Barely 2 years old, Talia Pisano is getting tough treatment for kidney cancer that spread to her brain. She’s also getting a chance at having babies of her own someday. To battle infertility sometimes caused by cancer treatment, some children’s hospitals are trying a futuristic approach: removing and freezing immature ovary and testes tissue, with hopes of being able to put it back when patients reach adulthood and want to start families.