[Clinical study of 1949 cases of port wine stains treated with vascular photodynamic therapy (Gu's PDT)]

M-CSAFN: Multi-Color Space Adaptive Fusion Network for Automated Port-Wine Stains Segmentation

Automatic segmentation of port-wine stains (PWS) from clinical images is critical for accurate diagnosis and objective assessment of PWS. However, this is a challenging task due to the color heterogeneity, low contrast, and indistinguishable appearance of PWS lesions. To address such challenges, we propose a novel multi-color space adaptive fusion network (M-CSAFN) for PWS segmentation. First, a multi-branch detection model is constructed based on six typical color spaces, which utilizes rich color texture information to highlight the difference between lesions and surrounding tissues. Second, an adaptive fusion strategy is used to fuse complementary predictions, which address the significant differences within the lesions caused by color heterogeneity. Third, a structural similarity loss with color information is proposed to measure the detail error between predicted lesions and truth lesions. Additionally, a PWS clinical dataset consisting of 1413 image pairs was established for the development and evaluation of PWS segmentation algorithms. To verify the effectiveness and superiority of the proposed method, we compared it with other state-of-the-art methods on our collected dataset and four publicly available skin lesion datasets (ISIC 2016, ISIC 2017, ISIC 2018, and PH2). The experimental results show that our method achieves remarkable performance in comparison with other state-of-the-art methods on our collected dataset, achieving 92.29% and 86.14% on Dice and Jaccard metrics, respectively. Comparative experiments on other datasets also confirmed the reliability and potential capability of M-CSAFN in skin lesion segmentation.

Experimental study of combined photodynamic and photothermal therapy in the treatment of port wine stain

Laser therapy has become the golden standard of port wine stain (PWS), but complete clearance of resistant PWSs is still difficult. The application of photodynamic therapy (PDT) in the treatment of PWS shows potential in clinical practice, especially for large-area and deep lesions. In this work, in vivo animal experimental investigation on the coupling effect of PDT with multi-pulse laser (MPL) irradiation on the treatment of PWS was conducted by using a dorsal skin window chamber model. Through visualization of the thermal response of blood vessels and damage evaluation, it is found that the combination of PDT with MPL results in 96.2% more vascular injury than PDT alone and 90% more than MPL alone, thus reducing side effects such as purpura after treatment. The combined therapy also has the benefit of large treatment area, uniform fading effect, shortened light duration, and reduced photosensitizer admit.

The Relationship Between the Effectiveness of HMME-PDT and the Dermoscopic Features of Port-wine Stains in Chinese Pediatric Patients: A Retrospective Study

Introduction

Although pulsed dye laser (PDL) remains the gold standard for the treatment of port-wine stains (PWS), hematoporphyrin monomethyl ether photodynamic therapy (HMME-PDT) is another treatment modality that has been shown to be effective in the treatment of PWS. This study aimed to observe the clinical efficacy and therapeutic response of HMME-PDT in the treatment of pediatric Chinese patients with PWS and to analyze the association between the efficacy of therapy and the dermoscopic features of PWS.

Methods

Pediatric patients with PWS and negative HMME skin test were enrolled between December 2017 and May 2021. Patients received an intravenous injection of 5 mg/kg HMME, and lesions were irradiated with 532-nm LED green light with a power density of 70–80 mW/cm² for 20–25 min. Digital photographs and dermoscopic images were taken before and after two treatment sessions, and the clinical response was observed. The relationship between the efficacy of HMME-PDT and the dermoscopic features of PWS was retrospectively analyzed.

Results

A total of 216 pediatric patients (1–14 years) were recruited. Sixty-six patients had the pink type, while 150 had the purple type. After two HMME-PDT sessions, 55 patients showed excellent efficacy (25.46%), 77 patients showed good efficacy (35.65%), 69 patients showed fair efficacy (31.94%), and 15 patients showed no improvement (6.95%). Dotted and globular vessels were highly associated with excellent efficacy (41.82%); linear vessels were mainly associated with good efficacy (54.55%); reticular vessels were mainly associated with fair (55.07%) and mixed vessels were mainly associated with no improvement (26.66%).

Conclusion

HMME-PDT is an effective and safe treatment for pediatric patients with PWS. Dotted and globular vessels as well as linear vessels showed better efficacy compared to the other dermoscopic patterns in patients with PWS. Dermoscopy can provide useful clinical information about treatment outcomes.

The Efficacy of Hematoporphyrin Monomethyl Ether Photodynamic Therapy in Adult Patients with Port-Wine Stains: A Retrospective Study

Introduction

Hematoporphyrin monomethyl ether-photodynamic therapy (HMME-PDT) has been showing promising results in the treatment of port-wine stains (PWSs). We evaluated the clinical efficacy and treatment response of HMME-PDT in adult Chinese patients with PWSs.

Methods

A single-center retrospective study recruited adult PWS patients with negative HMME skin test results from December 2017 to May 2020. Patients received an intravenous injection of 5 mg/kg HMME and the lesions were exposed to 532 nm LED green light with an irradiation power density of 85–95 mW/cm² for 20–25 min. Digital photographs were taken before and after two therapy sessions and observed by three blinded dermatologists for clinical response.

Results

A total of 72 patients aged between 18 and 55 years were recruited. There were 65 patients of the flat purple type, 5 of the hypertrophic type, and 2 of the nodular thickening type. Of the 65 patients, 7 showed excellent efficacy (10.77%), 13 patients indicated good efficacy (20.00%), 47 patients showed fair efficacy (64.62%), while 3 cases displayed no improvement (4.62%). All five patients of the purple and hypertrophic type showed fair efficacy (100%), and no improvement was observed in patients of the nodular thickening type (100%). Pain, pruritus, and a burning sensation were observed during treatment. Edema was noted on the treated areas post-treatment. No other obvious systemic adverse reactions were observed.

Conclusion

HMME-PDT is an effective and safe treatment for adult patients with purple PWSs. Multiple HMME-PDT treatments can improve the response and cure rate.

Histological Characteristics of Port-Wine Stains with Complete Regression After Photodynamic Therapy Treatment: A 7-Year Follow-Up

Background: Vascular-targeted photodynamic therapy (PDT) is an effective alternative treatment choice for port-wine stains (PWSs). The histological characteristics of PWSs after PDT treatment have not yet been reported. Objective: To investigate the morphological features of PWSs treated by PDT and define the histopathological characteristics of PWS that achieve clinical cure. Methods: Thirteen patients with facial PWSs, who presented with complete regressive PWS lesions after a mean of 4.38 (standard deviation = 4.907) sessions of PDT. Post-treatment biopsy samples were obtained from each patient. The number of blood vessels, vascular diameter, and depth were measured and compared in all samples of PDT-regressive sites, PDT-resistant sites, and normal skin. Results: Within the 7-year follow-up after PDT, there was no recurrence in the regression area of PDT. In the PDT-regressive sites, within 800 μm of the dermal-epidermal junction, the dilated vessels were occluded and remained fissure-like after PDT. Conclusions: When the vascular lesions within 800 μm of the dermal-epidermal junction were closed after PDT, a stable clinical cure (no recurrence) was achieved.

Efficacy of hemoporfin photodynamic therapy for pulsed dye laser-resistant facial port-wine stains in 107 children: A retrospective study

BACKGROUND

Port-wine stains occur in 0.3-0.5% newborns, mainly on the face and neck. Pulsed dye laser is recognized as the gold standard treatment; nevertheless, it is associated with a low cure rate and a high recurrence rate.

AIMS

This study aims to evaluate the efficacy of hemoporfin photodynamic therapy for pulsed dye laser-resistant port-wine stains in children.

METHODS

We studied 107 children who received hemoporfin photodynamic therapy for port-wine stains on the face and neck that were resistant to pulsed dye laser. After intravenous injection of 5 mg/kg hemoporfin, the local lesion was irradiated with 532 nm LED green light for 20 min with a power density of 80-100 mW/cm2. A total of 65 patients were given a second treatment after eight weeks. The efficacy and therapeutic responses were recorded at four days and eight weeks after each treatment.

RESULTS

The efficacy was positively correlated with the number of treatments received; two treatment sessions yielded significantly better results compared to a single treatment with a response rate of 96.9%, a significant response rate of 50.8% and a cure rate of 21.5%, respectively (P < 0.001). After two treatment sessions, the efficacy was negatively correlated with age (P = 0.04). The efficacy for port-wine stains located on the lateral part was better than that of the central face (P = 0.04). The efficacy for the pink type was better than that for the red and purple types (P = 0.03). No allergic or systematic adverse reactions were reported.

LIMITATIONS

No objective measurement data were available.

CONCLUSION

Hemoporfin photodynamic therapy is effective and safe for pulsed dye laser-resistant facial port-wine stains in children.

Self-assembly of Amphiphilic Porphyrins To Construct Nanoparticles for Highly Efficient Photodynamic Therapy

Hydrophobic photosensitizers greatly affect cell permeability and enrichment in tumors, but they cannot be used directly for clinical applications because they always aggregate in water, preventing their circulation in the blood and accumulation in tumor cells. As a result, amphiphilic photosensitizers are highly desirable. Although nanomaterial-based photosensitizers can solve water solubility, they have the disadvantages of complicated operation, poor reproducibility, low drug loading, and poor stability. In this work, an efficient synthesis strategy is proposed that converts small molecules into nanoparticles in 100 % aqueous solution by molecular assembly without the addition of any foreign species. Three photosensitizers with triphenylphosphine units and ethylene glycol chains of different lengths, TPP-PPh₃ , TPP-PPh₃ -2PEG and TPP-PPh₃ -4PEG, were synthesized to improve amphiphilicity. Of the three photosensitizers, TPP-PPh₃ -4PEG is the most efficient (singlet oxygen yield: 0.89) for tumor photodynamic therapy not only because of its definite constituent, but also because its amphiphilic structure allows it to self-assemble in water.

Light delivery device modelling for homogenous irradiation distribution in photodynamic therapy of non-spherical hollow organs

SIGNIFICANCE

Photodynamic therapy (PDT) is a useful treatment for select cancers. Homogeneous illumination is a key factor in the successful application of PDT treatment of tumours in hollow organs. Over illumination may damage normal tissue while under illumination may not ablate the target.

BACKGROUND

There have been many approaches to provide homogeneous irradiation for PDT treatment of hollow organs, including light-scattering medium and isotropic emitter to diffuse light, a balloon filled with solution to expand the organ wall, and shaped fibres. In most studies, the organ is assumed to be spherical. However, many hollow organs treated by PDT are non-spherical, and the uniformity of azimuthal irradiation remains an unsolved problem for cylindrical light sources.

OBJECTIVE

Find a design principle for homogeneous irradiation in a non-spherical cavity for PDT treatment.

METHOD

A PDT light delivery device is modeled by a series of sub light sources placed along the longitudinal axis of an ellipsoid. In order to achieve a homogeneous azimuthal irradiation distribution on the elliptical arc, a cost function is solved by adding modulation coefficient to the emission profile. The coefficient of variation of uniformity (U_cov) describes the statistical dispersion of the variation in irradiation over the ellipsoid to the average value. U_cov is used to evaluate the homogeneity of the azimuthal irradiation distribution.

RESULT

By minimizing the cost function, we found that the truncated Gaussian function can be chosen as the emission profile to generate homogeneous irradiation profile within an ellipsoid cavity model. The emission profile can be tailored to generate U_cov of 96.7 %. Further discussion shows that the light distribution could be generated practically by a side-emitting optical fibre, a LED array, or moving an isotropic emitter successively. The impact of emission angle of light sub-source is analysed and the irradiation profile from discrete longitudinal emissions is calculated.

CONCLUSION

Theory analysis and simulation indicate that a cylindrical emitter with a non-uniform longitudinal emission profile (truncated Gaussian functions) results in an approximate homogeneous irradiance profile within an ellipsoidal cavity.

Monitoring perfusion and oxygen saturation in port-wine stains during vascular targeted photodynamic therapy

Background

Vascular targeted photodynamic therapy (V-PDT) is a safe and effective therapeutic modality for port-wine stains (PWS) by targetedly damaging the dilated and malformed blood vessels. This study aims to monitor and quantify the changes in oxygen saturation (StO₂), blood volume fraction (BVF) and perfusion in PWS lesions before and during V-PDT.

Methods

Microvascular parameters (i.e., StO₂ and BVF) and skin perfusion were measured noninvasively by using diffuse reflectance spectroscopy (DRS) and laser Doppler imaging (LDI), respectively. The change in StO₂, BVF and perfusion that occurred in the PWS lesions of 26 patients were monitored and investigated before and during V-PDT in vivo with the systematic administration of the porphyrin-based photosensitizer HiPorfin.

Results

The mean StO₂ (P<0.05), BVF (P<0.05), and perfusion (P<0.001) in PWS lesions of all subjects significantly increased by 6%, 34%, and 113%, respectively, 3 min after the initiation of V-PDT. The StO₂ increased first and fluctuated during V-PDT. The overall trend of BVF change was consistent with the perfusion change. The BVF and the perfusion of PWS lesions increased after the initiation of V-PDT, and then gradually decreased.

Conclusions

V-PDT is an effective therapeutic modality in treating PWS. Results showed that LDI and DRS permitted the noninvasive monitoring of the changes in StO₂, BVF, and perfusion in PWS lesions during V-PDT, and these methods can be useful in facilitating our understanding of the basic physiological mechanisms during V-PDT.

Crosstalk between oxidative stress, autophagy and apoptosis in hemoporfin photodynamic therapy treated human umbilical vein endothelial cells

BACKGROUND

Photodynamic therapy (PDT) provides a treatment for port-wine stain (PWS) using hemoporfin (hematoporphyrin monomethyl ether, HMME), a novel photosensitizer, reporting better efficacy and lower recurrence rate. This study investigated the effects of HMME-PDT on human umbilical vein endothelial cells (HUVECs) as well as underlying mechanisms.

METHODS

Cell proliferation ability was measured by CCK8 assay and cell apoptosis was determined by TUNEL assay and Western blot analysis. Confocal fluorescence microscopy monitoring RFP-GFP-LC3 transfected HUVECs and Western blot analysis were used to evaluate autophagy. 3-Methyladenine (3-MA), Z-VAD-FMK, N-acetylcysteine (NAC) were used for inhibitor studies.

RESULTS

HMME-PDT decreased cell proliferation ability in an HMME concentration and light dose-dependent manner. Oxidative stress played an important role in HMME-PDT induced cell apoptosis and autophagy in HUVECs. Pretreatment with Z-VAD-FMK, the inhibitor of apoptosis, enhanced HMME-PDT induced autophagy. 3-MA, the suppressor of autophagy, significantly increased HMME-PDT induced apoptosis rates.

CONCLUSIONS

Our study demonstrated that HMME-PDT induced both apoptosis and autophagy in HUVECs via oxidative stress. Our data suggested that HMME-PDT- induced autophagy was able to prevent apoptotic cell death of HUVECs and rendered them more resistant to HMME-PDT induced toxicity.

Hematoporphyrin monomethyl ether photodynamic therapy for the treatment of facial port-wine stains resistant to pulsed dye laser

BACKGROUND

Pulsed dye laser is the first treatment choice for port-wine stains. However, as some facial port-wine stains are resistant to this modality, we evaluated the efficacy and safety of hematoporphyrin monomethyl ether (hemoporfin) photodynamic therapy for the treatment of such resistant port-wine stains.

METHODS

Patients were treated with two sessions of hemoporfin photodynamic therapy in our department. Patients received an intravenous injection of hematoporphyrin monomethyl ether (5 mg/kg) followed by 532 nm LED green light therapy. Three physicians graded the improvement in the port-wine stain, using a 4-level scale. Patients' satisfaction, reaction to treatment, and adverse effects were evaluated.

RESULTS

Thirty-one patients (mean age, 23.9 ± 11.9 years, range, 3-48 years) were enrolled in this study. Hypertrophic lesions accounted for 48.4% of port-wine stain, with 80.6% of lesions being larger than 40 cm². With regard to location, 41.9% were located on the central face and 32.3% involved a mix of the central and peripheral face. After one session, a treatment response was identified in 87.1% of cases, with the response deemed 'significant' in 29.0%. After two sessions, these rates increased to 100.0% and 61.3%, respectively. The clinical effect after two sessions was significantly greater than that after one session. Treatment reactions and adverse effects were well tolerated, and included pruritus, burning sensation, pain, edema, purpura-like change, blister, crust, and hyperpigmentation.

CONCLUSIONS

Hemoporfin photodynamic therapy is a promising treatment for port-wine stains resistant to pulsed dye laser therapy.

Retrospective study of photodynamic therapy for pulsed dye laser-resistant port-wine stains

Pulsed dye laser-resistant port-wine stains present a therapeutic challenge. The aim of this study was to evaluate the efficacy and safety of photodynamic therapy for treating these lesions. A total of 67 patients with pulsed dye laser-resistant cervicofacial port-wine stains were retrospectively assessed after undergoing photodynamic therapy mediated with a combination of hemoporfin and 532-nm light. For objective evaluation of photodynamic therapy efficacy, first, the colorimetric changes in the port-wine stain lesions were evaluated according to the L*a*b* color coordinate system, then the values of color changes (ΔE) and blanching rate were calculated. For subjective evaluation of improvement, photographs taken before and after photodynamic therapy were evaluated by three independent assessors blindly. Patient satisfaction was also used as a factor in the subjective evaluation. Adverse events were recorded after treatment. The median ΔE decreased significantly from the pretreatment value of 13.42 to 9.90 at the 2-month follow up (P < 0.001). The median blanching rate of port-wine stains was 28.04% after an average of 1.21 sessions of photodynamic therapy. Based on the overall visual assessment, 46.2% patients showed excellent or good levels of improvement (>50% color blanching). Adverse events were minimal, transient and self-limiting. In conclusion, photodynamic therapy serves as an alternative means to treat pulsed dye laser-resistant port-wine stains.

In vitro photodynamic therapy of endothelial cells using hematoporphyrin monomethyl ether (Hemoporfin): Relevance to treatment of port wine stains

Hemoporfin (hematoporphyrin monomethyl ether, HMME) is a relatively new photosensitizer that has achieved success in mediating photodynamic therapy (PDT) of port wine stains in China. However, the exact mechanism of Hemoporfin PDT on endothelial cell proliferation and apoptosis is unclear. The present study investigated the mechanism of action of HMME-PDT on endothelial cells in vitro. Human umbilical vein endothelial cells (HUVECs) were cultured in vitro. HMME-PDT treated the cells and detected the phototoxicity by cell counting kit-8 (CCK-8) assay, apoptosis by Flow cytometry assay and quantification of the secreted VEGF-A levels using ELISA and different proteins expression by quantitative real-time PCR and Western blotting. Phototoxicity was caused in an HMME and light dose-dependent manner. Apoptosis was induced as shown by Annexin-V/propidium iodide staining and morphological changes. The Bax/Bcl-2 ratio was increased as shown by Western blot for protein and RT-qPCR for mRNA. VEGF-A expression was reduced and signaling molecules in the Akt/mTOR pathway were inhibited as shown by ELISA and immunofluorescence. Hemoporfin (hematoporphyrin monomethyl ether, HMME) has achieved success in mediating photodynamic therapy (PDT) of port wine stains. The clinical success of HMME-PDT with low recurrence rates can be explained by inhibition of endothelial cell proliferation through VEGF/Akt /mTOR pathway.

Histologic changes associated with talaporfin sodium-mediated photodynamic therapy in rat skin

BACKGROUND AND OBJECTIVE

Alternative treatments are needed to achieve consistent and more complete port wine stain (PWS) removal, especially in darker skin types; photodynamic therapy (PDT) is a promising alternative treatment. To this end, we previously reported on Talaporfin Sodium (TS)-mediated PDT. It is essential to understand treatment tissue effects to design a protocol that will achieve selective vascular injury without ulceration and scarring. The objective of this work is to assess skin changes associated with TS-mediated PDT with clinically relevant treatment parameters.

STUDY DESIGN/MATERIALS AND METHODS

We performed TS (0.75 mg/kg)-mediated PDT (664 nm) on Sprague Dawley rats. Radiant exposures were varied between 15 and 100 J/cm² . We took skin biopsies from subjects at 9 hours following PDT. We assessed the degree and depth of vascular and surrounding tissue injury using histology and immunohistochemical staining.

RESULTS

TS-mediated PDT at 0.75 mg/kg combined with 15 and 25 J/cm² light doses resulted in vascular injury with minimal epidermal damage. At light dose of 50 J/cm² , epidermal damage was noted with vascular injury. At light doses >50 J/cm² , both vascular and surrounding tissue injury were observed in the forms of vasculitis, extravasated red blood cells, and coagulative necrosis. Extensive coagulative necrosis involving deeper adnexal structures was observed for 75 and 100 J/cm² light doses. Observed depth of injury increased with increasing radiant exposure, although this relationship was not linear.

CONCLUSION

TS-mediated PDT can cause selective vascular injury; however, at higher light doses, significant extra-vascular injury was observed. This information can be used to contribute to design of safe protocols to be used for treatment of cutaneous vascular lesions. Lasers Surg. Med. 49:767-772, 2017. © 2017 Wiley Periodicals, Inc.

The association between treatment reactions and treatment efficiency of Hemoporfin-photodynamic therapy on port wine stains: A prospective double blind randomized controlled trial

BACKGROUND

Research has focused on treatment efficiency and/or treatment reactions of photodynamic therapy (PDT) on port-wine stain (PWS). But few studies reported the association between them. Hence, here we investigated the association between the treatment efficiency and treatment reactions after Hemoporfin (HMME) mediated photodynamic therapy (PDT) on PWS through a prospective study.

METHODS

Patients (n=50) with PWS were randomly assigned to the HMME group or the placebo group. Three quit after the first treatment, and forty-seven received two sessions of treatment at an 8-week interval. They were given the treatment at day 1 and evaluations were performed at day 1, day 4 and week 8 in each session. HMME group was treated with HMME while the placebo group was given normal saline instead in the first session, double-blindly. While in the second session, both groups received HMME-PDT treatment.

RESULTS

After a single treatment, swelling was more severe in younger patients (p<0.05) and the lesion far from centro-facial showed more severe pruritus and scab. Compared with a single treatment, burning sensation had a higher occurrence rate, while burning sensation and scab were less severe in the second treatment. Importantly, severity of scab and pain (5min after irradiation) were found possibly correlated with the treatment efficiency.

CONCLUSION

HMME-PDT on PWS induces several treatment reactions, including pruritus, burning sensation, pain, swelling, blisters and scab. Two sessions of treatments do not have any accumulation effects on treatment reactions. And there might be a positive correlation between treatment efficiency and the severity of scab or pain (at early stage of the therapy), which might help in regulating treatment modalities.

Hemoporfin-mediated photodynamic therapy on normal vasculature: implications for phototherapy of port-wine stain birthmarks

Background

Port-wine stain (PWS) birthmarks currently are treated using a pulsed dye laser (PDL) combined with transient cooling of the epidermis. PDL treatment protocols utilize short pulses of light (585 or 595 nm wavelength) to heat selectively the microvasculature due to absorption by intravascular hemoglobin. Although most patients respond to PDL therapy, few experience complete removal of the PWS. An alternate treatment option to PDL therapy of PWS is photodynamic therapy (PDT). Research groups have reported on various photosensitizers for PDT of PWS, including Hemoporfin, Benzoporphyrin Derivative monoacid ring A, and talaporfin sodium.

Aim

Our aim was to evaluate, with an established preclinical in-vivo model, the efficacy of photodynamic therapy (PDT) with Hemoporfin to achieve persistent vascular shutdown.

Methods

To monitor the microvasculature, a dorsal window chamber was surgically installed on 24 adult mice. The PDT excitation source emitted 150mW of 532nm light, with an irradiance of 100mW/cm². A retroorbital injection of Hemoporfin (2 mg/kg) was performed to deliver the drug into the bloodstream. Laser irradiation was initiated immediately after injection. To monitor blood-flow dynamics in response to PDT, we used laser speckle imaging. We employed a dose-response experimental design to study the efficacy of Hemoporfin-mediated PDT to achieve persistent vascular shutdown observed on Day 7 after PDT.

Results

We observed four general hemodynamic responses to PDT: (1) At low radiant exposures, we did not observe any persistent vascular shutdown; (2) at intermediate radiant exposures, we observed delayed vascular shutdown effect with significant change to the vascular structure; (3) at intermediate radiant exposures, we observed an acute vascular shutdown effect with gradual restoration of blood flow and no significant changes to the vascular structure; and (4) at high radiant exposures, we observed acute vascular shutdown that persisted during the entire 7-day monitoring period, with no change in vascular structure. With light dose-response analysis, we estimated a characteristic radiant exposure of 359 J/cm² that was required to achieve persistent vascular shutdown observed on Day 7 after PDT.

Conclusions

The experimental data collectively suggest that Hemoporfin-mediated PDT can achieve persistent vascular shutdown of normal microvasculature. However, compared with our previous data using Talaporfin Sodium as photosensitizer, Hemoporfin-mediated PDT is less efficient and requires a considerably longer (~four times) irradiation time.

Relevance for patients

Patients with PWS lesions may benefit from the advantages that PDT potentially offers over conventional PDL therapy. PDT potentially is safer for patients of all skin types and more effective at treatment of recalcitrant lesions. Although clinical data suggest that Hemoporfin-mediated PDT is a promising alternative to PDL therapy, our results suggest that additional study of other photosensitizers is warranted.

The Role of Laser Speckle Imaging in Port-Wine Stain Research: Recent Advances and Opportunities

Here, we review our current knowledge on the etiology and treatment of port-wine stain (PWS) birthmarks. Current treatment options have significant limitations in terms of efficacy. With the combination of 1) a suitable preclinical microvascular model, 2) laser speckle imaging (LSI) to evaluate blood-flow dynamics, and 3) a longitudinal experimental design, rapid preclinical assessment of new phototherapies can be translated from the lab to the clinic. The combination of photodynamic therapy (PDT) and pulsed-dye laser (PDL) irradiation achieves a synergistic effect that reduces the required radiant exposures of the individual phototherapies to achieve persistent vascular shutdown. PDL combined with anti-angiogenic agents is a promising strategy to achieve persistent vascular shutdown by preventing reformation and reperfusion of photocoagulated blood vessels. Integration of LSI into the clinical workflow may lead to surgical image guidance that maximizes acute photocoagulation, is expected to improve PWS therapeutic outcome. Continued integration of noninvasive optical imaging technologies and biochemical analysis collectively are expected to lead to more robust treatment strategies.

Intraoperative monitoring of blood perfusion in port wine stains by laser Doppler imaging during vascular targeted photodynamic therapy: A preliminary study

OBJECTIVE

The objective of this study was to monitor blood perfusion dynamics of port wine stains (PWS) during vascular targeted photodynamic therapy (V-PDT) with laser Doppler imaging (LDI).

METHODS

The PWS lesions of 30 facial PWS patients received V-PDT, while the normal skins on the forearm of 5 healthy subjects were treated as light-only controls for comparison. Furthermore, two different PWS lesions in the same individual from each of 3 PWS patients successively received laser irradiation only and V-PDT, respectively. LDI was used to monitor intraoperative blood perfusion dynamics.

RESULTS

During V-PDT, the blood perfusion (278±96 PU) in PWS lesions for 31 of 33 PWS patients significantly increased after the initiation of V-PDT treatment, then reached a peak (638±105 PU) within 10min, followed by a slow decrease to a relatively lower level (515±100 PU). Furthermore, the time for reaching peak and the subsequent magnitude of decrease in blood perfusion varied with different patients. For light-only controls, an initial perfusion peak at 3min followed by a nadir and a secondary increase were found not only in normal skin, but also in PWS lesions.

CONCLUSION

The preliminary results showed that the LDI permits non-invasive monitoring blood perfusion changes of PWS lesions during V-PDT. There was a clear trend in blood perfusion responses during V-PDT and laser irradiation. The blood perfusion changes during treatment were due to V-PDT effects as well as local temperature increase induced by laser irradiation.

Photodynamic inactivation of Candida albicans by hematoporphyrin monomethyl ether

AIM

To evaluate the capacity of hematoporphyrin monomethyl ether (HMME) in the presence of light to cause photodynamic inactivation (PDI) of Candida albicans.

MATERIALS & METHODS

HMME photoactivity was evaluated against azole-susceptible and -resistant C. albicans. The mechanisms by which PDI of C. albicans occurred were also investigated.

RESULTS

HMME-mediated PACT caused a dose-dependent inactivation of azole-susceptible and -resistant C. albicans. Incubation with 10 μM HMME and irradiation with 72 J cm(-2) light decreased the viability of C. albicans by 7 log10, induced damage of genomic DNA, led to loss of cellular proteins and damaged the cell wall, membrane and intracellular targets.

CONCLUSION

Candida albicans can be effectively inactivated by HMME in the presence of light, and HMME-mediated PACT shows its potential as an antifungal treatment.

Hemoporfin Photodynamic Therapy for Port-Wine Stain: A Randomized Controlled Trial

BACKGROUND AND OBJECTIVES

Photodynamic therapy (PDT) has shown potentially beneficial results in treating port-wine stain, but its benefit-risk profile remains undefined. This study aimed to evaluate the efficacy and safety of PDT conducted with hemoporfin and a 532 nm continuous wave laser to treat port-wine stain clinically.

PATIENTS AND METHODS

This randomized clinical trial was conducted in eight hospitals in China. Participants were adolescent and adult patients (age range: 14-65 years old) with port-wine stain. During stage 1 (day 1 to week 8) all patients were randomized at a 3:1 ratio to treatment (532 nm laser irradiation (96-120 J/cm2) with hemoporfin (5mg/kg; PDT-hemoporfin, n = 330)) or placebo groups (irradiation with placebo (PDT-placebo, n = 110)); during stage 2 (week 8 to 16) patients in both groups were offered treatment. Clinician-evaluators, who were blind to the study, classified each case on the following four-level scale according to assessment of before and after standardized pictures of the lesion area: no improvement: <20%; some improvement: 20-59%; great improvement: 60-89%; or nearly completely resolved: ≥90%. The primary efficacy endpoint was proportion of patients achieving at least some improvement at week 8. The secondary efficacy endpoints were proportion of patients achieving nearly completely resolved or at least great improvement at week 8, proportion of patients achieving early completely resolved, at least great improvement, or at least some improvement at week 16, and the corresponding satisfaction of the investigators and the patients (designated as 'excellent', 'good', 'moderate', or 'ineffective') at weeks 8 and 16.

RESULTS

Compared to the PDT-placebo group, the PDT-hemoporfin group showed a significantly higher proportion of patients that achieved at least some improvement (89.7% [n = 295; 95% CI, 85.9%-92.5%] vs. 24.5% [n = 27; 95% CI, 17.4%-33.3%]) at week 8 (P < 0.0001) and higher improvements for all secondary efficacy endpoints. Treatment reactions occurred in 99.5% (n = 731; 95% CI, 98.7%-99.8%) of the PDT-hemoporfin treatments (n = 735). Hyperpigmentation occurred in 22.9 per 100 patient-treatments (n = 168; 95% CI, 20.0-26.0) in the PDT-hemoporfin treated patients.

CONCLUSIONS

Hemoporfin-mediated PDT is an effective and safe treatment option for adolescent and adult patients with port-wine stain.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR-TRC-08000213.

Hypericin-photodynamic therapy induces human umbilical vein endothelial cell apoptosis

The conventional photosensitizers used in photodynamic therapy (PDT), such as haematoporphyrin (HP), have not yet reached satisfactory therapeutic effects on port-wine stains (PWSs), due largely to the long-term dark toxicity. Previously we have showed that hypericin exhibited potent photocytotoxic effects on Roman chicken cockscomb model of PWSs. However, the molecular mechanism of hypericin-mediated photocytotoxicity remains unclear. In this study, we employed human umbilical vein endothelial cells (HUVECs) to investigate the hypericin-photolytic mechanism. Our study showed that hypericin-PDT induced reactive oxygen species (ROS), resulting in cell killings and an activation of the inflammatory response. Importantly, we have also discovered that photoactivated hypericin induced apoptosis by activating the mitochondrial caspase pathway and inhibiting the activation of the vascular endothelial growth factor-A (VEGF-A)-mediated PI3K/Akt pathway. Notably, we found that hypericin exhibited a more potent photocytotoxic effect than HP, and largely addressed the inconvenience issue associated with the use of HP. Thereby, hypericin may be a better alternative to HP in treating PWSs.

Optimization of irradiance for photodynamic therapy of port-wine stain

Controllable and effective irradiation of lesions is among the key factors that affect the potency of photodynamic therapy (PDT). An optimization method for the irradiance distribution of treatment was proposed which can be used to improve the efficacy of PDT and allow more lesions to receive the desired irradiance level in a single therapy session. With the proposed digital illumination binocular treatment system, the preferred surface normal vectors, irradiation angles, as well as area and weight coefficients of lesions can be achieved and used as characteristic parameters to optimize the irradiation direction. Two port-wine stain phantom experiments were performed. The comparison of the illumination area between preoptimization and postoptimization showed that the proposed method can effectively guide the light source control, improve the distribution of light dose, and increase the effective treatment area.

Cationic benzylidene cyclopentanone photosensitizers for selective photodynamic inactivation of bacteria over mammalian cells

Cationic modified benzylidene cyclopentanone photosensitizers selectively photo-inactivate bacterial cells over mammalian cells.

A medical manipulator system with lasers in photodynamic therapy of port wine stains

Port wine stains (PWS) are a congenital malformation and dilation of the superficial dermal capillary. Photodynamic therapy (PDT) with lasers is an effective treatment of PWS with good results. However, because the laser density is uneven and nonuniform, the treatment is carried out manually by a doctor thus providing little accuracy. Additionally, since the treatment of a single lesion can take between 30 and 60 minutes, the doctor can become fatigued after only a few applications. To assist the medical staff with this treatment method, a medical manipulator system (MMS) was built to operate the lasers. The manipulator holds the laser fiber and, using a combination of active and passive joints, the fiber can be operated automatically. In addition to the control input from the doctor over a human-computer interface, information from a binocular vision system is used to guide and supervise the operation. Clinical results are compared in nonparametric values between treatments with and without the use of the MMS. The MMS, which can significantly reduce the workload of doctors and improve the uniformity of laser irradiation, was safely and helpfully applied in PDT treatment of PWS with good therapeutic results.

Assessment of tissue perfusion changes in port wine stains after vascular targeted photodynamic therapy: a short-term follow-up study

The occlusion effect of vascular targeted photodynamic therapy (V-PDT) for malformed vessels in port wine stains (PWS) often last for some time after the treatment. A relatively longer period after V-PDT is needed to accurately assess the final response of PWS microcirculation to the treatment. In this study, we intended to use laser speckle imaging (LSI) to assess the tissue perfusion changes of PWS at follow-up after V-PDT and preliminarily analyze the relationship between perfusion change and color bleaching. Seventeen patients with 40 PWS lesions were scanned by LSI before and 3-6 months after they received V-PDT. The speckle flow indices of PWS lesions and normal skin before and at follow-up after V-PDT were recorded. We also performed analyses on the correlation between perfusion changes and color bleaching. Before V-PDT, the 40 PWS lesions showed higher perfusion than the normal skin (1,421 ± 463 and 1,115 ± 386 perfusion unit (PU), respectively, P < 0.01). The PWS lesions scanned at follow-up showed decreased perfusion level compared to the preoperative values (1,282 ± 460 and 1,421 ± 463 PU, respectively, P < 0.01). After V-PDT, the perfusion change rates coincide well with the color bleaching rates (correlation coefficient, 0.73). In conclusion, the LSI system is capable of imaging PWS perfusion precisely, and it has shown promising results in assessing the changes of tissue perfusion of V-PDT for PWS, with objective and quantitative data, real-time images, and a shorter detection time. It may also provide an effectiveness assessment method for the treatment of PWS.

Bactericidal effects of hematoporphyrin monomethyl ether-mediated photosensitization against pathogenic communities from supragingival plaque

Photodynamic antimicrobial chemotherapy (PACT) is proposed as a potential candidate to inactivate pathogens in localized infections due to the rapid evolution of bacterial resistance. The treatment modality utilizes nontoxic agents called photosensitizers and harmless visible light to generate reactive oxygen species which result in microbial cells' killing. Hematoporphyrin monomethyl ether (HMME) as a novel and affordable photosensitizer has been used in treating various clinical diseases for years, but few applications in infection. In this report, we studied the bactericidal effects of the HMME-mediated photodynamic reaction on the pathogenic microbes in supragingival plaque which can lead to many oral infectious diseases such as caries, gingivitis, and so on. Our findings demonstrated that HMME promoted an effective action in bacterial reduction with the application of laser energy. Moreover, the antimicrobial activities were dramatically enhanced as the HMME concentration and exposure time were increased, but reached a plateau when matched the appropriate agent concentration and illumination. It was found that the survival fraction of microorganisms is exponentially dependent on the product of HMME concentration and irradiation time. These promising results suggest the HMME may be an excellently cost-effective photosensitizing agent for mediating PACT in the treatment of supragingival plaque-related diseases. An optimized HMME concentration and irradiation time has been found to achieve the best results under our experimental conditions. The high HMME concentration matching short curative time, or vice versa, can achieve the similar therapeutic effect, which may provide more flexible treatment plans according to specific conditions.

Vascular targeted photodynamic therapy for bleeding gastrointestinal mucosal vascular lesions: a preliminary study

BACKGROUND

Vascular-targeted photodynamic therapy (V-PDT) has shown good selectivity and efficacy in the treatment of certain types of vascular disease, including port wine stains, age-related macular degeneration, and esophageal varices. This study was conducted to test the efficacy and safety of V-PDT in the treatment of gastrointestinal (GI) bleeding caused by the abnormal dilatation of capillaries.

METHODS

Patients with bleeding GI mucosal vascular lesions treated with V-PDT were included in this retrospective study. The efficiency of V-PDT was analyzed by comparing the documented endoscopy results, hemoglobin levels, and transfusion requirements before and at 6 months after the last V-PDT. Side effects during and after V-PDT and follow-up results were also analyzed.

RESULTS

Seven patients with bleeding GI mucosal vascular lesions were treated with V-PDT. After 1-4 V-PDT sessions, all patients no longer needed transfusions to maintain a stable hemoglobin level during the follow-up period of 6 months. The mean hemoglobin level of the seven patients improved from 6.21±1.48 g/dl to 11.66±1.21 g/dl (p<0.001), and the GI bleeding and melena of all the patients disappeared. No perforations, strictures, scars, or episodes of photosensitization occurred in the seven patients, and there were no recurrences of GI bleeding during the 1-21 months of further follow-up.

CONCLUSIONS

This preliminary study indicated that V-PDT is a highly selective, safe, well-tolerated, and effective treatment modality for bleeding GI mucosal vascular lesions. However, prospective studies with larger sample sizes are needed to confirm this finding.

Development and clinical evaluation of medical robot assisted photodynamic therapy of port wine stains

BACKGROUND

Port wine stains (PWS) are a kind of skin disease for which photodynamic therapy (PDT) has already achieved good results. With manual operation of clinical PDT, the laser density is uneven and laser irradiation of the lesion is arbitrary and non-uniform. In addition, lengthy manual operation tires doctors; thus a robot system has been developed to assist them.

METHODS

First, a novel medical manipulator consisting of five passive joints (robot arm) and two active joints (robot wrist) was developed to automatically improve the uniformity of laser irradiation. Second, image processing of the lesion was introduced. Third, kinematics and path planning of the robot were analysed, and safety precautions were introduced. Then, accuracy tests of the robot wrist and robot system were conducted separately before clinical application. Finally, a total of 50 PWS cases were treated using the robot system. The clinical outcomes and comparison of non-parametric values were employed to evaluate the robot system.

RESULTS

The accuracies of the robot wrist and robot system were shown to meet the requirements of clinical PDT treatment. The robot system performed successfully in 50 PWS cases. Doctors can devote more energy to clinical judgments during treatment with the assistance of the robot system. All the PWS have shown different degrees of improvement. The results show that the robot system is useful in assisting doctors for the PDT treatment of PWS.

CONCLUSIONS

The experiments show the feasibility and usefulness of the robot system in assisting doctors giving PDT treatment for PWS. The robot system can lighten the load on doctors and improve the therapeutic effect.

Study on the interaction between hematoporphyrin monomethyl ether and DNA and the determination of hematoporphyrin monomethyl ether using the resonance light scattering technique

The interaction between photosensitizer anticancer drug hematoporphyrin monomethyl ether (HMME) and ctDNA has been studied based on the decreased resonance light scattering (RLS) phenomenon. The RLS, UV-vis and fluorescence spectra characteristics of the HMME-ctDNA system were investigated. Besides, the phosphodiesters quaternary ammonium salt (PQAS), a kind of new gemini surfactant synthesized recently, was used to determine anticancer drug HMME based on the increasing RLS intensity. Under the optimum assay conditions, the enhanced RLS intensity was proportional to the concentration of HMME. The linear range was 0.8-8.4microgmL(-1), with correlation coefficient R(2)=0.9913. The detection limit was 0.014microgmL(-1). The human serum samples and urine samples were determined satisfactorily, which proved that this method was reliable and applicable in the determination of HMME in body fluid. The presented method was simple, sensitive and straightforward and could be a significant method in clinical analysis.

Effects of photodynamic therapy using hematoporphyrin monomethyl ether on experimental choroidal neovascularization

Hematoporphyrin monomethyl ether (HMME) is a novel and promising second-generation porphyrin-related photosensitizer for photodynamic therapy (PDT). To study the effects of HMME PDT on choroidal neovascularization (CNV) in rats, the PDT was performed 20 min after HMME bolus injection, which was investigated prior to the PDT by fluorescence microscopy with laser-induced CNV, and delivered at an irradiance of 400, 600 and 1000 mW cm(-2) corresponding to a fluence of 36, 54, 90 J cm(-2) in PDT plan I (15 mg kg(-1) HMME). In PDT plan II (30 mg kg(-1) HMME), the laser had a constant irradiance of 600 mW cm(-2), which was delivered for 60, 90 or 150 s, to also achieve total energy doses of 36, 54 or 90 J cm(-2). CNV closure rates assessed by fluorescein angiography and histologic damage to treated areas of choroid and retina varied as a function of the dose of HMME and of the activating light energy fluence. Endothelial cell labeled by platelet/endothelial cell adhesion molecule-1 presented treated CNV lesions that were significantly reduced in size (P < 0.01). It can be concluded that PDT using HMME can effectively occlude CNV. HMME is a potentially useful photosensitizer for the reduction in CNV size of irradiated areas.

Imaging port wine stains by fiber optical coherence tomography

We develop a fiber optical coherence tomography (OCT) system in the clinical utility of imaging port wine stains (PWS). We use our OCT system on 41 patients with PWS to document the difference between PWS skin and contralateral normal skin. The system, which operates at 4 frames with axial and transverse resolutions of 10 and 9 mum, respectively, in the skin tissue, can clearly distinguish the dilated dermal blood vessels from normal tissue. We present OCT images of patients with PWS and normal human skin. We obtain the structural parameters, including epidermal thickness and diameter and depth of dilated blood vessels. We demonstrate that OCT may be a useful tool for the noninvasive imaging of PWS. It may help determine the photosensitizer dose and laser parameters in photodynamic therapy for treating port wine stains.

Eczematous dermatitis after vascular laser therapy: a report of two cases

Eczematous dermatitis was found in two port wine stain (PWS) lesions in two different individuals following variable pulsed 532-nm laser therapy. Both of the individuals described in this report had received low-dose superficial X-ray several years prior to the development of the eczematous dermatitis. The eczematous dermatitis in the PWS lesions was characterized by oozing, crusting, and pruritus, which showed a tendency to expand to other sites when exacerbated. Treatment with topical corticosteroid ointments produced some temporary improvement, but the dermatitis in both cases recurred when the topical medications were stopped. The mechanism of action for the development of an eczematous dermatitis in a PWS remains unclear, but may be related to multiple factors including abnormal hemodynamic forces resulting from the malformed vessels, an abnormal production of cytokines, local pathophysiological and immunological changes resulting from either the X-ray therapy or the laser therapy, and atopic constitution inherent in these individuals. These hypotheses and ideas need further study for additional insight into this rare, but reported adverse event.

Treatment of hypertrophic and resistant port wine stains with a 755 nm laser: a case series of 20 patients

BACKGROUND AND OBJECTIVE

Port wine stains (PWS) are heterogeneous vascular malformations that can be treated with vascular-selective pulsed dye lasers (PDL). Hypertrophic PWS, especially in adults, are consistently less responsive to PDL. Furthermore, many PWS that respond well initially to PDL treatment may reach a response plateau, becoming unresponsive to further PDL treatments, a phenomenon termed "treatment resistance." Based on the theory of selective photothermolysis, vessels in such lesions may also be specifically targeted with a 755 nm laser that has selectivity for deoxyhemoglobin as well as oxyhemoglobin and increased depth of skin penetration.

STUDY DESIGN/PATIENTS AND METHODS

Retrospective case review of 20 patients with either hypertrophic or PDL-resistant PWS treated with a 755 nm laser alone or in combination with other lasers, including PDL.

RESULTS

Hypertrophic PWS showed significant lightening after treatment with a 755 nm laser in combination with PDL. Most PDL-resistant PWS showed moderate improvement after treatment with either a 755 nm laser alone or in combination with another laser, including PDL. Some lesions showed only mild improvement or did not respond. Serious side effects were infrequent. Most commonly encountered complications included pain, edema, bullae, crusting, and rare scarring.

CONCLUSIONS

Alexandrite 755 nm laser can be useful for the treatment of hypertrophic and treatment-resistant PWS in adult and pediatric patients. Complications are infrequent and predictable. Careful attention to using a fluence at or near the threshold for clinical response with this deeply penetrating laser is essential to prevent serious sequelae.

Combined benzoporphyrin derivative monoacid ring photodynamic therapy and pulsed dye laser for port wine stain birthmarks

BACKGROUND

Pulsed dye laser (PDL) is a commonly utilized treatment for port wine stain birthmarks (PWS) in the United States; however, results are variable and few patients achieve complete removal. Photodynamic therapy (PDT) is commonly used in China, but treatment associated photosensitivity lasts several weeks and scarring may occur. We propose an alternative treatment option, combined PDT+PDL and performed a proof-of-concept preliminary clinical trial.

METHODS

Subjects with non-facial PWS were studied. Each subject had four test sites: control, PDL alone, PDT alone (benzoporphyrin derivative monoacid ring A photosensitizer with 576 nm light), and PDT+PDL. Radiant exposure time for PDT was increased in increments of 15 J/cm(2). Authors evaluated photographs and chromametric measurements before and 12 weeks post-treatment.

RESULTS

No serious adverse events were reported; epidermal changes were mild and self-limited. No clinical blanching was noted in control or PDT-alone sites. At PDT radiant exposures of 15 and 30 J/cm(2), equivalent purpura and blanching was observed at PDL and PDT+PDL sites. At PDT radiant exposures over 30 J/cm(2), greater purpura was noted at PDT+PDL sites as compared to PDL alone. Starting at 75 J/cm(2), improved blanching was noted at PDT+PDL sites.

CONCLUSIONS

Preliminary results indicate that PDT+PDL is safe and may offer improved PWS treatment efficacy. Additional studies are warranted.