Irradiance-Dependent Photobleaching and Pain in δ-Aminolevulinic Acid-Photodynamic Therapy of Superficial Basal Cell Carcinomas

Cottrell, William; Paquette, Anne D.; Keymel, Kenneth R.; Foster, Thomas H.; Oseroff, Allan R.

doi:10.1158/1078-0432.ccr-07-5199

Cited by 133 publications

(147 citation statements)

References 38 publications

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“…As discussed in more detail in Liu et al, 7 a reduction in oxygen perfusion from local blood vessels during treatment was necessary to produce PpIX fluorescence photobleaching results in agreement with clinical measurements reported by Cottrell et al 3 early in the treatment (such as 1.2 J cm −2 ), the reduction in perfusion is the greatest for blue light due to the greatest absorption of PpIX at this wavelength as shown in Table 2. However, at 30 J cm −2 , there is little difference in the PDTinduced vascular responses.…”

Section: Treatment Simulationssupporting

confidence: 82%

“…In order to match clinical photobleaching data from Cottrell et al, 3 a PDT-induced reduction in blood perfusion was included. We recognize that there is no generally accepted independent evidence for this effect; measurements of blood flow during PDT have been inconclusive.…”

Section: Treatment Simulationsmentioning

confidence: 99%

“…2 Red light (633 nm) with its deeper penetration depth is usually used to treat superficial basal cell carcinoma (sBCC). 3 Studies have been conducted to investigate ALA-PDT efficacy at different wavelengths ranging from 405 to 420 nm (blue light) and 635 nm (red light). 4 Green light was also evaluated to compare ALA-PDT efficacy.…”

Section: Introductionmentioning

confidence: 99%

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Comparison of photodynamic therapy with different excitation wavelengths using a dynamic model of aminolevulinic acid-photodynamic therapy of human skin

2012

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Abstract. Different wavelength light sources are used in photodynamic therapy (PDT) of the skin to treat different conditions. Clinical studies show inconsistent results for the effectiveness of aminolevulinic acid (ALA)-PDT performed at different wavelengths. In order to understand the effect of treatment wavelength, a theoretical study was performed to calculate time-resolved depth-dependent distributions of PDT components including ground-state oxygen, sensitizer, and reacted singlet oxygen for different treatment wavelengths (405, 523, and 633 nm) using a numerical model of ALA-PDT of human skin. This model incorporates clinically relevant features of the PDT process including light attenuation, photobleaching, oxygen consumption, and diffusion, as well as tissue perfusion. The calculations show that the distributions of these quantities are almost independent of the treatment wavelength to a depth of about 1 mm. In this surface region, PDT-induced hypoxia is the dominant process. At greater depths, the production of singlet -oxygen is governed by the penetration of the treatment light. Two noninvasive PDT dosimetry approaches: the cumulative singlet oxygen luminescence (CSOL) and the fractional fluorescence bleaching metric, were investigated and compared for all three wavelengths. Although CSOL was more robust, both metrics provided correlations with the singlet oxygen dose in the upper dermis that were almost independent of treatment wavelength. This relationship breaks down at greater depths because light penetration depends on wavelength.

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Section: Treatment Simulationssupporting

confidence: 82%

Section: Treatment Simulationsmentioning

confidence: 99%

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Comparison of photodynamic therapy with different excitation wavelengths using a dynamic model of aminolevulinic acid-photodynamic therapy of human skin

2012

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“…It is not yet clear whether this relative nerve sparing is a feature particular to mTHPC or shared with other photosensitisers. Indeed, PDT using topical administration of another photosensitiser, 5-aminolevulinic acid, is associated with pain, perhaps through a direct interaction with peripheral nerve endings in skin undergoing treatment (Stender et al, 2006;Cottrell et al, 2008). A photosensitiser that enables PDT to be used effectively to destroy tumours but spares nerve tissue would be a valuable tool in the treatment of tumours whose location makes nerve damage a likely side effect of traditional surgical treatments.…”

mentioning

confidence: 99%

Peripheral neural cell sensitivity to mTHPC-mediated photodynamic therapy in a 3D in vitro model

et al. 2009

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BACKGROUND: The effect of photodynamic therapy (PDT) on neural cells is important when tumours are within or adjacent to the nervous system. The purpose of this study was to investigate PDT using the photosensitiser, meta-tetrahydroxyphenyl chlorin (mTHPC), on rat neurons and satellite glia, compared with human adenocarcinoma cells (MCF-7). METHODS: Fluorescence microscopy confirmed that mTHPC was incorporated into all three cell types. Sensitivity of cells exposed to mTHPC-PDT (0 -10 mg ml -1 ) was determined in a novel 3-dimensional collagen gel culture system. Cell death was quantified using propidium iodide and cell types were distinguished using immunocytochemistry. In some cases, neuron survival was confirmed by measuring subsequent neurite growth in monolayer culture. RESULTS: MCF-7s and satellite glia were significantly more sensitive to PDT than neurons. Importantly, 4 mg ml -1 mTHPC-PDT caused no significant neuron death compared with untreated controls but was sufficient to elicit substantial cell death in the other cell types. Initially, treatment reduced neurite length; neurons then extended neurites equivalent to those of untreated controls. The protocol was validated using hypericin (0 -3 mg ml -1 ), which caused neuron death equivalent to other cell types. CONCLUSION: Neurons in culture can survive mTHPC-PDT under conditions sufficient to kill tumour cells and other nervous system cells.

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“…Potentially, one of the most important of these variables in the planning of PDT dosimetry is the mucosal oxygen content. Some groups have used noninvasive fiber optic diffuse reflectance measurements to determine local oxygenation of various tissues (22,23).…”

Section: Discussionmentioning

confidence: 99%

Pilot Study on Light Dosimetry Variables for Photodynamic Therapy of Barrett's Esophagus with High-Grade Dysplasia

Gill

Wolfsen

Preyer

et al. 2009

Clinical Cancer Research

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Purpose: Photodynamic therapy (PDT) is used to treat Barrett's esophagus with high-grade dysplasia and mucosal carcinoma. Outcomes are variable with some patients having persistent disease, whereas others develop strictures. The aims of this study were (a) to compare porfimer sodium tissue uptake, light dose, and esophageal thickness with clinical outcomes and (b) to determine the selectivity of porfimer sodium uptake in diseased and normal epithelium. Experimental Design: Forty-eight hours after porfimer sodium infusion, patients underwent mucosal biopsy for quantification of the porfimer sodium. Laser light was delivered at 48 hours and again 24 or 48 hours later. Porfimer sodium was extracted from the biopsy samples and quantified using fluorescence spectroscopy. The enhanced photodynamic dose was determined as [porfimer sodium content * light dose/esophageal thickness]. PDT efficacy was determined 6 to 8 weeks later based on persistence or complete ablation of dysplasia or carcinoma. Results: Mean porfimer sodium content of 6.2 mg/kg (range, 2.6-11.2 mg/kg) and mean total light dose of 278 J/cm (range, 225-360 J/cm) resulted in a complete treatment. Mean porfimer sodium tissue content of 3.9 mg/kg (range, 2.1-8.1mg/kg) and mean total light dose of 268 J/cm (range, 250-350 J/cm) resulted in an incomplete treatment. The total esophageal thickness (range, 1.7-6.0 mm) and enhanced photodynamic dose were correlated with treatment outcome. Conclusions: Esophageal thickness is the strongest predictor of treatment outcome. The porfimer sodium content of Barrett's and normal tissue is not significantly different. ''Photodynamic dose'' for esophageal PDTshould incorporate the esophageal thickness.

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Irradiance-Dependent Photobleaching and Pain in δ-Aminolevulinic Acid-Photodynamic Therapy of Superficial Basal Cell Carcinomas

Cited by 133 publications

References 38 publications

Comparison of photodynamic therapy with different excitation wavelengths using a dynamic model of aminolevulinic acid-photodynamic therapy of human skin

Comparison of photodynamic therapy with different excitation wavelengths using a dynamic model of aminolevulinic acid-photodynamic therapy of human skin

Peripheral neural cell sensitivity to mTHPC-mediated photodynamic therapy in a 3D in vitro model

Pilot Study on Light Dosimetry Variables for Photodynamic Therapy of Barrett's Esophagus with High-Grade Dysplasia

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