Hospital

Operating / mom
During an operation, the doctor removes the nasty cancer cells. Mama has to go to the hospital for a few nights. After the operation she has a bandage around her breast, because the doctor not only removes the mean cancer cells but also a piece of the breast, or sometimes even the entire breast. After that the wound has to get better again.
Are the nasty cancer cells with your mother somewhere else? Even then the doctor sometimes has to operate.

Operating / dad
During an operation, the doctor removes the nasty cancer cells. Dad needs to go to the hospital for a few nights for that. If Daddy had surgery on his stomach, he has a large patch or bandage on his stomach. This way the wound can get better.
Are the mean cancer cells at your dad's somewhere else? Even then the doctor sometimes has to operate.

Chemotherapy
Chemotherapy is a special type of medicine that comes in a syringe, pill or bag. It sometimes has a crazy color. It helps if you imagine that there are little men in it. Those chemo males do their very best to chase away the nasty cancer cells. Your mom or dad gets a lot of chemomedicines. This is necessary because nasty cancer cells cannot be defeated that easily. Fortunately the chemo males have a lot and they are very strong.

Irradiation / mom
This mom is irradiated on her chest. First, stripes are drawn on her chest. This way the doctor knows exactly where the rays should go. Those rays come from a large device that is in the hospital. You don't see, hear and feel them, and yet they kill the nasty cancer cells. Is not it great. Mama has to go to the hospital every day for it.
If your mama is not irradiated on her breast but on another part of her body, the rays kill the nasty cancer cells there too.

Irradiation / dad
This dad is being irradiated on his lungs. First, stripes are drawn on his chest. This way the doctor knows exactly where the rays should go. Those rays come from a large device that is in the hospital. You don't see, hear and feel them, and yet they kill the nasty cancer cells. Is not it great. Daddy has to go to the hospital every day for it.
If your dad is not irradiated on his lungs but on another part of his body, the rays kill the nasty cancer cells there too.