“Long-Pulsed 1064nm Nd:YAG Laser Treatment of Basal Cell Carcinoma”
Basal cell carcinoma (BCC) is the most common skin cancer worldwide. Although this tumor is rarely life threatening, it is locally destructive and can cause significant cosmetic and functional morbidity. Standard therapeutic modalities for BCC often result in disfigurement from surgical treatments and recurrences with topical therapies. Thus, there is a need for alternative non-surgical options that are effective, efficient, and have a low risk of side effects. This has led to the emergence of laser investigations for the treatment of BCC due to the ease of treatment, lack of significant downtime, decreased risk of complications, and absence of a surgical scar. The primary objective of this study is to evaluate the safety, clinical and histological efficacy of high-fluence 1064 nm Nd:YAG laser therapy for the treatment of subjects with BCC on the trunk and extremities that do not meet the criteria for Mohs Micrographic Surgery.
|"Development of Clinic-Friendly Perfusion Measurement System to Aid in Light Dosimetry During Novel Port Wine Stain Treatment"
Port-wine stain (PWS) birthmarks affect approximately ~400,000 individuals annually and are characterized by potentially deleterious psychosocial and physical complications. The current standard of care for these lesions, photocoagulation using a pulsed dye laser (PDL), achieves unacceptable PWS lightening in >85% of subjects even after multiple treatments. Limited treatment efficacy is due in part to the fact that (1) PDL irradiation does not effectively photocoagulate blood vessels with diameters <20 μm; (2) epidermal melanin reduces the light dose reaching the target vessels; and (3) light dosimetry is often based solely on clinical experience, which can lead to inadequate or excessive energy deposition during treatment. To address the first and second shortcomings, we are currently conducting a clinical trial to investigate the efficacy of a novel dual-modality treatment for PWS. By utilizing photodynamic therapy (PDT) in addition to PDL irradiation, melanin’s absorption of incident light can be mitigated with proper wavelength choice, and blood vessels of all sizes can be treated with a smaller light dosage than would be required for PDL monotherapy. As such, the dual-modality treatment may increase PWS blanching while minimizing potential side-effects such as scarring. To address the third shortcoming, we propose to expand upon previous work by building a real-time perfusion measurement system for use during PWS phototherapy. This system will be clinician-operable and offer real-time dosimetry feedback during treatment. To accomplish this goal, we will first construct a cutaneous perfusion imaging system based upon the principal of laser speckle imaging. This system will benefit from our group’s extensive experience in creating customized laser speckle imaging system hardware and software, particularly exemplified by two previous systems created to monitor PWS perfusion during PDL treatment. We will subsequently use this perfusion measurement system to quantify the reduction in PWS perfusion during dual-modality treatment, as well as during PDT and PDL monotherapy. Treatment efficacy will be quantified as the degree of PWS blanching (measured using calibrated color photography and colorimetry), and the correlation between treatment efficacy and the decrease in perfusion will be computed for each treatment type. With this data, clinicians can then use the perfusion measurement system to quantitatively determine a treatment’s endpoint by targeting the drop in PWS perfusion that corresponds to the desired degree of PWS blanching. Clinicians will thus have the ability to quantitatively determine when treatment should cease, reducing the risk of under- or over-treating PWS lesions, therefore ameliorating the efficacy of each treatment session on an individualized basis.