[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-439680-105":59,"doc-detail-439680-en":130},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":123,"head_meta":125,"extra_data":127,"updated_unix":129},105,"en","flash-photodynamic-therapy-how-the-saturation-of-photosensitizer-absorption-enables-selective-and-deeper-tumor-treatments","Flash Photodynamic Therapy - How the Saturation of Photosensitizer Absorption Enables Selective and Deeper Tumor Treatments","","Flash photodynamic therapy (FLASH-PDT) is highlighted for its ability to spare normal tissues while preserving tumor-destroying efficacy compared with continuous radiation delivery. A theoretical model explains how pulsed lasers, together with photosensitizers, can achieve selective and deeper tumor ablation when photosensitizer absorption is saturated. Pulse number requirements for tumor destruction and normal-tissue sparing are validated in CT26 and 4T1 tumor models, including improved survival with redaporfin, supporting higher drug or light doses without harming healthy tissues.",{"@graph":69,"@context":122},[70,84,105],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":35,"@type":76,"position":81},"https://docshare.wps.com/document/healthcare/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/flash-photodynamic-therapy-how-the-saturation-of-photosensitizer-absorption-enables-selective-and-deeper-tumor-treatments/439680/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/flash-photodynamic-therapy-how-the-saturation-of-photosensitizer-absorption-enables-selective-and-deeper-tumor-treatments/439680.png","ImageObject",300,407,{"name":92,"@type":93},"Chumphorn","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-01","2026-09-29",true,{"@type":102,"interactionType":103,"userInteractionCount":14},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"What key condition enables the FLASH effect in photodynamic therapy?","Question",{"text":112,"@type":113},"Photosensitizer absorption must be saturated to obtain the FLASH effect.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"How does FLASH-PDT differ from conventional delivery in terms of treatment depth and selectivity?",{"text":117,"@type":113},"FLASH-PDT enables selective and deeper tumor treatments while sparing normal tissue compared with continuous delivery.",{"name":119,"@type":110,"acceptedAnswer":120},"Which tumor models were used to validate the model predictions?",{"text":121,"@type":113},"The model predictions and the superiority of FLASH-PDT were validated using subcutaneous CT26 and orthotopic 4T1 tumor models, with redaporfin increasing overall survival in 4 mm orthotopic 4T1 tumors and lung metastasis.","https://schema.org",{"og:url":83,"og:type":124,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":126,"canonical":83},"index,follow",{"doc_id":128,"site_id":62},439680,1790812932,{"code":4,"msg":5,"data":131},{"doc_id":128,"user_id":132,"nickname":92,"user_avatar":133,"doc_module":4,"category_id":34,"category_name":35,"doc_title":65,"doc_description":67,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":14,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":139,"language":140,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":141,"faqs":142,"seo_title":143,"seo_description":67,"update_tm":144,"read_time":145},2336475401981,"https://ap-avatar.wpscdn.com/avatar/22000c94efd8d5204d?x-image-process=image/resize,m_fixed,w_180,h_180&k=1786935347598174694","RESEARCH ARTICLE  \n[www.advancedscience.com](www.advancedscience.com)  \nFlash Photodynamic Therapy – How the Saturation of Photosensitizer Absorption Enables Selective and Deeper Tumor Treatments  \nLuis G. Arnaut,* Fábio A. Schaberle, José Sereno, and Lígia C. Gomes-da-Silva  \nFLASH therapies are attracting tremendous interest because they spare normal tissues while maintaining tumor-destroying efficacy, when compared with continuous delivery of radiation. In Photodynamic Therapy (PDT), it has been noted that continuous-wave and pulsed lasers give comparable results for a variety of tumors, but the conditions for increased tumor-to-peritumoral tissue selectivity have never been reported. This work presents a model that explains how pulsed lasers, in combination with photosensitizers, can offer selective and in-depth tumor ablation. It is shown that the photosensitizer absorption must be saturated to obtain the FLASH effect. The importance of the number of laser pulses to destroy tumor tissue and spare normal tissue is demonstrated. The predictions of the model and the superiority of  \nFLASH-PDT are validated with the treatment of subcutaneous CT26 and orthotopic 4T1 tumors models. Notably, FLASH-PDT with redaporfinsignificantly increases the overall survival of mice with 4 mm orthotopic 4T1 tumors and lung metastasis. FLASH-PDT allows for the use of  \norder-of-magnitude higher drug or light doses without affecting healthy tissues, while promoting selective and deeper tumor treatments.  \nprobability curves. In radiotherapy (RT), the radiation dose that kills normal tissues in only 1.5 to 3 times higher than that required to kill tumor cells. [1] The delivery of ultrahigh dose-rate radiation, named FLASHRT,[2] was shown to damage tumor cells with the same efficiency as the conventional delivery of radiation, but to spare ~~more~~ normal tissue, allowing for the use of 20–30% higher doses with the same toxicity.[3] Differences in reactive oxygen species (ROS) seem to account for differences in FLASH and conventional radiotherapies, but this is still a matter of debate. [4] ROS also mediates the photodynamic effect. Continuous and pulsed laser sources have been investigated in PDT, but FLASH selectivity in PDT has never been reported.  \nPDT uses red/infrared light to excite a photosensitizer molecule in the presence of molecular oxygen (3 O2 ), to generate ROS and trigger cell death. Photosensitizer development was driven by the maximization of intense electronic  \n1. Introduction  \nContinuous sources used in radiotherapy (electrons, protons, ionizing photons) or in photodynamic therapy (non-ionizing photons) are associated with narrow separations between the tumor control probability and the normal tissue complication  \nL. G. Arnaut, F. A. Schaberle, L. C. Gomes-da-Silva CQC-IMS  \nDepartment of Chemistry University of Coimbra Coimbra 3004-535, Portugal E-mail: [lgarnaut@ci. uc.pt](lgarnaut@ci. uc.pt)  \nJ. Sereno  \nCoimbra Institute for Biomedical Imaging and Translational Research (CIBIT)  \nUniversity of Coimbra  \nCoimbra 3000-548, Portugal  \nThe ORCID identification number(s) for the author(s) of this article  \ncan be found under [https://doi.org/10.1002/advs.202513199](https://doi.org/10.1002/advs.202513199)[ ](https://doi.org/10.1002/advs.202513199)© 2025 The Author(s). Advanced Science published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.  \nDOI: 10.1002/advs.202513199  \ntransitions in the phototherapeutic window (650–850 nm), where photons with sufficient energy to generate ROS penetrate more deeply in human tissues. [5] Singlet states have lifetimes (􀀂S ) that are too short to react with 3 O2 , and ROS precursors are the photosensitizers triplet states.  \nSolid tumor responses to PDT with continuous-wave (CWPDT) or pulsed lasers were typically compared using the sa","cbCaidMIoo0s31q7","https://ap.wps.com/l/cbCaidMIoo0s31q7","pdf",2133578,11,"English","# Introduction\n## Flash therapies in radiotherapy and PDT selectivity\n## PDT mechanism and photosensitizer roles\n## Comparison of continuous-wave and pulsed laser PDT studies\n## Rationale for saturation and modeling approach","[{\"question\":\"What key condition enables the FLASH effect in photodynamic therapy?\",\"answer\":\"Photosensitizer absorption must be saturated to obtain the FLASH effect.\"},{\"question\":\"How does FLASH-PDT differ from conventional delivery in terms of treatment depth and selectivity?\",\"answer\":\"FLASH-PDT enables selective and deeper tumor treatments while sparing normal tissue compared with continuous delivery.\"},{\"question\":\"Which tumor models were used to validate the model predictions?\",\"answer\":\"The model predictions and the superiority of FLASH-PDT were validated using subcutaneous CT26 and orthotopic 4T1 tumor models, with redaporfin increasing overall survival in 4 mm orthotopic 4T1 tumors and lung metastasis.\"}]","Flash Photodynamic Therapy - How the Saturation of Photosensitizer Absorption Enables Selective and Deeper Tumor Treatments | PDF",1790689857,28]