Leksell GK Perfexion: Does it plan the whole treatment itself ?!

[suzy33]

Hi everyone,

I am wondering whether experience is essential in GK, or following international dose guidelines etc, and having a good machine like Perfexion is sufficient to achieve good outcomes ?!   Apparently Leksell GK Perfexion is fully automated. Does that mean it calculates all the dose distribution etc by itself ?!

Because I decided on GK treatment option but the team is relatively new in providing GK treatment, and they treated limitted numbers of AN patients.

Anyone has knowledge about Leksell GK treatment planning please ?! I will really appreciate your input.
Cheers

[arizonajack]

No, the machine doesn't do the calculations. People do them and then they program the machine.

I'll give you an idea of how it works by quoting my treatment report written by my radiation oncologist:

After my doctors put the frame on my head I was

"taken to the MRI scanner where postcontrast axial SPGR imaging through the area of interest was obtained. These images were transferred over the network to the gamma knife treatment planning computer where the patient's frame, pin and post positions were entered. The area of interest was identified and outlined on a slice-by-slice bases. It was called R ES." (I have no idea what that means.) "The total volume was 321.7 cubic mm. Utilizing a total of 7 shots (including 4-mm shots) with the sector blocking and differential waiting for increased conformality, a plan was derived whereby 99% of this lesion was encompassed at the 50% isodose line. The total volume of tissue receiving dose at the 50% isodose line was found to be 278.2 cubic mm. This was felt to be excellent conformity and the dose was set at 13 GY to the 50% isodose line given the clinical scenario and lack of hearing as well as volume. At the conclusion of the planning process the patient was brought to the gamma knife unit where the X, Y and Z coordinates were set and double checked prior to use. All were found achievable."

The machine might run automatically during the treatment but it does what people tell it to do.

[suzy33]

Thanks a lot for explaining all that. I checked out the GK training at Pittsburg. it is a 5 and/or 3 days course. I am wondering is this the training the new teams get ?!

What does SSD mean ?!
Your tumor was considerably small, mine is 1.6mm, but they said they would give 12 Gy.

[arizonajack]

Thanks a lot for explaining all that. I checked out the GK training at Pittsburg. it is a 5 and/or 3 days course. I am wondering is this the training the new teams get ?!

Being trained on just the machine is a lot different than the many years of training and experience that the doctors might have that enables them to use the machine.

You wrote in another post that your team has done 20 ANs in the past 2 years.

That should be long enough to get a feel for their success ratio since the patients would have likely had at least one, maybe two, follow up MRIs.

I think I would question the doctors about the initial patient conditions and the follow up results.

What does SSD mean ?!
Your tumor was considerably small, mine is 1.6mm, but they said they would give 12 Gy.

SSD means single sided deafness. It's what these "benign" tumors do even when they are small.

I was given a slightly higher dose (13 Gy) because I had no hearing left on the AN side.

12 Gy is within the normal range.

[suzy33]

Thanks Jack ! It is really a good point. I think you are quite right. I should asked them a bit more. In the initial consultation, the radiation oncologist said that they can not show any results yet, because it is not been a lot of time since started doing the treatment. But I noticed on the internet that even 6 months after the treatment you can see some sort of effect apparently ?!

It feels bad wondering about their expertise or experience, but you can't help wondering.

thanks again, I think you are quite right !!

[arizonajack]

It feels bad wondering about their expertise or experience, but you can't help wondering.

You also have to consider that your team members have plenty of experience in surgery long before they started GK.

You can google them individually for more comprehensive information about the doctors. I found the following about Dr John Fuller:

Clinical Senior Lecturer, Australian School of Advanced Medicine, Macquarie University
Neurosurgical Director, Gamma Knife Surgery Program, Macquarie University Hospital
Consultant Neurosurgeon, Macquarie University Hospital
Consultant Neurosurgeon, National Capital Private Hospital
Consultant Neurosurgeon, Gosford Private Hospital
 
Dr Fuller graduated from the University of New South Wales in 1987. He undertook neurosurgical training in Sydney at the Prince of Wales, Sydney Childrens and Royal Prince Alfred Hospitals obtaining his RACS Fellowship in Neurosurgery in 1996. Since obtaining his fellowship he has been practicing in Canberra managing all aspects of cerebral, spinal and peripheral nerve surgery.
 
A strong involvement with neurosurgical education has been maintained by his position on the RACS Board of Neurosurgery and the Board of the Neurosurgical Society of Australasia for the past 10 years. He has been directly involved with neurosurgical training of the Royal Australasian College of Surgeons as a consultant and Clinical Director of Neurosurgery at The Canberra Hospital. Medical student teaching has been through the postgraduate medical schools the University of Sydney and subsequently the Australian National University.
 
Dr Fuller has joined Macquarie Neurosurgery to combine his sub-specialty interest in surgical neuro-oncology with radiosurgery as Neurosurgical Director of the Gamma Knife Surgery Program. This is in addition to maintaining his expertise in complex spinal surgery, including spinal oncology.
 
He is a member of the Neurosurgical Society of Australasia and the Royal Australasian College of Surgeons

Also found the following article:

http://www.genesiscare.com.au/Portals/0/Announcements/First%20Gamma%20Knife%20Treatment%20-%20Macquarie%20University%20Hospital.pdf

Impressive.

I think I already suggested that you join ANAA (Acoustic Neuroma Association Australia).

http://www.anaa.org.au/

That'll give you the opportunity to communicate with other Australian AN patients, some of whom are likely to already have been treated with GK at MUH.

[PaulW]

Feedback on GK at MUH has been excellent.

[suzy33]

Thanks Jack and Paul,

Yes, it is true they have all their previous knowledge and experience. thanks for all that information you found and posted, much appreciated.
I joined ANAA and spoke to a person yesterday who had GK at MUH almost 2 years ago, and she said a year later they could see the tumor got slightly smaller, she will have the next MRI in two weeks time. It was reassuring to speak with someone-she did not have any complications either.

If I remember right, you live in Australia Paul?! But you had CK, and it appears you are doing well, which is excellent. You said feedback on MUH GK has been excellent, you must have heard about them. This is also reassuring, thanks for telling me. Where abouts you are living in Australia?

[nftwoed]

   Gee; And I wrote and told my Neurotologist it was Accuray Perfexion and suggested it was much smarter than the head of the GK unit!  ; )

[arizonajack]

   Gee; And I wrote and told my Neurotologist it was Accuray Perfexion and suggested it was much smarter than the head of the GK unit!  ; )

The machine is not a HAL 9000 (thankfully). It's only as good as the people who program it.

[nftwoed]

Hi;

   There's something that bugs me about Oncologists ( cancer specialists of the entire body ) working w/o AN specialists ( Neurotologists ) .