Wbrt, Now, Later, or (Hopefully) Never - 1265506

Wed, 08/20/2014 - 16:15

Male, 61, in good overall general health. Diagnosed Aug 2012 NSCLC Adeno, primary RUL approx 3cm, met to right iliac, one to cerebellum. Cyberknife for brain met, EGFR positive on Tarceva 150 since Nov. 2012. Side effects manageable. PET/CTs in Aug and Nov 2013 show very low level activity in primary, still there but smaller and wispy, hardly any on iliac, but showed low but new and increasing activity in a <1cm secondary spot in LRL. Had SBRT to both lung lesions and ileac in Feb 2014. MRIs every 3 months since Cyberknife have shown no new brain mets until May 2014. New 5mm met in cerebellum treated with Cyberknife. Followup MRI at 6 weeks showed new 5mm met in cerebrum, Cyberknife again. PET/CT in May 2014 and CT in Aug 2014 of chest, abdomen and pelvis showed areas radiated have inflammation which is clearing, no sign of cancer there or anywhere new. So overall Tarceva seems to still be working quite nicely.
Onc says to treat any new brain mets with Cyberknife, if possible. Rad Onc says low dose wbrt as preventative, that studies show high rate of prevention with low chance long term side effects.

My question: Since I had no new brain mets for a year and a half, and now 2 within a couple of months, if new brain mets keep coming, what are the guidelines for continued treatment of individual mets with Cyberknife as opposed to wbrt, and furthermore, in the absence of new mets, for doing preventive low dose wbrt now so that I hopefully don't wake up one day with twenty new brain mets, probably necessitating wbrt in much higher doses with worse prognosis? Could low dose wbrt successfully prevent future brain mets in someone with my low or no tumor load profile, and could it be worth the risk of long term side effects?

I would very much like to know your opinion/guidelines on these matters, as there seems to be much controversy and differences of opinion, and after all, these can be questions of life and death for a lot of people.

Thank you very much.

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JimC

Hi yandtg,

Welcome to GRACE. It's good to hear that Tarceva seems to be controlling your cancer in the rest of your body, but I'm sorry to hear of the new brain mets. It is not uncommon for lung cancer which is well-controlled by an EGFR inhibitor such as Tarceva to progress in the brain first.

The fact that a second lesion appeared within 6 weeks of the first tends to indicate that there are lung cancer cells present in the brain, even when observable lesions have not yet appeared. That is what concerns your radiation oncologist now, and makes him/her recommend WBRT, in order to kill all the cancer cells which may be present in the brain. However, when he mentions "low dose" WBRT that is not a particular type of WBRT, which is by definition low dose compared to the higher doses used in Cyberknife or other focused radiation. Essentially, the total radiation dose is spread out over a number of sessions, which allows the normal tissue time to recover and minimizes side effects. If you suddenly developed a number of lesions, you would likely receive the same total dosage that your rad onc is recommending now.

Although they are in a bit of a different context, these comments of Dr. Weiss may be helpful: http://cancergrace.org/forums/index.php?topic=11066.msg90425#msg90425

On the other hand, this is not something that you must necessarily decide right now. As long as you are followed closely with scans, and report any new neurological symptoms to your oncologist, you can also make that decision later, at the time of progression, based on how long the interval has been and how many lesions appear.

Good luck.

JimC
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yandtg

JimC,
Thank you so much for your quick and thorough reply.
Just to clarify, the rad onc, who is head of radiation oncology at a major university hospital, said that a number of studies have shown a difference in the dose required to prevent brain mets as opposed to treating measurable ones. Presumably, when none are visible, we're trying to kill a much lower concentration of cells than when lesions are visible. He said that the cumulative dose he would use is much lower than that necessary to treat visible mets, and is statistically very likely to prevent future mets in someone without active ones, with a relatively low chance of long term side effects.

He is saying that the reason to do it now as opposed to waiting is because now a lower dose can be used with a greater likelihood of success of preventing future mets, whereas if I wait until a whole bunch pop up, it will require a much higher cumulative dose to treat them and also to try to prevent future ones, as the cow would be "already out of the barn" so to speak. What are your thoughts on this?

Again, thank you for your help.

Steve

Dr West

In people who have developed multiple brain metastases and don't undergo some form of WBR, future brain mets are exceptionally likely. It makes good sense to minimize that risk by doing some preventive action.

Good luck.

-Dr. West

yandtg

Dr. West,
Thank you very much for your reply.
As a followup, I've read that a recent study showed that the protective effect of wbrt only lasts for about six months, and that therefore as long as there are few enough mets to be treated stereotactically, wbrt may be of limited value. It was in an article published in The Lancet Oncology online in March 2014.

1. Yamamoto M, Serizawa T, Shuto T, et al. Stereotactic radiosurgery for patients with multiple brain metastases (JLGK0901): a multi-institutional prospective observational study. The Lancet Oncol 2014:15:387-395

“The essential criticism of employing Gamma Knife radiosurgery without WBRT for patients with several lesions is that microscopic tumors might go untreated, necessitating salvage stereotactic radiosurgery or an alternative therapy,” he adds. “Thus, WBRT is widely advocated. However, a recent study showed that WBRT is only able to prevent the emergence of new tumors for no more than six months post-treatment. Many patients with brain mets can survive for more than a year, thereby outliving the effects of WBRT."

What is your opinion of this finding, and how it may pertain to cases similar to mine?
Thank you again for your help. It's so hard to get clear answers, I really appreciate CancerGrace and your input.

Steve

Dr West

I think that you will never find an answer to a controversial, open question that doesn't have some counterpoint to it, though a single institution observational study doesn't constitute especially strong evidence.

There is a clear choice here that you must make: either DO some form of WBRT or DON'T. Right now, I would say the trend is for over-use of stereotactic radiosurgery. It is clearly a great idea when someone has one or a few lesions, but I see it increasingly being used when a patient has 15 or more brain lesions. I cannot help but believe this is largely related to a financial incentive in the radiation oncology world for doing more and more and more stereotactic radiosurgery -- I simply don't think SRS would be so heavily promoted over WBRT if there was financial parity or the advantage was for WBRT. And doing SRS for 15 brain lesions leaves a patient with an exceptionally high probability of needing more SRS ($$$!!!).

You yourself said that the doctor recommending relatively "light" WBR is a highly regarded chair of the radiation oncology department of a major academic medical center. He is providing a clear recommendation, and I completely concur and am not wavering in that. It's easy to suffer from "analysis paralysis" if you are going to study the literature looking for ways to not make a decision, but here I can do no more than say that you will never get 100% agreement on a controversial question, but not making a decision is actually following a path by default. It is the path that goes against the recommendation of the most knowledgeable person involved in your case and also the opinion I share.

Good luck.

-Dr. West

Dr West

I think that you will never find an answer to a controversial, open question that doesn't have some counterpoint to it, though a single institution observational study doesn't constitute especially strong evidence.

There is a clear choice here that you must make: either DO some form of WBRT or DON'T. Right now, I would say the trend is for over-use of stereotactic radiosurgery. It is clearly a great idea when someone has one or a few lesions, but I see it increasingly being used when a patient has 15 or more brain lesions. I cannot help but believe this is largely related to a financial incentive in the radiation oncology world for doing more and more and more stereotactic radiosurgery -- I simply don't think SRS would be so heavily promoted over WBRT if there was financial parity or the advantage was for WBRT. And doing SRS for 15 brain lesions leaves a patient with an exceptionally high probability of needing more SRS ($$$!!!).

You yourself said that the doctor recommending relatively "light" WBR is a highly regarded chair of the radiation oncology department of a major academic medical center. He is providing a clear recommendation, and I completely concur and am not wavering in that. It's easy to suffer from "analysis paralysis" if you are going to study the literature looking for ways to not make a decision, but here I can do no more than say that you will never get 100% agreement on a controversial question, but not making a decision is actually following a path by default. It is the path that goes against the recommendation of the most knowledgeable person involved in your case and also the opinion I share.

Good luck.

-Dr. West

Dr West

I think that you will never find an answer to a controversial, open question that doesn't have some counterpoint to it, though a single institution observational study doesn't constitute especially strong evidence.

There is a clear choice here that you must make: either DO some form of WBRT or DON'T. Right now, I would say the trend is for over-use of stereotactic radiosurgery. It is clearly a great idea when someone has one or a few lesions, but I see it increasingly being used when a patient has 15 or more brain lesions. I cannot help but believe this is largely related to a financial incentive in the radiation oncology world for doing more and more and more stereotactic radiosurgery -- I simply don't think SRS would be so heavily promoted over WBRT if there was financial parity or the advantage was for WBRT. And doing SRS for 15 brain lesions leaves a patient with an exceptionally high probability of needing more SRS ($$$!!!).

You yourself said that the doctor recommending relatively "light" WBR is a highly regarded chair of the radiation oncology department of a major academic medical center. He is providing a clear recommendation, and I completely concur and am not wavering in that. It's easy to suffer from "analysis paralysis" if you are going to study the literature looking for ways to not make a decision, but here I can do no more than say that you will never get 100% agreement on a controversial question, but not making a decision is actually following a path by default. It is the path that goes against the recommendation of the most knowledgeable person involved in your case and also the opinion I share.

Good luck.

-Dr. West