Neurosurgery Department Shuang Ho Hospital

New Taipei City, Taiwan

Wei-Lun Lo, M.D.

THE APPLICATION OF

PERFEXION GAMMA KNIFE

RADIOSURGERY

FOR INFRA-SKULL BASE LESIONS

TECHNICAL LIMIT OF GKS

Traditional lower limit of treatment related to lesion

locations: Foramen mangnum

Kondziolka et al: Radiosurgery of meningiomas. Neurosurg Clin N Am 3:219–230,

1992

However, the data from new Perfexion version was not

included.

J Craniovertebr Junction Spine. 2010 Jan-Jun; 1(1): 23-28

• Primary lesion at

neck

• Extracranial

↑↓

Intracranial

POSTING DIFFICULTY FOR GKS

COMPARISON OF GK SYSTEMS

CASE DISTRIBUTION (N = 14)

Meningioma

Paraganglioma

Low brain stem cavernoma

Trigeminal neuroma

Low cranial nerve

neuroma

Skull base metastasis

Dural arteriovenous

fistula

3

4

1

3

Paraganglioma

39 y/o female

horseness and dysphonia; paraganglioma from posterior fossa with extension to neck region s/p partial resection by ENT doctor

2013/10/15

TV: 18.32014/4/22

TV: 7

Volume: 18.3c.c.

RV: 23.5c.c.

PD: 12.5 Gy

MD: 22.3 Gy

ID: 56%

Mean dose: 16.7 Gy

Foramen Mangnum

Meningioma

37 year-old female

Meningiomatosis inpetroclival, foramen magnum , and ventral C5 regions

s/p surgical excision of C5 meningioma

2013/8/23

TV: 1.2

2014/2/24

TV: 1.2

Volume: 1.2 c.c.

RV: 3.3 c.c.

PD: 12 Gy

MD: 21.8 Gy

ID: 55%

Mean dose: 16.6 Gy

Skull Base

Metastasis

74 year-old female

Hx of breast cancer

s/p operation; facial

numbness, difficult

swallowing, tongue

atrophy

2013/7/11

TV: 27.2

2014/7/24

TV: 3.5

Marked regression

Improvement of tongue atrophy

& swallowing function

Volume: 27.2 c.c.

RV: 35.2 c.c.

PD: 12.8 Gy

MD: 24.6 Gy

ID: 52%

Mean dose: 17.5 Gy

PRELIMINARY RESULT

Tumor

• Tumor shrinkage, stationary, or loss of central

enhancement in all cases

Vascular lesion

• No interval hemorrhage in follow up period

MOTION ERROR

J Neurosurg (Suppl) 117: 211-216, 2012

Cervical

Immobilization !!

GKS FOR EXTRACRANIAL LESION:

CAROTID BODY TUMOR

C2

C3

PRE-TREATMENT MANAGEMENT

Cervical immobilizationFeasibility evaluation

TV: 3.2 c.c.

Radiation volume: 4.8 c.c.

Peripheral dose: 15.5 Gy

Maximum dose: 28.2 Gy

Isodose level at periphery: 55%

Mean dose: 22.4 Gy

THANKS FOR ATTENTION