The importance of fluence rate in photodynamic therapy: is there a parallel with ionizing radiation dose-rate effects?

Abstract Several similarities can be found between dose-rate effects in radiotherapy and fluence-rate effects in photodynamic therapy (PDT). At low dose rates repair of sublethal damage can occur, whereas at high dose rates oxygen depletion can decrease the effects of both therapies. The available literature for fluence-rate effects in PDT is discussed here in relation to therapeutic implications.