Osteosarcoma is a type of bone cancer that predominantly affects adolescents. Reliable models that can predict prognosis and treatment response can help improve patient outcomes. However, conventional methods relying on the measurement of necrosis rate are limited by inter-assessor variability and may not accurately predict prognosis. Now, researchers have developed an AI model that can accurately measure the density of viable tumor cells after treatment which correlates well with prognosis and individual tumor cell response.