The Application of a Compact Multispectral Imaging System with Integrated Excitation Source to In vivo Monitoring of Fluorescence During Topical Photodynamic Therapy of Superficial Skin Cancers¶

Hewett, Jacqueline; Nadeau, Valerie; Ferguson, J.; Moseley, Harry; Ibbotson, Sally H.; Allen, John; Sibbett, W.; Padgett, Miles J.

doi:10.1562/0031-8655(2001)0730278taoacm2.0.co2

Cited by 44 publications

(18 citation statements)

References 15 publications

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“…We have shown that the majority of the PpIX fluorescence signal has disappeared halfway during treatment, is no longer visible to the naked eye, and is again further reduced albeit to a lesser extent at the end of treatment. Similar clinical findings have been reported by Hewett et al, 36 where they point out that there was a discernible reduction in PpIX fluorescence after only 100 s (dose = 12 J/cm 2 ). Furthermore, they state that the 630-nm fluorescence was reduced to the surrounding tissue background level by 300 s into the treatment.…”

Section: Discussionsupporting

confidence: 89%

Monte Carlo modeling of in vivo protoporphyrin IX fluorescence and singlet oxygen production during photodynamic therapy for patients presenting with superficial basal cell carcinomas

et al. 2011

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We present protoporphyrin IX (PpIX) fluorescence measurements acquired from patients presenting with superficial basal cell carcinoma during photodynamic therapy (PDT) treatment, facilitating in vivo photobleaching to be monitored. Monte Carlo (MC) simulations, taking into account photobleaching, are performed on a three-dimensional cube grid, which represents the treatment geometry. Consequently, it is possible to determine the spatial and temporal changes to the origin of collected fluorescence and generated singlet oxygen. From our clinical results, an in vivo photobleaching dose constant, β of 5-aminolaevulinic acid-induced PpIX fluorescence is found to be 14 ± 1 J/cm(2). Results from our MC simulations suggest that an increase from our typical administered treatment light dose of 75-150 J/cm(2) could increase the effective PDT treatment initially achieved at a depth of 2.7-3.3 mm in the tumor, respectively. Moreover, this increase reduces the surface PpIX fluorescence from 0.00012 to 0.000003 of the maximum value recorded before treatment. The recommendation of administrating a larger light dose, which advocates an increase in the treatment time after surface PpIX fluorescence has diminished, remains valid for different sets of optical properties and therefore should have a beneficial outcome on the total treatment effect.

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Section: Discussionsupporting

confidence: 89%

Monte Carlo modeling of in vivo protoporphyrin IX fluorescence and singlet oxygen production during photodynamic therapy for patients presenting with superficial basal cell carcinomas

et al. 2011

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“…This has allowed for the use of PpIX fluorescence to detect and visualize tumors and other abnormal tissues. (Hewett, et al, 2001) More recently, PpIX was conjugated with cyclic RGDfK peptide, and the conjugate showed significant retention and accumulation in tumor tissue along with higher tumor to normal tissue ratios than the free PpIX in a mouse CaNT tumor model. (Conway, et al, 2008)…”

Section: Commentarymentioning

confidence: 99%

Near‐Infrared Molecular Probes for In Vivo Imaging

et al. 2012

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Cellular and tissue imaging in the near‐infrared (NIR) wavelengths between 700 and 900 nm is advantageous for in vivo imaging because of the low absorption of biological molecules in this region. This unit presents protocols for small animal imaging using planar and fluorescence lifetime imaging techniques. Included is an overview of NIR fluorescence imaging of cells and small animals using NIR organic fluorophores, nanoparticles, and multimodal imaging probes. The development, advantages, and application of NIR fluorescent probes that have been used for in vivo imaging are also summarized. The use of NIR agents in conjunction with visible dyes and considerations in selecting imaging agents are discussed. We conclude with practical considerations for the use of these dyes in cell and small animal imaging applications. Curr. Protoc. Cytom. 60:12.27.1‐12.27.20. © 2012 by John Wiley & Sons, Inc.

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“…They used this multi-color imaging system to construct a false color-coded image to use as a tool for delineation of malignant tumors, and for monitoring PS levels during PDT. Other groups took similar approaches, constructing false-color maps from fluorescent images recorded at two or three wavelengths, which could be used to try to monitor PpIX levels during PDT [61, 62]. …”

Section: Detection Of Ppix In the Skin Using Surface Measurementsmentioning

confidence: 99%

Techniques for fluorescence detection of protoporphyrin IX in skin cancers associated with photodynamic therapy

Rollakanti

Kanick

Davis

et al. 2013

Photonics &Amp; Lasers in Medicine

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Photodynamic therapy (PDT) is a treatment modality that uses a specific photosensitizing agent, molecular oxygen, and light of a particular wavelength to kill cells targeted by the therapy. Topically administered aminolevulinic acid (ALA) is widely used to effectively treat cancerous and precancerous skin lesions, resulting in targeted tissue damage and little to no scarring. The targeting aspect of the treatment arises from the fact that ALA is preferentially converted into protoporphyrin IX (PpIX) in neoplastic cells. To monitor the amount of PpIX in tissues, techniques have been developed to measure PpIX-specific fluorescence, which provides information useful for monitoring the abundance and location of the photosensitizer before and during the illumination phase of PDT. This review summarizes the current state of these fluorescence detection techniques. Non-invasive devices are available for point measurements, or for wide-field optical imaging, to enable monitoring of PpIX in superficial tissues. To gain access to information at greater tissue depths, multi-modal techniques are being developed which combine fluorescent measurements with ultrasound or optical coherence tomography, or with microscopic techniques such as confocal or multiphoton approaches. The tools available at present, and newer devices under development, offer the promise of better enabling clinicians to inform and guide PDT treatment planning, thereby optimizing therapeutic outcomes for patients.

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The Application of a Compact Multispectral Imaging System with Integrated Excitation Source to In vivo Monitoring of Fluorescence During Topical Photodynamic Therapy of Superficial Skin Cancers¶

Cited by 44 publications

References 15 publications

Monte Carlo modeling of in vivo protoporphyrin IX fluorescence and singlet oxygen production during photodynamic therapy for patients presenting with superficial basal cell carcinomas

Monte Carlo modeling of in vivo protoporphyrin IX fluorescence and singlet oxygen production during photodynamic therapy for patients presenting with superficial basal cell carcinomas

Near‐Infrared Molecular Probes for In Vivo Imaging

Techniques for fluorescence detection of protoporphyrin IX in skin cancers associated with photodynamic therapy

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