Preliminary results after multisession gamma knife radiosurgery for perioptic meningiomas.Keywords: meningioma, outcome, gamma knife, fractionated stereotactic radiotherapy, visionInteractive Manuscript
Ask Questions of this Manuscript:
What is the background behind your study?
Parasellar meningiomas create challenges for vision and neurologic function.
What is the purpose of your study?
Our purpose was to evaluate the effectiveness and safety of a Gamma Knife treatment in
three consecutive days (multisession) in patients with parasellar
meningioma in close contact to the optic nerve and chiasm.
Describe your patient group.
Between January 2006 and September 2010 49 patients (41 females, 8
males, mean age 57 years) underwent multisession gamma knife treatment
at San Raffaele Hospital for a meningioma in close contact to the optic
nerve and chiasm. Five patients have been treated for optic nerve
meningioma, 44 for a parasellar meningioma.
Describe what you did.
Preoperative decreased visual acuity or visual fields defect was found in 28 patients. Gamma Knife radiosurgery was delivered in three sessions with a mean prescription isodose of 6.8 Gy per session (range 6.5-7 Gy) and a mean total prescription isodose of 20.7 Gy (range 19.5-21 Gy). Mean tumor volume was 8.8 ml (median 7.6, range 0.33-34.2). Maximum dose to the optic apparatus was always below 7 Gy for each session (mean 5 Gy).
Describe your main findings.
Median follow-up was 29.5 months (range 6-57). Overall tumor control rate was 100%. Tumor volumetric reduction was observed in 33 patients (67%), whereas in 16 patients (33%) no volumetric change was recorded. No patient experienced worsening of visual function, in 5 patients (10%) visual acuity improved after treatment; visual field improvement occurred in 4 patients (8%). Cranial nerve function improvement was recorded in 2 patients (4%); one patient experienced VI cranial nerve paresis (2%).
Describe the main limitation of this study.
This was a retrospective series.
Describe your main conclusion.
This preliminary experience suggests that multisession radiosurgery with Gamma Knife can be a safe and effective treatment for tumors immediately adjacent to segments of the optic apparatus.
Describe the importance of your findings and how they can be used by others.
These findings should be validated by other centers.
Parasellar meningiomas create challenges for vision and neurologic function.
Our purpose was to evaluate the effectiveness and safety of a Gamma Knife treatment in
three consecutive days (multisession) in patients with parasellar
meningioma in close contact to the optic nerve and chiasm.
Between January 2006 and September 2010 49 patients (41 females, 8
males, mean age 57 years) underwent multisession gamma knife treatment
at San Raffaele Hospital for a meningioma in close contact to the optic
nerve and chiasm. Five patients have been treated for optic nerve
meningioma, 44 for a parasellar meningioma.
Preoperative decreased visual acuity or visual fields defect was found in 28 patients. Gamma Knife radiosurgery was delivered in three sessions with a mean prescription isodose of 6.8 Gy per session (range 6.5-7 Gy) and a mean total prescription isodose of 20.7 Gy (range 19.5-21 Gy). Mean tumor volume was 8.8 ml (median 7.6, range 0.33-34.2). Maximum dose to the optic apparatus was always below 7 Gy for each session (mean 5 Gy).
Median follow-up was 29.5 months (range 6-57). Overall tumor control rate was 100%. Tumor volumetric reduction was observed in 33 patients (67%), whereas in 16 patients (33%) no volumetric change was recorded. No patient experienced worsening of visual function, in 5 patients (10%) visual acuity improved after treatment; visual field improvement occurred in 4 patients (8%). Cranial nerve function improvement was recorded in 2 patients (4%); one patient experienced VI cranial nerve paresis (2%).
This was a retrospective series.
This preliminary experience suggests that multisession radiosurgery with Gamma Knife can be a safe and effective treatment for tumors immediately adjacent to segments of the optic apparatus.
These findings should be validated by other centers.
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