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CyberKnife, basic questions
hopeful and optimistic
Posted: Sunday, July 22, 2012 2:00 PM
Joined: 7/9/2012
Posts: 11


Dual Post ... CyberKnife.com and CSN.cancer.org My friend has just been diagnosed with intermediate low level PCa 3+4=7, 0.2 involvement, one of twelve cores positive,(confirmed by an expert second opinion), had a rising PSA, high PCA3, MRI with Tesla 3.0 shows various suspicious lesions, one at 2.0 CM. No extracapsular extension. MRI indicates a 104 enlarged prostate size while the biopsy comes out at 75. He has some trouble with urnination. Right now he is taking flowmax. He had a quad bypass surgery in the nineties, he has some heart irregularity. He will be 71 in October. He is exploring surgery, cyberknife, and other radiation such as tomo therapy. Some radiation treatments such as bracky are not acceptable because of his large prostate size. (As a man who is currently being treated with "Active Surveillance with Delayed Treatment" I am also very interested in reading of any inputs...........THANK YOU VERY MUCH) Some questions now aboutCyberKnife Radiosurgery for Prostate Cancer: What are the advantages and disadvantages of CyberKnife over Novalis, if any? What are advantage and disadvantages of Novalis over CyberKnife, if any? Bsically will Novalis do the same job as Cyberknife in delivering the the radiation. What is an IRIS Variable Collimator? How is this used, what are the benefits? What is a LINAC? Please talk about a fused MRI in planning planning a CT scan., as opposed to a CT Scan only used at Stanford? What generation CyberKnife and Novalis machines are most up to date? Are the above mentioned equipment automated in these late model machines. How does his current urinary problems need to be treated if he selects CyberKnife. Is a single modality of treatment appropriate, or would some kind of homone treatment appropriate. What is the ideal total dose of Gy that needs to be delivered in 5 fractions, every other day.( I hope that I am using the right terminology). What are the effects on erectile function preservation rate(what are the rates?) Grade 3+ Late Urinary Toxicity; and Late Bowel Toxicity, and PSA Freedom from Relapse? What margin is recommended for him, would close, I think 1mm be appropriate or is a wider one a better choice? Not being a health care professional or very knowledgeable about cyberknife radiation delivery, I tried to think of everything important, however is there anything that you can think of that will be important for us to know? Thank you very much.
ChicoXXX
Posted: Sunday, July 22, 2012 4:24 PM
Joined: 10/10/2008
Posts: 366


Hopeful and opptimistic

Re:""Not being a health care professional or very knowledgeable about cyberknife radiation delivery, I tried to think of everything important, however is there anything that you can think of that will be important for us to know?""

 

I  also,  am not a healthcare professional and realize that you have a lot of valid concerns. I would suggest that you begin to look through  the 12 pages of Topics in the Postate Section of the Cyberknife forum.. That would cover approximately 600 topics. I am sure that if you have a sincere interest in getting answers, it will be worth you while to attempt your research in the topics of the forum since many of them have been discussed in individual topics.

 

While others who contribute to this forum are much more qualified than I to answer parts of your questions, doing justice to all of your questions would, in my opinion, require something akin to a PHd Thessis on Cancer Treatment Comparisons or extensive, fee paid, consultations from a urologist/oncologist team dealing speficifally with one patient.

 

You have listed many valid concerns that I suspect have been indiviually listed , and discussed in a lot of detail in individual topics in the Prostate Section of this forum.  I believe an extensvie review  of the Prostate Forum would help you break down your topic into individual questions that might have already been covered in great detail.   The type of questions that  you pose, regarding the various types of  treatments  should probably be answered by the prospective candidate's  Medical Professional Team who woud know "all the risks involved relating to specific patient 

 ""My friend has just been diagnosed with intermediate low level PCa 3+4=7, 0.2 involvement, one of twelve cores positive,(confirmed by an expert second opinion), had a rising PSA, high PCA3, MRI with Tesla 3.0 shows various suspicious lesions, one at 2.0 CM. No extracapsular extension. MRI indicates a 104 enlarged prostate size while the biopsy comes out at 75. He has some trouble with urnination. Right now he is taking flowmax. He had a quad bypass surgery in the nineties, he has some heart irregularity."""

I think that Google, would be a good place to start to find answers to :

 

"""What are the advantages and disadvantages of CyberKnife over Novalis, if any? What are advantage and disadvantages of Novalis over CyberKnife, if any? Bsically will Novalis do the same job as Cyberknife in delivering the the radiation. What is an IRIS Variable Collimator? How is this used, what are the benefits? What is a LINAC? Please talk about a fused MRI in planning planning a CT scan., as opposed to a CT Scan only used at Stanford? What generation CyberKnife and Novalis machines are most up to date? """

While there are a number of researchers and "posties" who have gone into great detail in some of the topics, which include references and links to volumes of studies that might provide some information to questions you have posed, I am not sure that they could be adequately covered in an attempt to answer all of your questions in one topic.

 

I apologize for my inadequate response and hope that someone else will provide a better answer to you complex set of questions.


JAV
Posted: Sunday, July 22, 2012 5:16 PM
Joined: 10/29/2010
Posts: 602


H&O : Good questions !! I Googled "Novalis" and from what I have found, Novalis, I believe refers to a "family" of stereotactic radiosurgery systems. It looks like their machine that is used for CaP is the RapidArc machine. If this is true, Allen, who is a regular on this forum can tell you all about the RapidArc machine - it knows his prostate intimately. Cyberknife refers to the machine produced by Accuray that is a very versatile machine that is used to treat various tumors and some other conditions, including CaP. Both machines use a Linear Accelerator (LINAC) to produce a beam of 6 MeV photons - the radiation used to kill the nasty CaP. Both machines track the position of the prostate capsule, but in a slightly different manner. The CK machine uses two built in X-Ray machines. The Rapid Arc, I believe uses a CTScanner. The CK machine keeps tract of the capsule more often than the Rapid Arc machine does, and it is debatable if the CK machine is superior in this regard. The CK machine has the LINAC mounted on a robotic arm. The LINAC in the RA machine can swing in an arc only. The robotic arm is much more maneuverable, without a doubt. The IRIS is a type of collimator - a device that is used to vary the size of the photon beams. A multileaf collimator (MLC) does about the same thing, but may be more versatile. We are still looking for an answer to that question. Both machines, because of the tracking of the position of the prostate, can be used to deliver a higher dose of radiation compared to standard radiation treatments (IMRT). So fewer, but higher dose treatments are just as or more effective because of the believed higher alpha/beta ratio of CaP. This is called hypo-fractionization. So better results with lower side effects can result. The biomedical equivalent dose is just as high or even higher compared to IMRT (treatments that last 5 days a week, for 6-7 weeks) JAV ( not a MD, DO, PhD, or Radiation Physicist)
Allen_E.
Posted: Sunday, July 22, 2012 10:06 PM
Joined: 8/8/2010
Posts: 511


If you haven't seen his website yet, Dr Katz's website is a great resource and may answer many of your questions. The 2 cm lesion is pretty big -- was that sampled by the biopsy? It might be a large calcification. LOL@"it knows his prostate intimately." I don't know what I can add to JAV's very good response (except that he always gets the alpha/beta thing backwards ) I'll just confirm what JAV said. The key thing is that it's hypofractionated (4-5 fractions or treatments) and that it's stereotactic (beams coming from different directions converging on the prostate) and that it's delivered by a machine capable of depositing that intense dose of radiation exactly where it's needed and not where it isn't. RapidArc, Truebeam, CyberKnife, Elektra, etc. are all machines that can do the job well. All of those machines can be used to deliver radiation in the old normal fractionated way too. But once you agree that prostate cancer is killed better by more intense dosing (low alpha/beta), you would only want that. There are also a number of good systems for tracking intrafractional motion during treatment. Some of the advantages of one delivery system over another have a lot to do with speed. Each treatment I had took only about 5 minutes. The new CyberKnife VSI machines are faster than the old ones, and Truebeam is even faster than RapidArc. You can argue the fine points of conformality and homogeneity, but they are really just fine points, imho -- it's the results they give you that matter most. Most importantly, does it deliver no more and no less than the full dose to the prostate. The other major point is the dose-volume histogram to organs at risk; i.e., how much of the rectum and bladder are exposed to significant doses of radiation. That's a matter of good machines, but also of good planning by good doctors. I think that and Dr. Katz's website answers most of your questions. Others: Fused CT/MRI gives the best of both, I think. The more precise the image, the better the plan. However, some docs use one or the other. Dose: They all use something in the range of 35-40 Gy, which is biologically equivalent to the cancer-killing power of 85-114 Gy if it were delivered the way most IMRT is: 80 Gy delivered in 40 doses of 2 Gy, assuming an alpha/beta=1.5. This gives you a feel for the power of hypo-fractionation -- only half the amount of radiation delivered to the body with up to 42% more cancer-killing power. Dr. Katz, who practices his Hypo-cratic [sic] Oath to "do no harm," uses 35 Gy (7 Gy in 5 fractions), and gets great results with minimal toxicity. Dr. Fuller uses 37 Gy=9.25 Gy x 4 fractions in his "heterogeneous" protocol. Dr. King gives 40 Gy= 8 Gy x 5 fractions. Most CK docs give 36.25 Gy = 7.25 Gy x 5 fx. Which is best? They all get great results with low toxicity, and I'm sure they each feel strongly about why theirs is better than the others. Hormones: Unlike IMRT, I've never seen results for CyberKnife that said hormone therapy improved results. Dr Katz even did a study on that which is posted on his site. That said, your friend has one huge double-whopper-sized prostate, and I would think that shrinking it for a few months with some hormones might improve his treatment plan as well as giving him lots of relief from urinary issues from which he suffers. The radiation treatment causes acute swelling that may give him problems with his already enlarged prostate. This is a good thing to discuss with his RO and Urologist. I may be wrong, but I don't think a lot of surgeons would operate on him given his previous heart problems.
- Allen (not an MD)
viperfred
Posted: Monday, July 23, 2012 12:52 AM
Joined: 10/10/2008
Posts: 778



Good questions!

Radiation (ionizing) therapy can be very confusing.

The unit of measure is Gy for the total dose and dose per session.

Several ways to look a this therapy, one is dose per session/fraction, high or low dose.  Published literature suggest Prostate cancer has improved biological control(cure) with higher dose.

High dose radiation also called extreme hypo fractionation has been used for over 30 years (HDR Brachytherapy, a surgical procedure requiring anesthesia while a robot places radioactive material in capillaries  that are inserted in the prostate ) with very high biological control (mid to high 90%).  The Cyberknife (first US patient treated in Dec. 2003 at Stanford) delivers a similar dose however the procedure uses an external beam without anesthesia or surgical procedure.  The Cyberknife total dose ranges from 35 to 38 Gy.          

Low dose radiation Brachytherapy-permanent seeds.  And external beam typically 1.8 Gy / session,  (in the past called 2D RT, 3D RT) called IMRT or IGRT.  The total dose has increased from approx 50 Gy 30 years ago to 80 or more Gy today.

The treatment is achieved by aiming beams at the target (tumor), as the beams converge a higher dose is generated.  The region of converged dose is called the dose plan and is very important for biological control and toxicity which results in side effects.   Patients can discuss their plan and options (margins,  high dose regions targeting specific area of interest, etc.) with their radiation oncologist to better understand the treatment
 
Imaging is critical because that is how the target is defined and the prescribed dose volume and margins defined.  A digital merge of CT and MRI improves the definition of prostate and surrounding critical structures.  Imaging is improving constantly which I would expect to improve planning and patient outcome.

There are always risk and no therapy is 100% effective.

Good Luck and keep asking questions.

Fred

Not a MD

Cyberknife treatment completed May 2008 for PCa  


JAV
Posted: Monday, July 23, 2012 5:21 AM
Joined: 10/29/2010
Posts: 602


Thanks, Allen. I stand corrected (again). Yes, the alpha/beta ratio of CaP is believed to be lower than other cancer cells and normal tissue. So the interesting ramification of this is a delivered total hypofractionated dose of about 35 Gy results in a biological equivalent dose of at least 80 Gy !! Very good for CK, Rapid Arc, and other non-standard (IMRT) patients. BTW, I had my 5 treatments done every other day ( two treatments were 3 days apart because of the weekend). There was a study done by King/Freeman that indicated a possible reduction in short term serious effects using every other day treatments and my Center was more than willing to do that for me. Usually they delivered treatments every day. Various Centers use slightly different protocols - manner of fiducial placement, CTScan only or CTScan & MRI, homogeneous or heterogenous dosing, etc. Like Allen said, different Centers feel differently about these points, but all Centers use hypofractionization for CaP and use machines that keep track of the prostate capsule so the energy can be delivered to within about a 1 mm accuracy inside the prostate. Those are the important points for effective treatment without serious side effects. But there is always a risk for some toxicity or serious side effects as in any medical procedure. Of course, if you aren't risk adverse, robotic surgery is an option. But whatever treatment you choose, there is a 3-4% chance (even after removal of the prostate) that CaP cells are already outside the prostate and that CaP may reoccur down the road. JAV ( not a MD, DO, or PhD)
ChicoXXX
Posted: Monday, July 23, 2012 11:27 AM
Joined: 10/10/2008
Posts: 366


Allen, JAV and Viperfed.

 

You guys are really great, concerned forum members.

 

I am frequenty very impressed with your insputs.

 

In this regard, I would expect that Hopeful and Optimistic understands the efforts that you have expended in getting information relating to his inquiry.

 

 

 

Your interest in the various aspects of treatments availble for PCa consideration and  your detailed explanations, which overwhelm me most of the time, provide extensive insight and and clarity into very complex issues.

 

Chico


JAV
Posted: Monday, July 23, 2012 1:14 PM
Joined: 10/29/2010
Posts: 602


Chico; Thanks. I have a B.S. and M.S. degree. Everyone knows what B.S. stands for..... and M.S. stands for "More-of-the-Same". And as an engineer, I find the technical aspects of CK very interesting. When I learned about the fiducials & built-in Xray machines and having the LINAC mounted on a robotic arm, I could see the advantage of the CK machine. I didn't mind the 45 minute treatment time. It was relaxing for me. JAV (not a MD, DO, or PhD)
vtrombone
Posted: Monday, July 23, 2012 2:13 PM
Joined: 6/11/2011
Posts: 43


My treatments took 50 minutes, and the room was fantastic. The ceiling had a beautiful, lush tropical effect, and they had a fabulous sound system that allowed you to pick your genre of music. I picked jazz and mostly slept through the whole process. The only thing I didn't like is that my RO chose to insert a baloon in my arse for each treatment, and that was somewhat uncomfortable. I later found out that this is the exception rather than the rule.
hopeful and optimistic
Posted: Monday, July 23, 2012 7:47 PM
Joined: 7/9/2012
Posts: 11


Dear informed, non M.D.'s...... Thank you very much. I am studying the information that you provided. I have some questions, but I think that it's best to wait until I complete my research based on your inputs. Allen, you asked, "The 2 cm lesion is pretty big -- was that sampled by the biopsy? It might be a large calcification." My friend had an MRI with a Tesla 3.0 magnet with the intent of have a biopsy in real time using the MRI machine, but, he and his doc decided to do a random biopsy instead, 12 cores, so it is very difficult to know if that suspicious lesion was sampled...it is possible since the core in the biopsy was in the same general area as the suspicious lesion....my friend has pretty much discounted Active Surveillance because of this lesion, and in that he watches himself and lives a pretty healthy life style( Guidelines recommend AS for those with a 3+4=7 with less than 10 year life expectency) Thanks again all Not an M.D. but a great cook and bottle washer Now off to Dr.Katz's site.
viperfred
Posted: Monday, July 23, 2012 10:29 PM
Joined: 10/10/2008
Posts: 778


I have created a couple websites for prostate cancer patients this one http://www.ipubmd.com/ is a site to help with insurance appeals.  If you login published articles can be read to educate patients.

http://www.iprostatecancer.com/  is my web site with my opinion about treatments for prostate cancer.

Fred


JAV
Posted: Tuesday, July 24, 2012 7:56 AM
Joined: 10/29/2010
Posts: 602


vtrombone: That baloon sounds kind of kinky to me .... just saying. JAV ( not a MD, DO, PhD )
alan katz md
Posted: Tuesday, July 24, 2012 8:35 AM
Joined: 10/10/2008
Posts: 463


Why use a balloon with CK? You will track and pick up any movement so the ballon as immobilization is unnecessay

BTW I have treqated many men with large glands and there is no issue as long as they have good flow. If not, I recommend a green light laser first to open up the urethra and then SBRT in two months


Alan J Katz MD JD

Flushing Radiation Oncology

40-22 Main St  Flushing NY

akatzmd@msn.com

 


Allen_E.
Posted: Tuesday, July 24, 2012 10:42 PM
Joined: 8/8/2010
Posts: 511


Maybe I'm a worrywart. But because he has BPH, cardiovascular risk factors, and a significant prostatic lesion, I tend to think he might have hypoxic areas in his prostate that may be resistant to any kind of radiation. Proscar and Avodart may decrease hypoxia over time. It seems like a precaution worth taking.

- Allen (not an MD)
viperfred
Posted: Friday, July 27, 2012 7:23 AM
Joined: 10/10/2008
Posts: 778


One reason to use a ballon is the Medical Team lacks a good understanding of the Cyberknife tracking.  Or they wanted to stack the billing codes.  Either of which is not optimal for the patient.

 

Fred

Not a MD


JAV
Posted: Friday, July 27, 2012 3:06 PM
Joined: 10/29/2010
Posts: 602


I still say the balloon thing sounds a little kinky to me..... I hope the medical staff isn't getting their jollies from the placement ........ (IMHO). JAV
DanL
Posted: Saturday, August 04, 2012 9:31 AM
Joined: 11/17/2011
Posts: 30


The Iris automatically changes the beam size , as opposed to the original manual type , and allows for more sizes to be used and faster treatment with more precise focus , thus less side effects . About half the C/K doctors use it , including Dr. Katz . In a couple of years an even more precise collimeter will be approved for use by the FDA , dwarfing all in use today per accuracy , but unless one was putting off treatment anyway (watchfull waiting) , it's not worth the wait vs. a possible advanced disease by then . Winthrop Hospital doesn't use the Iris . Their reason was rather confusing to me - that "their Physicist is not comfortable with its accuracy" . While true , the specific size(s) where problems exist are WAY below any used in Prostate Radiation , and when needed (for , say , brain radiation) manual adjustments are used in those sizes . So why Winthrop has a problem with the Iris for Prostate is beyond me . The reduced symptoms with its use for Prostate attest to its accuracy .
hopeful and optimistic
Posted: Thursday, August 09, 2012 5:00 PM
Joined: 7/9/2012
Posts: 11


My friend has urinary problems, My friend interviewed a surgeon who said that radiation would cause swelling and increase urinary problems instead of alleviating it. Is this true? Along with CyberKnife, what need to be done to treat. How effective would this be? Thanks for your continued help.
Allen_E.
Posted: Friday, August 10, 2012 3:41 PM
Joined: 8/8/2010
Posts: 511


I had some urinary symptoms (increased frequency, slow stream, some retension)before treatment, but they did slowly go away as my prostate shrank and are now all gone. What is he taking for his urinary symptoms? Rapaflo? Proscar? Cialis? They are all good to take preceding and during and after CK treatment. No question that RP will get rid of urinary symptoms, unless you consider incontinence and climacturia to be urinary symptoms
- Allen (not an MD)
viperfred
Posted: Saturday, August 11, 2012 12:16 AM
Joined: 10/10/2008
Posts: 778


Radiation is toxic to normal tissue. The degree of toxicity depends on the specific DNA of the tissue, dose plan specifically dose to bladder, rectum, urethra and prostrate. The majority of patients may have no symptoms, however urination urgency and frequency; may be expereinced for a few days which usually resolve in a few weeks, depending on your specific prostate size etc.  You may be lucky like me.   My urination function improved after CK.  Before CK I was up a few times a night.  Today 4 years post CK, no night trips,  A patient's starting base line, dose plan and patients, radiobiology responce all play a role in the outcome.  However these risk are small compared to surgery. IMRT or Proton Therapy. 

 

 FredK Not an MD


hopeful and optimistic
Posted: Saturday, August 11, 2012 12:25 PM
Joined: 7/9/2012
Posts: 11


Thanks Yesterday,we spoke with the R.O. for SBRT who confirms the information that you posted. It is interesting that the robotic surgeon was not accurate about the effects of SBRT, and I guess was "selling" the surgery option with him. An edumucated patient will get the best treatment. Thanks again, NO degrees, except from P.S. 104 , Bronx, N.Y.
Allen_E.
Posted: Saturday, August 11, 2012 5:35 PM
Joined: 8/8/2010
Posts: 511


Was the RO concerned about hypoxia? Did he put him on Proscar or Avodart?

- Allen (not an MD)
hopeful and optimistic
Posted: Sunday, August 12, 2012 4:15 AM
Joined: 7/9/2012
Posts: 11


The R.O. made no comment. I emailed my friend to let him know of your comment. I asked him to post about any input from his cardiogist.
DanL
Posted: Tuesday, September 25, 2012 7:26 AM
Joined: 11/17/2011
Posts: 30


After C/K , swelling of the prostate may cause initial urinary flow symptoms , but that should quickly subside within a couple of days or weeks , and managed with medication . Longer term , prostate shrinkage from C/K treatment MAY , as a "side benefit" , decrease urinary flow symptoms experienced prior to C/K treatment .
 

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