Photodynamic therapy of actinic keratosis at varying fluence rates: assessment of photobleaching, pain and primary clinical outcome

Ericson, Marica B.; Sandberg, Carin; Stenquist, Bo; Gudmundson, Fredrik; Karlsson, Matilda; Am, Ros; Rosén, Arne; Larkö, Olle; Wennberg, Ann‐Marie; Rosdahl, Inger

doi:10.1111/j.1365-2133.2004.06211.x

Cited by 144 publications

(138 citation statements)

References 42 publications

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“…Our report has shown that the 4 parameters cannot be easily correlated, although PpIX fluorescence intensity, photobleaching and the clinical outcome can be. Surprisingly, to our knowledge [29,44,45,46], only a very limited number of publications have addressed this issue in detail. Our report demonstrates that this correlation, although not perfect, does exist, including in the medium to long term (>33 months), and that it can be measured with a set-up mainly made of commercially available parts.…”

Section: Discussionmentioning

confidence: 99%

“…Finally, there is a possibility that measuring the PS's photobleaching (i.e. the reduction in the fluorescence intensity of PpIX, caused by the PDT irradiation) may be a useful way to evaluate - and adjust - the administration of the PDT light dose [27,28,29,30,31]. If demonstrated, this simple way to individualize treatment parameters would render more complicated approaches unnecessary.…”

Section: Introductionmentioning

confidence: 99%

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Correlation between Protoporphyrin IX Fluorescence Intensity, Photobleaching, Pain and Clinical Outcome of Actinic Keratosis Treated by Photodynamic Therapy

Piffaretti

Zellweger

Kasraee³

et al. 2013

Dermatology

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Background: Photodynamic therapy (PDT) with Metvix® is a good therapeutic option to treat actinic keratosis, but it presents drawbacks (pain, lesion recurrences, heterogeneous outcome), emphasizing the possible need to individualize treatment. Objective: We assessed whether PDT clinical outcome and pain during treatment were correlated with protoporphyrin IX fluorescence intensity and photobleaching. Methods: 25 patients were treated by Metvix PDT. The outcome was evaluated after 1.3 (±0.4), 7.6 (±1.8), 13.2 (±1.2) and 33.6 (±3.0) months. After administration of Metvix, red light (632 ± 10 nm) was delivered with a light-emitting diode panel device. The outcome was assessed on a cosmetoclinical scale. Results: All patients who showed a fluorescence level before PDT treatment above a certain threshold had a complete recovery at 33.6 (±3.0) months. Conclusion: Our approach could be used to individualize PDT treatment based on the pretreatment fluorescence level, and to predict its long-term outcome.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Correlation between Protoporphyrin IX Fluorescence Intensity, Photobleaching, Pain and Clinical Outcome of Actinic Keratosis Treated by Photodynamic Therapy

Piffaretti

Zellweger

Kasraee³

et al. 2013

Dermatology

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“…With decreasing oxygen concentration, the quantum yield of singlet oxygen is also decreasing (42). Therefore, the light excitation of photosensitizers in photodynamic therapy of cancer is fractionated by using irradiation breaks of several minutes to allow oxygen supply to tumor areas (24,(43)(44)(45). This procedure was also used with biofilms of Streptococcus mutans, which were efficiently inactivated by light dose fractionation (46).…”

Section: Singlet Oxygen Luminescence For Variable and High Bacterial mentioning

confidence: 99%

The role of singlet oxygen and oxygen concentration in photodynamic inactivation of bacteria

Maisch¹,

Baier²,

Franz³

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

381

289

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New antibacterial strategies are required in view of the increasing resistance of bacteria to antibiotics. One promising technique involves the photodynamic inactivation of bacteria. Upon exposure to light, a photosensitizer in bacteria can generate singlet oxygen, which oxidizes proteins or lipids, leading to bacteria death. To elucidate the oxidative processes that occur during killing of bacteria, Staphylococcus aureus was incubated with a standard photosensitizer, and the generation and decay of singlet oxygen was detected directly by its luminescence at 1,270 nm. At low bacterial concentrations, the time-resolved luminescence of singlet oxygen showed a decay time of 6 ؎ 2 s, which is an intermediate time for singlet oxygen decay in phospholipids of membranes (14 ؎ 2 s) and in the surrounding water (3.5 ؎ 0.5 s). Obviously, at low bacterial concentrations, singlet oxygen had sufficient access to water outside of S. aureus by diffusion. Thus, singlet oxygen seems to be generated in the outer cell wall areas or in adjacent cytoplasmic membranes of S. aureus. In addition, the detection of singlet oxygen luminescence can be used as a sensor of intracellular oxygen concentration. When singlet oxygen luminescence was measured at higher bacterial concentrations, the decay time increased significantly, up to Ϸ40 s, because of oxygen depletion at these concentrations. This observation is an important indicator that oxygen supply is a crucial factor in the efficacy of photodynamic inactivation of bacteria, and will be of particular significance should this approach be used against multiresistant bacteria.luminescence ͉ oxygen depletion ͉ Staphylococcus aureus

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“…The experience of pain varies from patient to patient, but studies have suggested that the factors of importance for the discomfort of the patients are type of lesion, localization of lesion, size of area treated, sex, intensity of light delivery and light source [5, 6]. …”

Section: Introductionmentioning

confidence: 99%

Pain and Photodynamic Therapy

Lindeburg¹,

Brogaard²,

Jemec³

2007

Dermatology

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Background: Photodynamic therapy (PDT) is increasingly used in the treatment of various skin diseases. The main adverse effect in PDT treatment is pain. Each lesion is generally treated twice, and clinical experience suggests that the 2nd treatment causes more pain than the 1st and thus becomes a therapy-limiting factor. Objectives: To investigate the intrapatient variation in the experience of pain, between 1st and 2nd PDT treatments. Methods: We registered patients treated with PDT by using a mechanical visual analogue scale (VAS). Patients were tested immediately after the 1st and 2nd PDT treatments. Intrapatient comparison was made comparing 1st and 2nd treatments. Results: A total of 38 patients were included. The median VAS score increased significantly according to the Wilcoxon matched-pairs signed-ranks test (p < 0.02) from 4 after the 1st PDT (range 0–8) to 4.75 (range 1–10) after the 2nd PDT treatment. The VAS score of pain was increased in the 2nd treatment for 21 patients, remained unchanged in 6 patients and was reduced in 11 patients who reported less pain after the 2nd treatment. Patients who scored low (VAS <5) after the 1st treatment experienced an increase in mean VAS score of 1.4 at the 2nd PDT treatment. In contrast, subjects with a high VAS score (>5) after the 1st PDT had a mean decrease in the VAS score of 0.26 at the 2nd PDT treatment. The difference (p = 0.005) suggests that the pain at the 1st PDT treatment may be predictive of future pain. Conclusion: The 2nd treatment of PDT was significantly more painful than the 1st, although some patients experienced reduced pain on the 2nd treatment. The pain experienced at the 1st PDT treatment may be predictive of the pain at subsequent treatments.

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Photodynamic therapy of actinic keratosis at varying fluence rates: assessment of photobleaching, pain and primary clinical outcome

Abstract: Our results imply that the photobleaching rate and primary treatment outcome are dependent on fluence rate, and that a low fluence rate (30 mW cm(-2)) seems preferable when performing PDT of AK using noncoherent light sources.

Cited by 144 publications

References 42 publications

Correlation between Protoporphyrin IX Fluorescence Intensity, Photobleaching, Pain and Clinical Outcome of Actinic Keratosis Treated by Photodynamic Therapy

Correlation between Protoporphyrin IX Fluorescence Intensity, Photobleaching, Pain and Clinical Outcome of Actinic Keratosis Treated by Photodynamic Therapy

The role of singlet oxygen and oxygen concentration in photodynamic inactivation of bacteria

Pain and Photodynamic Therapy

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