TH-C-T-6C-02: A Kernel-Based Model for Light Fluence Rate Calculation in Prostate Photodynamic Therapy

2005 ◽  
Vol 32 (6Part21) ◽  
pp. 2161-2162
Author(s):  
J Li ◽  
T Zhu
2010 ◽  
Vol 37 (6Part5) ◽  
pp. 3140-3140
Author(s):  
J Sandell ◽  
C Chang ◽  
T Zhu

2019 ◽  
Vol 25 (1) ◽  
pp. 1-6 ◽  
Author(s):  
J. A. Rodrigues ◽  
R. Amorim ◽  
M. F. Silva ◽  
F. Baltazar ◽  
R. F. Wolffenbuttel ◽  
...  

1992 ◽  
Vol 132 (1) ◽  
pp. 120 ◽  
Author(s):  
Q. Chen ◽  
M. Chopp ◽  
M. O. Dereski ◽  
B. C. Wilson ◽  
M. S. Patterson ◽  
...  

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 1842 ◽  
Author(s):  
Nadine James ◽  
Ravindra Cheruku ◽  
Joseph Missert ◽  
Ulas Sunar ◽  
Ravindra Pandey

Photodynamic therapy (PDT) of cancer is dependent on three primary components: photosensitizer (PS), light and oxygen. Because these components are interdependent and vary during the dynamic process of PDT, assessing PDT efficacy may not be trivial. Therefore, it has become necessary to develop pre-treatment planning, on-line monitoring and dosimetry strategies during PDT, which become more critical for two or more chromophore systems, for example, PS-CD (Photosensitizer-Cyanine dye) conjugates developed in our laboratory for fluorescence-imaging and PDT of cancer. In this study, we observed a significant impact of variable light dosimetry; (i) high light fluence and fluence rate (light dose: 135 J/cm2, fluence rate: 75 mW/cm2) and (ii) low light fluence and fluence rate (128 J/cm2 and 14 mW/cm2 and 128 J/cm2 and 7 mW/cm2) in photobleaching of the individual chromophores of PS-CD conjugates and their long-term tumor response. The fluorescence at the near-infrared (NIR) region of the PS-NIR fluorophore conjugate was assessed intermittently via fluorescence imaging. The loss of fluorescence, photobleaching, caused by singlet oxygen from the PS was mapped continuously during PDT. The tumor responses (BALB/c mice bearing Colon26 tumors) were assessed after PDT by measuring tumor sizes daily. Our results showed distinctive photobleaching kinetics rates between the PS and CD. Interestingly, compared to higher light fluence, the tumors exposed at low light fluence showed reduced photobleaching and enhanced long-term PDT efficacy. The presence of NIR fluorophore in PS-CD conjugates provides an opportunity of fluorescence imaging and monitoring the photobleaching rate of the CD moiety for large and deeply seated tumors and assessing PDT tumor response in real-time.


2012 ◽  
Vol 10 (Suppl_2) ◽  
pp. S-14-S-17 ◽  
Author(s):  
Gary S. Rogers

A principal factor in determining the biologic consequences of photodynamic therapy (PDT) is the light fluence rate. Preclinical and, more recently, clinical studies have focused on low-irradiance schemes, suggesting that prolonged light exposure, better known as CLIPT (continuous low-irradiance PDT), may improve tumor control while reducing morbidity. After a brief look at the origin of light therapy and photosensitizers, this article turns to the promising animal research supporting the use of low- and ultra-low fluence rate PDT, which serves as the basis of the ongoing CLIPT dosimetry trials for patients with chest wall progression of breast cancer. The future of CLIPT seems to be a home-based therapy using a portable, self-contained energy delivery system.


Author(s):  
Nadine James ◽  
Ravindra R. Cheruku ◽  
Joseph R. Missert ◽  
Ulas Sunar ◽  
Ravindra K. Pandey

Photodynamic therapy (PDT) of cancer is dependent on three primary components: photosensitizer (PS), light, and oxygen. Because these components are interdependent and vary during the dynamic process of PDT, assessing PDT efficacy may not be trivial. Therefore, it has become necessary to develop pre-treatment planning, on-line monitoring and dosimetry strategies during PDT, which become more critical for two or more chromophore systems, e.g. PS-CD conjugates developed in our laboratory for fluorescence-imaging and PDT of cancer. In this study, we observed a significant impact of variable light dosimetry; (i) high light fluence and fluence rate (light dose: 135 J/cm2, fluence rate: 75 mW/cm2) and (ii) low light fluence and fluence rate (128 J/cm2 and 14 mW/cm2 and 128 J/cm2 and 7 mW/cm2) in photobleaching of the individual chromophores and their long-term tumor response. The fluorescence at the near-infrared (NIR) region of the PS-NIR fluorophore conjugate was assessed intermittently via fluorescence imaging. The loss of fluorescence, photobleaching, caused by singlet oxygen from the PS was mapped continuously during PDT. The tumor responses (BALB/c mice bearing Colon26 tumors) were assessed after PDT by measuring tumor sizes daily. Our results showed distinctive photobleaching kinetics rates between the PS and CD. Interestingly, compared to higher light fluence, the tumors exposed at low light fluence showed reduced photobleaching and enhanced long-term PDT efficacy. The presence of NIR fluorophore in PS-CD conjugates provides an opportunity of fluorescence imaging and monitoring the photobleaching rate of the CD moiety for large and deeply seated tumors and assessing PDT tumor response in real-time.


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