Mother has radio resistant brain mets - where to now? - 1267746

karenv67
Posts:5

My mother was diagnosed with bowel cancer (rectal) in November 2010 at the age of 65, she had surgery, chemo wasn't considered essential, she had one round of 5fu, had a toxic reaction and discontinued.

Blood tests showed raised CEA in November 2013 and a met to her lung was discovered. Throughout 2014 she received various rounds of chemo - 5fu and avastin which kept the tumour stable. In November 2014 she became suddenly delirious and scans showed mets to her brain, two large tumours (around 2.5cm each) and a large amount of swelling. She received Dexamethosone and underwent whole brain radiotherapy around 7 weeks ago. After little improvement, a week ago she had more scans which showed major swelling in her brain, the tumours the same size, and the lung tumour stable, no other cancer in her body. The oncologist was to speak to the neurologists about operating to remove the brain tumours and then beginning a course of Cetuximab and/or Irinotecan. We left feeling very confident.

Last week Mum was back in hospital with increased confusion. We were told that WBRT was ineffective (it's radio resistant), that the tumours have increased in size and are aggressive and surgery isn't an option, that Irinotecan is not an option (it was an option a week ago), they will send her home palliative. Other than the brain mets my mother is fit and healthy; she is active, has no other illness or disease other than the controlled lung met. She is wanting to continue to fight this disease.

I have been doing some research and consider there are two options and would like your thoughts please (I will be passing these by my Mum's doctors as well):

- stereotactic radiosurgery - the hospital does not do this but can refer us - they suggest that Mum may not be a candidate due to her age and status and that it's rigorous
- Irinotecan which I understand can work on brain mets

We are based in Australia.

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JimC
Posts: 2753

Hi karenv67,

I'm sorry to hear that WBR did not resolve your Mum's brain mets. As you probably know, WBR consists of a series of relatively low dose radiation treatments to the entire brain, while stereotactic radiation uses a concentrated, high dose of radiation to specified spots. This may be what is necessary to treat her lesions. You can read about this use of focused radiation here: https://www.google.com/url?q=http://cancergrace.org/radiation/wp-conten…

JimC
Forum moderator

cards7up
Posts: 636

If it were me or my mother, I would be pushing for the SBRT which for the brain is either gamma or cyber knife. Is she still taking steroids? Take care, Judy

Dr West
Posts: 4735

Stereotactic radiosurgery (Cyber Knife, Gamma Knife) is really an option that is far more likely to be beneficial for patients with one or a few brain metastases. Unfortunately, it's not likely to be very fruitful if there are many brain lesions, especially if they have been growing through whole brain radiation.

The term SBRT stands for stereotactic body radition therapy (SBRT), so it is meant to apply to radiation to body lesions, not treatment for brain lesions.

As for irinotecan, there have been some reports of it being active against brain metastases, but that really hasn't been borne out to a significant degree.

Good luck.

-Dr. West

karenv67
Posts: 5

Thanks for your replies.

Jim, that is very useful reading thank you. The issue we seem to have here is that SRS doesn't seem to be as commonplace as it does in the US - there is only one hospital in our state that offers it and they have only treated a couple of hundred patients.

Judy, my mother is still taking steroids, they have upped her dosage to deal with the increased swelling, given that the WBRT was ineffective.

Dr West, thank you very much for your response, I really appreciate receiving advice from another medical professional. It is a very difficult situation and hard for us to accept that we are running out of options. My mother only has two brain lesions and no others are showing on her scans. These tumours have been growing throughout WBRT. But from my reading it appears that radio resistant tumours actually respond better to SRS? I do however think we face a battle for my mother to be considered for SRS, given that it is not widely available here. I am hoping to speak to her oncologist further about Irinotecan but have a sinking feeling that it won't be a favourable response.

Dr West
Posts: 4735

The dose to the specific area of the lesions is much higher with SRS, and that would definitely be a strong consideration for someone with just two lesions. I presume that it's CONCLUSIVE that the lesions are progressing -- I'll just mention that you can definitely see a bit of enlargement of treated brain lesions shortly after WBRT, which may just be a short-term post-treatment response before later shrinkage. If you have the opportunity to meet with a radiation oncologist who can comment on the feasibility of SRS, a first question to be sure of is whether there is definite progression and not just post-treatment effect.

-Dr. West

karenv67
Posts: 5

Thank you Dr West, that is very interesting and definitely something I will ask of the radiation oncologist. It has been 7 weeks since the WBRT - when we met with the oncologist last week he just noted that there was still quite a bit of swelling of the brain and no real change in the lesions. It wasn't until this week a registrar commented to me that there had been progression, but they didn't say how much. Generally how long after WBRT does the enlargement last for before shrinkage, or is that too variable?

Dr West
Posts: 4735

I can't say anything definitive. I don't do this radiation and don't read brain imaging as my primary job. I just know that the interpretation of these scans after radiation is a bit of a black art.

-Dr. West

karenv67
Posts: 5

Hmm it's interesting - I have been doing more research and a PET scan can give a better indication of tumour activity as it can differentiate between scar tissue and necrosis and new tumour growth. I really appreciate you raising this issue because we would have taken the doctors at their word and assumed that the lesions are progressing without them having done any definitive testing. But now we will be questioning this - we are getting a referral for the SRS so will ask the radiation oncologist. Thank you very much for raising this, much appreciated I appreciate your advice.

JimC
Posts: 2753

While that may be true about PET scans in general, when it comes to imaging the brain standard PET scans don't tend to be very helpful, as the entire brain lights up on such a scan.

As Dr. Pennell has written previously:

“The PET scan does not show the brain very well and an MRI or at least a CT scan with contrast is necessary to show the brain with sufficient resolution to see small metastases. The brain uses a lot of glucose (the labeled substance that lights up on a PET scan is a form of glucose, a sugar) and so thus “lights up” on the PET scan quite a bit, making it unreliable. There are special brain PET scans that can show metastases, but these are different than the ones we use to stage patients with lung cancer.”
http://cancergrace.org/forums/index.php?topic=2381.msg14271#msg14271

JimC
Forum moderator