Assessment:
1. MRI shows a brain tumor that is most likely a type of cancer called meningioma. A biopsy would be needed to
confirm the diagnosis, but is not safely able to be done. A spinal tap may be able to diagnose lymphoma, which is
one of the lesser possibilities of tumor type. A spinal tap would likely be nondiagnostic for other tumor types.
2. The tumor is damaging the optic nerves as the cause of blindness and dilated pupils.
3. The MRI is convincing for a tumor. I am surprised as Molly is only 4.5 years old.4. I naturally wonder if her episodes of staring out are caused by this mass as well. I think it makes sense, except
that means she had a brain tumor starting at 2.5 years of age, which seems both extremely young, and extremely
slow growing. Though young dogs sometimes do get cancer, their tumors are usually aggressive and rapidly
growing. So, the bottom line is I don't know what the cause of the episodes are.
The best treatment option for Molly is radiation. I would consider both stereotactic 5. radiation (SRT) and
conventional radiation. The best next step is to discuss radiation with a radiation oncologist. I recommend an
appointment with either Dr. Ira Gordon or Dr. Pamela White at The Oncology Service. They travel to several
locations; calling 571-209-1176 is the number to start to make an appointment.
6. Since the owners are not sure about pursuing radiation, one option they have is to repeat the MRI in a month and
pursue radiation if the tumor is rapidly growing (based on the notion that a rapidly growing tumor will be more
radiation responsive than a slow growing one). I asked the owner to ask the radiation oncologist their thoughts on
this logic and a reasonable time for repeating the MRI to determine this. As is stands, the owner is considering
repeating the MRI in a month. Two risks of waiting to radiate that we discussed are: radiation is generally more
effective during the more rapid growth phase of a smaller tumor; and that waiting may allow the tumor to
irreversibly damage a part of the brain that is currently healthy.
7. Hydroxyurea may be a good treatment option for Molly if radiation is not done. It may be effective (it's been shown
to temporarily shrink meningiomas), and is relatively safe and inexpensive. However, radiation is more effective
and lasting, and would help fight tumor types other than meningioma.
Recommendations:
1. Pursue consultation with Radiation Oncologist as described above.
2. If the plan is to repeat the MRI after a prescribed length of time, please call to schedule it.
3. If radiation will not be pursued, I would recommend starting hydroxyurea. Starting it now may cause the tumor to
shrink in a month, so if the follow up MRI is going to be used to make a decision about radiation, using hydroxyurea
may muddy the waters. Please discuss potential use of this drug with the radiation oncologist.
Follow-up and reassessment: Please call with an update after making a plan with the radiation oncologist.
I do know you also have to consider her quality of life for the time she has left. Do you want to prolong her life for such a short time when she'd be sick from the treatment? I can't advise you, other than to say - take a dog day - and do things she likes and give her treats and take lots of pictures.
