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Background Daylight-activated PDT has seen increased support in recent years as a treatment method for actinic keratosis and other non-melanoma skin cancers. The inherent variability observed in broad-spectrum light used in this methodology makes it difficult to plan and monitor light dose, or compare to lamp light doses. Methods The present study expands on the commonly used PpIX-weighted effective surface irradiance metric by introducing a Monte Carlo method for estimating effective fluence rates into depths of the skin. The fluence rates are compared between multiple broadband and narrowband sources that have been reported in previous studies, and an effective total fluence for various treatment times is reported. A dynamic estimate of PpIX concentration produced during pro-drug incubation and treatment is used with the fluence estimates to calculate a photodynamic dose. Results Even when there is up to a 5x reduction between the effective surface irradiance of the broadband light sources, the effective fluence below 250 μm depth is predicted to be relatively equivalent. An effective threshold fluence value (0. 70 J e f f / c m 2 ) is introduced based on a meta-analysis of previously published ALA-PpIX induced cell death. This was combined with a threshold PpIX concentration (50 nM) to define a threshold photodynamic dose of 0.035 u M J e f f / c m 2 . Conclusions The threshold was used to generate lookup tables to prescribe minimal treatment times to achieve depth-dependent cytotoxic effect based on incubation times and irradiance values for each light source.

Daylight-mediated photodynamic therapy (d-PDT) as a treatment for actinic keratosis (AK) is an increasingly common technique due to a significant reduction in pain, leading to better patient tolerability. While past studies have looked at different light sources and delivery methods, this study strives to provide equivalent PpIX-weighted light doses with the hypothesis that artificial light sources could be equally as effective as natural sunlight if their PpIX-weighted fluences were equalized. Normal mouse skin was used as the model to compare blue LED light, metal halide white light, and natural sunlight, with minimal incubation time between topical ALA application and the onset of light delivery. A total PpIX-weighted fluence of 20 J(eff)/cm(2) was delivered over 2 hours, and the efficacy of response was quantified using three acute bioassays for PDT damage: PpIX photobleaching, Stat3 crosslinking, and quantitative histopathology. These bioassays indicated blue light was slightly inferior to both sunlight and white light, but that the latter two were not significantly different. The results suggest that metal halide white light could be a reasonable alternative to daylight PDT, which should allow a more controlled treatment that is independent of weather and yet should have similar response rates with limited pain during treatment.

Abdominal wall transplants are relatively new procedures that are frequently performed in conjunction with multivisceral transplants. The skin of the abdominal wall transplant is often the first site for graft rejection to manifest itself. Prompt recognition can lead to appropriate treatment before the involvement of the underlying viscera. However, the signs of graft rejection are nonspecific and can overlap with other entities. We present a case of a patient who received a multivisceral and abdominal wall transplant from 2 different donors, who presented with acute and eventually chronic graft rejection of the abdominal wall graft. Serial biopsies performed during the course of her treatment demonstrated progressive sclerotic changes in the dermis. Because these changes were confined to the abdominal wall graft, they could represent either chronic graft rejection or graft-versus-graft disease. To date, graft-versus-graft disease has not been documented in these patients. This case illustrates the possibility that patients with multidonor transplants may be at an increased risk for graft failure secondary to multiple potential etiologies.

Background: Little is known about whether history of allergies and atopy is related to the occurrence of keratinocyte cancers. Thus, we evaluated the association between history of allergies and atopy and the incidence of squamous cell carcinoma (SCC) and early onset basal cell carcinoma (BCC). Methods: As part of a population-based case–control study, interviews were conducted with 1,050 residents of New Hampshire (375 early onset BCC cases and 251 controls, 254 SCC cases and 432 controls). ORs of SCC and early onset BCC and history of allergy and atopic dermatitis were computed using logistic regression, while controlling for potential confounding factors. Results: An overall inverse association was observed between a history of allergy and early onset BCC [OR, 0.61; 95% confidence interval (CI), 0.38–0.97] but not SCC (OR, 1.18; 95% CI, 0.78–1.79). Among women, we found reduced ORs of both early onset BCC and of SCC in relation to allergy history (early onset BCC OR, 0.53; 95% CI, 0.31–0.92 and SCC OR, 0.59; 95% CI, 0.29–1.19). Among men, we observed no clear association with early onset BCC (OR, 0.87; 95% CI, 0.39–1.99) and an increased risk of SCC (OR, 1.58; 95% CI, 0.93–2.69). Conclusion: Our findings suggest that allergies and atopy may influence risk of early onset BCC and SCC, and that effects may be gender specific. Impact: A deeper understanding of the immune mechanisms underlying allergies and atopy may provide new routes of preventing keratinocyte cancers. Cancer Epidemiol Biomarkers Prev; 24(4); 749–54. ©2015 AACR.