Daylight Photodynamic Therapy: At-Home Delivery.

This pilot study evaluated the design, usability, and practicality of the dPDT@home kit for treating actinic keratoses (AKs) on the face and scalp. The kit allowed patients to manage their treatment at home, reducing hospital visits and utilizing natural sunlight. While patients were very willing to use the kit again, further studies are required to evaluate outcomes and ascertain the need for additional improvements and support.

Far-UVC: The impact of optical filters on real-world deployment.

In 2015, a study showed that Krypton-Chloride (KrCl) excimer lamps could induce erythema and basal layer DNA damage in human skin. Later studies found that filtering out longer wavelength emissions from these lamps resulted in no acute skin effects. However, there is a limited understanding of how much to reduce unwanted emissions and which wavelengths are important.

Low-dose daylight exposure induces nitric oxide release and maintains cell viability in vitro.

Any potential positive effects conferred via sunlight exposure have to be carefully balanced against carcinogenic effects. Here we provide evidence UK sunlight exposure upregulates the cardio protectant nitric oxide (NO) within in vitro skin cell lines with negligible increases in DNA damage and cell death at 1 SED, when compared against unexposed samples. The whole of the ultraviolet A (UV-A) spectrum appears to be responsible for NO release, with efficiency higher at exposures closer to shorter UV-A wavelengths and decreasing with wavelength increases.

222 nm Far-UVC from filtered Krypton-Chloride excimer lamps does not cause eye irritation when deployed in a simulated office environment.

Far-UVC, from filtered Krypton-Chloride lamps, is promising for reducing airborne transmission of disease. While significant research has been undertaken to investigate skin safety of these lamps, less work has been undertaken on eye safety. There is limited data on human eye safety or discomfort from the deployment of this germicidal technology.

Potential harm to the skin from unfiltered krypton chloride 'far-ultraviolet-C' lamps, even below an occupational exposure limit.

Ultraviolet-C (UVC) radiation can effectively inactivate pathogens on surfaces and in the air. Due to the potential for harm to skin and eyes, human exposure to UVC should be limited within the guideline exposure limits produced by the International Commission on Non-Ionising Radiation Protection (ICNIRP) or the American Conference of Governmental Industrial Hygienists (ACGIHs). Both organisations state an effective spectrally weighted limit of 3 mJ cm, although the spectral weighting factors of the two organisations diverged following a revision of the ACGIH guidelines in 2022.

Far-UVC (222 nm) efficiently inactivates an airborne pathogen in a room-sized chamber.

Many infectious diseases, including COVID-19, are transmitted by airborne pathogens. There is a need for effective environmental control measures which, ideally, are not reliant on human behaviour. One potential solution is Krypton Chloride (KrCl) excimer lamps (often referred to as Far-UVC), which can efficiently inactivate pathogens, such as coronaviruses and influenza, in air.

Computer Modeling Indicates Dramatically Less DNA Damage from Far-UVC Krypton Chloride Lamps (222 nm) than from Sunlight Exposure.

This study aims to investigate, with computer modeling, the DNA damage (assessed by cyclobutane pyrimidine dimer (CPD) formation) from far-ultraviolet C (far-UVC) in comparison with sunlight exposure in both a temperate (Harwell, England) and Mediterranean (Thessaloniki, Greece) climate. The research utilizes the published results from Barnard et al. [Barnard, I.

Fluorescence and thermal imaging of non-melanoma skin cancers before and during photodynamic therapy.

Background: Photodynamic therapy (PDT) has been shown to be less effective on the extremities. Protoporphyrin-IX (PpIX) fluorescence and skin surface temperature are variables that have been implicated in the differences in efficacy with body site, but objective studies have not been undertaken.

Objectives: To further investigate observations from our previous study that temperature and fluorescence during pro-drug incubation are correlated, through a prospective objective investigation of the relationships between fluorescence and skin surface temperature before and during PDT and relationships with body site and efficacy.

Global verification of a model for determining daylight photodynamic therapy dose.

Daylight photodynamic therapy is an effective treatment for actinic keratoses and relies on a minimum PpIX-effective light exposure dose being delivered during treatment. As such, daylight dosimetry is an important aspect of this treatment. Relatively simple measurements of illuminance may be converted to PpIX-effective irradiance, and subsequently exposure dose, via a conversion model (the O'Mahoney model).

Development of a Predictive Monte Carlo Radiative Transfer Model for Ablative Fractional Skin Lasers.

It is possible to enhance topical drug delivery by pretreatment of the skin with ablative fractional lasers (AFLs). However, the parameters to use for a given AFL to achieve the desired depth of ablation or the desired therapeutic or cosmetic outcome are hard to predict. This leaves open the real possibility of overapplication or underapplication of laser energy to the skin.

Research Techniques Made Simple: Experimental UVR Exposure.

UVR exposure is a widely applied technique in clinical and preclinical studies. Such experimental conditions provide crucial information on the biological responses of skin and cell models, which may then be extrapolated and interpreted, for example, in the context of equivalent daylight exposures. It is therefore important to fully understand the characteristics of UVR and the principles behind correct and appropriate UVR exposure in experimental settings.

Bring the Sunshine Indoors: Easy Dosimetry for Indoor Daylight Photodynamic Therapy.

Daylight photodynamic therapy (DPDT) is an effective and patient preferred treatment for the management of field change actinic keratosis. An important factor in DPDT is light dosimetry, to ensure that patients receive sufficient daylight for effective treatment, and this is the focus of the contribution to this issue by (La Rochelle et al. [2019] Photochem.

Measuring Daylight: A Review of Dosimetry in Daylight Photodynamic Therapy.

Successful daylight photodynamic therapy (DPDT) relies on the interaction of light, photosensitisers and oxygen. Therefore, the 'dose' of light that a patient receives during treatment is a clinically relevant quantity, with a minimum dose for effective treatment recommended in the literature. However, there are many different light measurement methods used in the published literature, which may lead to confusion surrounding reliable and traceable dose measurement in DPDT, and what the most appropriate method of light measurement in DPDT might be.

Ultraviolet radiation exposure during daylight Photodynamic Therapy.

Background: Daylight photodynamic therapy (dPDT) is an effective treatment for field-change actinic keratoses (AK), with similar efficacy to conventional PDT but lower patient pain scores. Whilst AK occur consequent to chronic solar ultraviolet (UV) exposure, paradoxically solar visible radiation is used during PDT.

Objectives: To investigate the nature and levels of UV exposure, both erythemal UV and UVA, occurring during dPDT.

A novel light source with tuneable uniformity of light distribution for artificial daylight photodynamic therapy.

Objectives: Implementation of daylight photodynamic therapy (dPDT) is somewhat limited by variable weather conditions. Light sources have been employed to provide artificial dPDT indoors, with low irradiances and comparable treatment times to dPDT. Uniform light distribution across the target area is desirable in effective treatment planning, particularly for large areas.

Using GoPro to Give Video-Assisted Operative Feedback for Surgery Residents: A Feasibility and Utility Assessment.

Objective: As an adjunct to simulation-based teaching, laparoscopic video-based surgical coaching has been an effective tool to augment surgical education. However, the wide use of video review in open surgery has been limited primarily due to technological and logistical challenges. The aims of our study were to (1) evaluate perceptions of general surgery (GS) residents on video-assisted operative instruction and (2) conduct a pilot study using a head-mounted GoPro in conjunction with the operative performance rating system to assess feasibility of providing video review to enhance operative feedback during open procedures.

Surgeon Annual and Cumulative Volumes Predict Early Postoperative Outcomes after Rectal Cancer Resection.

Objective: To determine if 5-year surgeon cumulative and annual volumes predict improved early postoperative outcomes in patients with rectal cancer.

Background: Operative experience has been shown to effect surgical outcomes. The differential role of cumulative versus annual volume has not yet been explored for rectal surgery.

Use of illuminance as a guide to effective light delivery during daylight photodynamic therapy in the U.K.

Background: Daylight PDT (dPDT) is an effective and nearly painless treatment for field-change actinic keratosis. Measuring the protoporphyrin-IX (PpIX)-weighted exposure dose can give an indication of when conditions are most viable for effective dPDT. It would be advantageous for practitioners if more detailed information of exposure dose and appropriate treatment conditions were available.