Purpose/Objective(s): Both FLASH radiotherapy (FLASH-RT) and spatially fractionated radiation therapy (SFRT) demonstrate remarkable normal tissue sparing while preserving antitumor efficacy comparable to conventional radiotherapy (CONV-RT). However, FLASH-RT and SFRT are quite different therapeutical strategies, FLASH-RT adopts ultra-high dose rates to protect normal tissue temporally, while SFRT uses alternating radiation of peak and valley dose to protect normal tissue spatially. We wondered whether FLASH-RT combined with SFRT exert a winning alliance.