We had a relatively eventful day yesterday, with some potentially exciting news from the doctors about a possible treatment route for Summer that would allow us to avoid radiation for a while longer.
They discussed Summer's case and reviewed her post-op scans at the tumor board meeting yesterday, and everyone was very happy with the "drastic" reduction in size of the cyst and Dr. Browd's placement of the catheter.
We met with Dr. Browd and Dr. Douglas (the radiation oncologist here) after the tumor board meeting. Dr. Douglas explained our radiation options in a little more detail.
We learned that Summer's tumor is uniquely positioned in front of her pituitary, rather than above it where most craniopharyngiomas are located. Dr. Douglas was quite surprised that she isn't showing any sign of pituitary damage so far.
We talked about conformal radiation therapy (also called standard, or IMRT), which isn't really an option in my mind because it radiates more normal tissue than proton therapy, the route we were told to start planning for now.
We also talked about something called Gamma Knife, which can be done here. It is a radiation treatment that lasts 1-5 days, with 195 beams aimed at the tumor. It's not available to children under three, but is an option we should consider if we can delay radiation a bit longer.
Just the reduction of the cyst doesn't buy us a lot of extra time. The cyst has proven that it will continually refill, and it will be quick about it. The problem with just continually draining the cyst as a way to control things for a while is that the cyst may not fill uniformly. It could section off (as it appears to already have done once) and start filling in a portion that is not reached by the catheter.
Moving directly to proton radiation should keep the cyst from continually refilling. But, it isn't ideal to do it at such a young age. Her vision shouldn't be affected by proton therapy because the reduction of the cyst has pulled it away from the optic nerves, so the field of radiation wouldn't need to include that critical structure. Also, the major language and motor control centers are far enough away that they will not be affected. Proton therapy has the ability to aim the beams to avoid these areas.
What it can affect, and likely will to some extent, is her cognitive reasoning, short-term memory and pituitary function. There are some essentially guaranteed losses from radiation - growth hormone production being one of 5 or so hormones that she is quite likely to lose the ability to produce. All of them can be replaced. Some of the more difficult hormones to control, like the one that regulates urine output, is pretty unlikely to be affected, so that bodes well for Summer's quality of life going forward.
Dr. Douglas and Dr. Browd both touched on a new treatment option that came up in tumor board. I'll give an overview of it here, but we still have a lot of questions to ask Dr. Geyer about it too.
There is a treatment called Intracystic Bleomycin therapy (ICB), which is essentially localized chemotherapy, and that they think may help us buy time for radiation. Chemotherapy is generally not effective in treating this particular type of brain tumor. In fact, even ICB wouldn't really do any damage to the tumor mass itself, but it could help control the cyst and keep it from re-filling.
They would inject Bleomycin directly into the cyst through the Ommaya reservoir and catheter they implanted on Monday. The when/frequency/dosage sort of details are all still questions I have. This should kill the tumor cells that line the cyst walls and produce the motor oil-like fluid that the tumor produces to fill the cyst.
I did some initial research online, and found that it seems to be a relatively successful treatment, with very few side effects. They would first need to test for leaks from the cyst by injecting contrast into the cyst and then performing a CT scan to check for leaks. If there are leaks present, the side-effects are much more concerning. If there aren't, the only side effect reported seems to be possible headaches at the time of injection.
Like I said, we still have TONS of questions for Dr. Geyer and I want to have him confirm the things I found online. But, this definitely sounds like something to consider.
If it doesn't work, we would just go on to radiation anyway. If it does, we have bought some time. I'm also curious to know how much time Dr. Geyer thinks it could realistically buy, given the growth in the tumor mass so far. Studies done report an average somewhere around two years. Even six months could be a compelling reason to try it.
I'll post more when I know more. We're hoping to see Dr. Geyer today, before we GO HOME! Summer has been like a broken record with that request the past couple of days. I certainly can't blame her!