Laying down in the plastic donut for half an hour gives you time to think.
It would be nice, usually, to be left alone with your thoughts for awhile.

But your head is packed tightly into a cage that covers your face so you can't move.
Your arm has a Mickey Mouse bandaid covering your vein because you've just had a shot.
The clanks and whirls of the machine are so loud you can hear them through the head padding and ear plugs.
It starts to give you a killer headache.

29 minutes to go.

What can you think about except your brain?
Every repeated scan or long interlude between them seals your fate in your mind.
"They've found another one" you say over and over because what else could account for it?

The lights come on and they slide you out.
They take off the cage and the pads and ask you if you're okay.
You actually have a really bad headache and are dizzy from lying down flat so long, but you say "yep" and go upstairs anyway.
There you wait on a paper-covered chair for the results.
You aren't afraid to die or to live, but you are still filled with anxiety.

"No growth" they say.
Your remaining 85% of your brain is tumor-free.
That's nice.
But even that doesn't completely dispel your fear because you know your odds.
40/60 your tumor will come back.
Those sound like good odds, but "good odds" don't exist when you get one of the rarest brain cancers on Earth at age 15.

You go home to your family with good news and wait three months to face it all over again.