報告題目：Radioluminescence Imaging Based Spatiotemporal dosimetry and oximetry for FLASH radiotherapy
報 告 人：張榮曉
報告地點：騰訊會議925 189 211
Radiation therapy is anessential component of cancer care and over 14 million people a year, which is50% – 60% of total cancer patients. The capabilities available for cliniciansto localize and deliver precise amounts of radiation to specific anatomies haveimproved dramatically over recent years, due to advances in imaging guidance,treatment planning and dose delivery technologies. However, we are now facing along-lasting bottleneck to further improve the therapeutic ratio, i.e. tumorcontrol vs. normal tissue toxicity. Recent advances in ultra-high doseradiotherapy, abbreviated as FLASH, have shown the potential for reduction inhealthy tissue damage while preserving tumor control. FLASH therapy relies on very highdose rate of > 40Gy/sec with sub-second temporal beam modulation, taking aseemingly opposite direction from the conventional paradigm of fractionatedtherapy. With this, FLASH brings unique challenges to its dosimetry. Whilespatial dose conformity delivered to a target volume has been pushed to itspractical limits with advanced treatment planning and delivery, FLASH RTnecessitates novel spatiotemporal dosimetry techniques. The FLASH effect hasbeen reported mainly based upon phenomenological observations with tissuefunction assays, rather than mechanistic in situ measurements. There areseveral radiobiological hypotheses around the mechanisms for less damage, howeverto date none are directly proven, and indeed the data supporting any mechanismis glaringly absent. The central feature dominating most proposed mechanisms islinked to the fact that oxygen depletion, which is expected to occur rapidly atFLASH dose rates, via oxygen radical production with consumption from oxidationreactions.