Clin Oncol | Volume 6, Issue 1 | Research Article | Open Access

Stereotactic Gamma Knife Surgery in the Management of Deep-Seated Pilocytic Astrocytomas: Long-Term Outcomes

Raef FA Hafez*, Magad S Morgan, Osama M Fahmy, Yasser Omar Riyad, Wael K Zakaria and Hamdy T Hassan

Department of Neurosurgery and Gamma Knife Center, International Medical Center (IMC), Egypt

*Correspondance to: Raef FA Hafez 

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Background: While complete surgical extirpation of pilocytic astrocytoma is usually curative, however when these tumors are deeply-seated gross total resection is ill-advised because of the high morbidities.
Objective: This study aims to evaluate the outcomes of gamma knife surgery in the management of symptomatic residual and recurrent deep-seated pilocytic astrocytomas.
Patients and Methods: This study included 14 consecutive patients with residual or recurrent solid and mixed PAs treated at the International Medical Center-Gamma knife center- Cairo Egypt, from 2003 till the end of 2017. The mean follow-up period was 60 months (range 24 to 180). Five patients had solid tumors only and 9 had mixed tumor types. The mean treated solid tumor or mural nodule volume is 2 cc, the mean peripheral prescription dose is 11.7 Gy and the mean maximum dose is 28 Gy.
Results: At last follow-up, 11 patients (78.6%) achieved tumor growth control and three patients reported having a progression of the whole tumor. The actuarial tumor Progression-Free Survival (PFS) at 2, 3, 5 and 10 years is 76.9%, 72.7%, 71%, and 60% respectively. The tumor control rate with a mixed type tumor is 77.7% and is 80% for solid tumor type.
Conclusion: This series demonstrates and supports the favorable GKS long-term outcomes in the management of symptomatic critically located deep-seated residual and recurrent PAs<3 cm in maximum diameters after targeting the solid tumor or mural nodule rather than the entire cystic, allowing for better coverage of the nidus with the maximum radiation dose and consequently tumor growth control.


Astrocytoma; Gamma knife surgery; Pilocytic astrocytoma; Stereotactic radiosurgery


Hafez RFA, Morgan MS, Fahmy OM, Riyad YO, Zakaria WK, Hassan HT. Stereotactic Gamma Knife Surgery in the Management of Deep-Seated Pilocytic Astrocytomas: Long-Term Outcomes. Clin Oncol. 2021;6:1856..

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