Hematoporphyrin Monomethyl Ether Photodynamic Therapy of Port Wine Stain: Narrative Review

Recent Advances in Photodynamic Therapy for Vascular Abnormalities

Abstract Background: Photodynamic therapy (PDT) is a minimally invasive therapy that was gradually established as a first-line treatment for vascular abnormalities. Its action depends on the appropriate wavelength of light and photosensitizer to produce toxic oxygen species and cause cell death. Objective: Several new clinical improvements and trends in PDT have been described in recent years. The aim of this review is to provide an overview of the current data from clinical trials. Methods: In this review, we introduce and generalize the wavelength, duration, dose, strength, and photosensitizer of PDT for the treatment of vascular abnormalities, such as circumscribed choroidal hemangiomas (CCH), choroidal neovascularization (CNV) and capillary malformation (CM). Results: The systematic review findings indicate that the application of PDT is a safe effective method to treat CCH, CNV and CM. However, PDT also has early onset side effects and late onset side effects. Conclusions: Based on the discussion of the effectiveness of PDT, we conclude that PDT has great potential for clinical use, although PDT has possible side effects.

Clinical Observation on the Therapeutic Effect of Port-Wine Stains with Intravenous Injection of Hematoporphyrin Monomethyl Ether (HMME)

Background

Hematoporphyrin monomethyl ether (HMME) is a promising photosensitizer for photodynamic therapy (PDT) and has found wide application in the treatment of port-wine stains (PWS).

Objective

This study aims to observe and analyze the clinical efficacy and safety of HMME-PDT in the treatment of PWS patients. It also aims to evaluate the usefulness of color Doppler flow imaging (CDFI), an ultrasound technique for detecting blood flow in skin lesions, in assessing clinical efficacy.

Methods

Thirty-three patients with PWS underwent HMME-PDT at our dermatology outpatient clinic between January 2019 and March 2020. Data on patient demographics, lesion location, lesion type (pink, purple, nodular thickening), treatment frequency, and pre- and post-treatment images were collected and retrospectively analyzed. CDFI was performed on three patients.

Results

All patients received intravenous HMME and underwent irradiation with 532 nm green LED light. Of these, 5 patients received 1 session of HMME-PDT, 14 received 2 sessions, 9 received 3 sessions and the remaining 5 patients received more than 3 sessions. Of the 33 patients, 9 were cured (27.27%), 10 showed improvement (30.30%), 11 experienced a reduction in symptoms (33.33%), and 3 showed no significant improvement (9.09%). Most patients reported local pain and oedema, and no systemic adverse effects were observed. Clinical efficacy correlated with lesion type and total number of treatment sessions. CDFI appears to be an excellent technique for assessing clinical efficacy.

Conclusion

HMME-PDT is a safe and effective method for the treatment of PWS. CDFI examination appears to be a promising assessment tool. However, further validation with larger sample sizes is warranted.

Photodynamic therapy for the treatment of port-wine stains in phakomatosis pigmentovascularis

BACKGROUND

Phakomatosis pigmentovascularis (PPV) is a rare congenital syndrome. Only a few studies have reported the treatment of PPV, including a case using photodynamic therapy (PDT) to treat PPV-associated port-wine stains (PWS).

OBJECTIVE

To investigating the efficacy and adverse effects of hemoporfin-PDT in PPV-associated PWS.

METHODS

The efficacy and adverse effects in patients with PPV who underwent two sessions of hemoporfin-PDT from January 2019 to December 2022 were retrospectively analyzed.

RESULTS

Twenty patients were included (13 females, 7 males, age range: 2-31 years; mean: 8.20 ± 8.92 years). Two, nine, seven, and two patients had PPV types Ia, IIa, IIb, and IIIa, respectively. After two treatments, the visual evaluation indicated the color of the PWS in 4, 5, 6, and 5 patients showed poor, fair, good, and excellent improvements, respectively. The combined good and excellent improvement rates in patients with PWS and pigmentary nevus overlapping in the same treatment area and in patients with PWS in the treatment areas only were 33.3% versus 87.5%, respectively, and were significantly different (p = 0.02). Minor side effects, such as edema, scabbing, hyperpigmentation, and blistering, were observed in some patients after PDT.

CONCLUSION

Hemoporfin-PDT is an effective treatment for PPV-associated PWS. Patients with PWS and pigmentary nevus overlapping in the same treatment area showed poorer efficacy than patients with PWS in the treatment areas only.

Vascular Malformations

Vascular malformations are intricate anomalies of the circulatory system, presenting a diverse array of clinical manifestations, and posing significant challenges in diagnosis and treatment. The pathogenesis of vascular malformations is explored through the lens of genetic and molecular mechanisms, shedding light on the pivotal role of somatic mutations and dysregulated signaling pathways. Clinical presentations of vascular malformations are widely variable, ranging from cosmetic concerns to life-threatening complications. The utility of imaging techniques, such as magnetic resonance imaging (MRI), computed tomography (CT), and angiography, are discussed in detail, emphasizing their role in precise delineation and characterization. Therapeutic strategies for vascular malformations are multifaceted, considering factors such as lesion size, location, potential complications, and patient-specific factors. Traditional interventions, including surgical excision and embolization, are appraised alongside emerging approaches like targeted molecular therapies and minimally invasive procedures. The manuscript underscores the need for an individualized treatment approach, optimizing outcomes while minimizing risks and complications. In summation, this manuscript offers a comprehensive analysis of vascular malformations, encompassing their underlying pathogenesis, clinical nuances, diagnostic methods, and therapeutic considerations. By synthesizing current knowledge and highlighting gaps in understanding, this review serves as a valuable resource for clinicians, researchers, and medical practitioners, fostering an enhanced comprehension of vascular malformations and paving the way for improved patient care and innovative research endeavors.

Current clinical evidence is insufficient to support HMME-PDT as the first choice of treatment for young children with port wine birthmarks

BACKGROUND

Port wine birthmark (PWB) is a congenital vascular malformation of the skin. Pulsed dye laser (PDL) is the "gold standard" for the treatment of PWB globally. Hematoporphyrin monomethyl ether (HMME or hemoporfin)-mediated photodynamic therapy (HMME-PDT) has emerged as the first choice for PWB treatment, particularly for young children, in many major hospitals in China during the past several decades.

AIM

To evaluate whether HMME-PDT is superior to PDL by comparing the clinical efficacies of both modalities.

METHOD

PubMed records were searched for all relevant studies of PWB treatment using PDL (1988-2023) or HMME-PDT (2007-2023). Patient characteristics and clinical efficacies were extracted. Studies with a quartile percentage clearance or similar scale were included. A mean color clearance index (CI) per study was calculated and compared among groups. An overall CI (C0), with data weighted by cohort size, was used to evaluate the final efficacy for each modality.

RESULT

A total of 18 HMME-PDT studies with 3910 patients in China were eligible for inclusion in this analysis. Similarly, 40 PDL studies with 5094 patients from nine different countries were eligible for inclusion in this analysis. Over 58% of patients in the HMME-PDT studies were minors (<18 years old). A significant portion (21.3%) were young children (<3 years old). Similarly, 33.2% of patients in the PDL studies were minors. A small proportion (9.3%) was young children. The overall clearance rates for PDL were slightly, but not significantly, higher than those for HMME-PDT in cohorts with patients of all ages (C0, 0.54 vs. 0.48, p = 0.733), subpopulations with only minors (C0, 0.54 vs. 0.46, p = 0.714), and young children (C0, 0.67 vs. 0.50, p = 0.081). Regrettably, there was a lack of long-term data on follow-up evaluations for efficacy and impact of HMME-PDT on young children in general, and central nervous system development in particular, because their blood-brain barriers have a greater permeability as compared to adults.

CONCLUSION

PDL shows overall albeit insignificantly higher clearance rates than HMME-PDT in patients of all ages; particularly statistical significance is nearly achieved in young children. Collectively, current evidence is insufficient to support HMME-PDT as the first choice of treatment of PWBs in young children given: (1) overall inferior efficacy as compared to PDL; (2) risk of off-target exposure to meningeal vasculature during the procedure; (3) administration of steriods for mitigation of side effects; -and (4) lack of long-term data on the potential impact of HMME on central nervous system development in young children.

Efficacy and influential factors of hematoporphyrin monomethyl ether mediated photodynamic therapy in the treatment for port-wine stains

BACKGROUNDS

Hematoporphyrin monomethyl ether mediated photodynamic therapy (HMME-PDT) has emerged as an alternative approach for port-wine stain (PWS), which was primarily treated with pulsed dye laser (PDL). This study was aimed to evaluate the efficacy and safety of HMME-PDT for PWS and to explore influential factors on the efficacy.

METHODS

A total of 254 patients were enrolled. Patients received an intravenous injection of HMME at 5 mg/kg. Lesion areas were irradiated with 532-nm light for 20-25 min. Efficacy was assessed according to fading of lesions and graded as excellent (≥90 %), good (60 %-89 %), fair (20 %-59 %), or poor (<20 %). Adverse events were recorded. Clinical data were analyzed including gender, age, lesion sub-type, lesion location and number of treatments.

RESULTS

Overall, 72.4 % of patients achieved an effective response, with 27.6% showing excellent efficacy, 24.8 % showing good efficacy and 20.1 % showing fair efficacy. Only 27.6 % showed poor efficacy. Patients under the age of 18 obtained a better efficacy than adults. Lesions in face showed a better therapeutic outcome than those in neck or trunk and extremities. A more effective response was seen in pink type compared with nodular thickening type. Multiple HMME-PDT treatments could improve the clinical response. Lesion location, lesion sub-type, number of treatments were independent influential factors on efficacy. Adverse events included edema, blister, crust, hypopigmentation, hyperpigmentation, pain, itch and burning sensation. No severe systemic side events were observed.

CONCLUSIONS

HMME-PDT was effective for treating PWS and was safe and well-tolerated by patients. It is worth further investigation in efficacy and safety involving more patients from medical institutions in different regions in China. The optimal treatment parameters and treatment protocols are still being explored in the clinical treatment for PWS.