Superficial blood flow following photodynamic therapy of malignant non-melanoma skin tumours measured by laser Doppler perfusion imaging

Wang, I; Andersson‐Engels, Stefan; Nilsson, Gert; Wårdell, Karin; Svanberg, Katarina

doi:10.1046/j.1365-2133.1997.d01-1166.x

Cited by 48 publications

(35 citation statements)

References 19 publications

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“…The administration of light doses up to 90 J/cm 2 and above seemed to cause similar damage to arterioles at both light fluence rates. At the light dose of 18 J/cm 2 , an increase of RBCCD rel occurred under 150 mW/cm 2 illumination, which might be due to a physiological reaction such as the vasospasm-induced subsequent dilation observed during PDT by Wang et al [15] and the increases in pulse caused by the photosensitizer injection [16]. The RBCCD rel of venules decreased more quickly against light dose than that of the arterioles, as shown in Fig.…”

Section: Changes Of Rbccd In Pdt At Different Fluence Ratesmentioning

confidence: 72%

Application of lower fluence rate for less microvasculature damage and greater cell-killing during photodynamic therapy

2005

Lasers Med Sci

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During the process of photodynamic therapy (PDT), problems arise such as stasis or occlusion of microvasculature, tumor oxygen depletion, and photosensitizer bleaching. This study shows that the first problem could be reduced by using a lower fluence rate light source in PDT. Microvasculature damage was studied experimentally in hematoporphyrin derivativemediated PDT against light fluence rate, and, to some extent, less microvasculature damage was induced under 75 mW/cm 2 illumination than under 150 mW/cm 2 . Histology of vessels at the end of PDT showed that vessel damage could be observed in both groups, indicating that the microvasculature would eventually be damaged as long as the administration of light fluence was sufficient and regardless of the illuminating fluence rates. Thus microvasculature damage induced by low fluence rate illumination could also be effective in tumor control after PDT. The cell-killing experiment was performed in vitro and designed so that cell-killing rate was influenced only by light characteristics. The higher cellkilling rate caused by 75 mW/cm 2 illumination indicated that lower fluence rate light could enhance the light absorbency or decrease the bleaching of photosensitizer.

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Section: Changes Of Rbccd In Pdt At Different Fluence Ratesmentioning

confidence: 72%

Application of lower fluence rate for less microvasculature damage and greater cell-killing during photodynamic therapy

2005

Lasers Med Sci

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“…Furthermore, the results from LDI also showed a decreased blood flow 3 and 6 days after the PDT treatment, which further verifies the above theory. The decreased blood flow following PDT after haematoporphyrin derivative or ALA systemic administration is in contrast to the increased blood flow observed after topical administration of ALA (Wang et al, 1996). This indicates that different mechanisms are in action for the two administration modalities.…”

Section: Discussionmentioning

confidence: 87%

Photodynamic therapy using intravenous δ-aminolaevulinic acid-induced protoporphyrin IX sensitisation in experimental hepatic tumours in rats

Svanberg

Liu²,

Wang³

et al. 1996

Br J Cancer

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Summary The efficacy of photodynamic therapy (PDT) using 6-aminolaevulinic acid (ALA)-induced protoporphyrin IX (PpIX) sensitisation and laser light at 635 nm was investigated in the treatment of experimental hepatic tumours. The model of liver tumours was induced either by local inoculation or by administration of tumour cells through the portal vein in rats. ALA at a dose of 60 mg kg-' b.w. was intravenously administered 60 min before PDT. PpIX accumulation in tumour, normal liver and abdominal wall muscle was detected by means of laser-induced fluorescence (LIF). Laser Doppler imaging (LDI) was used to determine changes in the superficial blood flow in connection with PDT. Histopathological examinations were performed to evaluate the PDT effects on the tumour and the surrounding liver tissue, including pathological features in the microvascular system. The accumulation of PpIX, as monitored by LIF, showed high fluorescence intensities at about 635 nm in both the hepatic tumour tissue and normal liver and low values in the abdominal wall. LDI demonstrated that the blood flow in the treated tumour and its surrounding normal liver tissue decreased immediately after the PDT, indicating an effect on the vascular system. A large number of thrombi in the irradiated tumour were found microscopically 3 h after the PDT. The tumour growth rate showed a marked decrease when evaluated 3 and 6 days after the treatment. These results show that the ALA-PDT is effective in the inhibition of growth of experimental hepatic tumours.

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“…Additionally, disturbances of the fluid refractive index resulting from large temperature fluctuations have caused the incident laser beam to wander and defocus [100]. In spite of this, LDPI technology has been demonstrated and used in the assessment of a plethora of clinical situations; for instance, assessment of burn extent [14,15] and relative perfusion [41,101,102], post-operative malignant skin tumour assessment [103], and in the study of arthritis and joint inflammation [104].…”

Section: Laser Doppler Imagingmentioning

confidence: 99%

‘Go with the flow ’: A review of methods and advancements in blood flow imaging

Daly

Leahy

2012

Journal of Biophotonics

110

108

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Physics has delivered extraordinary developments in almost every facet of modern life. From the humble thermometer and stethoscope to X‐Ray, CT, MRI, ultrasound, PET and radiotherapy, our health has been transformed by these advances yielding both morphological and functional metrics. Recently high resolution label‐free imaging of the microcirculation at clinically relevant depths has become available in the research domain. In this paper, we present a comprehensive review on current imaging techniques, state‐of‐the‐art advancements and applications, and general perspectives on the prospects for these modalities in the clinical realm. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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Superficial blood flow following photodynamic therapy of malignant non-melanoma skin tumours measured by laser Doppler perfusion imaging

Cited by 48 publications

References 19 publications

Application of lower fluence rate for less microvasculature damage and greater cell-killing during photodynamic therapy

Application of lower fluence rate for less microvasculature damage and greater cell-killing during photodynamic therapy

Photodynamic therapy using intravenous δ-aminolaevulinic acid-induced protoporphyrin IX sensitisation in experimental hepatic tumours in rats

‘Go with the flow ’: A review of methods and advancements in blood flow imaging

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