Argon-pumped Tunable Dye Laser Research Articles

Pharmacokinetics and clinical effects of mono‐l‐aspartyl chlorin e6 (NPe6) photodynamic therapy in adult patients with primary or secondary cancer of the skin and mucosal surfaces

Mono-L-aspartyl chlorin e6 (NPe6) is a photosensitizer that exhibits chemical purity, absorption at 664 nm wavelength and may be useful in photodynamic therapy (PDT). This open label phase I clinical trial at the University of California, Davis Medical Center examined the pharmacokinetic properties of Npe6 and clinical response to PDT with this photosensitizer. A single intravenous dose of Npe6 was administered to 14 cancer patients with superficial malignancies (basal cell carcinoma = 22 lesions, squamous cell cancer = 13 lesions, papillary carcinoma = 14 lesions). Patients received one of five ascending doses (0.5 mg/kg (n = 4), 1.0 mg/kg (n = 3), 1.65 mg/kg (n = 3), 2.5 mg/kg (n = 3), or 3.5 mg/kg (n = 1)) 4-8 h prior to light activation. The total light dose (range 25-200 J/cm2) depended on the tumor shape and size. Light was delivered using an argon-pumped tunable dye laser. Serum NPe6 concentrations were measured over a 28-day period. The toxicity and cutaneous clinical efficacy of NPe6 were observed. Four weeks post-PDT, 20 of 22 basal cell carcinoma tumors (91%) showed a complete response. Eighteen of 27 other malignant cutaneous tumors showed a complete (n = 15/27, 56%) or partial (n = 3/27, 11%) response. Fewer non-responders were seen at an Npe6 dose level of 1.65 mg/kg or higher. Only 2 of 14 patients experienced an adverse event that was definitely related to NPe6 administration. Photosensitivity resolved within 1 week of NPe6 dosing in 12 of 14 patients. Analysis of serum levels of 11 individual patients indicated that a two-compartment model with a residual phase best fits the data. The mean alpha, beta, and terminal half-lives were 8.63+/-2.92, 105.90+/-37.59 and 168.11+/-53.40 h (+/-1 SD), respectively. The observed mean volume of distribution was 5.94+/-2.55 l, and the mean clearance was 0.0394+/-0.0132 l/h. These values were independent of the dose administered. The photosensitizer, NPe6, was well tolerated with minimal phototoxic side effects, and demonstrated preliminary efficacy against cutaneous malignancies.

Pilot study to assess patient outcomes following endoscopic application of photodynamic therapy for advanced cholangiocarcinoma

Photodynamic therapy (PDT) has demonstrated promise in the palliative treatment of advanced cholangiocarcinoma. The aim of this pilot study was to assess the outcome in patients with non-resectable cholangiocarcinoma following endoscopic application of PDT directly into the biliary tract. In patients with advanced cholangiocarcinoma, endoscopic retrograde cholangiopancreatography (ERCP) was performed to define the proximal and distal extent of intraductal tumor. Sodium porfimer was administered intravenously to all patients. Forty-eight hours later, a commercially available cylindrical diffusing laser fiber (1-2.5 cm in length, OptiGuide) designed for esophageal use was advanced across the biliary strictures. Laser light was applied at a power of 400 mW/cm fiber for a total energy of 180 J/cm(2) using an argon-pumped tunable dye laser. Patients received endoscopic PDT every 3 months provided they maintained a favorable performance status. Plastic biliary stents were replaced immediately following light application and were maintained in all patients. Using a preloaded catheter, adequate positioning of the laser fiber was achieved in all patients. Eight patients with advanced cholangiocarcinoma received a total of 19 PDT treatments, range 1-5 treatments/patient. All eight patients were followed until death; mean follow-up was 9.8 months. Median survival from the date of the first PDT treatment was 276 days, which compares favorably with published series that have reported median survival times between 45 and 127 days for patients with bismuth type III and IV tumors treated with stenting alone. Endoscopic application of PDT demonstrates promise in prolonging survival in patients with advanced cholangiocarcinoma. Additional randomized clinical trials using commercially available fibers are needed to fully evaluate both the optimum frequency and treatment interval of endoscopic PDT in the management of advanced cholangiocarcinoma.

Argon-pumped tunable dye laser for the treatment of cutaneous lesions

Argon-pumped tunable dye laser for the treatment of cutaneous lesions

Argon-pumped tunable dye laser.

The argon-pumped tunable dye laser (APTDL) is useful in the treatment of a wide variety of superficial vascular and melanocytic lesions. Safety is enhanced by the use of a computerized scanning device--the Hexascan. Over a 1-year period, 140 patients (33 patients under the age of 21, and 21 patients from 0 to 10 years of age) were treated. Facial rosacea/telangiectasia was the most frequently treated lesion, followed by port-wine stain. Although multiple treatments were often necessary, fading was successfully achieved in most patients without scarring or other complications.

Use of the argon-pumped tunable dye laser for port-wine stains in children : A Scheibner, RG Wheeland. J Dermatol Surg Oncol 17:735–739, 1992

Use of the argon-pumped tunable dye laser for port-wine stains in children : A Scheibner, RG Wheeland. J Dermatol Surg Oncol 17:735–739, 1992

Use of the Argon‐Pumped Tunable Dye Laser for Port‐wine Stains in Children

The authors reported previously a new technique using a low power argon-pumped tunable dye laser at a wave-length of 577nm (yellow light) to treat port-wine stains in adults. The authors report their results using this same technique as a form of treatment for 92 children with facial port-wine stains.

Argon-pumped tunable dye laser therapy for facial port-wine stain hemangiomas in adults--a new technique using small spot size and minimal power.

A low power, argon-pumped tunable dye laser was used to deliver yellow light of 577 nm. Individual blood vessels within port-wine stain hemangiomas were treated with a 0.1-mm beam of light using 8 X magnification. This technique permits excellent resolution of facial and nuchal port-wine stain hemangiomas in adults without the adverse complications of textural change, permanent pigmentation abnormality, or hypertrophic scarring.

Photodynamic Laser Therapy: A Bladder Cancer Protocol

This data, along with data from other research studies, indicate that PDT is a promising new treatment for noninvasive bladder cancer. In the current study at Veterans Administration Medical Center, three of the four patients who received Thiotepa have had recurrences of their bladder tumors or positive urine cytology. The three patients who received PDT have not experienced any recurrences or positive urine cytology. Since we have been involved in this trial, we have developed some recommendations that other institutions may want to follow. The tip of the laser fiber is very bright. To decrease eye strain and fatigue, a lens cap with a green eye shield should be used on the cytoscope. All staff should wear green-colored safety eye glasses. This will protect their eyes from constant exposure to the intense incandescent radiation, and if the fiber should break, it would protect their eyes from the bright red color. With all the extra equipment such as ultrasound, power meters, light sources, and anesthesia equipment, it is important to avoid tripping over extension cords. The cords should be covered. Also, it is important not to bump into the equipment, which can happen because the OR is dark. At this time, the laser technician is the only person authorized at our medical center to operate the argon-pumped tunable dye laser. In the future, if more research programs are started or therapy is approved for other uses, additional personnel will be trained.

Photodynamic therapy for treatment of malignant cutaneous lesions

Photodynamic therapy, employing either hematoporphyrin derivative or dihematoporphyrin ether as the photosensitizer and an argon-pumped tunable dye laser as the activating light source, was used to treat ten patients who had primary or recurrent basal or squamous cell carcinoma or infiltrating ductal cell carcinoma lesions metastatic to the skin. Of the 155 sites that were treated, various degrees of edema, erythema, and necrosis, sometimes accompanied by blistering, were evident in all areas within 24 to 48 hours of light treatment. While our follow-up periods are short, four patients are free of disease at eight months or more posttreatment, two patients have had recurrent and/or persistent disease within four months, and four patients died within nine months from metastatic disease or unrelated disorders. Continued investigation into the use of photodynamic therapy for treatment of malignant lesions appears warranted, based on these preliminary clinical results.