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Brain Metastasis
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Overview
Although most patients with metastatic kidney cancer never get brain metastasis, it is also far from rare, and it's a special and serious situation. I am including a separate article because it looks to me like many patients with this problem are not getting the most effective therapies for this problem, specifically I think whole brain radiation is ineffective either as sole treatment or as mop-up therapy, and can have catastrophic long term side- effects. I also think that another form of radiation, stereotactic radiosurgery, can be effective in more cases than is often realized.
Diagnosis and Initial Treatment
Diagnosis
The diagnosis of brain metastasis is usually triggered by your reporting symptoms since brain scans are not normally included in routine follow-up testing. For a few kidney cancer patients, symptoms of brain metastasis are the first sign they have cancer.
Typically, your doctor will give you a simple neurological exam, which involves things like testing reflexes, vision, muscle strength, gait, mental status and so on. Depending on the symptoms, history, and results of the exam, if there is concern MRI or CT scan of the brain may be ordered. MRI is usually considered to be the better test.
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I am not advocating brain scans as part of routine follow-up at this time, but if it were to be done it'd make the most sense for patients who were in the intensive follow-up period in the few years after diagnosis with high risk RCC. |
Brain Metastasis Symptoms
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Brain metastasis is usually diagnosed after investigation of symptoms. Most patients do not get brain imaging as part of routine follow-up so usually brain metastasis is found is because the patient reports symptoms.
A brain metastasis can cause many different symptoms depending on where in the brain it's located. No one specific symptom automatically means you have a brain metastasis. All of the symptoms below can also have other causes, including problems entirely unrelated to your kidney cancer, problems due to your cancer but not due to brain metastasis, and problems due to treatment side effects. Some of them are much more likely to be due to something else than to a brain metastasis. So please don't assume you have a brain metastasis because you have a symptom listed here.
Instead, see your doctor who will evaluate your symptoms based on your history and treatments. You may be given a simple neurological exam and possibly other tests, especially an MRI or CT scan of the brain.
This list of symptoms is not a complete list but it should cover the more common symptoms of brain metastasis:
- Vision problems such as double vision or partial blindness
- Headaches possibly with nausea
- Headaches are very common. Almost everyone gets a headache now and then and many people get headaches frequently. Headaches that fit your usual pattern are probably nothing to worry about. Call your doctor if you are having unusually severe or unusually frequent headaches or if the headaches are accompanied by other symptoms.
- Numbness or tingling in part of the body
- Note that numbness in the hands and feet is a side effect of a number of anti-cancer drugs.
- Paralysis or difficulty moving any part of the body
- Inability to walk
- Difficulties with balance or unusual gait
- Difficulty speaking, including slurring words or incoherent speech
- Problems with thinking such as not being able to read a clock, or not being able to tell who and where you are etc.
- Stupor - difficult to arouse
- Seizure or convulsions
Initial Care
Before actual treatment starts, several things will probably be done to help relieve symptoms reduce any immediate risk of complications.
On Steroids: Often some of the symptoms from brain metastasis are the result of swelling caused by the tumor. Usually you will be given an oral steroid such as decadron to reduce swelling and symptoms. In addition to reducing swelling, decadron may improve your mood and energy, and greatly increase your appetite. Sometimes the mood changes are extreme though. You may also have trouble sleeping and it can cause high blood sugar, particularly in diabetics. Be sure to remind your doctor if you're a diabetic. If the brain metastasis can be effectively treated, the steroids can be discontinued at some point after treatment. You can't stop taking steroids all at once - the dose has to be reduced over a few weeks.
Anticonvulsant: If you had a seizure or are thought to be at risk of one, you will be also prescribed an anticonvulsant drug such as dilantin.
Treating the Brain Metastasis is The Top Priority: Even if there are tumors elsewhere in the body, the brain metastasis will usually be treated first, both because brain metastasis is life threatening and because the treatment is different from and often incompatible with treatment of tumors elsewhere. Some patients have brain metastasis as the only site of recurrence and so don't have any other tumors to deal with. This situation naturally has a better prognosis than if there is also other metastasis.
Current Treatment May Be Stopped Or Interrupted: If you are on treatment for metastasis elsewhere, particularly if you're on immunotherapy, the treatment will probably be interrupted. The steroids which are almost universally prescribed depress the immune system and abrogate the beneficial effect of immunotherapy, Interleukin-2 definitely included. It may be possible to resume immunotherapy after treatment is completed and you are off steroids. Appearance of a new brain metastasis would be considered progression in almost all clinical trials and is likely to mean you will be taken off study because of it. This doesn't seem quite fair since many drugs do not cross the blood brain barrier and would not have been expected to affect growth of a brain metastasis anyway. Whether treatments can be continued or resumed is a case by case decision.
Main Treatment
Treatments for brain metastases include surgery and two very different types of radiation, stereotactic radiosurgery, and whole brain radiation. Surgery and stereotactic radiation are used to eliminate individual tumors, while whole brain radiation is intended to mop-up tumors too small to see yet, or as palliative treatment if other treatment isn't possible. As you will see I am very skeptical that whole brain radiation has any benefit in kidney cancer and advise against it in most cases.
Surgery
- Typically surgery is used for 1-3 tumors.
- Surgery can handle large tumors.
- Whether surgery is possible depends on the location of the tumor
- Surgery can be used even if whole brain radiation has been done, or stereotactic radiosurgery was done elsewhere in the brain.
Although brain surgery is notoriously technical and delicate that doesn't mean it's hard to go through. Having talked to several people who've been through brain surgery, and read the stories of several others, my impression is that often it is surprisingly easy to go through with only a few days in the hospital and relatively little pain. Obviously, this won't always be the case, and risks of permanent neurological damage are always a consideration. The risks vary considerably depending on the precise situation.
Stereotactic Radiation
Stereotactic radiosurgery (SRS) isn't actually surgery - it's actually a high tech form of radiation therapy which effectively focuses very high doses of radiation on the tumor while sparing normal brain tissue. The good news is it's very effective in RCC brain metastasis. There are actually several forms of radiosurgery, and I don't feel qualified to discuss the pros and cons of each, however results seem to be good regardless of which system is used. Most studies report over 90% of treated tumors are "controlled" (which means they don't grow), and most patients don't die of brain metastasis. See the Stereotactic Radiosurgery References for details. After treatment tumors may be stable or be slowly absorbed.
The basic concept behind SRS is simple: A large number of beams are aimed from different places so that they converge on the tumor. The tumor then gets a much higher dose of radiation than the surrounding brain tissue. This dose is also much higher than can be achieved with whole brain radiation and is enough to overcome the high inherent resistance of RCC to radiation. While this basic principle is simple, ensuring that the beams are actually aimed at the tumor and that the zone of convergence exactly matches the shape of the tumor are highly technical.
Radiosurgery is usually done as a single outpatient procedure, although there may be appointments for assessment and planning first. In most forms of radiosurgery a metal frame is attached to your head (with screws!). This is actually the most painful part, and is reported to be not as bad as it sounds. The stereotactic frame allows precise and consistent determination of the position of your head during the procedure so that the tumor can be targeted accurately. The procedure itself is painless much like a CT scan. Afterwards you'll probably be released after a short observation period. A little residual pain from the head frame is usually all you'll feel. I've had reports of patients going out to dinner or shopping immediately after they're released.
Some of the advantages of stereotactic radiosurgery are:
Some of the limitations are:
- Size Limit: Most references I've found give 3cm as the maximum size
which can be treated, but because this technology is evolving rapidly, I would
research this further if necessary.
- Number of Tumors Treated: Well actually, in practice we find that although many sites limit the number of tumors that can be treated, but in fact SRS has been successfully used with over a dozen RCC brain metastases[Amendola 2000]. If you are told you have too many tumors to treat with SRS consider finding a site which is willing to go further.
Choosing Between Surgery and Stereotactic Radiosurgery
The choice between surgery and stereotactic RT when both are options, is obviously complex. I certainly can't give definitive advice. It's always important to get the guidance of expert physicians - here even more than usual.
A Few Thoughts
- The surgery seems to me to be a more certain way to eliminate
individual tumors, but is more difficult to go through although as I mentioned
above, often less difficult than you might imagine. My impression is that surgery
is usually advised if it's feasible.
- If you have metastases elsewhere and are planning on drug treatment,
particularly immunotherapy, then it's important to get off steroids as
quickly as possible. While SRS requires less immediate recovery time, the
tumor is not gone the instant SRS is completed, so it might be longer until
swelling caused by the tumor resolves after successful treatment. I am not sure
of this though. You should discuss it with your doctor! Likewise if the tumor
is causing symptoms by increasing pressure within the cranium, surgery might
resolve symptoms faster. Again discuss with your doctors.
- If the location of the tumor makes surgery risky even though possible, then SRS may be the better bet.
Stereotactic Radiosurgery Resources
- International Radiosurgery Association: A patient-friendly introduction to radiosurgery.
Whole Brain Radiation
Whole Brain Radiation is just what it sounds like: the whole brain is radiated in a series of treatments, usually one each day for a few weeks. While the treatment is not painful and usually doesn't cause severe side effects immediately, there is a risk of severe long term damage to the brain. These late effects can begin months or years after the treatment and at worst can include a devastating generalized radiation necrosis with dementia and many other adverse effects.
Whole brain radiation is used in two different ways:
- As Sole Treatment: I would say this is becoming less frequent which
is good because the data I have seen shows that whole brain radiotherapy gives
very poor results in kidney cancer metastatic to the brain with very poor
survival and as well as poor control of the tumors as documented by the high
percentage of patients who die from the brain metastases themselves. If whole
brain radiation is recommended to you for your main treatment, you must obtain
second opinions. If the reason WBR is recommended is because you aren't a
candidate for surgery or stereotactic radiosurgery, then it's important to get
second opinions to be sure that these other treatments really aren't possible.
On the positive side, a few members of the KIDNEY-ONC mailing list have reported tumor
shrinkage and improvements in symptoms with WBR. In some cases it probably does
have some benefit as a palliative treatment. For details on the evidence see
the Whole Brain Radiation References.
- As a Mop-Up Treatment After Surgery or Stereotactic Radiosurgery:
The idea here is to kill tiny metastases which can't yet be seen on scans. That
sounds good but I can't find any good evidence that WBR after surgery or
stereotactic radiosurgery actually has benefit in kidney cancer. While the data
aren't from randomized studies, case series which looked at patients who had
WBR versus those who didn't found little suggestion that WBR was beneficial.
This is no surprise since kidney cancer is relatively resistant to radiation.
What is a surprise is how often doctors reach for WBR after surgery or
radiosurgery "just to make sure" despite what seems to be a considerable lack
of evidence. Keep in mind that surgery and especially stereotactic radiosurgery
can be repeated in many cases in the event that new brain metastases do show
up.
References
Whole Brain Radiation
Stereotactic Radiosurgery
The general pattern here, a high rate of tumor control and a low rate of death due to brain metastasis is clear, so I don't comment on each paper.
They were also able to retreat patients who developed new brain metastases - one patient was treated seven times.
Half the patients had already had whole brain radiation but this didn't affect the ability to get a great result with radiosurgery.
Whole Brain Radiation and Sterotactic Radiation Combined
It will be very clear looking at the abstracts that the pattern is that WBR adds nothing to SRS. These aren't randomized studies, but then there is no randomized study showing WBR does add something either.
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This CancerGuide Page By Steve Dunn. © Steve Dunn
Page Created: July 29, 2002, Last Updated: January 13, 2004