Topical 5-aminolaevulinic acid-photodynamic therapy for the treatment of urethral condylomata acuminata

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.

In-Tumor Biosynthetic Construction of Upconversion Nanomachines for Precise Near-Infrared Phototherapy

Targeted construction of therapeutic nanoplatforms in tumor cells with specific activation remains appealing but challenging. Here, we design a cancer-motivated upconversion nanomachine (UCNM) based on porous upconversion nanoparticles (p-UCNPs) for precise phototherapy. The nanosystem is equipped with a telomerase substrate (TS) primer and simultaneously encapsulates 5-aminolevulinic acid (5-ALA) and d-arginine (d-Arg). After coating with hyaluronic acid (HA), it can readily get into tumor cells, where 5-ALA induces efficient accumulation of protoporphyrin IX (PpIX) via the inherent biosynthetic pathway, and the overexpressed telomerase prolonged the TS to form G-quadruplexes (G4) for binding the resulting PpIX as a nanomachine. This nanomachine can respond to near-infrared (NIR) light and promote the active singlet oxygen (¹O₂) production due to the efficiency of Förster resonance energy transfer (FRET) between p-UCNPs and PpIX. Intriguingly, such oxidative stress can oxidize d-Arg into nitric oxide (NO), which relieves the tumor hypoxia and in turn improves the phototherapy effect. This in situ assembly approach significantly enhances targeting in cancer therapy and might be of considerable clinical value.

Polymeric Nanoparticles as Tunable Nanocarriers for Targeted Delivery of Drugs to Skin Tissues for Treatment of Topical Skin Diseases

The topical route is the most appropriate route for the targeted delivery of drugs to skin tissues for the treatment of local skin diseases; however, the stratum corneum (SC), the foremost layer of the skin, acts as a major barrier. Numerous passive and active drug delivery techniques have been exploited to overcome this barrier; however, these modalities are associated with several detrimental effects which restrict their clinical applicability. Alternatively, nanotechnology-aided interventions have been extensively investigated for the topical administration of a wide range of therapeutics. In this review, we have mainly focused on the biopharmaceutical significance of polymeric nanoparticles (PNPs) (made from natural polymers) for the treatment of various topical skin diseases such as psoriasis, atopic dermatitis (AD), skin infection, skin cancer, acute-to-chronic wounds, and acne. The encapsulation of drug(s) into the inner core or adsorption onto the shell of PNPs has shown a marked improvement in their physicochemical properties, avoiding premature degradation and controlling the release kinetics, permeation through the SC, and retention in the skin layers. Furthermore, functionalization techniques such as PEGylation, conjugation with targeting ligand, and pH/thermo-responsiveness have shown further success in optimizing the therapeutic efficacy of PNPs for the treatment of skin diseases. Despite enormous progress in the development of PNPs, their clinical translation is still lacking, which could be a potential future perspective for researchers working in this field.

Photodynamic therapy in the treatment of condyloma acuminata: A systematic review of clinical trials

INTRODUCTION

Condylomata acuminata (CA) is a sexually transmitted infection with a high prevalence associated with psychosexual morbidity in both men and women of various age. Up to now, treatment modalities yield low clearance and recurrence rate (RR) and are also deemed low quality evidence-wise. Photodynamic therapy (PDT) is a novel and promising therapy to effectively cure and prevent CA recurrence.

METHOD

This systematic review was reported according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) and registered to the International Prospective Register of Systematic Review (PROSPERO) (CRD42022332760).

RESULTS

Ten studies were included in this systematic review. A significant value of complete response (CR) ranging from 63-100% in patients with genital warts after receiving several sessions of PDT. A relatively low recurrence rate was seen in all 10 studies, with an RR of less than 17%. Quality assessment of included studies reported mostly high-quality research.

CONCLUSIONS

PDT therapy resulted in a higher CR with significantly lower RR compared to other therapies. Thus, PDT can be an alternative treatment of CA with low RR and minimal side effects. Additional research, especially randomized clinical trials in various countries, is needed to further substantiate this treatment and formulate definitive protocols.

Modified photodynamic therapy of vulvar giant condyloma acuminatum complicated by systemic lupus erythematosus: A case report

Giant condyloma acuminatum (GCA) is a rare disease characterized by cauliflower-like tumors in the genital area, with a peculiar smell, bleeding, and local infection. Its occurrence is related to a variety of risk factors, such as human papillomavirus infection, immune deficiency, poor sanitary conditions, multiple sexual partners, and chronic genital infection. Surgical resection is still the preferred treatment for the disease. This paper reports that a patient with GCA complicated by systemic lupus erythematosus (SLE) and persistent thrombocytopenia who could not be treated surgically was treated with modified photodynamic therapy (M-PDT) in our outpatient department. After several treatments, the pain, odor, and secretion on the surface of the wart were significantly reduced, although the size of the wart was not significantly improved. Unfortunately, the patient died subsequently due to the aggravation of SLE. However, clinical treatment with M-PDT may be used as a palliative treatment when similar patients are encountered.

An insight into photodynamic therapy towards treating major dermatological conditions

Photodynamic therapy (PDT), as the name suggests is a light-based, non-invasive therapeutic treatment method that has garnered immense interest in the recent past for its efficacy in treating several pathological conditions. PDT has prominent use in the treatment of several dermatological conditions, which consequently have cosmetic benefits associated with it as PDT improves the overall appearance of the affected area. PDT is commonly used for repairing sun-damaged skin, providing skin rejuvenation, curbing pre-cancerous cells, treating conditions like acne, keratosis, skin-microbial infections, and cutaneous warts, etc. PDT mediates its action by generating oxygen species that are involved in bringing about immunomodulation, suppression of microbial load, wound-healing, lightening of scarring, etc. Although there are several challenges associated with PDT, the prominent ones being pain, erythema, insufficient delivery of the photosensitizing agent, and poor clinical outcomes, still PDT stands to be a promising approach with continuous efforts towards maximizing clinical efficacy while being cautious of the side effects and working towards lessening them. This article discusses the major skin-related conditions which can be treated or managed by employing PDT as a better or comparable alternative to conventional treatment approaches such that it also brings about aesthetic improvements thereof.

A new option for the treatment of condyloma acuminatum in the male urethra: Multimodal ultrasound image-guided scraping and photodynamic therapy (USP)

OBJECTIVES

Condyloma acuminatum (CA) is a sexually transmitted disease with a high recurrence rate due to the rapid replication of human papillomavirus (HPV) and its subtle immune escape mechanism, which makes the diagnosis and treatment of CA in the male urethra particularly difficult. This study aims to evaluate the efficacy of comprehensive treatments for male urethral CA after accurate localization of warts under ultrasound guidance.

METHODS

The study included 15 men with intraurethral CA. Before treatment, the urethra was examined by ultrasonography and HPV-PCR. After examination of the invisible urethral warts, wart curettage (penetrating operation with a special stainless steel medical curettage tool) combined with ALA-PDT was used for treatment. The ultrasound and HPV load were reviewed 1 week after treatment, and again at 1, 3, and 6 months after treatment.

RESULTS

All patients achieved satisfactory results 1 week after the last treatment. The viral load of human papilloma was significantly reduced or turned negative, ultrasound imaging exploration showed no neoplasm in the urethra, and no obvious intraoperative or postoperative complications were observed. The side effects in patients included a mild burning or tingling sensation confined to the treated area. After a 6 month follow-up period, only 2 patient relapsed.

CONCLUSION

The combined diagnosis and treatment of CA in the male urethra under the guidance of multi-mode ultrasound imaging is an effective, economical, safe, and well-tolerated treatment method.

Chinese guidelines on the clinical application of 5-aminolevulinic acid-based photodynamic therapy in dermatology (2021 edition)

Photodynamic Therapy with 5-aminolevulinic acid (ALA-PDT) has been widely applied in the treatment of skin diseases in China. To further standardize, guide, and promote the clinical applications of ALA-PDT in dermatology, the Chinese Society of Dermatology, Chinese Association of Rehabilitation Dermatology, Photomedicine Therapeutic Equipment Group of Committee on Skin Disease, and Cosmetic Dermatology of China Association of Medical Equipment invited relevant experts engaged in ALA-PDT to revise and update the first edition of "Clinical application of 5-aminolevulinic acid-based photodynamic therapy: an expert consensus statement" and establish a more current edition, to provide an updated reference for Chinese dermatologists in clinical practice. In the guideline, the expert group reached consensus opinions on ALA-PDT with regard to mechanisms of action, therapeutic protocol, clinical applications, adverse reactions and countermeasures, precautions, care, and evaluation of efficacy.

Update on the Medical and Surgical Management of Urethral Condyloma

INTRODUCTION

Condyloma acuminata (CA) of the urethra presents a management challenge due to high recurrence rates, difficulty in accessing urethral lesions, risk of stricture formation, and potential for sexual dysfunction. While standard treatment modalities are acceptable for some external genital condyloma, they are not always feasible or appropriate for urethral lesions.

OBJECTIVES

We sought to review the literature on epidemiology, presentation, diagnosis and treatment of urothelial CA with a focus on surgical treatment options.

METHODS

We performed a comprehensive literature search of PubMed to identify all studies pertaining to urethral CA through November 2020.

RESULTS

Urethral CA is a relatively rare, but challenging disease to manage with a considerable amount of treatment side effects and downstream morbidity associated. In our comprehensive review we have found a wide selection of treatment modalities ranging from minimally invasive strategies to surgical reconstructive techniques. Proper follow-up to monitor for disease recurrence at the 3-4 month mark is appropriate and will determine subsequent treatment strategies as needed. Future studies and treatment directions include novel drug delivery models to optimize minimally invasive topical drug efficacy.

CONCLUSION

Treatment of urethral CA should be approached in a step-wise fashion. Medical therapy would be an appropriate option for asymptomatic or minimally symptomatic patients with small lesions who desire to avoid any interventions. If patient is symptomatic, has extensive disease burden or has failed medical therapy intervention should be considered with options including PDT, laser ablation or surgical excision with or without urethral reconstruction. Appropriate selection depends on patient characteristics and preferences along with prior treatment history. Kim CJ, Campbell SP, Allkanjari A, et al. Update on the Medical and Surgical Management of Urethral Condyloma. Sex Med Rev 2021;xxx:xxx-xxx.

A prospective study of photodynamic therapy for cervical squamous intraepithelial lesion

OBJECTIVE

To evaluate the efficacy and safety of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) for the treatment of cervical squamous intraepithelial lesion (SIL).

METHODS

We prospectively screened and enrolled patients with cervical SIL and persistent high-risk human papilloma virus (HR-HPV) infection to receive ALA-PDT from March 27, 2019, to January 23, 2020, at Beijing Youan Hospital, China. The primary outcome was the remission rate of SIL and HPV. The secondary outcome was the symptom improvement and adverse events of ALA-PDT in these cases.

RESULTS

54 patients with cervical SIL and persistent HR-HPV infection were enrolled and divided these individuals into three groups: high-grade squamous intraepithelial lesion (HSIL) group (10 patients), low-grade squamous intraepithelial lesion (LSIL) group (33 patients), and simple HR-HPV infection group (11 patients). 49 of 54 patients finished six sessions treatment and 46 of 49 patients complete the follow-up. After six sessions' treatment, HR-HPV remission rates were 71.43 %(5/7)in the simple HR-HPV infection group, 63.64 %(14/22) in the LSIL group, and 50 %(4/8) in the HSIL group. The histology remission rates were 80 %(4/5) in the simple HR-HPV infection group, 69.57 %(16/23)in the LSIL group, and 75 % (6/8) in the HSIL group. Symptoms improvement rates in the simple HR-HPV infection, LSIL group, and HSIL group were 100 %(5/5), 66.67 %(5/15) and 71.43 %(5/7). No severe adverse events or systemic side effects were observed in treatment.

CONCLUSION

Topical ALA-PDT is an effective and safe treatment for cervical SIL.

Modified photodynamic therapy to minimize pain in the treatment of condylomata acuminata: A prospective, randomized, self-controlled study

BACKGROUND

Pain is a major concern associated with conventional photodynamic therapy (C-PDT).

OBJECTIVE

To evaluate the efficacy, pain and safety of modified photodynamic therapy(M-PDT) for the treatment of condylomata acuminata.

METHODS

A prospective, randomized, self-controlled study was conducted. Warts were randomized to the M-PDT or C-PDT side. 5-aminolevulinic acid (ALA; 20 %) was incubated for 3 h before patients were exposed to LED red light (100 J/cm2) on the C-PDT side and for 30 min before being exposed to LED red light (300 J/cm2) on the M-PDT side. Treatment was administered with 1-week interval for three weeks. The clearance rates were determined at one week and the recurrence rates at 4, 8, and 12 weeks after treatment. The pain and other side effects were also investigated.

RESULTS

A total of 24 patients with condylomata acuminata were enrolled in this trial. Twenty patients completed the trial. The clearance rates were 98.17 % in the M-PDT side and 98.20 % in the C-PDT side(P > 0.05). The recurrence rates were 11.11 % and 10.53 % (P > 0.05). However, M-PDT was almost painless (mean score 0.3 ± 0.47, range 0∼1), which was significantly less than that on the C-PDT side (mean score 3.6 ± 0.94, range 0∼1) (P < 0.05). Local erythema, mild edema and erosion were observed on both sides.

CONCLUSION

The modified PDT is basically painless with similar efficacy to conventional PDT, which is a major breakthrough of pain management in PDT.

A Critical Reappraisal of Off-Label Use of Photodynamic Therapy for the Treatment of Non-Neoplastic Skin Conditions

BACKGROUND

In the past 30 years, topical photodynamic therapy (PDT) has been investigated for the treatment of a broad spectrum of cosmetic, inflammatory, and infectious skin conditions with variable, and often contrasting, results. However, the non-expert clinician may be in difficulty evaluating these results because different sensitizers, concentrations, formulations, light sources, and irradiation protocols have been used. In addition, many of these studies have poor quality design being case reports and uncontrolled studies of few cases.

SUMMARY

With the aim to clarify the potential usefulness of PDT for the treatment of infectious and inflammatory skin diseases as well as selected cosmetic indications, we searched for randomized controlled clinical trials, non-randomized comparative studies, retrospective studies, and case series studies with a number of at least 10 patients, published since 1990. Later, we reappraised the results in order to give a simple critical overview. Key Messages: Evidence from the literature seems to strongly support the use of ALA- and MAL-PDT for the treatment of common skin diseases such as acne, warts, condylomata, and Leishmania skin infection and for photorejuvenation, i.e., the correction of selected cosmetic changes of aging and photoaging. For other disorders, the level of evidence and strength of recommendation are lower, and controlled randomized studies with prolonged follow-ups are necessary in order to assess the clinical usefulness and other potential advantages over current treatment options.

Advanced application of holmium: YAG laser combined ALA-PDT for the treatment of refractory condylomata acuminata in anal canal

BACKGROUND

Anal canal condylomata acuminata is a disease caused by the human papilloma virus. Conventional cauterizing laser treatment cannot achieve a satisfactory result owing to a high recurrence rate, and the application of 5-aminolaevulinic acid-photodynamic therapy (ALA-PDT) also has limitations in the anal canal. Holmium yttrium aluminum garnet (Ho: YAG) laser with fiber is found to be effective at removing canal lesions, and may create suitable conditions for ALA-PDT. We aim to investigate the feasibility of Ho: YAG laser combined with ALA-PDT and to explore a more optimal therapy in refractory anal canal condylomata.

METHODS

Data of 37 patients with anal canal condylomata (number of warts≥ 10 lesions) from May 2017 to March 2019 were reviewed. In total 17 cases were treated with Ho: YAG laser plus ALA-PDT, and 20 patients treated with CO₂ laser plus ALA-PDT were selected as control. Wart clearance and recurrence rates were evaluated as well as laser complications.

RESULTS

Most warts (88.23 %) were removed after a session of Ho: YAG laser pretreatment. The average number of laser sessions required to clear all warts was 1.94 in the Ho: YAG laser plus ALA-PDT group. Meanwhile, no wound infections or defecation disfunctions were found. Ho: YAG laser with ALA-PDT could significantly reduce wart recurrence rates (17.6 %) in comparison with CO₂ laser with ALA-PDT (55 %).

CONCLUSIONS

Ho: YAG laser combined with ALA-PDT raised the cure rate of refractory anal canal condylomata and has important guidance implications for clinical application.

European Dermatology Forum guidelines on topical photodynamic therapy 2019 Part 2: emerging indications - field cancerization, photorejuvenation and inflammatory/infective dermatoses

In addition to approved indications in non-melanoma skin cancer in immunocompetent patients, topical photodynamic therapy (PDT) has also been studied for its place in the treatment of, as well as its potential to prevent, superficial skin cancers in immune-suppressed patients, although sustained clearance rates are lower than for immune-competent individuals. PDT using a nanoemulsion of ALA in a daylight or conventional PDT protocol has been approved for use in field cancerization, although evidence of the potential of the treatment to prevent new SCC remained limited. High-quality evidence supports a strong recommendation for the use of topical PDT in photorejuvenation as well as for acne, refractory warts, cutaneous leishmaniasis and in onychomycosis, although these indications currently lack approvals for use and protocols remain to be optimized, with more comparative evidence with established therapies required to establish its place in practice. Adverse events across all indications for PDT can be minimized through the use of modified and low-irradiance regimens, with a low risk of contact allergy to photosensitizer prodrugs, and no other significant documented longer-term risks with no current evidence of cumulative toxicity or photocarcinogenic risk. The literature on the pharmacoeconomics for using PDT is also reviewed, although accurate comparisons are difficult to establish in different healthcare settings, comparing hospital/office-based therapies of PDT and surgery with topical ointments, requiring inclusion of number of visits, real-world efficacy as well as considering the value to be placed on cosmetic outcome and patient preference. This guideline, published over two parts, considers all current approved and emerging indications for the use of topical photodynamic therapy in Dermatology prepared by the PDT subgroup of the European Dermatology Forum guidelines committee. It presents consensual expert recommendations reflecting current published evidence.

5-aminolevulinic acid photodynamic therapy for condyloma acuminatum of urethral meatus

Objectives: Condyloma acuminatum are the most common sexually transmitted diseases worldwide, and they are closely associated with human papillomavirus (HPV) infection. Urethral meatus is one of the places that warts occur. Many treatments for uretheral warts have limitations. In this study, we performed 5-aminolevulinic acid-photodynamic therapy (ALA-PDT) on patients and investigated the effectiveness of reducing HPV viral loads. Materials and Methods: In our study, 21 patients diagnosed with urethral condyloma acuminatum were included. After 4 h treatment of ALA, patients received PDT. Each patient received HPV test before every PDT cycle. The frequency of PDT was dependent on viral load changes. Results: All patients achieved complete clinical remission after the last session of ALA-PDT. There were significant differences in HPV viral loads between pretherapy and after one or three rounds of PDT treatment. Conclusions: ALA-PDT is a safe and effective method for treatment of condyloma acuminatum in urethra meatus. Dynamic monitoring of HPV viral loads can more objectively demonstrate the effectiveness and guide the treatment of PDT.

Topical 5-aminolevulinic acid photodynamic therapy for intra anal-rectal warts

Background: Condylomata acuminata (CA) are a common sexually transmitted disease. The recurrence rate of condyloma acuminatum using traditional treatments is higher than that of applying photodynamic therapy, and a variety of adverse reactions after treatment. At the same time, different parts of condyloma acuminatum after treatment recurrence rate is also different, especially for intra anal-rectal warts.Objective: To evaluate whether using photodynamic therapy (PDT) can effectively reduce recurrence of condylomata acuminata for intra anal-rectal warts.Methods: After the confirmation of the diagnosis of intra anal-rectal warts, the patients were treated with PDT with 5-aminolevulinic acid hydrochloride (ALA). PDT was performed with irradiation of 18-36 J/cm² at an irradiance of 20-40 mW/cm² with light-emitting diode (LED) light energy, wavelength 635 nm. We used a special PDT light equipment for intra anal-rectal area warts. PDT was repeated once every week for 4 weeks.Results: After PDT, the complete clearance rate was 76.1% (35 of 46 patients). At the end of the 12 weeks followed, recurrence occurred in five cases. We recorded pain in all 46 patients and the average visual analog scale (VAS) pain score was 6.96 ± 1.41 points.Conclusion: The treatment with PDT is effective in reducing the high rate of recurrence for intra anal-rectal warts. Pain is still a great challenge for the therapy.

Successful Treatment of Adult-Onset Recurrent Respiratory Papillomatosis with CO2 Laser and Photodynamic Therapy

Recurrent respiratory papillomatosis is a noninvasive benign epithelial tumor caused by human papillomavirus. Clinically, it featured rapid growth, multifocus, and frequent recurrence. Though a number of therapies have been investigated, the recurrence after treatment is always a challenge. In this report, we describe a 27-year-old male patient with recurrent respiratory papillomatosis who was treated with CO₂ laser therapy followed by 5-aminolevulinic acid photodynamic therapy (ALA-PDT). There was no adverse reaction after treatment and no recurrence during the follow-up time.

Photoinactivation of Neisseria gonorrhoeae: A Paradigm-Changing Approach for Combating Antibiotic-Resistant Gonococcal Infection

Antimicrobial resistance in Neisseria gonorrhoeae is a major issue of public health, and there is a critical need for the development of new antigonococcal strategies. In this study, we investigated the effectiveness of antimicrobial blue light (aBL; wavelength, 405 nm), an innovative nonpharmacological approach, for the inactivation of N. gonorrhoeae. Our findings indicated that aBL preferentially inactivated N. gonorrhoeae, including antibiotic-resistant strains, over human vaginal epithelial cells in vitro. Furthermore, no aBL-induced genotoxicity to the vaginal epithelial cells was observed at the radiant exposure used to inactivate N. gonorrhoeae. aBL also effectively inactivated N. gonorrhoeae that had attached to and invaded into the vaginal epithelial cells in their cocultures. No gonococcal resistance to aBL developed after 15 successive cycles of inactivation induced by subtherapeutic exposure to aBL. Endogenous aBL-activatable photosensitizing porphyrins in N. gonorrhoeae were identified and quantified using ultraperformance liquid chromatography, with coproporphyrin being the most abundant species in all N. gonorrhoeae strains studied. Singlet oxygen was involved in aBL inactivation of N. gonorrhoeae. Together, these findings show that aBL represents a potential potent treatment for antibiotic-resistant gonococcal infection.

Successful treatment of oral human papilloma by local injection 5-aminolevulinic acid-mediated photodynamic therapy: A case report

Oral human papilloma (HPV) virus is very common in patients. Deep location of lesions can lead to poor therapeutic effects. We are reporting a case of 52-year-old male who was diagnosed of oral papilloma on the left side of the palatoglossal arch. He was treated with local injection of 5-aminolevulinic acid-mediated photodynamic therapy for 2 sessions. There was no obvious recurrence at 6 months of follow-up. This case suggests that sodium chloride injection diluted ALA photosensitizer and injection at lesion basement can achieve good therapeutic results.

Photodynamic Therapy for Genital Warts Causes Activation of Local Immunity

BACKGROUND

5-aminolevulinic acid photodynamic therapy (PDT) for genital warts is effective, safe, and can prevent recurrence. It is believed that PDT can induce immune responses, but the mechanism is not completely understood.

OBJECTIVES

The objectives of this article are to confirm the effect of PDT for genital warts on local immunity and to investigate the recruitment and significance of immune cells in tissues.

METHODS

Local immune changes in T lymphocytes (CD3+, CD4+, CD8+), plasmacytoid dendritic cells (pDCs) (CD123+), and myeloid dendritic cells (CD1a+) after PDT in patients were evaluated by immunohistochemistry staining. Changes in mRNA levels of IFN-γ, IFN-α, IFN-ß, interferon-stimulated gene 15 kDa (ISG-15), Mx2, Toll-like receptor 9 (TLR9), and interferon regulatory factor 7 (IRF7) were analyzed by real-time quantitative polymerase chain reaction.

RESULTS

At 4 hours after PDT, CD4+ increased, accompanied by increased levels of mRNA expression of IFN-γ, but CD4+ and mRNA expression levels of IFN-γ were decreased at 24 hours after PDT. CD123+ pDCs showed an increasing trend. CD1a+ LCs in the epidermis gradually decreased, and DCs in the epidermis gradually increased. CD3+ infiltrated and migrated to the superficial dermis, but CD8+ did not change significantly after PDT. The mRNA expression levels of IFN-α, IFN-ß, ISG-15, Mx2, TLR9, and IRF7 showed an increasing trend after PDT. As compared with the patients without significantly increased IFN-α and IFN-ß after PDT sessions, patients with significant increases needed fewer sessions of PDT for remission.

CONCLUSIONS

PDT for genital warts can activate T lymphocyte-mediated, DC-related, and pDC-related immunity. The clinical efficacy of PDT for genital warts may be related to the increased levels of IFN-α and IFN-ß after treatment.

What is the most relevent factor causing pain during ALA-PDT? A multi-center, open clinical pain score research trial of actinic keratosis, acne and condylomata acuminata

BACKGROUND

To date, it has been reported that the intrinsic factors(lesions location, lesions area, disease tynpes) and extrinsic factors(fluence rate) contribute to the pain during 5-aminolevulinic acid photodynamic therapy (ALA-PDT). But there are few studies on pain during ALA-PDT and lack of sufficient clinical evidence related to the pain intensity.

OBJECTIVE

To investigate pain intensity and its relative factors during ALA-PDT and to provide clinical implication.

METHODS

The pain numeric rating scale (PNRS) score was used to evaluate the patients' pain intensity at different times during ALA-PDT irradiation from 0 to 10 min during treatment. Gender, age, lesions location, lesions area, ALA concentration and fluence rate were recored.

RESULTS

The trial enrolled 274 patients in total, including 118 acne patients (in face), 30 actinic keratosis(AK)patients(in face), 126 Condylomatata acuminate patients(in genitalia). The average pain score in PDT was highest in the patients with actinic keratosis(7.3 ± 0.7), and that of condylomata acuminata was the lowest (4.5 ± 1.1) (p < 0.05). The highest pain score in patients with AK, acne and condylomata acuminata was 8, 6 and 6 respectively which occurred at 4 min, 4 min and 6 min respectively. The pain score of males was higher compared with females in all of the three diseases (p < 0.05). The pain score of facial diseases (5.6 ± 1.2) was higher than that of the genitalia (4.5 ± 1.1) (p < 0.05). The lesions area was positively correlated with the pain score (p < 0.05). In facial diseases, the pain score of patients with high fluence rate (7.3 ± 0.7) was higher than patients with low fluence rate (5.1 ± 0.9) (p < 0.05).

CONCLUSIONS

Intrinsic and extrinsic factors both correlate with pain during PDT. Intrinsic factors are difficult to change, so extrinsic factors are the key point to control. We can reduce the fluence rate and extend the treatment time, relieving pain intensity while still ensuring equivalent efficacy.

Perspective clinical study on effect of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) in treating condylomata acuminata in pregnancy

OBJECTIVE

To observe the clinical efficacy of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) in treating vulval condylomata acuminata (CA) in pregnancy.

METHODS

The clinical efficacies of ALA-PDT on 16 cases of CA in pregnancy as well as cryotherapy on 22 cases of CA in pregnancy were analyzed in this prospective study.

RESULTS

The treatment group showed a wart clearance rate of 93.8% after 3 PDT treatments, while the control group showed a wart clearance rate of 72.7% after 3 cryotherapy treatments. After the 3-month follow-up period, the treatment group registered a recurrence rate of 6.3%, whereas the control group recorded a recurrence rate of 36.4%, indicating a statistically significant difference (χ2 = 4.674, p = 0.031 < 0.05). After the 1-month postpartum follow-up period, the newborns grew and developed well, without any abnormality in physical examinations.

CONCLUSION

ALA-PDT is safe and effective in treating CA in pregnancy.

Human papillomavirus DNA detection-guided ALA-photodynamic therapy for anogenital condyloma acuminata: A report of two cases

5-aminolevulinic acid (ALA) mediated photodynamic therapy (PDT) is a highly effective, safe, and promising treatment for human papillomavirus (HPV)-induced anogenital condyloma acuminata (CA). Specific HPV subtypes are responsible for the pathogenesis of CA and dynamic changes in viral loads may reflect the efficiency of PDT. Here we present two cases of anogenital CA successfully treated by ALA-PDT under the guidance of HPV DNA detection including genotype identification and viral load measurement, which provided clues for unexpected intra-anal infection. Both of these male patients were free of detectable HPV at the end of the treatment and no recurrence was observed after 1 year. We conclude that the HPV DNA detection can accurately guide ALA-PDT, indicate unnoticed lesions, as well as improve and evaluate the efficiency.

Antitumor Effects of DC Vaccine With ALA-PDT-Induced Immunogenic Apoptotic Cells for Skin Squamous Cell Carcinoma in Mice

Targeted immunotherapy using dendritic cell vaccine has been employed for the treatment of solid tumors. Topical 5-aminolevulinic acid-mediated photodynamic therapy, an established approach for topical cancers, can induce an effective antitumor immune response. We have previously shown that 5-aminolevulinic acid-mediated photodynamic therapy–induced tumor lysates could considerably enhance antigen-presenting capacity of ex vivo-generated dendritic cells. The current study further demonstrates that 5-aminolevulinic acid-mediated photodynamic therapy dendritic cell vaccine can induce immune responses against cancers. Dendritic cells pulsed by photodynamic therapy–treated skin squamous cell carcinoma cells inhibited squamous cell carcinoma to a greater extent than tumor lysates treated by photodynamic therapy alone or dendritic cells pulsed by freeze–thawed treated tumor cells. Immunohistochemistry showed that photodynamic therapy dendritic cell vaccine could increase the activity of CD4⁺ and CD8⁺ T cells in the tumor implantation sites. Flow cytometry assays showed that CD4⁺ and CD8⁺ T cells in the spleens of photodynamic therapy dendritic cell vaccine immunized mice increased significantly. Furthermore, we observed increased amounts of interleukin 12 and Interferon gamma (IFN-γ) and decreased amounts of interleukin 10 in the splenocytes and peripheral blood of photodynamic therapy dendritic cell vaccine immunized mice by enzyme linked immunosorbent assay (ELISA). Taken together, our findings suggest that photodynamic therapy dendritic cell vaccination is an effective prophylactic therapy for squamous cell carcinoma.

Treatment of latent or subclinical Genital HPV Infection with 5-aminolevulinic acid-based photodynamic therapy

BACKGROUND

Genital HPV infections are widely prevalent. HPV can persist and be transmitted to partners even after warts are gone. The HPV genotype and viral load assay can reveal whether infections are persistent or latent, and it can serve as a predictor of infection clearance. Although numerous studies have demonstrated that photodynamic therapy (PDT) is effective against condyloma acuminata, there is no data on its effects on latent, persistent infections.

METHODS

A total of 20 patients with latent or subclinical HPV infection were evaluated. At each patient visit, polymerase chain reaction was used to identify HPV genotypes and measure the viral loads, which reflect the status of HPV infection. We administered 5-aminolevulinic acid (ALA)-based PDT weekly for patients with active infections, while no treatment was administered to patients with regressing infections.

RESULTS

PDT treatment can effectively eliminate HPV, significantly reducing viral loads after three rounds of treatment (p < 0.001). The rate of negative HPV DNA test results was higher in patients with latent or subclinical infections than in patients with genital warts after one round of PDT treatment.

CONCLUSIONS

ALA-PDT can effectively eliminate latent or subclinical HPV infections. Additionally, our assay for identifying HPV genotypes and viral loads, which reflect the status of HPV infection, can accurately guide ALA-PDT treatment.

Successful treatment of penile condyloma acuminata accompanied with lichen planus with photodynamic therapy

Condyloma acuminata and lichen planus are different cutaneous diseases with disparate etiologies. Simultaneous appearance of two diseases in the same area is rare. This report aims to share the clinical and pathological features of a rare case; introduce an effective and safe therapy of it so as to broaden the therapeutic spectrum of Photodynamic Therapy (PDT) indications.

A case series pilot study on the combination of 5-aminolevulinic acid and photodynamic therapy (ALA-PDT) for treatment of vitiligo

BACKGROUND

To study the effective therapeutic concentration, drug application duration, irradiation duration and irradiation dosage of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) for treating vitiligo and observe its clinical efficacy.

OBJECTIVE

To assess the clinical efficacy of ALA-PDT for treating vitiligo.

METHODS

ALA with different drug concentrations, drug application durations, irradiation durations and irradiation dosages were adopted to treat skin lesions caused by vitiligo to determine the effective drug concentration, drug application duration, irradiation duration and irradiation dosage for treating three vitiligo volunteers and observe the therapeutic results.

RESULTS

The clinical trial suggested that ALA at a drug concentration of 1.5%, drug application duration for 3 hours, irradiation dosage of 80mw/cm2 and irradiation duration for 20 min was effective in treating vitiligo. Under these parameters, ALA-PDT was effective to the three vitiligo volunteers, with mild pain and feeling of burning but no other adverse reaction during treatment.

STUDY LIMITATIONS

Due to the small sample size in this study for the effectiveness of PDT in treating vitiligo and the potential variations in the efficacy for treating the disease at different areas, further studies shall be conducted for confirmation.

CONCLUSIONS

ALA with a drug concentration at 1.5%, drug application duration for 3 hours, irradiation dosage of 80 mw/cm2 and irradiation duration for 20 min is effective in treating vitiligo. Therefore, ALA-PDT is safe and effective in treating the disease, with minor adverse events, providing a new method for treating vitiligo in the future.

The inducers of immunogenic cell death for tumor immunotherapy

Immunotherapy is a promising treatment modality that acts by selectively harnessing the host immune defenses against cancer. An effective immune response is often needed to eliminate tumors following treatment which can trigger the immunogenicity of dying tumor cells. Some treatment modalities (such as photodynamic therapy, high hydrostatic pressure or radiotherapy) and agents (some chemotherapeutic agents, oncolytic viruses) have been used to endow tumor cells with immunogenicity and/or increase their immunogenicity. These treatments and agents can boost the antitumor capacity by inducing immune responses against tumor neoantigens. Immunogenic cell death is a manner of cell death that can induce the emission of immunogenic damage-associated molecular patterns (DAMPs). DAMPs are sufficient for immunocompetent hosts to trigger the immune system. This review focuses on the latest developments in the treatment modalities and agents that can induce and/or enhance the immunogenicity of cancer cells.

Dynamics of HPV viral loads reflect the treatment effect of photodynamic therapy in genital warts

BACKGROUND

Photodynamic therapy (PDT) has demonstrated good clinical cure rates and low recurrence rates in the treatment of genital warts. Human papillomavirus (HPV) genotypes and viral load assays can reflect the status of persistent or latent infection and serve as a predictor of infection clearance.

METHODS

Specimens from 41 patients with HPV infection were obtained, and the HPV genotypes and viral load were analyzed using real-time polymerase chain reaction (PCR) assays. Traditional treatment, such as radiofrequency, microwave, or surgical therapy, was used to remove the visible lesions, and then PDT treatment was performed every week. HPV DNA testing was performed at every patient visit and the frequency of PDT treatment was determined by changes in HPV viral loads.

RESULTS

HPV viral loads decreased significantly after PDT treatment. There were significant differences in HPV viral loads between pretherapy and three or six rounds of PDT treatment. Significant differences were also observed between single and multiple type HPV infection after six rounds of PDT treatment. Patients with single type HPV infection had significantly higher rates of negative HPV DNA test results, as compared with patients with multiple infections after six rounds of PDT treatment; however, there was no difference in recurrence rates between the two groups.

CONCLUSIONS

Dynamic monitoring of HPV genotypes and viral loads can be used to guide PDT treatment and indicate PDT treatment efficacy in eliminating HPV.

Doxycycline potentiates antitumor effect of 5-aminolevulinic acid-mediated photodynamic therapy in malignant peripheral nerve sheath tumor cells

Neurofibromatosis type 1 (NF1) is one of the most common neurocutaneous disorders. Some NF1 patients develop benign large plexiform neurofibroma(s) at birth, which can then transform into a malignant peripheral nerve sheath tumor (MPNST). There is no curative treatment for this rapidly progressive and easily metastatic neurofibrosarcoma. Photodynamic therapy (PDT) has been developed as an anti-cancer treatment, and 5-aminolevulinic (ALA) mediated PDT (ALA-PDT) has been used to treat cutaneous skin and oral neoplasms. Doxycycline, a tetracycline derivative, can substantially reduce the tumor burden in human and animal models, in addition to its antimicrobial effects. The purpose of this study was to evaluate the effect and to investigate the mechanism of action of combined doxycycline and ALA-PDT treatment of MPNST cells. An 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that the combination of ALA-PDT and doxycycline significantly reduce MPNST survival rate, compared to cells treated with each therapy alone. Isobologram analysis showed that the combined treatment had a synergistic effect. The increased cytotoxic activity could be seen by an increase in cellular protoporphyrin IX (PpIX) accumulation. Furthermore, we found that the higher retention of PpIX was mainly due to increasing ALA uptake, rather than activity changes of the enzymes porphobilinogen deaminase and ferrochelatase. The combined treatment inhibited tumor growth in different tumor cell lines, but not in normal human Schwann cells or fibroblasts. Similarly, a synergistic interaction was also found in cells treated with ALA-PDT combined with minocycline, but not tetracycline. In summary, doxycycline can potentiate the effect of ALA-PDT to kill tumor cells. This increased potency allows for a dose reduction of doxycycline and photodynamic radiation, reducing the occurrence of toxic side effects in vivo.

Improvement of DC vaccine with ALA-PDT induced immunogenic apoptotic cells for skin squamous cell carcinoma

Dendritic cell (DC) based vaccines have emerged as a promising immunotherapy for cancers. However, most DC vaccines so far have achieved only limited success in cancer treatment. Photodynamic therapy (PDT), an established cancer treatment strategy, can cause immunogenic apoptosis to induce an effective antitumor immune response. In this study, we developed a DC-based cancer vaccine using immunogenic apoptotic tumor cells induced by 5-aminolevulinic acid (ALA) mediated PDT. The maturation of DCs induced by PDT-treated apoptotic cells was evaluated using electron microscopy, FACS, and ELISA. The anti-tumor immunity of ALA-PDT-DC vaccine was tested with a mouse model. We observed the maturations of DCs potentiated by ALA-PDT treated tumor cells, including morphology maturation (enlargement of dendrites and increase of lysosomes), phenotypic maturation (upregulation of surface expression of MHC-II, DC80, and CD86), and functional maturation (enhanced capability to secrete IFN-γ and IL-12, and to induce T cell proliferation). Most interestingly, PDT-induced apoptotic tumor cells are more capable of potentiating maturation of DCs than PDT-treated or freeze/thaw treated necrotic tumor cells. ALA-PDT-DC vaccine mediated by apoptotic cells provided protection against tumors in mice, far stronger than that of DC vaccine obtained from freeze/thaw treated tumor cells. Our results indicate that immunogenic apoptotic tumor cells can be more effective in enhancing a DC-based cancer vaccine, which could improve the clinical application of PDT-DC vaccines.

Topical PDT in the Treatment of Benign Skin Diseases: Principles and New Applications

Photodynamic therapy (PDT) uses a photosensitizer, light energy, and molecular oxygen to cause cell damage. Cells exposed to the photosensitizer are susceptible to destruction upon light absorption because excitation of the photosensitizing agents leads to the production of reactive oxygen species and, subsequently, direct cytotoxicity. Using the intrinsic cellular heme biosynthetic pathway, topical PDT selectively targets abnormal cells, while preserving normal surrounding tissues. This selective cytotoxic effect is the basis for the use of PDT in antitumor treatment. Clinically, PDT is a widely used therapeutic regimen for oncologic skin conditions such as actinic keratosis, squamous cell carcinoma in situ, and basal cell carcinoma. PDT has been shown, under certain circumstances, to stimulate the immune system and produce antibacterial, and/or regenerative effects while protecting cell viability. Thus, it may be useful for treating benign skin conditions. An increasing number of studies support the idea that PDT may be effective for treating acne vulgaris and several other inflammatory/infective skin diseases, including psoriasis, rosacea, viral warts, and aging-related changes. This review provides an overview of the clinical investigations of PDT and discusses each of the essential aspects of the sequence: its mechanism of action, common photosensitizers, light sources, and clinical applications in dermatology. Of the numerous clinical trials of PDT in dermatology, this review focuses on those studies that have reported remarkable therapeutic benefits following topical PDT for benign skin conditions such as acne vulgaris, viral warts, and photorejuvenation without causing severe side effects.

Periurethral and vulval condylomata acuminata: an unusual juvenile venereal disease in a 3-year-old girl

We present a case of giant condyloma acuminatum (CA) in a 3-year-old girl with rapidly growing vulval and periurethral lesions, which was investigated thoroughly and successfully treated with excision biopsy. Genital warts in the form of giant alarming vestibular, vulval and periurethral lesions of CA are very rare in children. There is need for a multidisciplinary approach with potential sociomedicolegal implications. Surgical excision is safe, effective and provides an opportunity to assess the extent of the lesion and tissue for accurate diagnosis. Genital warts in the form of giant alarming vestibular, vulval and periurethral lesions of CA are very rare in children. Indications for surgical treatment include large, recurrent or refractory lesions, as well as the need for histological identification and acquiring tissue for immunotherapy when necessary. The strategy of an extended follow-up is recommended so as to ensure identification of any risk situations.

Photodynamic therapy with topical aminolevulinic acid

Photodynamic therapy (PDT) is a relatively new therapy in dermatology that uses the topical application of a porphyrin derivative to selectively destroy a cutaneous target. The action is implemented by the application of a specific light frequency. The ability of porphyrin to selectively target tumor tissue has been known since the 1960s. In the late 1970s, the underlying mechanism was defined, and Dougherty’s discovery of the first chromophore led to the production and commercialization of Photofrin^®. Many other chromophores that can act as photosensitizers have been studied since then, with aminolevulinic acid currently the most commonly used chromophore in clinical practice. PDT is simple, minimally invasive and can be administered on an outpatient basis. The efficacy of PDT has been proven for actinic keratosis, Bowen’s disease and basal cell carcinoma; another of its well-known applications is the treatment of photoaging. Indications for its use are continuously increasing, and promising results are reported for various skin diseases. In this paper we report the mechanism of action of PDT with aminolevulinic acid, the literature concerning the most common diseases treated with PDT and the subsequent level of evidence.

Comparative study of photodynamic therapy with 5%, 10% and 20% aminolevulinic acid in the treatment of generalized recalcitrant facial verruca plana: a randomized clinical trial

BACKGROUND

Generalised recalcitrant facial verruca plana responds poorly to current therapeutic options, including cryotherapy, topical drugs and carbon dioxide (CO2 ) laser. Case reports and uncontrolled studies suggested that topical photodynamic therapy (PDT) is effective choice of treatment free from potential complications associated with invasive therapies.

AIMS

To investigate the efficacy and safety of PDT with different concentrations of photosensitiser in the treatment of verruca plana.

MATERIALS & METHODS

The two sides of a subject's face were separately randomized to receive aminolevulinic acid (ALA) of 5%, 10% or 20% concentration. All patients were irradiated with 633-nm red light for 339 J/cm(2) total dose. Complete response (CR) rate was assessed on Week 4, 8, and 16 respectively.

RESULTS

The mean overall clearance rate was 74.1%, 68.8%, and 64.6% on Week 4, 8, and 12, respectively, in the 110 treated sides. The CR rate was lower in the 5%-ALA group than in the 10%-ALA group (14.3% vs. 33.3%, p < 0.05) and 20%-ALA group (14.3% vs. 26.3%, p < 0.05) after 12 weeks. The mean severity of pain measured by visual analogue scale (VAS) scoring was 3.8 (range: 2 to 10, depending on the lesion location). The overall recurrence rate was 16.7% (4/24) on Week 12. Hyperpigmentation was observed in 61% (67/110) of all treated sides. On Week 4, 8, and 16, hyperpigmentation was more developed in the 20%-ALA group than in the other two groups (p < 0.05).

DISCUSSION

In terms of complete clearance rate, the 5% ALA-PDT group was significantly inferior to the 10% and 20% ALA-PDT groups at each follow-up. In contrast, the 20% ALA group showed a higher incidence rate of transient hyperpigmentation than the other two groups.

CONCLUSIONS

This randomised clinical trial suggests that PDT with ALA of 10% concentration offers better efficacy and safety than 5% or 20% concentration for generalised recalcitrant facial verruca plana.

Clinical analysis of five methods used to treat condylomata acuminata

OBJECTIVE

Treatments for condylomata acuminata (CA) include pharmacotherapy and surgical therapies, but each treatment has its limitations. The aim of this study was to investigate the virus clearance rate, wart cure rate and safety of 5 methods on CA.

METHODS

361 patients diagnosed with CA were divided into groups A (<0.5 cm), B (0.5-2.0 cm) and C (>2.0-4.0 cm) according to the maximum diameter of their lesion. Five treatments were compared in each group, and the clinical outcomes were evaluated during follow-ups.

RESULTS

A 5-aminolevulinic acid-mediated photodynamic therapy (ALA-PDT) is preferred if the maximum lesion diameter is <0.5 cm and an ALA-PDT plus cryotherapy treatment is preferred for lesions 0.5-2.0 cm. For lesions >2.0- 4.0 cm, an ALA-PDT retreatment (after cryotherapy or CO2 laser treatment) should be the first choice.

CONCLUSIONS

The treatments for CA should be chosen according to the maximum diameter of each patient's lesion.

In vitro evaluation of 5-aminolevulinic acid (ALA) loaded PLGA nanoparticles

Background

5-Aminolevulinic acid (ALA) is a prodrug for topical photodynamic therapy. The effectiveness of topical ALA can be limited by its bioavailability. The aim of this study was to develop a novel ALA delivery approach using poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs).

Methods

A modified double emulsion solvent evaporation method was used to prepare ALA loaded PLGA NPs (ALA PLGA NPs). The characteristics, uptake, protoporphyrin IX fluorescence kinetics, and cytotoxicity of ALA PLGA NPs toward a human skin squamous cell carcinoma cell line were examined.

Results

The mean particle size of spherical ALA PLGA NPs was 65.6 nm ± 26 nm with a polydispersity index of 0.62. The encapsulation efficiency was 65.8% ± 7.2% and ALA loading capacity was 0.62% ± 0.27%. When ALA was dispersed in PLGA NPs, it turned into an amorphous phase. ALA PLGA NPs could be taken up by squamous cell carcinoma cells and localized in the cytoplasm. The protoporphyrin IX fluorescence kinetics and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay showed that ALA PLGA NPs were more effective than free ALA of the same concentration.

Conclusion

PLGA NPs provide a promising ALA delivery strategy for topical ALA-photodynamic therapy of skin squamous cell carcinoma.

Efficacy of 5-Aminolevulinic Acid Photodynamic Therapy in treatment of nasal inverted papilloma

OBJECTIVE

Evaluate the efficacy of 5-Aminolevulinic Acid Photodynamic Therapy (PDT) in medical treatment of nasal inverted papilloma (NIP).

METHODS

Three patients with nasal inverted papilloma were treated with 5-Aminolevulinic Acid Photodynamic Therapy at our department from April to September 2012. The efficacy and adverse effects of 5-Aminolevulinic Acid Photodynamic Therapy were evaluated during 6-8 months of follow-up medical examination.

RESULTS

After treated with 5-Aminolevulinic Acid Photodynamic Therapy, the nasal inverted papillomas were removed. No recurrence was found during the 6-8 months of follow-up medical examination. The major adverse effects were mild erosion, pain, and exudation.

CONCLUSION

5-Aminolevulinic Acid Photodynamic Therapy appears to be an effective treatment of nasal inverted papilloma. It can clear the papilloma lesions and is well tolerated by the patients.

Acute urinary retention in elderly female patients after photodynamic therapy of urethral condyloma--report of two cases

We report two cases of acute urinary retention (AUR) occurred after intra-urethral aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) in elderly females (>66 years old) with urethral condylomas.

Needle-free injection of 5-aminolevulinic acid in photodynamic therapy for the treatment of condylomata acuminata

The external application of 5-aminolevulinic acid (ALA) in photodynamic therapy (PDT) results in a shallow penetration depth in thick or extensive condylomata acuminata (CA) lesions, thus demonstrating a poor therapeutic effect for those patients. To compare the efficacy of needle-free injection with external application of ALA in PDT for the treatment of CA, 160 CA patients with thick or extensive warts received ALA-PDT by means of external application or needle-free injection of ALA, respectively. The complete response (CR) rate and recurrence rate in the two groups were analyzed. The CR rate after the first treatment in the needle-free injection group (68.8%) was significantly higher compared with that in the external application group (52.5%; P=0.035). The recurrence rates in the needle-free injection group and external application group were 4.1 and 15.4%, respectively (P=0.022). The needle-free injection of ALA increases the therapeutic effect of PDT for CA patients with thick or extensive lesions. It shortens the treatment time and reduces the recurrence rate, and has great potential in the treatment of CA.