The use of photodynamic therapy in medical practice

Cancer therapy, especially for tumors near sensitive areas, demands precise treatment. This review explores photodynamic therapy (PDT), a method leveraging photosensitizers (PS), specific wavelength light, and oxygen to target cancer effectively. Recent advancements affirm PDT's efficacy, utilizing ROS generation to induce cancer cell death. With a history spanning over decades, PDT's dynamic evolution has expanded its application across dermatology, oncology, and dentistry. This review aims to dissect PDT's principles, from its inception to contemporary medical applications, highlighting its role in modern cancer treatment strategies.

A Review of the Dermatologic Clinical Applications of Topical Photodynamic Therapy

Topical photodynamic therapy is a widely approved therapy for actinic keratoses and low-risk nonmelanoma skin cancers with a rapidly growing range of emerging indications for other cutaneous diseases. This review summarizes the best-available evidence to provide a clinical update for dermatologists on the approved and emerging indications of photodynamic therapy. The body of evidence suggests that photodynamic therapy is superior or noninferior to other available treatment modalities for actinic keratoses, low-risk basal cell carcinomas, Bowen's disease, skin field cancerization, chemoprevention of keratinocyte carcinomas in organ transplant recipients, photoaging, acne vulgaris, and cutaneous infections including verrucae, onychomycosis, and cutaneous leishmaniasis. There is emerging evidence that photodynamic therapy plays a role in the management of actinic cheilitis, early-stage mycosis fungoides, extramammary Paget disease, lichen sclerosis, and folliculitis decalvans but there are no comparative studies with other active treatment modalities. Common barriers to topical photodynamic therapy include procedural pain, costs, and the time required for treatment delivery. There is significant heterogeneity in the photodynamic therapy protocols reported in the literature, including different photosensitizers, light sources, number of treatments, time between treatments, and use of procedural analgesia. Topical photodynamic therapy should be considered in the management of a spectrum of inflammatory, neoplastic, and infectious dermatoses. However, more comparative research is required to determine its role in the treatment algorithm for these dermatologic conditions and more methodological research is required to optimize photodynamic therapy protocols to improve the tolerability of the procedure for patients.

Pain Management in Dermatology

BACKGROUND

The dermatologist has to deal with many situations where the patient feels pain and must therefore know how to manage it.

SUMMARY

The aim of this review was to explore the treatments available to manage pain in dermatology in different circumstances, with an emphasis on pharmacological and non-pharmacological interventions specifically studied in dermatology.

Hemoporfin-mediated photodynamic therapy with general anesthesia showed superior efficacy in the treatment of port-wine stains: a retrospective evaluation

Background

Hemoporfin-mediated photodynamic therapy (PDT) is an effective treatment for port-wine stains (PWS), and pain is the main adverse effect of this therapy. General anesthesia is commonly used for pain management during PDT, but the effect of general anesthetics on the subsequent treatment efficacy of PDT in PWS has not been reported.

Objectives

To assess the use of general anesthesia combined with PDT compared with PDT alone in 207 PWS patients, and to provide further safety and efficacy data on this combined therapy.

Methods

Propensity score matching (PSM) was used at a 2:1 ratio to create a general anesthetic group (n = 138) and a highly comparable nonanesthetic group (n = 69). The clinical outcomes were evaluated, and the treatment reactions and adverse effects were recorded after one treatment with PDT.

Results

After matching, there was no significant difference in the demographic data of the patients in the two groups (p > 0.05), while the treatment efficacy was significantly higher in the general anesthetic group than in the nonanesthetic group (76.81 vs. 56.52%, p < 0.05). Moreover, logistic regression analysis confirmed that patients receiving general anesthesia showed an association with a good response to PDT (OR = 3.06; 95% CI, 1.57-6.00; p = 0.0011). Purpura lasted longer in the general anesthetic group, but the other treatment reactions and adverse effects were similar in the two groups (p > 0.05). No serious systemic adverse reactions were observed.

Conclusion

We recommend this combined therapy, which is associated with painless, as a high efficacy treatment option for PWS patients, especially for patients with a poor response to multiple PDT alone treatments.

Advances in Photodynamic Therapy for the Treatment of Actinic Keratosis and Nonmelanoma Skin Cancer: A Narrative Review

Photodynamic therapy (PDT) with photosensitization using 5-aminolevulinic acid (ALA) [including a nanoemulsion (BF-200 ALA)] is approved in the USA for the treatment of actinic keratoses (AKs); another derivative, methyl aminolevulinate, is not approved in the USA but is used in Europe. For AK treatment, the photosensitizer may be applied to individual AK lesions or, depending on treatment regimen, to broader areas of sun-damaged skin to manage field cancerization, although not all products are approved for field treatment. ALA-PDT and photosensitizers have also been used off-label for the treatment of nonmelanoma skin cancers, primarily basal cell carcinomas (BCCs) and cutaneous squamous cell carcinomas (cSCC). Advantages of PDT include potentially improved cosmesis and patient satisfaction; disadvantages include pain and duration of treatment. Alternative illumination approaches, including intense pulsed light as well as pulsed-dye lasers, have also been used successfully. Pretreating the affected tissue or warming during incubation can help to increase photosensitizer absorption and improve therapeutic efficacy. Combinations of multiple treatments are also under exploration. Reducing incubation time between photosensitizer application and illumination may significantly reduce pain scores without affecting treatment efficacy. Substituting daylight PDT for a conventional illumination source can also reduce pain without compromising efficacy. The objective of this narrative review is to describe current and ongoing research in the use of topical photosensitizers and modified light delivery regimens to achieve improved therapeutic outcomes with less toxicity in patients with AK, cSCC, BCC, and field cancerization.

General anaesthesia for photodynamic therapy of port-wine stain in children: A retrospective study

AIMS

This report intended to assess the safety and efficiency of general anaesthesia with preserved spontaneous breathing for pain management in photodynamic therapy (PDT) of port-wine stains (PWS) in paediatric patients.

METHODS

This study included 1960 Hemoporfin PDT procedures performed under general anaesthesia on 560 PWS patients. Medical records were retrospectively analysed. All of the procedures performed under general anaesthesia with preserved spontaneous breathing.

RESULTS

The patients comprised males (43.93%) and females (56.07%). Ninety percent of cases were ASA class I, and 10% were class II, no case was class III or higher. Adverse events accompanying general anaesthesia included postoperative irritability (8.98%), carbon dioxide pressure (PCO₂) >50 mmHg (15.97%), movement during surgery (6.98%), vomiting (0.2%), laryngospasm (0.2%), unplanned endotracheal intubation (0.05%), upper airway obstruction (0.05%), and hypoxia (0.1%). The FLACC score was <4 points in 84% of cases and 4∼6 points in 16% of cases.

CONCLUSIONS

General anaesthesia with preserved spontaneous breathing has few complications and appears safe and feasible for PDT in most children with PWS.

Efficacy of two different methods of cold air analgesia for pain relief in PDT of actinic keratoses of the head region - a randomized controlled comparison study

BACKGROUND

Photodynamic therapy (PDT) is an effective method for treating actinic keratosis (AK) with pain during illumination representing the major side effect. The efficacy of two different cooling methods for pain relief in PDT of AK in the head region was compared.

METHODS

Randomized, assessor-blinded, half side comparison study in 20 patients with symmetrically distributed AK on the head. Conventional PDT was performed on both halves of the scalp or face by applying 20% aminolevulinic acid cream (ALA) and subsequent illumination with incoherent red light. During illumination one side was cooled with a cold air blower (CAB) and the other with a standard fan (FAN) in a randomized fashion. Pain and skin temperature were recorded during and after PDT. The phototoxic skin reaction was evaluated up to seven days after PDT. The clearance rate of AK was assessed at 3 and 6 months after PDT.

RESULTS

Mean pain (VASmean), maximum pain intensity (VASmax) and the mean skin temperature during PDT were significantly lower with CAB as compared to FAN (VASmean: 2.7 ± 1.4 vs. 3.7 ± 2.1, p = 0.003; VASmax: 3.8 ± 2.0 vs. 4.8 ± 2.5, p = 0.002; 26.8 ± 2.0 °C vs. 32.1 ± 1.7 °C; p=<0.001). The severity of the phototoxic skin reaction and the clearance rate of AK did not differ between the two cooling methods.

CONCLUSION

Cooling with CAB during PDT has a greater analgesic effect than cooling with FAN. Patients with a lower skin temperature during illumination tended to experience less pain, however, this effect did not reach the level of statistical significance.

Effects of Photodynamic Therapy on Nav1.7 Expression in Spinal Dorsal Root Ganglion Neurons

OBJECTIVE

The aim of this study was to examine the effects of photodynamic therapy (PDT) on the expression of Nav1.7 in spinal dorsal root ganglion (DRG) neurons.

METHODS

The primary DRG neurons from newborn SD rats were cultured. The cells were identified by neuron-specific enolase immunofluorescence staining. DRG neurons were divided into four groups: control group, photosensitizer group, laser group, and PDT group. The cell viability was detected by a cell counting kit-8 (CCK8) assay. qRT-PCR and Western blotting were used to determine the mRNA and protein expression levels of Nav1.7 in DRG neurons.

RESULTS

The purity of the cultured primary DRG neurons was greater than 90%. Compared with the control group, no significant change was found in the cell viability of the photosensitizer group, while the viability in the laser group and the PDT group was significantly reduced. The mRNA and protein expression levels of Nav1.7 were significantly greater in the laser group and the PDT group than in the control group. At the same time, the mRNA and protein expression levels of Nav1.7 were greater in the laser group than in the PDT group.

CONCLUSION

Both laser and PDT could upregulate the expression of Nav1.7 in DRG neurons, and the promoting effect might be related to the pain induced by clinical treatment. This study provides a research basis for the use of laser and PDT to treat pain. A better understanding of the relationship between Nav1.7 and PDT can help clinicians better manage PDT-related pain.

Three-step irradiance schedule versus two-step irradiance schedule for pain control during topical 5-aminolevulinic acid-photodynamic therapy of facial acne in Chinese patients: A prospective randomized comparative study

BACKGROUND

A two-step irradiance schedule has been found to be useful for pain control during photodynamic therapy (PDT) on nonmelanotic skin cancer and condyloma acuminatum.

OBJECTIVES

To evaluate the efficacy of a new three-step irradiance schedule derived from the psychological "peak-end rule" and two-step irradiance schedule in relieving pain during 5-aminolevulinic acid PDT (ALA-PDT) on acne.

METHODS

A total of 90 moderate to severe acne patients were enrolled in our study and randomly divided into two groups with a ratio of 1:1. They were treated by a light-emitting diode light source of 633 ± 10 nm after being incubated with 5% ALA for an hour using a two-step or three-step irradiance schedule, respectively. The total irradiance intensity was 84 J/cm² of each session and the treatment interval was 2 weeks. Pain was recorded 30 min after each PDT using a visual analog scale (VAS). Follow-up was done at baseline and 2 weeks after each treatment. The numbers of lesions were counted after the third treatment through the pictures taken before and all the side effects were recorded at each follow-up visit.

RESULTS

Eighty-seven subjects completed the total three treatments (44 cases in Group A and 43 cases in Group B). The average VAS of Group B (1.61 ± 0.67) was significantly lower than that of Group A (3.14 ± 0.67), with a difference of 1.52 ± 0.08 (p < 0.0001) between them. Both groups received a similar effective rate after the total three sessions (88.64% vs. 88.37%, p > 0.05).

CONCLUSIONS

The new three-step irradiance method could relieve pain during ALA-PDT more significantly than the two-step schedule with a similar effective rate.

Possibilities of pain management during photodynamic therapy

The authors consider the possibilities of pain management during photodynamic therapy (PDT) of visible tumors based on the observation of 102 patients. Of the total number of patients, 62 had verified basal cell skin cancer, 10 people - squamous cell skin cancer, another 10 - oral and oropharynx mucosa cancer, 8 - oral leukoplakia and dysplasia, in 6 - lower lip cancer, in 4 - breast cancer, in 2 - other localizations of neoplasms. In 15 patients, nonsteroidal anti-inflammatory drugs (NSAID) were used as pain management, in 69 - a combination of NSAID with tramadol, in 14 - nerve block anesthesia, in 4 - PDT was performed under general anesthesia. The intensity of pain syndrome during laser irradiation of the tumor was assessed on the verbal rating scale (VRS). The absence of pain was recorded in 9% of cases. Mild pain was noted by 58% of patients, moderate pain - 20%, severe pain - 10%, very severe pain was noted by 3% of patients.

The degree of expression of pain syndrome during PDT depends on the incidence of a lesion, histological form of tumor, and method of anesthesia. NSAID alone, or in combination with an opioid analgesic, allows effective control of pain syndrome in PDT of basal cell skin cancer in 89%, in PDT of squamous cell skin cancer in 66% of observations. Nerve block anesthesia allows stoping pain syndrome during PDT of oropharyngeal tumors.

Methadone enhances the effectiveness of 5-aminolevulinic acid-based photodynamic therapy for squamous cell carcinoma and glioblastoma in vitro

Although having shown promising clinical outcomes, the effectiveness of 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT) for squamous cell carcinoma (SCC) and glioblastoma remains to be improved. The analgesic drug methadone is able to sensitize various tumors to chemotherapy. In this in vitro study, the influence of methadone to the effectiveness of ALA-PDT for SCC (FADU) and glioblastoma (A172) was investigated on the protoporphyrin IX (PpIX) fluorescence, survival rates, apoptosis, and cell cycle phase, each with or without the presence of methadone. The production of PpIX was increased by methadone in FADU cells while it was decreased in A172 cells. The survival rates of both cell lines treated by ALA-PDT were significantly reduced by the combination with methadone (P < .05). Methadone also significantly increased the percentage of apoptotic cells and improved the effect of ALA-PDT on the cell cycle phase arrest in the G0/G1 phase (P < .05). This study demonstrates the potential of methadone to influence the cytotoxic effect of ALA-PDT for both SCC and glioblastoma cell lines.

Rosacea Flare - Up after Photodynamic Therapy (PDT) for Field Cancerization and a Review on Adverse Events with PDT in General

BACKGROUND:

Actinic keratoses (AKs) are precancerous epidermal lesions induced by chronic exposure to ultraviolet light. Several topical and surgical treatments are available. For field cancerization, photodynamic therapy (PDT) is a very effective noninvasive treatment with excellent outcome and cosmesis. The management of treatment-associated adverse events, however, is crucial to achieve the treatment aims and to ensure patients adherence to PDT.

CASE REPORT:

We report on adverse events and their management related to PDT. We conducted literature research on PUBMED (R). Also, we present a case of an uncommon adverse event-PDT-induced rosacea flare-up on scalp and eyes. The patient was treated successfully by submicrobial slow-release doxycycline orally.

Conclusions:

PDT is an excellent treatment option for multiple AKs such as in bald scalp field cancerization. The management of adverse events during and after PDT is an essential part of a successful treatment plan.

Field Cancerization Therapies for Management of Actinic Keratosis: A Narrative Review

Actinic keratoses (AKs) are atypical, precancerous proliferations of keratinocytes that develop because of chronic exposure to ultraviolet (UV) radiation. Treatment of AK can be lesion-directed or field-directed. Field cancerization theory postulates that the skin surrounding AK is also at increased risk for possible malignant transformation since it has been exposed to the same chronic UV light. Field-directed therapies thus have the potential to address subclinical damage, reduce AK recurrence rates, and potentially reduce the risk of squamous cell carcinoma (SCC) development. Published clinical studies have found lesion clearance rates ranging from 81 to 91% for photodynamic therapy (PDT) with either aminolevulinic acid (ALA) or methylaminolevulinate (MAL). Clinical studies have also been published on various topical treatments. Complete clinical clearance (CCC) was significantly higher in patients treated with a combination of 5-fluorouracil and salicylic acid (5-FU-SA) than in the vehicle group across multiple studies, and CCC ranged between 46 and 48% following treatment with imiquimod. Additionally, treatment with diclofenac sodium (DFS) found reduction in lesion sizes to range from 67 to 75%. Reported results have been similar for another non-steroidal anti-inflammatory drug (NSAID), piroxicam, which has more cyclooxygenase (COX)-1 activity than DFS. Active treatments with ingenol mebutate were also significantly more effective than vehicle at clearing AK lesions. All treatments resulted in mild, localized skin reactions. PDT using conventional light sources was associated with increased severity of pain and/or discomfort, while PDT using daylight as the light source was associated with less pain and occasionally no pain at all. Though no widely accepted algorithm for the treatment of AKs exists, field-directed therapy can be particularly useful for treating photo-exposed areas containing multiple AKs. Additional research with more direct comparisons between these field-directed therapies will help clinicians determine the best therapeutic approach. Here, we provide a balanced and comprehensive narrative review of the literature, considering both light-based and topical therapies with a focus on their field-therapy aspects, and propose a therapeutic algorithm for selecting an appropriate treatment in the clinical setting.

Two-step irradiance schedule versus single-dose cold compress for pain control during 5-aminolevulinic acid-based photodynamic therapy of condyloma acuminatum

OBJECTIVE

The purpose of this study was to investigate the effect of two-step irradiance schedule in relieving pain during PDT of CA.

METHODS

The study was a prospective, controlled trial of 141 CA patients who were randomly divided into Group A (two-step irradiance schedule) and Group B (single-dose cold compress). The numeric rating scales (NRS) of patients' pain were recorded at 5, 10, 15, and 20 minutes during each PDT.

RESULTS

The efficacy of PDT and NRS scores of patients in the two groups were compared. There was no significant difference in gender, age, lesion site, and disease course between the two groups (P > 0.05). In addition, the cure rate of patients in the two groups was not significantly different (97.1% vs. 95.8%, χ²  = 0.000, P = 1.000). However, the NRS scores at different time points and number of PDT sessions were significantly different (F = 198.233 and 165.224, respectively, P < 0.05). The NRS scores of patients in Group A were significantly lower than those of patients in Group B (F = 82.762, P < 0.0001). Moreover, the NRS scores at different positions were significantly different (F = 28.286, P < 0.0001). The NRS scores of penis were significantly lower than those of the vulva and crissum (P < 0.05).

CONCLUSIONS

Compared with single-dose cold compress, two-step irradiance schedule could more significantly reduce the patients' pain degree during treatment, especially for vulva and crissum. Lasers Surg. Med. 49:908-912, 2017. © 2017 Wiley Periodicals, Inc.