APRIL, 2020 | THE HEALTH
| Issue |
Gamma
Knife
treatment
gaining
popularity
There has been
increased demand
for Gamma Knife
stereotactic
radiosurgery
BY KIRTINI K. KUMARAN
A
T UNIVERSITI Kebangsaan
Malaysia Specialist Centre
(UKMSC) alone, more than
30 patients have undergone
treatment since November
last year.
Although relatively new
in Malaysia, its popularity
around the world is telling. In 2017,
there were 1,124,000 patients treated
with Gamma Knife worldwide. A total
of 415 Gamma Knife machines have
been installed worldwide (see table).
In Malaysia, there are currently three
Gamma Knife machines.
Gamma Knife stereotactic
radiosurgery is a non-invasive
neurosurgical treatment with
high-intensity radiation. The precise
beam of radiation attacks tumours
and abnormalities, shrinking them
overtime or stopping their growth.
UKMSC houses the state-of-the-art
stereotactic radiosurgery (SRS) machine,
the Leksell Gamma Knife Icon. Gamma
Knife treatment in UKMSC is carried out
within its own Gamma Knife Centre. It is
one of the few services in the world that
has a building dedicated to it. The Centre
off ers a full complement of specialists
such as neurosurgeons, oncologists,
radiotherapists and physicists.
Since its soft launch in November
2019, the UKMSC Gamma Knife Centre
has treated patients with various
brain problems such as arteriovenous
malformations (AVM), cavernoma,
meningioma, vestibular schwannoma,
pituitary tumours, metastatic tumour,
trigeminal neuralgia and epilepsy.
The Health spoke with Assoc
Prof Dr Ramesh Kumar, Neurosurgeon
at UKMSC, on the benefi ts of this form
of treatment.
What is Gamma Knife radiosurgery?
Gamma Knife is a form of stereotactic
radiosurgery. Stereotactic refers to the
use of a three-dimensional coordinate
system (X, Y and Z coordinates) via a
head frame to locate a target in the
brain. Radiosurgery is the use of focused
radiation to treat abnormalities in the
Prof Dr Ramesh
Kumar,
Neurosurgeon
at UKMSC.
brain. We need to acknowledge the
work of Lars Leksell, who was a Swedish
neurosurgeon and the founder of
radiosurgery and the Gamma Knife.
Despite its name, the procedure does
not involve a surgical incision into the
brain. Also, the “blades” of the gamma
“knife” actually focuses on gamma ray
radiation. Here at the UKMSC Gamma
Knife, we call it the ‘virtual scalpel”.
Also referred to as “surgery without a
scalpel”, the Gamma Knife procedure
does not require the surgeon to make an
incision in the scalp, nor an opening in
the skull.
How diff erent is the Gamma Knife
procedure today compared to when
it was introduced during the UKMSC
groundbreaking ceremony in
February 2017?
There is no diff erence in the procedure
today compared to 2017. In 2015, Elekta
launched the Gamma Knife Icon. To
date, it remains the latest model. One
of the advantages of Gamma Knife
Icon is that it allows us to treat larger
lesions using fractionation (multiple
sessions). Traditionally, Gamma Knife
radiosurgery was performed in a single
session, and this was limited to a size of
3 cm. However, with fractionation we
are now able to treat larger lesions. It
also allows us to treat tumours that are
situated close to critical structures. The
other advantage of the Icon is that it
allows us to treat brain lesions without
a frame. This is done via a thermoplastic
mask and the use of CT scanner in the
Gamma Knife Icon.
What are the advantages of
Gamma Knife?
• No surgery or general anaesthesia is
required
• It is painless
• Can be done as a day case
• Fewer side eff ects compared
with traditional whole-brain
radiotherapy
• Eff ective alternative treatment
for inoperable cases or paediatric
patients
• Shorter recovery time. Most patients
are back to work the next day
• We can treat multiple lesions
The radiosurgery treatment centre
benefi ts especially those who have
abnormal lesions, cancerous and
non-cancerous tumours. What is the
success rate with these conditions?
The conditions treated with Gamma
Knife can be divided into four headings:-
• Vascular disorders (blood vessel
problems)
• Non-cancerous (benign growth/
non-malignant)
• Cancerous growth (malignant)
• Functional
The tumour control rate is more
than 90% for meningioma, 93-100 per
cent for vestibular schwannoma with
hearing preserved in 60-90 per cent is
reported. The tumour control rate of 93
per cent is for pituitary adenomas; 90
per cent obliteration of AVM’s within
three years; 75 per cent of patients
achieved or maintained pain control
at three years, and 59 per cent had pain
relief at three years for facial pain.
In the UKMSC Gamma Knife Centre,
we have treated patients with AVM,
cavernoma, meningioma, vestibular
schwannoma, pituitary tumours,
metastatic tumours, trigeminal
neuralgia and epilepsy.
What is involved in a typical Gamma
Knife treatment?
At our Gamma Knife Centre, local
anaesthetic is used to secure a head
frame to the patient’s head. The frame
is used in conjunction with an imaging
procedure to locate the target accurately.
With the frame in place, the patient
undergoes an MRI or CT scan or in the
case of AVM, angiography, to locate
lesions in the brain. Using the imaging
procedure, our treating team can defi ne
the position of the lesions inside the
patient’s head.
Gamma Knife installations worldwide
Country
North America
Asia (Malaysia: 3)
Europe
Japan
South Korea
South America
Taiwan
Middle East
Australia
Total
Number of installations
126
126
61
54
21
11
8
6
2
415
While the patient rests, the
treatment team (which comprises
neurosurgeons, radiation oncologists
and physicists) uses a computer to
devise a treatment plan. This takes from
30 to 90 minutes to complete, depending
on the geometry and location of the
target. When the individual treatment
plan is completed, the patient lies on the
Gamma Knife couch so that their head is
precisely positioned for treatment. The
patient is then moved automatically
into the machine and treatment begins.
Treatment typically lasts from 20
minutes to two hours, during which
time the patient feels nothing.
How long does it take to perform
Gamma Knife radiosurgery?
At our Gamma Knife Centre and
in most centres, the treatment is
typically completed in a single-day
with patients arriving in the morning
and able to return home later in the
day. Occasionally patients may need
treatment delivered over a few days
(fractionation).
Is Gamma Knife safe?
Yes, if it’s done correctly.
What does the patient feel during
Gamma Knife treatment and after
treatment?
There might be mild pain from the
administration of the local anaesthetic
used during placement of the head
frame. Patients have reported that they
feel a pressure sensation when the
frame is applied, but not pain. Some
patients do complain of mild headaches
and dizziness after treatment.
How quickly do you see results?
These eff ects of Gamma Knife
radiosurgery occur over a period that
can range from several weeks to several
years, depending on the condition being
treated.
Can Gamma knife be given more than
once?
Yes
Can the Gamma Knife be used for
cranial artery blockage?
I am not aware of Gamma Knife treating
cranial artery blockages. However,
research is ongoing to see if it can be.
Gamma Knife can treat aneurysms.
How would I know if Gamma Knife is
an option for me?
Consult a neurosurgeon or oncologist
at a centre that has the Gamma Knife
service. — The Health
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