Physics of Photodynamic Therapy

Madsen, Steen J.

doi:10.1007/978-1-4939-1758-7_18

Cited by 3 publications

(4 citation statements)

References 87 publications

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“…Inelastic scattering (Raman and Brillouin) is negligible in PDT applications and can be safely ignored . Major highly absorbing molecules in tissue include water, oxyhemoglobin, deoxyhemoglobin, melanin, and cytochromes . When light absorption occurs, the absorbed radiation is mainly converted into heat by the absorbing chromophore in tissue.…”

Section: Introductionmentioning

confidence: 99%

Light Sources and Dosimetry Techniques for Photodynamic Therapy

Kim

Darafsheh

2020

Photochem & Photobiology

302

225

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Effective treatment delivery in photodynamic therapy (PDT) requires coordination of the light source, the photosensitizer, and the delivery device appropriate to the target tissue. Lasers, light‐emitting diodes (LEDs), and lamps are the main types of light sources utilized for PDT applications. The choice of light source depends on the target location, photosensitizer used, and light dose to be delivered. Geometry of minimally accessible areas also plays a role in deciding light applicator type. Typically, optical fiber‐based devices are used to deliver the treatment light close to the target. The optical properties of tissue also affect the distribution of the treatment light. Treatment light undergoes scattering and absorption in tissue. Most tissue will scatter light, but highly pigmented areas will absorb light, especially at short wavelengths. This review will summarize the basic physics of light sources, and describe methods for determining the dose delivered to the patient.

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Section: Introductionmentioning

confidence: 99%

Light Sources and Dosimetry Techniques for Photodynamic Therapy

Kim

Darafsheh

2020

Photochem & Photobiology

302

225

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“…In Rayleigh scattering, the size of the particles involved in scatterings, such as atoms or molecules, is much less than the wavelength of incident light (1). In contrast, for Mie scattering, the size of the particles involved in scattering is comparable to the wavelength of the incident light [47,49]. Rayleigh scattering depends more strongly on the wavelength of the incident light compared to Mie scattering, and the intensity of scattered light in Rayleigh scattering is proportional to (1/ ) [50].…”

Section: Non-invasive Glucose Sensing Methods Based On Intrinsic Propmentioning

confidence: 99%

“…Elastic and inelastic scattering are two types of scattering of light. For elastic scattering, the energy of scattered light is equal to the energy of incident light (i.e., λ1 = λ scattered_light ) while in inelastic scattering, the energy of scattered light is less or greater than incident light (i.e., λ1 λ scattered_light ) [48,49]. Scattered light can be in any direction/angle (from backscattering to forward scattering), and is affected by material structure and energy of incident light.…”

Section: Mid-infrared and Near-infrared Spectroscopymentioning

confidence: 99%

Review of Non-Invasive Glucose Sensing Techniques: Optical, Electrical and Breath Acetone

Shokrekhodaei

Quinones

2020

Sensors

156

109

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Annual deaths in the U.S. attributed to diabetes are expected to increase from 280,210 in 2015 to 385,840 in 2030. The increase in the number of people affected by diabetes has made it one of the major public health challenges around the world. Better management of diabetes has the potential to decrease yearly medical costs and deaths associated with the disease. Non-invasive methods are in high demand to take the place of the traditional finger prick method as they can facilitate continuous glucose monitoring. Research groups have been trying for decades to develop functional commercial non-invasive glucose measurement devices. The challenges associated with non-invasive glucose monitoring are the many factors that contribute to inaccurate readings. We identify and address the experimental and physiological challenges and provide recommendations to pave the way for a systematic pathway to a solution. We have reviewed and categorized non-invasive glucose measurement methods based on: (1) the intrinsic properties of glucose, (2) blood/tissue properties and (3) breath acetone analysis. This approach highlights potential critical commonalities among the challenges that act as barriers to future progress. The focus here is on the pertinent physiological aspects, remaining challenges, recent advancements and the sensors that have reached acceptable clinical accuracy.

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“…The difference between apoptosis and necrosis is that the apoptosis is ordinarily lasts a lifetime and be profitable for the body, whereas the necrosis is cell death caused by the cellular damage acutely. 3,11 Apoptosis has characteristic morphological advantage like plasma membrane blebbing, cell shrinkage, chromatin condensation and deoxyribonucleic acid fragmentation, and commences with the enzymes of the caspase proteases form a complex series of Cysteine protease activation of multi unit called. 5,12 Figure 1: Biological mechanism of apoptosis programmed cell death.…”

Section: Introductionmentioning

confidence: 99%

Cancer Treatment Based on the Selective Accumulation of a Photosensitiser and Laser Light Irradiation: A Review

Timimi

2021

Bangladesh Med Res Counc Bull

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Background: Cancer Photodynamic Therapy (CPDT) is a promising future treatment quality based on the selective accumulation of a photosensitiser in the malignant tissues and the dependent irradiation with laser light. Objective: The aim of this work was to estimate an optimum effect involves the performance of a photosensitizing agent served by irradiation at a wavelength corresponding to an absorbance band of the sensitizer. In the appearance of oxygen, a series of effects lead to direct tumour cell death and damage to the microvasculature and initiation of a local inflammatory reaction. Methods: Photosensitiser is a material that sensitizes an organism, cell, or tissue to the light. It is a deeprooted part of CPDT, which absorbed by cancerous cells and exposed to laser light, gets activated, damaging and killing cancer cells. The direct targeting of laser source on hyper proliferative tissue and its preferential origin absorption at the targeted site gives rise CPDT double selectivity with least damage to adjacent normal tissues. Results: Photosensitiser absorbs the light and then produces an active form of oxygen, which destroys nearby cancer cells. The photosensitiser is able to spoil the blood vessels in the tumour, that way preventing cancer from receiving any necessary nutrients. The light which needed to activate most of the photosensitisers cannot pass through more than about one-third of an inch of tissue, because of that reason, the CPDT is usually used to treat cancer on or just under the skin or on the lining of internal organs. In addition, CPDT may activate the immune system to attack the tumour cells, directly killing cancer cells. Conclusion: This review focuses on the aspects of CPDT as an advanced and original site directed therapy for cancer treatment and the other non-oncogenic diseases. Minimal average of tissue toxicity controlled a long-term morbidity, deficiency of intrinsic or acquired resistance mechanisms. Bangladesh Med Res Counc Bull 2020; 46(3): 150-153

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Physics of Photodynamic Therapy

Cited by 3 publications

References 87 publications

Light Sources and Dosimetry Techniques for Photodynamic Therapy

Light Sources and Dosimetry Techniques for Photodynamic Therapy

Review of Non-Invasive Glucose Sensing Techniques: Optical, Electrical and Breath Acetone

Cancer Treatment Based on the Selective Accumulation of a Photosensitiser and Laser Light Irradiation: A Review

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