CYBER KNIFE

CK, a form of SBRT, is almost always a good choice for PCa cases, although in its earliest years it first became popular against innaccessable brain tumors.   SBRT basically applies stronger bursts of radiation in fewer doses to equal the total Gray of radiation provided over a longer period of treatment by IGRT or IMRT.  Total recommended Gray for localized PCa is ordinarily 76-80.  Varian, a medical equipment manufactures, also builds an SBRT device.  Most large cancer centers today own either the Varian or the CK out of marketing necessity. A better mouse trap for the average mouse, but still a mouse trap.  My center has the Varian.

SBRT overall does not have fewer, or more, side-effects than IGRT; they are equal in effectiveness.  Its main bragging point is more convenience in delivery -- fewer drives to the radiation oncoliogist.  CK also has precision of delivery equal to or slightly better than IGRT, although the difference in accuracy with the newest IGRT machines is almost none; a Calipso IGRT device gates for breathing, even bowel activity.   My own R.O, who does IGRT and SBRT, said he preferred doing IGRTs, but I don't recall his reasoning now.  CK also benefits from slick marketing techniques, but of course the same is true of DaVinci robots, and a thousand other medical devices.

CK and IGRT (and perhaps seeding also) will ordinarily cure a man with PCa. 

max

Swingshiftworker said:

My CK Experience

I disagree w/Max's characterization of CK as merely a product of "slick" medical marketing.  I also disagree that CK has not been proven to reduce the potential of negative side effects as compared w/other radiation delivery methods, including IMRT and IGRT.

CK is one of (if not) the most precise method of radiation delivery for a wide array of cancers, including prostate cancer.  It's effectiveness in treating PCa, as well as brain, lung and spinal cancers (much more delicate tissue) is proof of it's effectiveness.  The degree of precision with with CK can deliver radiation is unmatched by any other method of radiation delivery -- including IMRT and IGRT -- and, as a result, this makes it the least likely to cause negtive side effects such as collateral tissue damage which can result in injury to the bladder leading to temporary or permament incontinence and/or impotence.

I was diagonsed w/PCa in Jan 2010 and treated w/CK in Sep 2010; Gleason 6.  I received 3 treatments every other day over a week.  No time was lost from work or any other activity.   After a disconcerting "bounce" about 3 years later (not uncommon for any form of radiation treatment), my PSA dropped below 1 (an indication of remission) and continues to drop w/each test I take.  So, I am not essentially considered "cured." Nothing could have been easier or better.  Many other men on this forum had a similar experience w/CK and I recall only one who said he experienced any negative side effects; sorry don't recall the details.

I also chose CK after ruling out surgery and BT, which were the only other options presented to me.  I was aware of IMRT.  It was not an option presented to me but all of the "old" data about the negative side effects of radiation treatment for PCa arise out of the use of IMRT (and its predecessors) because of the lack of precision with which radiation was delivered to the prostate which led to rectal, bladder and other tissue damage, which in turm led to a greater incidence of incontinence and impotence.  It didn't help that IMRT required (at that time) 5 daily treatments over 8 weeks (40 total).  I ruled out proton beam therapy also because of the long duration required for treatment.  While the precision of IMRT and IGRT has improved over the years, I believe there is still a greater chance of side effects with it than w/CK and, although I believe that the required number of treatments has been reduced from 40 to 25 (by increasing the radiation strength), I believe that CK is still far superior in only requiring 3 (or 4) treatments to achieve the same outcome w/less risk of side effects.

In any event, as a happy and healthy CK patient and PCa survivor, I highly recommend of the use of CK for the treatment of PCa for all early stage and capsule defined PCa cases. 

 

 

 

My friend SSW,

I did not say that CK or its popularity was "merely" from or due to "slick marketing."  Reread my post. I said that CK and its popularity have benefitted from such marketing. Open any Oncology Journal, and there it is.  Here, as always, I have granted that CK is an excellent choice and frequent lifesaver.

I contend that IGRT is virtually, today, as precise in delivery as CK, but have no interest in agruing this further.

Currently known side-effects from CK are indeed as few, or fewer, than IGRT.  New studies are in progress to determine if the larger bursts of CK energy potentially engender late, secondary cancers at a rate higher than IGRT.  By "late," oncologists ordinarily mean ten years or more out from treatment.  Many, many chemos and chemo-radiation protocols (not ones employeed against PCa) are now known to (very slightly) elevate the chances of secondary cancers or diseases -- facts not known until many years after they were begun.

If I had to guess, I would guess that CK does NOT increase these risks, but it is part of the current RT discussion.

max

Individual reports, such as many on this forum, aren't really acceptable medical evidence for a wider audience. We need carefully conducted studies with many patients to provide that sort of evidence, pro or con. Fortunately, SBRT using CyberKnife has been studied for about ten years now, and peer reviewed papers have appeared in the medical literature. The study that has run the longest comes from Dr. Alan J Katz and coworkers. Here is a link to his latest findings

http://meetinglibrary.asco.org/content/157284-172

Note that I just broke my own rule since this link relates to a poster presentation, but Dr Katz has published very similar results in peer-reviewed journals. From the poster presentation:

Conclusions: SBRT alone produces excellent biochemical control rates at up to 9 years with mild toxicity and minimal impact on quality of life. These long-term results appear superior to standard IMRT with lower cost and are strikingly similar to HDR therapy. These results also strongly suggest that 35 Gy is as effective as 36.25 Gy for patients with Gleason < 4+3, with less urinary toxicity.

You make the fundamental, key point that what this or that individual person experienced has no statistical merit, being only anecdotal. Important to them, of course, but by itself not generalizable. But they are accounts that men awaiting treatment want to read and find comforting and reassuring.

I appreciate the link and will read it, and it sounds probably very sound. I would make the small note that in most areas, IMRT has been supplanted by IGRT however.

If you search on SBRT you may find others. There was not a Cyberknife within 100M. but 'SBRT' found 2 within 25M.  I was told the machine was used for both SBRT and IGRT.  Then is there any difference in precesion?

leamon

leamon said:

If you search on SBRT you may

If you search on SBRT you may find others. There was not a Cyberknife within 100M. but 'SBRT' found 2 within 25M.  I was told the machine was used for both SBRT and IGRT.  Then is there any difference in precesion?

leamon

Ford versus Chevy,

I researched these machines a couple of years ago.....each have advantages and disadvantages, and the is basically no difference

To add,  there are differences in procedures among the various doctors who adminsiter the treatments that one need to be more concerned about...which affect cure and side effects

ie.

most treat in 5 days while others in 4 days.

Some doctors administer higher amounts of radiation than others...generally the range is between 35 and 40,......... so there are other factors that one can consider in seeking SBRT...........as more studies by individual doctors are published, an optimum universal procedure will be developed.

We can debate which 'machine' is better (a 'toss-up', apparently), but what is also important is the experience of the team administering the radiation. "My" team was great; by now they have done more than one thousand (CyberKnife) prostate cancer procedures.

http://www.medstargeorgetown.org/2016/04/12/cyberknife-treats-1000th-man-for-prostate-cancer-at-medstar-georgetown/#q={}

Debo56 said:

Cyber Knife

I just completed my 5th cyber knife treatment 2 days ago.  I have a prostate that is 3x normal so after much research, I felt this was the best option.  The side effects I am experiencing are frequency (every few minutes throughout the day and evening), increased bowel movements (13 yesterday), and burning.  If anyone has had similar side effects, how long does this last?

I did not have an enlarged prostate but I don't recall having any signficant issues with frequency after treatment.  During treatment, with the nightly dulcalax and liquid diet bowel movements were a pain but after treatment, that went away quickly.  I never had any burning sensations.  I would just call them and tell them what is happening. 

In RT treatments (CK, IMRT,PB, etc) the status of the patient will define the treatment protocol and field of attack. You have not shared such details (your diagnosis) but the decision in choosing CK in spite of the enlarged prostate means that the radiologist saw it possible in delivering/directing the rays successfully with the lesser injury to surrounding tissues, however, one should expect higher probabilities for RT injury in larger prostate cases than in smaller, normal sizes glands. CK planning for your case may have been difficult.

The risks and side effects from all types and modalities of RT are equal. The intense of the radiation may turn hypofractionate modalities (higher doses at one time) more prune to damages but better in treatment outcomes. The most common proctitis, colitis and cystitis are predictable and expected. Salvage IMRT, in my case made me to experience loosed and soft stools during two months past RT. Regarding urination, apart from three weeks of burning sensation when peeing, I did not experienced any other urinary problem (urgency, retention or voiding issues), but since 2013 (7 years after the treatment) I started having urgency symptoms as a cause of radiation scars/cystitis (late side effects) which may be there forever. RT also caused partial loss of sensation when passing stool, which condition has improved in time.

Best wishes for quicker improvements.

VGama