A Comparison of Dose Metrics to Predict Local Tumor Control for Photofrin-mediated Photodynamic Therapy
Haixia Qiu, Michele M. Kim, Rozhin Penjweini, Jarod C. Finlay, Theresa M. Busch, Tianhao Wang, Wensheng Guo, Keith A. Cengel, Charles B. Simone II, Eli Glatstein and Timothy C. Zhu
Version of Record online: 22 FEB 2017 | DOI: 10.1111/php.12719
This preclinical study examines light fluence, photodynamic therapy (PDT) dose and “apparent reacted singlet oxygen,” [1O2]rx, to predict local control rate (LCR) for Photofrin-mediated PDT of radiation-induced fibrosarcoma (RIF) tumors. LCR was stratified for different dose metrics for 74 mice (66 + 8 control). Complete tumor control at 14 days was observed for [1O2]rx ≥ 1.1 mm or PDT dose ≥1200 µm J cm−2 but cannot be predicted with fluence alone. LCR increases with increasing [1O2]rx and PDT dose but is not well correlated with fluence. Comparing dosimetric quantities, [1O2]rx outperformed both PDT dose and fluence in predicting tumor response and correlating with LCR.