Novalis, anyone?

[womack_b]

Hi,

I was wondering if anyone has had a treatment using the Novalis system.  What did you think?  How would you rate your experience and results?

Bart

[Pascale]

Hello

I did CK in Stanford and they have the Novalis machine. It was really good and I would rate my experience a 10 out 10. It was great and I had a great team to help me. It was very comfortable too! 

Good luck!
Pascale

[ppearl214]

Hi Bart and welcome.  Good to have you here and posting.... hoping you find answers you seek.

Here in Boston, I know of the Novalis system at Brigham/Woman's Hospital. As a courtesy to my brain surgeon (who is based at B/W), I decided to meet with their Novalis team.  The radio-onc explained to me about his proposal (for me) for 30 day treatment. I told him I couldn't take that long off from work (you can go back to work after radiation same day, but for me, the commute to Boston to have it done would have put me at 30-days 1/2 day work at my office, which I could not do) and then, he noted he could cut it down to 5 days.  By doing that, I would have had a larger "hit" of radiation per day.  My concern was "total accuracy" for the beam to hit the growth.  There is some data (I believe publically noted on the Novalis website) that states they have a "total accuracy" of approx 2mm-3mm (I'd have to double check the website for the exact stat).... in checking GammaKnife and Cyberknife, both are noted to have "total accuracy" of 0.85-0.89mm.  My personal attitude at the time was.... if you are going to zap my brain, you better hit the booger.  Right or wrong, in my case, it has paid off (I had Cyberknife, stats noted in my sig line here).

Hoping those that post here that had Novalis done will chime in with their experiences. 

Again, welcome.
Phyl

[womack_b]

Pascale and Phyl,

I was glad to hear about your successful experience with Novalis, Pascale.  I am sure that Steven Chang (I hope I spelled his name correctly) was on your team - I have heard amazing things about him with the use of CK - I am glad to hear that Stanford now also has a Novalis machine.  Phyl, I am very interested in your note that the accuracy rate for Novalis seems less than CK- I will need to pay attention to that since I hear that CK precision is now down to .65mm.  Can I ask both of you what you may know about she "shaping" of the rays that the Novalis system offers - to fit the tumor shape more specifically?  I find that attractive.

Bart

[ppearl214]

Hey Bart,

glad to help. If my old age memory serves me well, Pascale had Cyberknife, not Novalis, at Stanford with Chang. Chang is top of the line and I know of many CK patients that participate on this site that will share their experiences with Stanford and Chang.  I am only aware of 6 AN CK failures overall (out of the high number that have been performed) and a woman that is on these forums is one of the 6 that just had surgery on her AN within the past 2 mos. but overall, their/his/CK success rate is very high.

I was able to find some info here.  This one is from the Novalis website that is a marketing document for patients that talks about Novalis Brain treatments and the beams:

http://www.novalis-surgery.com/download/pdf/NovalisPatient.pdf

Here is another page from their site, targeted for physcian's that does note the beam shaper, their accuracy notations and such... this is definately an interesting read:

http://www.shapedbeamsurgery.com/scripts/website_english_novalis.asp?menuDeactivate=1&articleID=2113&articleTypeID=192&pageTypeID=14&article_short_headline=Novalis%20Technology

Another member here, Mark, did pose the same question to the docs on the Cyberknife Patient Support Board and came back with this response from the docs (dated 8/27/07):

http://anausa.org/forum/index.php?topic=4124.msg44319#msg44319

"Susan,

For my money, CK is a clear choice over Novalis.

From Dr. Medbery on the CPSG site in response to a patient

Could I get some information regarding the benefits of Novalis vs. Cyberknife for a AN of approx. 1.9 cm. The last doctor I saw touted the benfits of Novalis over Cyberknife, and now I feel a bit confused!


Novalis is an accelerator based system that achieve accuracy of about 2.5 mm. We don't feel that is accurate enough for critical brain work, although it is often used that way. You have to decide for yourself whether to accept the lower accuracy (compared with 0.89 mm for CyberKnife). In other words, they could either miss 2.5 mm of tumor (13% the diameter of your tumor) or treat 2.5 mm of brainstem, cochlea, or other critical structures.

Mark"
also noting the 2.5mm as the Novalis website info I shared above.

Ok, back to work for me now! I hope this helps!
Phyl

[womack_b]

Phyl,

Thanks!  I read every site you posted.  I sure don't like hearing that Novalis has an error of 2.5mm.... and I noted from reading your suggested sites that Novalis is vague on what their accuracy is so I guess it's not enough to brag about.  I went all over their web site looking for accuracy specifications but found nothing except language stating that the delivery was very precise.  This was about all I could find:

Featuring Varian’s Trilogy linear accelerator and HD120 multi-leaf collimator—with 2.5 mm high-definition leaves—Novalis Tx delivers sharp, powerful beams that are suitable for treating deep-seated tumors while effectively reducing doses to healthy surrounding tissue.

Integrated ExacTrac® technology from BrainLAB ensures Novalis Tx targets lesions with millimeter precision.


Novalis Tx at a glance

Powerful dedicated stereotactic radiosurgery system featuring latest Trilogy linear accelerator
Finest beam-resolution in the industry via Varian HD120 multi-leaf collimator—with 2.5 mm high-definition leaves
Frameless Radiosurgery—greater patient comfort and greater flexibility for the clinician without compromising accuracy. 
High-precision target definition and delivery through BrainLAB iPlan and ExacTrac technologies
etc...

I hear that homogeniety of the radiation delivery is important (no overlapping isocenter spheres that might occur from CK or GK as they try to fill the volume of the tumor - causing lumpy radiation delivery) and that Novalis may have an advantage here that comes from their shaped beam technology.  Have you, as a veteran, heard anything about the impact or importance of this homogeniety factor? 

Bart

[ppearl214]

Hi Bart,

Glad to help... I personally have not but Mark is better versed on this that I am (I'm not a techhie type of person when it comes to radio-treatment but he is more versed on it....). Will pop him a note in hopes he can elaborate and answer your question.

Phyl

[sgerrard]

Hi Bart,

The world of radiation technology loves to chat about millimeters of precision and beam homogeneity. It is a wonderful subject area for the technically inclined.

I would suggest, though, that you might want to look at outcomes as the real measure. It all boils down to whether the treatment stops growth, and whether it has any side effects. None of the available systems are perfect. The track record for CK is very good on both scores, and I believe it tops both GK and Novalis in this respect. GK is close behind, and I think Novalis, combined with the BrainLab enhancements, is a capable system as well.

You should also note that all three systems are used for a variety of head tumors, not just ANs, and some factors apply more to other types of tumors. ANs, for instance, are not as straggly shaped as some tumors, and the beam shaping is less of a factor (I think). The question for us is how well these systems do with acoustic neuromas, not brain tumors in general.

Good luck on your quest for a PhD in acoustic neuroma radiation treatment.

Steve

[Mark]

Bart,

Regarding your question on the importance of homogeneity in radiosurgery I would direct  to the CPSG web site and pose the issue to the doctors there for a more complete answer, but here is my 2 cents:

In my view and understanding, it is certainly as important as the the issue of total accuracy and typically not a question asked by patients in choosing a machine. In a an overly simplistic view, accuracy essentially is important in understanding how much of the dose hits the target ( tumor) and how much can spill over to what extent onto adjacent healthy tissues and structures. Clearly the less that occurs the better  . Homogeneity of treatment addresses the ability to deliver a lethal level dose uniformly across the tumor. This is more of an issue that most think since most tumors are somewhat irregular in shape and not perfect spheres etc. Too little creates a "cold spot" and runs the risk that not all the cells received a lethal does and could regrow, too much creates a "hot spot" and runs the risk of too much swelling and irritation, especially if it is around one of the involved cranial nerves.

While accuracy is a function of machine,  CT scan and frame (if required) error, homogeneity is more a function of the flexibility of targeting in the machine. In that context, it would not be correct to say Novalis or GK achieve it better than CK. Both those machines have fixed beam capability and are limited to that range. CK utilizes a robotic arm which can rotate and establish a wider range of beam entry points that the other two, thus giving the computer treatment plan a better possibility of addressing irregular tumor shapes. The shaped beam is a system enhancement that improves their ability to achieve homogeneity given the other design limitations but I'm pretty sure it does not exceed what is possible in the CK technology.

Again, check it out with the docs over on the other board, but that's my understanding

Mark

[ppearl214]

thanks Mark... I'm tickled you are not as technically-challenged as I am.

[womack_b]

Phyl, Steve, and Mark,

Thanks for the info.  Yes, the Novalis system must make entry points in a single plain so the moveable couch the patient lies on becomes an important contributor to the number of entry points the machine can make.  I'm thinking that might contribute to its limited accuracy.   I hope the problems with the Novalis system can be resolved - conformality and homogeniety in zapping a tumor seem to make sense since the Choclear nerve has a better chance of surviving radiation delivery if it absorbs fewer hot spots, and greater conformality means vital healthy tissue should be less involved.  And Mark, you are right that it may not matter that much since the Cyberknife can achieve good tumor coverage and great results right now.  I get the feeling that changes are coming fast and soon a machine will combine the multiple entry angles and high accuracy of the Cyberknife along with the homogeniety and conformality of the Novalis system. 

For now, I agree that probably the most important consideration in finalizing which system to use is to look at an institution's success statistics.

Mark - I looked all over for the CPSG web site you mentioned and ultimatel decided it was the Cyberknife Support Group, right?

Thanks again to all of you, I can't tell you how much your contributions mean to me and how important your information is!

Bart

[Mark]

Bart, sorry for the acronym, yes CPSG is www.cyberknifesupport.org 

Mark

[jb]

Hi Bart,
For what it's worth, Dr. Medbery (on the "CPSG" forum) is on record as saying Novalis doesn't achieve better homogeneity than CK:

  "...although the CK used round collimators, it does not simply overlap round spots. It uses non-isocentric treatment that "paints" the dose throughout the tumor. I am quite confident that Novalis cannot get better homogeneity."  (see http://www.cyberknifesupport.org/forum/default.aspx?f=16&m=16054)

But he also points out that it's not certain that better homogeneity = better outcome.

In my case, I was treated on CK and the treatment plan was about 25% "hotter" at the center of my AN than at the margin, and my radiation oncologist seemed pretty happy with it.  I'm not sure how that would compare with other systems.

Good luck with your decision,
JB

[womack_b]

JB (and Mark),

Thanks for the site reference - I read everything there and found it very helpful.  I see that Mark was well represented and asked the questions that I certainly wanted answered.  For now it seems that Cyberknife has the strongest endorsement by patients and physicians. 

Bart

[ppearl214]

Hi Bart,

Glad you are finding the info you are looking for and that all have been able to share the "tech" details with you (one day, I'll catch up to them).

IMO... for the 1 cent that its worth... I don't believe that its all based on physician/patient endorsements..... I believe the overall success rate is the key.  Although CK has not been around as long as GK.... if you look at all radio options available.... for sole treatment of AN's... and look at the data available for overall success rates... to me, that is the key.  Granted GK has been around close to (or over) 40 yrs... .CK for approx 15 yrs, Novalis (lordy, I have no clue).... the data, regardless if long or short term, is available for their overall success rates in the treatment of AN's...so, for me, it wasn't just how physicians or patients recommended it.... but I had to look at its success rate.  To me, if the odds are high... works for me.. (and ultimately, it has!).

Again, just my 1 cents worth.

Phyl