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PDT Treatment (pdt + treatment)
Selected AbstractsPhotodynamic Therapy of Cutaneous Lymphoma Using 5-Aminolevulinic Acid Topical ApplicationDERMATOLOGIC SURGERY, Issue 8 2000Arie Orenstein MD Background. Photodynamic therapy (PDT) with topical application of 5-aminolevulinic acid (ALA) is a new and effective modality for treatment of superficial basal and squamous cell carcinomas. Objective. We present the kinetics of ALA-induced protoporphyrin IX (PP) accumulation and the results of ALA PDT treatment on two patients with different stages (stage I and stage III) of mycosis fungoides (MF)-type cutaneous T-cell lymphoma (CTCL). Methods. ALA-Decoderm cream was applied to the lesions for 16 hours. Spectrofluorescence measurements of PP accumulation were carried out before, during, and 1 hour after photoirradiation (580,720 nm) using the VersaLight system. Results. Different patterns of PP fluorescence kinetics were observed in patients with early and advanced stages of the disease. During photoirradiation the intensity of fluorescence decreased depending on the lesion thickness. One hour after the photoirradiation procedure no PP fluorescence was observed in the stage I MF lesion, while in the thick stage III MF lesions, PP fluorescence reappeared; after an additional 10,15 minutes of irradiation PP fluorescence disappeared. Complete response with excellent cosmetic results was observed in the stage I lesion after a single irradiation with a light dose of 170 J/cm2; in five stage III lesions, complete response was achieved after fractionated irradiation with a total light dose of 380 J/cm2 (follow-up at 27 and 24 months, respectively). Conclusion. The results showed a high response of both stage I and stage III MF lesions to ALA PDT. This modality appears to be very effective and can be used successfully for MF treatment. [source] Photodynamic Therapy for the Treatment of Intranasal Tumors in 3 Dogs and 1 CatJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 5 2003Michael D. Lucroy Three dogs and 1 cat with intranasal tumors were treated with pyropheophorbide-a-hexyl ether-based photodynamic therapy (PDT). PDT was well tolerated by all the animals, and no adverse effects from photosensitizer injection, such as cutaneous photosensiti-zation, were observed. Facial swelling was observed in all animals after each PDT treatment but resolved spontaneously within 72 hours after treatment. All animals had a decrease in severity of epistaxis, frequency of sneezing, and amount of nasal discharge after PDT. Clinical signs were controlled for variable time, although long-term responses were comparable with radiation therapy in 2 animals. This small case series demonstrates another application for PDT in veterinary medicine. On the basis of these findings, further studies are warranted to define the role of PDT in the management of intranasal tumors in dogs and cats. [source] Fluorescence Kinetics of Protoporphyrin-IX Induced from 5-ALA Compounds in Rabbit Postballoon Injury Model for ALA-PhotoangioplastyPHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 5 2008Oh-Choon Kwon Protoporphyrin IX (PpIX) is one of the photodynamically active substances that are endogenously synthesized in the metabolic pathway for heme as a precursor. Aminolevulinic acid-esters are more lipophilic than conventional 5-aminolevulinic acid (ALA) and some of them are currently being approved as new drugs for photodynamic diagnosis (PDD) and photodynamic therapy (PDT). In order to investigate the pharmacokinetics of ALA and ALA-ethyl ester (ALA-ethyl) in the atheromatous plaque and normal aortic wall of rabbit postballoon injured artery, each 60 mg kg,1 of ALA or ALA-ethyl was injected intravenously followed by serial detection of PpIX fluorescence of harvested arteries at 0,48 h post-injection. Maximum PpIX build-up in the atheromatous plaque was seen at 2 h after injecting ALA. In contrast, it occurred at 9 h after injecting ALA-ethyl. In addition, the selective build-up of ALA in the atheromatous plaque compared to normal vessel wall was much higher (10 times) than that of ALA-ethyl. The time of maximum fluorescence intensity of PpIX was employed as drug-light-interval for subsequent PDT treatment of the atheromatous plaque with 50,150 J cm,1 of light dose. Significant reduction in plaque was observed without damage of the medial wall at both groups, but smooth muscle cell (SMC) was still present in the media region below the PDT-treated atheromatous plaque. In conclusion, ALA may be a more effective compound for endovascular PDT treatment of the atheromatous plaque compared with ALA-ethyl based on their pharmacokinetics, but further optimization of PDT methodology remains to remove completely residual SMC in the media for preventing potential restenosis. [source] Alterations in Mitochondrial and Apoptosis-regulating Gene Expression in Photodynamic Therapy-resistant Variants of HT29 Colon Carcinoma Cells,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 2 2005Xiao Yun Shen ABSTRACT Photodynamic therapy (PDT) is a novel cancer therapy inducing irreversible photodamage to tumor tissue via photosensitizer-mediated oxidative cytotoxicity. The cellular and molecular responses associated with PDT are only partially understood. We have reported previously the generation of several photosensitizer-specific PDT-resistant cell variants of HT29 human colon adenocarcinoma cells by selecting cells from sequential PDT treatment using different photosensitizers. In this report, we describe the use of messenger RNA (mRNA) differential display to identify genes that were differentially expressed in the parental HT29 cells compared with their resistant variants. In comparison with parental HT29 cells, mRNA expression was increased in the PDT-resistant cell variants for BNIP3, estrogen receptor-binding fragmentassociated gene 9, Myh-1c, cytoplasmic dynein light chain 1, small membrane protein I and differential dependent protein. In contrast, expression in the PDT-resistant variants was downregulated for NNX3, human HepG2 3,region Mbol complementary DNA, glutamate dehydrogenase, hepatomaderived growth factor and the mitochondrial genes coding for 16S ribosomal RNA (rRNA) and nicotinamide adenine dinucleotide (NADH) dehydrogenase subunit 4. The reduction for mitochondrial 16S rRNA in the PDT-resistant variants was confirmed by Northern blotting, and the elevated expression of the proapoptotic BNIP3 in the PDT-resistant variants was confirmed by Northern and Western blotting analysis. We also examined the expression of some additional apoptosis-regulating genes using Western blotting. We show an increased expression of Bcl-2 and heat shock protein 27 and a downregulation of Bax in the PDT-resistant variants. In addition, the mutant p53 levels in the parental HT29 cells were reduced substantially in the PDT-resistant variants. We suggest that the altered expression in several mitochondria1 and apoptosisregulating genes contributes to PDT resistance. [source] Enhancement of Laser Cancer Treatment by a Chitosan-derived Immunoadjuvant,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 1 2005Wei R. Chen ABSTRACT A chitosan derivative, glycated chitosan (GC), has been used as an immunostimulant for cancer treatment in laser immunotherapy. The function of GC is to enhance the host immune response after direct cancer cell destruction by a selective laser photothermal interaction. To further test its effects, laser immunotherapy was extended to include several different adjuvants for immunological stimulation and to include photodynamic therapy (PDT) as a different tumor-destruction mechanism. Complete Freund (CF) adjuvant, incomplete Freund (IF) adjuvant and Corynebacterium parvum (CP) were selected for treatment of metastatic mammary tumors in rats, in combination with a selective photothermal interaction. The solution of the immunoadjuvants admixed with indocyanine green (ICG), a light-absorbing dye, was injected directly into the tumors, followed by noninvasive irradiation of an 805 nm laser. Combined with PDT, in the treatment of tumors in mice, GC was administered peritumorally immediately after laser irradiation. The survivals of treated animals were compared with untreated control animals. In the treatment of rat tumors, CF, IF and CP raised the cure rates from 0% to 18%, 7% and 9%, respectively. In comparison, GC resulted in a 29% long-term survival. In the treatment of EMT6 mammary sarcoma in mice, GC of 0.5% and 1.5% concentrations increased the cure rates of Photofrin-based PDT treatment from 38% to 63% and 75%, respectively. In the treatment of Line 1 lung adenocarcinoma in mice, a 1.67% GC solution enabled a noncurative meso -substituted tetra(meta -hydroxy-phenyl)chlorin,based PDT to cure 37% of the tumor-bearing mice. The experimental results of this study confirmed our previous studies, showing that immunoadjuvants played an active role in laser-related cancer treatment and that GC significantly enhanced the efficacy of laser cancer treatment. [source] Topical aminolaevulinic acid-based photodynamic therapy as a treatment option for psoriasis?BRITISH JOURNAL OF DERMATOLOGY, Issue 2 2005Results of a randomized, observer-blinded study Summary Background, Topical aminolaevulinic acid-based photodynamic therapy (ALA-PDT) has recently been tried in small open studies for several inflammatory dermatoses including psoriasis. Objectives, The purpose of this randomized, within patient comparison study was to investigate whether topical ALA-based PDT using a range of light doses can induce a satisfactory response in localized psoriasis. Patients and methods, Twenty-nine patients with chronic plaque type psoriasis were enrolled in the study. After keratolytic pretreatment three psoriatic plaques in each patient were randomly allocated to PDT with 1% ALA and a light dose of 5 J cm,2, 10 J cm,2 or 20 J cm,2, respectively. Treatment was performed twice weekly until complete clearance or for a maximum of 12 irradiations. As a measure of clinical response the psoriasis severity index (PSI) of the three target plaques was assessed separately by an observer blinded to the treatment at baseline, before each PDT treatment and 3,4 days after the last irradiation. Results, Eight patients withdrew prematurely from the study. Keratolytic pretreatment alone reduced the baseline PSI in all three dose groups by about 25%. Subsequent PDT with 20 J cm,2 resulted in a final reduction of PSI by 59%, PDT with the lower doses of 10 J cm,2 and 5 J cm,2 decreased the baseline PSI by 46% and 49%, respectively. The difference in clinical efficacy between 20 J cm,2 and 10 J cm,2 or 5 J cm,2 was statistically significant (P = 0·003; P = 0·02), whereas no difference was found between 10 J cm,2 and 5 J cm,2 (P = 0·4). All patients reported some degree of PDT-induced stinging or burning during irradiation. Conclusions, The unsatisfactory clinical response and frequent occurrence of pain during and after irradiation renders topical ALA-based PDT an inadequate treatment option for psoriasis. [source] Ocular haemodynamic changes after single treatment with photodynamic therapy assessed with non-invasive techniquesACTA OPHTHALMOLOGICA, Issue 6 2009Noemi Maar Abstract. Purpose:, To investigate in patients with neovascular age-related macular degeneration (ARMD) the changes in ocular perfusion caused by single treatment with photodynamic therapy (PDT) by different non-invasive methods; to evaluate correlations between relative changes of ocular haemodynamic parameters after PDT among each other and compared to morphological parameters; and to assess this in relation to early changes of visual acuity. Methods:, Study population: 17 consecutive patients with subfoveal choroidal neovascularization (CNV) caused by ARMD scheduled for PDT without previous PDT treatment (four patients with predominantly classic CNV and 13 patients with occult CNV). Observation procedures: best-corrected visual acuity (before PDT, 6 and 8 weeks after PDT), fundus photography, fluorescein angiography, haemodynamic measurements with laser Doppler flowmetry (LDF), laser interferometry and ocular blood flow (OBF) tonometry (baseline and 1, 2, 6 and 8 weeks after treatment). Main outcome measures: choroidal blood flow (CHBF), fundus pulsation amplitude (FPA), pulsatile ocular blood flow (POBF), visual acuity. Changes smaller than 20% were considered clinically irrelevant. Results:, Ocular haemodynamic parameters did not change significantly in the follow-up period. Changes of haemodynamic parameters showed no correlation to treatment spot, morphological changes or visual acuity. Changes of visual acuity were comparable to results of earlier studies. Conclusion:, Single treatment with PDT did not modify ocular blood flow parameters above 20% as assessed with different non-invasive methods. [source] Reduction in the Incidence of Squamous Cell Carcinoma in Solid Organ Transplant Recipients Treated with Cyclic Photodynamic TherapyDERMATOLOGIC SURGERY, Issue 5 2010ANDREA WILLEY MD BACKGROUND AND OBJECTIVES Squamous cell carcinomas (SCCs) produce significant morbidity in solid organ transplant recipients (SOTRs), particularly in patients who develop multiple tumors. Topical photodynamic therapy (PDT) has been shown to decrease the number of keratotic lesions in SOTRs, but the duration of the beneficial effect is limited. The aim of this study was to evaluate the potential benefit of cyclic PDT in the prevention of new SCCs in SOTRs. METHODS Twelve high-risk SOTRs received cyclic PDT treatments at 4- to 8-week intervals for 2 years. The development of new SCCs (invasive and in situ) performed 12 and 24 months after the start of cyclic PDT were compared with the number of SCCs developed during the year before initiation of cyclic PDT. RESULTS The median reduction in the 12- and 24-month post-treatment counts from the 1-month pretreatment counts was 79.0% (73.3,81.8%) and 95.0% (87.5,100.0%), respectively. Treatments were well tolerated. CONCLUSION Cyclic PDT with 5-aminolevulinic acid may reduce the incidence of SCC in SOTRs. Additional studies with larger numbers of patients and optimized protocols are necessary to further explore the potential benefits of cyclic PDT in the prevention of skin cancer in this high-risk patient population. Dr. Lee is member of the Medical Advisory Board of Dusa Pharmaceuticals, Inc. [source] Antivascular Tumor Eradication by Hypericin-mediated Photodynamic Therapy,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 5 2002Bin Chen ABSTRACT Photodynamic therapy (PDT) with hypericin has been shown to inhibit tumor growth in different tumor models, and tumor vascular damage was suggested to be mainly responsible for the antitumoral effect. Here, we demonstrate tumor vascular damage and its consequence on local tumor control after hypericin-mediated PDT by using both short and long drug,light intervals. Radiation-induced fibrosarcoma-1 tumors were exposed to laser light at either 0.5 or 6 h after a 5 mg/kg dose of hypericin. Tumor perfusion was monitored by fluorescein dye,exclusion assay and by Hoechst 33342 staining of functional blood vessels. Significant reduction in tumor perfusion was found immediately after both PDT treatments. A complete arrest of vascular perfusion was detected by 15 h after the 0.5 h-interval PDT, whereas well-perfused areas could still be found at this time in tumors after the 6 h-interval PDT. A histological study confirmed that primary vascular damage was involved in both PDT treatments. Tumor cells appeared intact shortly after light treatment, degenerated at later hours and became extensively pycnotic at 24 h after the 0.5 h-interval PDT. PDT under this condition led to complete tumor cure. In contrast, significant numbers of viable tumor cells, especially at the tumor periphery, were found histologically at 24 h after the 6 h-interval PDT. No tumor cure was obtained when PDT was performed at this time. Our results strongly suggest that targeting the tumor vasculature by applying short drug,light interval PDT with hypericin might be a promising way to eradicate solid tumors. [source] Photodynamic therapy for chronic central serous chorioretinopathyACTA OPHTHALMOLOGICA, Issue 3 2010José M. Ruiz-Moreno Abstract. Purpose:, This study aimed to evaluate the efficacy of photodynamic therapy (PDT) in treating chronic central serous chorioretinopathy (CSC). Methods:, We describe a non-randomized, multicentre, interventional case series. A total of 82 eyes of 72 patients with chronic CSC were treated by conventional PDT. LogMAR best corrected visual acuity (BCVA) (ETDRS charts) and central foveal thickness (CFT) measured by optical coherence tomography before and after PDT, number of PDT treatments and complications were used as outcome indicators. Results:, Mean follow-up was 12 ± 10 months and mean age was 46 ± 10 years. Mean logMAR BCVA changed from 0.53 (standard deviation [SD] 0.43) before PDT to 0.38 (SD 0.41) at 3 months and 0.48 (SD 0.50) at 6 months (p < 0.0001 and p = 0.007, respectively, Student's t- test for paired data). Mean BCVA at the end of follow-up was 0.37 (SD 0.45; p < 0.0001 from baseline). Macular detachment was resolved and subretinal fluid (SRF) disappeared in all cases. Central foveal thickness decreased from 325 ,m (SD 95), to 229 ,m (SD 70) at 1 month after PDT, 206 ,m (SD 68) at 3 months, and 202 ,m (SD 76) at 6 months (all p < 0.0001, Student's t- test for paired data). No cases developed severe visual loss or complications derived from PDT. Reactive retinal pigment epithelium hypertrophy appeared in nine cases after PDT. Conclusions:, Photodynamic therapy with verteporfin may be useful in chronic CSC for improving BCVA and reducing SRF and CFT. Randomized studies with longer follow-up are needed to assess the real role of this treatment in chronic CSC. [source] Photodynamic therapy with intravitreal application of triamcinolone acetonide in age-related macular degeneration: functional results in 54 patientsACTA OPHTHALMOLOGICA, Issue 2 2009Adjoa Frimpong-Boateng Abstract. Purpose:, This study aimed to investigate the functional results, efficacy and complications after photodynamic therapy (PDT) combined with intravitreal triamcinolone acetonide injection (IVTA) in patients with choroidal neovascularization (CNV) caused by age-related macular degeneration (AMD). Methods:, A retrospective analysis of clinical data for 54 patients with CNV resulting from AMD was carried out. All patients had a follow-up of 12 months. The patients were treated with standardized PDT and IVTA (4 mg) as a first-line treatment or following PDT failure. Visual acuity (VA), greatest linear diameter (GLD) of the CNV and foveal thickness were evaluated. Results:, Mean VA at baseline was 0.8 logMAR (0.4,1.4). After 12 months VA improved (> 2 lines) in 20.4% of patients and stabilized (± 2 lines) in 64.8%. There was no statistical significance in VA outcome between patients undergoing first-line treatment and patients with PDT failure; however, fewer PDT treatments were required to stop CNV activity in patients undergoing first-line treatment. At 12 months, a reduction in foveal thickness was seen in 67.7% of patients and a reduction in CNV GLD in 32.7%. Complications occurred in 22% of patients and included a transient rise in intraocular pressure, cataract and sterile hypopyon. Conclusions:, Our analysis shows that fewer PDT treatments were required to stop CNV activity when triamcinolone was used as first-line treatment. We can thus conclude that PDT combines synergistically with IVTA and the combination may lead to a cost reduction compared with PDT therapy alone. The overall complication rate of 22% is high and must be compared with complication rates caused by new intravitreal anti-VEGF (vascular endothelial growth factor) drugs in combination with PDT. [source] | ||||||||||