with progressive headache. Cranial MRI showed an intraxial mass lesion in close proximity to pineal region. Patient refused biopsy and considered for gamma knife. Mass disappeared at 6th month post-SRS and didn't recur during 6 year follow ups. (Figure 2)

Fig. 2. Left: pre-SRS axial contrast enhanced MRI view. Middle: 6 months after SRS. Right: 6 years after SRS.

**Case 2.** 37 years old male presented with complete loss of vision at the right eye and progressive loss of vision on the left eye for months. MRI scan revealed an optic glioma located on the right half of the chiasm. Patient underwent low dose fractionated SRS to avoid the damage to the chiasm and optic nerve. (Figure 3) Patient was followed up 66 months following SRS, and neither tumor progression, nor visual deterioration was seen. (Figure 4)

Stereotactic Radiosurgery for Gliomas 289

Fig. 5. a) MRI scans of the patient at the time of initial diagnosis. b) Pre-SRS MRI scan of the

Although the guideline indications of SRS in the management of gliomas are not definite yet, favorable results are being reported especially for pilocytic astrocytoma and ependymoma. SRS also makes significant contributions to multimodal treatment modality of GBM as an adjuvant, as well. SRS might safely be used for carefully selected patients with low complication rates and high efficacy. Many prudential studies are also conducted in this growing field of neurosurgery. Successful results were reported for combination of SRS with agents like thalidomide, marimastat and gefitinib, hyperbaric oxygen therapy or with

patient following stereotactic biopsy, RT and temazolamide. c) 6 months after SRS;

progressive tumor is visible at the left trigon

**5. Conclusion** 

Fig. 3. Gamma knife dose planning.

Fig. 4. 39 *(left)* and 66 *(right)* months after SRS; complete disappearance of the tumor.

**Case 3.** 52 years old male presented with slight right hemiparesis, numbness and progressive headache. Multiple intracranial lesions were detected on MRI scan. Stereotactic biopsy of the tumor revealed GBM. Patient received conventional RT followed by temazolamide immediately after pathologic diagnosis. Regression in two of three tumors and progression in one tumor located at the left trigonal region was found 6 months after diagnosis. Thereupon, adjuvant SRS was performed to the progressive tumor. Nevertheless, tumor kept progressing and required decompressive resection 6 months after SRS. (Figure 5)

Fig. 4. 39 *(left)* and 66 *(right)* months after SRS; complete disappearance of the tumor.

**Case 3.** 52 years old male presented with slight right hemiparesis, numbness and progressive headache. Multiple intracranial lesions were detected on MRI scan. Stereotactic biopsy of the tumor revealed GBM. Patient received conventional RT followed by temazolamide immediately after pathologic diagnosis. Regression in two of three tumors and progression in one tumor located at the left trigonal region was found 6 months after diagnosis. Thereupon, adjuvant SRS was performed to the progressive tumor. Nevertheless, tumor kept progressing and required decompressive resection 6

Fig. 3. Gamma knife dose planning.

months after SRS. (Figure 5)

Fig. 5. a) MRI scans of the patient at the time of initial diagnosis. b) Pre-SRS MRI scan of the patient following stereotactic biopsy, RT and temazolamide. c) 6 months after SRS; progressive tumor is visible at the left trigon
