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CyberKnife as Treatment

Wein
Posts: 5
Joined: Mar 2010

Has anyone heard of or been through the treatment that uses CyberKnife. I'm only reading really good things about this noninvasive type of treatment. CyberKnife.com.

hopeful and opt...
Posts: 2224
Joined: Apr 2009

I've heard of, but don't know too much about CyberKnife Radiation. As a type of radiation it is an invasive procedure.

The cyberKnife delivers a high dose(similar to Brachytherapy) per session, radiation source is on a robot that delivers the dose from a 100-200 angles.

The CyberKnife also has real time target (prostate ) tracking that no other treatment can offer. The result is that the radiation margin used by IMRT/3D=rt to cover the prostate and its movement can be reduced as the movement is tracked real time by CyberKnife. Reducing the margin reduces the dose to the surrounding critical structures such as the rectum.

Bottom line the CyberKnife delives a high dose per session that increase the cure rate, reduces the dose to surrounding good tissue which reduces the side effects. Treatment is 4/5 days depending on the doctors plan.

Ira

d-rt to cov

Swingshiftworker
Posts: 1013
Joined: Mar 2010

Why do you call CyberKnife (CK) an "invasive" radiation procedure? My understanding is that brachytherapy is the only invasive radiation reatment for prostate cancer because they have to "invade" your body by placing seeds in the prostate. CK involves no "penetration" of the body. So, I don't understand why you'd call it "invasive." Please explain.

FWIW, CyberKnife, Proton Beam and Brachytherapy are on my short list of potentially acceptable treatments and I'm still doing research on each of them. They offer CK at the University of California San Francisco Medical Center and I have an appointment with the Director of Radiation Oncology (who does all of the CK treatments at UCSF) next month to discuss the treatment. I spoke by phone with a resident physician familiar with the use of CK and (of course) he says that it is as good as proton beam therapy (PBT) in terms of effectiveness and minimization of side effects (particularly impotence and incontinence) because of the precision -- in terms of location and dosage -- available in applying the radiation.

The risks associated w/the higher radiation dosage used in CK (which makes fewer treatments necessary) are offset by the precision of the technology but(like surgery) the precision is only as good as the person planning and administering the treatment. Also, since it's still a relatively new procedure, there isn't much data on in the use of CK to know if it really is "as good as" PBT (which now has a well-established track record). On the other hand, the limited number of PBT treatment sites and the much longer treatment period (2 months) and the number of treatments required (typically 40), which requires moving to the treatment site until treatment is completed, make PBT less convenient than CK as a form of treatment. However, effectiveness trumps convenience and, if I can't find enough information to assure me of the effectiveness and safety of the procedure, I may still opt for PBT (or Brachytherapy) when the time to make a choice arrives.

hopeful and opt...
Posts: 2224
Joined: Apr 2009

the cancerous cells) and the structure of the tissue is diminished, one would have significant difficulty having an operation after radiation. Also, there are side effects to radiation that can occur approximately two years afterward, that include the same type of stuff as for an operation, and in addition (I'm sure of the term) but radiation of the anus.

Not being a medical professional.........I tend to believe that radiation is more invasive than an operation to remove the prostate.

Ira

Swingshiftworker
Posts: 1013
Joined: Mar 2010

Surgeons like to tell you that there are no options following radiation so that you'll agree to surgery, but that's simply not true.

Recent reports suggest that the side effects of radiation treatment are overstated and relate to past practices using EBRT which is kind of a "shotgun" approach to radiation and cannot be controlled like CyberKnife (CK), Proton Beam Therapy (PBT) and Brachytherapy (BT). Those reports also relate to older patients with high grade cancers who required higher doses which caused significant collateral tissue damage, particularly in the rectum. One of the other stories is that if you get radiation and still have full erectile function after the treatment (which most do), you could lose it later. Recent reports are that this is false and that, if you lose it later, it's more likely due to your age and not due to any prolonged effects of radiation.

That said, no radiation treatment is without the possibility of side effects. However, it is now also pretty well known (based on some studies and anecdotal evidence) that PBT, IMRT (which includes CK) and BT are more likely to be LESS HARMFUL than radical and/or robotic surgery. The reason more people are choosing some form of radiation (other than EBRT) now is because most people retain or regain erectile function and urinary control shortly following treatment. This is not the case with surgery.

When you get surgery, you are absolutely sure to be impotent and incontinent following the procedure. The recovery from ED is only around 50% -- that means you have about a 50% chance to be impotent for LIFE if you have surgery and, if you recover, erectile function it could take as long as 2 years to achieve it. Those are NOT good odds in my book! After surgery, you are also guaranteed to have a catheter shoved up your penis and a urine bag at your side. The catheter usually comes out after a few days, but you will be incontinent and will have to wear a diaper and or use pads for up to a year and maybe longer. This doesn't even take into account the potential for infection and mistakes (like a perforated rectum or bladder) or the scars that are left over following surgery.

Now, THAT is what I call invasive!!!

You can also end up wearing a catheter following BT, but is not common following IMRT or PBT. However, the problem with BT will more likely be the "inability" to pee -- not incontinence -- and you need the catheter to keep things flowing. If things go really bad w/BT, you'll develop a "stricture" or blockage in the urethra (where it's reattached to the bladder) and will need a follow up procedure to clear it. This is one of the reasons by BT is at the bottom of my short list of acceptable treatments. With PBT and IMRT, you'll probably have an "urgency" to pee (as reported by Marckini) but probably won't be incontinent.

Also it is not necessarily true that surgery cannot be performed following radiation treatment. In the past (before IMRT and PBT), the prostate and all of the surrounding tissue was zapped to oblivion by EBRT making followup surgery impractical because of all of tissue damage. Surgery in the past and now is also usually not recommended because, if the radiation treatment has failed, the cancer has probably spread beyond the prostate and cutting the prostate out would not "fix" the problem. Chemo and EBRT would be better treatments in that event. Another reason why surgery is not recommended following radiation treatment is that the remaining cancer may still contained within that prostate within a small and localized area, which would make it amenable to treatment by cyrosurgery (cold) or HIFU - high intensity focused ultrasound (heat) or readministration of BT, IMRT or PBT which would all still be better choices than surgery.

So, the bottom line is that surgery is really worse than radiation and IMHO there is NO reason to resort to surgery, unless your cancer is ADVANCED but still contained within the prostate AND your life depends on the immediate removal of the prostate to avoid the spread of your cancer to other parts of your body. In that case, concerns over ED and incontinence are only secondary. But, if you're not in that situation and your cancer is at an early stage and not immediately life threatening, radiation treatment (whether it's PBT, IMRT or BT) are clearly much better alternatives to surgery.

hopeful and opt...
Posts: 2224
Joined: Apr 2009

I forgot to mention in my post that UCSF has a very good reputation.....you are definately going the the right institution.........At the end of December, here in Southern CA. I met someone who was going up to ucsf to get involved in their active surveillance program (which I've heard postive things about from others that I've met on the net.

I personally am going to UCLA, which I guess is similar in a lot of ways, but to be honest I heard more positive about ucsf.

Since I haven't done recent research about radiation, so I am not able to really comment on the information that you provided; I believe that its time for me to do some more research about radiation....thanks for the information, and at some time in the near future I may be able to respond.

Ira

Swingshiftworker
Posts: 1013
Joined: Mar 2010

Just had a meeting (which BTW I paid $702 out-of-pocket for) w/Dr. Alexander Gottschalk, the Director of CyberKnife RadioSurgery at UCSF today. Spent about 3 hours there and over an hour w/Dr. G and another 1/2 hr w/a resident and nurse. So, I think I got my money's worth.

CK is used to treat prostate and other cancers at UCSF, but Dr. Gottschalk is the only physician who treats prostate cancer patients there. Even so, he has only treated about 60 PCa patients over the past 5 years, who range in age from around 50-80, but are mostly over 65. The CK is usually offered only to early stage PCa patients (Gleason 6; PSA less than 10) and protocol involves 4 consecutive daily factional treatments of 9.5 Grays each for a total of 38 Grays, which about 1/2 the amount of radiation received under Proton Beam Treatment(PBT) cumulatively over 8-9 weeks. The precision of CK is such that they can program the CK machine to treat a margin of as little as 1-2mm and can minimize the radiation dosage delivered to the rectum, bladder, prosthetic urethra, nerves and penile bulb (which is of major importance in order to avoid ED). All of the treatments are done on an outpatient basis and NO catheter is required (a BIG plus) during or following treatment! Also no body cast is required to restrict movement, since CK can adjust for body movement during treatment.

Dr. G reports that most CK patients experience urinary irritation and urgency following treatment, but those symptoms are usually resolved w/in a couple of weeks. Beyond that, Dr. G reports only 1 case of rectal bleeding about 3 months after treatment (earlier than reported for proton beam patients) and only 2 cases of more serious urinary problems - one for urge incontinence (inability to pee even though he had the urge) for an 80 yr old patient and another for an actual frequency/urgency problem which was treated w/steroid injections. Not a bad track record. Regarding ED, the results are the same as for other radiation therapies -- "young men" under 60 have fewer problems than older men, but there's not enough of a history to determine if the radiation has a prolonged effect on erectile function independent of age.

Also not enough time to determine if CK is an effective long term "cure" but his earliest patient (has achieved a PSA less than 0.1, but it took 5 years to get there. So, regular PSA testing following treatment to see a pattern of PSA reduction is dictated. If subsequent higher PSA tests and a followup biopsy indicate that the CK treatment has failed, Dr. G would currently recommend brachytherapy (BT) as a subsequent treatment (based on his experience with failed external beam treatments, rather than cyrotherapy because of its greater adverse (over 90%) effect on erectile function) and if the BT also fails then salvage surgery (which has been performed successfully on failed BT and external beam radiation patients at UCSF.

However, like most other treatments for early stage PCa patients, Dr. G. thinks that CK is as effective as any other form of available treatment, but with lesser negative side effects than all other treatments, except for BT, which he thinks is the most comparable to CK. However, this doesn't address the "quality of life" issue in BK of having to live w/the seeds in your body FOREVER following treatment (even after the radioactivity of the seeds has expired) and the possible migration of the seeds over time; notwithstanding the need for a special ID to get onto an airplane because of all of the metal and the lingering radioactivity in your prostate.

That said, I'm still favorably inclined towards CK. I have an pending consultation at Loma Linda in June (yet to be scheduled) to discuss PBT as well. However, the CK and PBT consultations may be rendered moot if, after getting a 2nd opinion on my biopsy, it is determined that I don't actually have any PCa at all, because of an possibly erroneous pathology report. See my post on this date in the "A Million Overdiagnosed -- and Counting" thread for further explanation about this.

Needless to say, this is all very confounding and I just hope I have the proper information upon which to base a treatment decision.

lewvino's picture
lewvino
Posts: 1010
Joined: May 2009

I researched it. If I remember correctly they like for you to be Gleason 6 or below for best results. I had Davinci with my gleason 7.

Larry

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