Gamma Knife Radiosurgery A tool for treating intracranial conditions CNSA Annual Congress 2016 Radiation Oncology Pre-congress Workshop ANGELA McBEAN Gamma Knife CNC State-wide Care Coordinator Gamma Knife Centre of QLD Princess Alexandra Hospital
- Overview of Stereotactic Radiosurgery (SRS) - What is Gamma Knife?? How does it differ from other SRS The stereotactic head frame & nursing management Clinical indications Purpose - The Gamma Knife Centre of QLD (GKCoQ) - Use of Gamma Knife in the management of Brain Metastases
Stereotactic = Precision - 3D co-ordinate system - Enables precise localisation - Particularly useful in brain Small lesions Adjacent critical structures Radiosurgery - Destruction/ablation of tissue - Single high dose 15-24 Gy - Fundamentally different from radiotherapy Radiosurgery is surgery using radiation, that is, the destruction of precisely selected areas of tissue using ionizing radiation rather than excision with a blade.
Stereotactic Machines Linac based SRS Cyber Knife
Gamma Knife Intracranial Radiosurgery unit
Advantages of Gamma Knife Accuracy - Gold standard for radiosurgery - delivery accuracy <0.2-0.4mm Rapid dose fall off - Less dose to adjacent normal/critical tissue - low treatment morbidity Workflow efficiency & time treating patients - Pt seen, planned & treated in one day - Can treat multiple targets in single session - reduction in inpatient stay > mean 9 days surgery vs 1 day Gamma Knife Requires multidisciplinary input Neurosurgeon Radiation Oncologist Medical Physicists Radiation Therapists Nursing
Day of treatment processes & nursing management Leksell Coordinate G frame & CT localization box Frame placed using local anaesthetic, with oral sedation pre-med Nursing staff provide emotional comfort to patient & assist Neurosurgeon with procedure Most discomfort to patient experienced during frame fitting > lasts 4-5 minutes head frame application > MRI & CT > Gamma Plan > treatment delivered
Clinical indications for Gamma Knife Radiosurgery Conditions we treat: Brain mets Glioma Malignant/Atypical meningioma Benign meningioma Pituitary tumours Acoustic Neuroma Haemangiopericytoma Cavernomas Ateriovenous Malformation (AVM) Trigeminal neuralgia
GKCoQ Service Detail State-wide service Based at PAH 1 st public Gamma Knife service in Australia Do receive referrals from interstate Multidisciplinary team approach Neurosurgeons, Radiation Oncologists, Radiation Therapists, Medical Physicists, Nursing and Allied Health staff. Weekly Multidisciplinary Meeting (10:00 11:00 Thursday) Dial in facilities (regional) Welcome attendance (metropolitan) Weekly MDT Clinic (Wednesday 10:00-12:00) Held on site PAH Telehealth service for regional and remote patients (UQ Centre for Online Health) Treatment Day - Single treatment delivered in Outpatient setting - Frame attachment Planning CT Planning MRI Treatment Plan Treatment
Service to Date: 26/10/15 06/05/16 1 12 Malignant 18 4 2 3 2 55 Benign 6 5 TOTAL 108 GLIOMA MELANOMA LUNG BREAST CRC RCC OVARIAN TUMOUR FUNCTIONAL VASCULAR
Go Live: 24 th October 2015
100 th Patient Treatment: 26 th April 2016
Significance of Brain Metastases (BMs) Clinical context: Patients living longer with advanced disease Brain metastases very common> 20-40% of cancer population will develop BMs Many systemic agents have variable CNS penetration Consequences of uncontrolled disease Radiosurgery provides good local control (80%) Equal/better than surgery OS remains poor (6 months)
Historical Perspective WBRT Nihilistic approach WBRT 30Gy in 10# 20Gy in 5# Intention (palliative) and doses not for durable control Cognitive deficits & associated poor QOL
Gamma Knife for management of BMs Equivalent local control to surgery Low morbidity particularly for multiple lesions For single lesion improves overall survival For 1-4 lesions improves neurologic function May avoid neurocognitive effects of whole brain radiotherapy
METASTATIC DISEASE: Patient Selection Criteria Who is referred? Newly diagnosed brain mets Patients with recurrence > previous WBRT or SRS or GK Post op for consideration of cavity boost Complex cases Radiology opinions after treatment> 3/12 f/u post treatment Inclusion criteria: Solid malignancy confirmed histologically or radiologically All patients with a single brain metastasis 5cm Patients with 2-5 brain metastases for consideration of local therapy ECOG 0-2 Controlled or controllable extra-cranial disease, prognosis >6/12 Complex cases requiring advice regarding sequencing or selection of treatment modalities Advice on radiology after local therapy Old patients for consideration of further local therapy at recurrence
CASE STUDY Diagnosis: Metastatic Melanoma History: August 2015> WLE Melanoma L) shoulder & Axillary dissection > T3N2MO November 2016> Staging CT HCAP prior to commencing Pembrolizimab > 2 x intracranial lesions identified Nov/Dec 2015> MRI confirmed Referred for consideration of Gamma Knife Gamma Knife : both lesions less than 3cm in diameter controllable extra cranial disease > for Pembro post GK Patient otherwise fit and healthy
Pre & Post Treatment MRI
QUESTIONS/COMMENTS???
REFERENCES Gamma Knife Surgery. [online] Irsa.org. Available at: <http://www.irsa.org/gamma_knife.html> [Accessed 13 January 2016]. Lee, C., Lee, S., Cho, J., Yang, K. and Kim, S., 2011. Therapeutic Effect of Gamma Knife Radiosurgery for Multiple Brain Metastases. J Korean Neurosurg Soc, 50(3), p.179. Lippitz, B., 2008. Treatment of Brain Metastases Using Gamma Knife Radiosurgery The Gold Standard. European Neurological Review, 3(1), p.81. Team, E., 2016. Leksell Gamma Knife Perfexion. [online] Elekta AB. Available at: <https://www.elekta.com/radiosurgery/leksell-gamma-knife-perfexion.html> [Accessed 13 January 2016].
ANGELA MCBEAN GAMMA KNIFE CNC STATE-WIDE CARE COORDINATOR (07) 3176 1908 angela.mcbean@health.qld.gov.au