chemoradiotherapy

noun

che·​mo·​ra·​dio·​ther·​a·​py -ˌrād-ē-ō-ˈther-ə-pē 

: treatment that combines chemotherapy and radiotherapy

Concomitant chemoradiotherapy is an attractive option for the treatment of head and neck cancer. In concomitant chemoradiotherapy, chemotherapy is used primarily to sensitize tumor cells to radiation therapy and increase locoregional control.

—Everett E. Vokes, Scientific American Medicine

called also chemoradiation