Comparison of red and green light in the treatment of Bowen's disease by photodynamic therapy

Metronomic photodynamic therapy for deep organ cancer by implantable wireless OLEDs

Metronomic photodynamic therapy (mPDT) is a method of continuously delivering low-intensity light to a cancer lesion. This approach does not require high-intensity light, enabling the miniaturization of light devices and making them suitable for implantation within the body. However, the application of mPDT to tumors in deep organs such as the liver and pancreas has yet to reach practical implementation. In this study, we developed an mPDT system designed to meet three key requirements deemed essential for practical use: (1) uniform light irradiation throughout the tumor, (2) maintenance of constant light intensity within the body with sufficient operational duration, and (3) avoidance of immunological complications and thermal damage. The newly constructed mPDT system incorporates an ultra-thin organic light-emitting diode (OLED) device and wireless energy transfer technology, allowing it to be designed for implantation in deep organs. In experiments using a rat model of orthotopic hepatoma, the new mPDT system effectively induced widespread cell death deep within the tumor and exhibited high therapeutic efficacy against cancer. This study is the first study to demonstrate that mPDT utilizing a biocompatible and wirelessly powered OLED device has strong anti-tumor effects against parenchymal organ cancers. The findings represent a significant advancement toward the clinical application of mPDT for the treatment of deep organ cancers.

5-aminolevulinic acid photodynamic therapy for the treatment of basal and squamous cell carcinoma: A systematic review

BACKGROUND

5-aminolevulinic acid photodynamic therapy (ALA-PDT) is used off-label in the US to treat basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and Bowen disease (BD). We performed a systematic review to assess the efficacy and safety of published ALA-PDT protocols for these conditions.

METHODS

A PubMed search was conducted through August 8, 2024, to identify studies evaluating 10% or 20% ALA-PDT in BCC, SCC, and BD. Randomized controlled trials, observational studies, and case series with >5 patients were included. Quality assessment was performed using the Grading of Recommendations Assessment, Development, and Evaluation approach.

RESULTS

Fifty-eight studies were included in the analysis (BCC, n = 40; SCC, n = 9, BD, n = 27). Considerable heterogeneity was observed in ALA concentration, light sources, incubation times, and pretreatment strategies, precluding a standardized synthesis of outcomes. ALA-PDT achieved high clearance rates for superficial BCC and BD, with superior cosmetic outcomes compared to surgery or cryosurgery. Studies of ALA-PDT for SCC were limited with short follow-up times. Nodular BCC and SCC lesions demonstrated lower response rates, particularly with ALA-PDT monotherapy. Recurrence rates varied widely and were highest in patients with SCC. The most frequent adverse events were erythema, pain, and scaling.

CONCLUSIONS

This review provides a comprehensive summary of evidence-based ALA-PDT protocols for BCC, BD, and SCC, but published protocols are heterogeneous without a clear consensus. While ALA-PDT is effective, safe, and cosmetically favorable for less invasive tumors, protocol variability underscores the need for further randomized controlled trials to determine optimal treatment parameters.

Efficacy of interventions for cutaneous squamous cell carcinoma in situ (Bowen's disease): A systematic review and meta-analysis of proportions

BACKGROUND

Cutaneous squamous cell carcinoma in situ (Bowen's disease) is a precancerous condition confined to the epidermis of the skin. Despite the critical need for effective interventions to halt its progression, there remains a notable shortage of comprehensive data comparing the efficacy of various therapeutic approaches.

OBJECTIVES

This systematic review and meta-analysis endeavour to compare the different efficacies of interventions by investigating and synthesizing data from numerous trials.

METHODS

A pre-defined protocol was registered in PROSPERO (CRD42021242224, registration date: 16 April 2021). Systematic searches in Medline, Embase and Central, along with manual trial register searches, identified studies reporting lesion clearance rates (LCR), participant clearance rates (PCR) or recurrence rates (date of last search: 12 June 2024). Quality assessment followed guidelines from the National Heart, Lung, and Blood Institute (NHLBI). After the study arms were categorized into treatment groups and groups of study quality, the proportions were pooled using the generalized linear mixed model (GLMM) as meta-analytical method.

RESULTS

A comprehensive inclusion of 71 studies facilitated an evaluation of 3783 lesions for LCR, 1225 patients for PCR, 4073 lesions for lesion recurrence rates (LRR) and 740 patients for participant recurrence rates (PRR). Surgery demonstrated the highest LCR and PCR (0.97, 95% confidence interval (CI): 0.90-0.99) and the lowest LRR (0.04, 95% CI: 0.02-0.07).

CONCLUSIONS

This study provides a thorough overview of reported efficacy outcomes for practice-relevant interventions for Bowen's disease. Surgery outperformed other treatments for Bowen's disease. For the other intervention groups, it was not possible to show clear differences in effectiveness: LCR, PCR, LRR and PRR showed various treatment rankings, and the comparability was restricted by different numbers of studies between treatment groups and outcome measures, methodical and clinical heterogeneity. Further high-quality studies are needed to investigate practice-relevant interventions for Bowen's disease.

Combined use of 5-ALA-induced protoporphyrin IX and chlorin e6 for fluorescence diagnostics and photodynamic therapy of skin tumors

Different types of photosensitizers (PSs) have different dynamics and intensities of accumulation, depending on the type of tumor or different areas within the same tumor. This determines the effectiveness of fluorescence diagnostics and photodynamic therapy (PDT). This paper studies the processes of 5-aminolevulinic acid (5-ALA)-induced protoporphyrin IX (PpIX) and chlorin e6 (Ce6) accumulation in the central and border zones of a tumor after combined administration of two PSs into the patient's body. Fluorescence diagnostic methods have shown that sublingual administration of 5-ALA leads to the more intense accumulation of PpIX in a tumor compared to oral administration. Differences have been identified in the dynamics of 5-ALA-induced PpIX and Ce6 accumulation in the central and border zones of the tumor, as well as normal tissues. Ce6 accumulates mainly in the central zone of the tumor while PpIX accumulates in the border zone of the tumor. All patients with combined PDT experienced complete therapeutic pathomorphosis and relapse-free observation.

Phototherapy as a Treatment for Dermatological Diseases, Cancer, Aesthetic Dermatologic Conditions and Allergenic Rhinitis in Adult and Paediatric Medicine

The development of light-emitting diodes (LEDs) has led to an increase in the use of lighting regimes within medicine particularly as a treatment for dermatological conditions. New devices have demonstrated significant results for the treatment of medical conditions, including mild-to-moderate acne vulgaris, wound healing, psoriasis, squamous cell carcinoma in situ (Bowen's disease), basal cell carcinoma, actinic keratosis, and cosmetic applications. The three wavelengths of light that have demonstrated several therapeutic applications are blue (415 nm), red (633 nm), and near-infrared (830 nm). This review shows their potential for treating dermatological conditions. Phototherapy has also been shown to be an effective treatment for allergenic rhinitis in children and adults. In a double-anonymized randomized study it was found that there was 70% improvement of clinical symptoms of allergic rhinitis after intranasal illumination by low-energy narrow-band phototherapy at a wavelength of 660 nm three times a day for 14 consecutive days. Improvement of oedema in many patients with an age range of 7-17 were also observed. These light treatments can now be self-administered by sufferers using devices such as the Allergy Reliever phototherapy device. The device emits visible light (mUV/VIS) and infra-red light (660 nm and 940 nm) wavelengths directly on to the skin in the nasal cavity for a 3 min period. Several phototherapy devices emitting a range of wavelengths have recently become available for use and which give good outcomes for some dermatological conditions.

Preliminary low-dose photodynamic exposure to the skin cancer with chlorin e6 photosensitizer

BACKGROUND

The study was aimed to investigate the chlorin e6 photosensitizer distribution in the tumor and tumor border (5 mm) during low-dose photodynamic treatment and to increase the effectiveness of the therapy for skin neoplasms.

METHODS

Sensitized boundaries of neoplasms were evaluated by video fluorescence imaging. The study of changes in the chlorin e6 distribution before/after photodynamic therapy and in the process of low-dose photodynamic exposure was carried out by the method of spectral fluorescence diagnostics.

RESULTS

All 19 patients with basal-cell skin cancer had a contrast of chlorin e6 accumulation compared to normal tissues. 3 hours after intravenous administration of the photosensitizer at a dose of 1 mg/kg, the chlorin e6 concentration was: in normal tissues - 0.18 mg/kg, in the tumor - 1.26 mg/kg, in the tumor border - 0.63 mg/kg. In most cases, the fluorescence indices of chlorin e6 in tumor tissues after low-dose photodynamic therapy increased and exceeded the values before light exposure.

CONCLUSION

Low-dose photodynamic therapy seems to be the optimal method for treating neoplasms, which does not cause severe pain in patients during the light exposure and allows locally increasing of the photosensitizer concentration in tumor tissues. This method of photodynamic therapy can improve the effectiveness of thе treatment.

Durable Clearance Rate of Photodynamic Therapy for Bowen Disease and Cutaneous Squamous Cell Carcinoma: A Systematic Review and Meta-Analysis

BACKGROUND

Although surgery is the treatment of choice for Bowen disease (BD) and cutaneous squamous cell carcinoma (cSCC), nonsurgical treatments such as photodynamic therapy (PDT) may be preferred for select tumors. Previous meta-analysis have failed to gather strong evidence to recommend PDT.

OBJECTIVE

This study evaluates the effectiveness of PDT in the treatment of cSCC and BD for clearance rate (CR) after 1 year.

METHODS

A literature search of studies of biopsy-proven BD and cSCC treated with PDT was performed. Pooled CRs were estimated. Subgroup analyses were performed based on follow-up, treatment regimen, lesion size, and site.

RESULTS

Forty-three studies were included, enrolling 1943 BD lesions and 282 SCC lesions. Pooled CRs for BD and SCC were 76% (95% CI: 71%-80%; I2 = 78.9%) and 51% (95% CI: 35%-66%; I2 = 85.7%), respectively.

CONCLUSION

Our findings support the selective use of PDT for BD; however, patients should be advised of potential for recurrence. Although PDT can be used for certain cases of cSCC, the high rate of treatment failure necessitates close surveillance for residual or recurrent disease. Further studies are needed to justify the usage of PDT in the treatment of BD and cSCC.

Efficacy of Non-excisional Treatment Modalities for Superficially Invasive and In Situ Squamous Cell Carcinoma: A Systematic Review and Meta-analysis

BACKGROUND

Squamous cell carcinoma in situ (SCCIS) and squamous cell carcinoma (SCC) are prevalent conditions that are increasing in incidence worldwide. Many non-excisional treatments are commonly used, but the efficacy of these treatments is not well delineated.

OBJECTIVE

To examine the recurrence rates of SCCIS and SCC treated with non-excisional treatment modalities.

METHODS

A systematic review and meta-analysis was performed for SCCIS and SCC treated with 5-fluorouracil, imiquimod, electrodessication, curettage, photodynamic therapy, ablative lasers, or cryotherapy.

RESULTS

We included 186 studies describing treatment of 9,336 tumors. The recurrence rates of SCC and SCCIS following electrodessication with curettage (2.0%; 95% CI, 1.1%-3.0%) or cryotherapy with curettage (1.6%; 95% CI, 0.4%-2.8%) were lower than other treatments, such as photodynamic therapy (29.0%; 95% CI, 25.0%-33.0%), 5-fluorouracil (26.6%; 95% CI, 16.9%-36.4%), or imiquimod (16.1%; 95% CI, 10.3%-21.8%).

LIMITATIONS

Limitations include publication bias of mostly observational data and heterogeneity of treatment regimens.

CONCLUSION

Electrodessication and cryotherapy, in combination with curettage, are more effective than photodynamic therapy, 5-flurouracil, or imiquimod for treating SCCIS and SCC.

Red and blue light in antitumor photodynamic therapy with chlorin-based photosensitizers: a comparative animal study assisted by optical imaging modalities

The goal of this study is a comparative analysis of the efficiency of the PDT protocols for CT26 tumor model treatment in Balb/c mice employing red and blue light with both topical and intravenous administration of chlorin-based photosensitizers (PSs). The considered protocols include the doses of 250 J/cm² delivered at 660 nm, 200 J/cm² delivered at 405 nm, and 250 J/cm² delivered at both wavelengths with equal energy density contribution. Dual-wavelength fluorescence imaging was employed to estimate both photobleaching efficiency, typical photobleaching rates and the procedure impact depth, while optical coherence tomography with angiography modality (OCT-A) was employed to monitor the tumor vasculature response for up to 7 days after the procedure with subsequent histology inspection. Red light or dual-wavelength PDT regimes with intravenous PS injection were demonstrated to provide the most pronounced tumor response among all the considered cases. On the contrary, blue light regimes were demonstrated to be most efficient among topical application and irradiation only regimes. Tumor size dynamics for different groups is in good agreement with the tumor response predictions based on OCT-A taken in 24h after exposure and the results of histology analysis performed in 7 days after the exposure.

A heavy-atom-free π-extended N-confused porphyrin as a photosensitizer for photodynamic therapy

A heavy-atom-free π-extended N-confused porphyrin is reported that is suitable for use as a photosensitizer for photodynamic therapy in both the green region and therapeutic window.

Efficacy of photodynamic therapy for the treatment of Bowen's disease: An updated systematic review and meta-analysis of randomized controlled trials

BACKGROUND

This is a systematic review and meta-analysis on the effectiveness of Photodynamic Therapy (PDT) in Bowen's Disease (BD), with further summary of the data from all randomized controlled trials (RCTs).

METHODS

Relevant data were extracted after conducting a literature search via PubMed, Embase, Scopus, the Cochrane Library, CNKI, and Wanfang databases, from inception until 31 July 2019. Meta-analyses of the data were performed using RevMan V.5.3. A total of 392 published RCTs related to the efficacy of PDT in BD treatment were identified. The papers were screened for duplicates and excluded based on title and abstract. Subsequently, 85 full-text articles were thoroughly reviewed and finally, data from 446 patients with 1147 skin lesions across 12 eligible studies were collated.

RESULTS

Our findings revealed significant differences between the efficacies of PDT and other treatments, where a higher lesion reduction rate was observed after the first treatment session following PDT (P < 0.00001, Z = 4.98). PDT was found to be more effective than 5-fluorouracil (P < 0.00001, Z = 4.42) and cryotherapy (P = 0.008, Z = 2.67). However, there were no significant differences in recurrence rates following treatments with PDT, cryotherapy, and 5-fluorouracil.

CONCLUSIONS

This systematic review and meta-analysis confirms and collates data from all RCTs pertaining to the efficacy of PDT for BD treatment. Our study has reiterated that PDT is more effective than 5-fluorouracil and cryotherapy for the treatment of BD.

Sulfonated hydroxyaluminum phthalocyanine-biogenic Au/Ag alloy nanoparticles mixtures for effective photo-eradication of Candida albicans

In response to the increasingly widespread resistance of fungi to traditional treatment, we have reported successful photodynamic inactivation of Candida albicans planktonic cells using di-(AlPcS₂) and trisulfonated (AlPcS₃) hydroxyaluminum phthalocyanines in combination with Au/Ag alloy nanoparticles synthesized by the cell-free filtrate of Trichoderma koningii. These nanostructures with Au:Ag molar ratios 2:1, 1:1 and 1:2 have individual plasmonic band at 513-515 nm, 505-509 nm and 486-489 nm, respectively. XPS analysis of the ratio of gold to silver on the surface of these alloys indicated that Au and Ag formed a bimetallic system, wherein Au was coated with Ag. The XRD pattern revealed the angles at 38.2, 44.5, 64.9 and 78.0°. TEM analysis indicated that the average diameter of the synthesized alloys was 9 ± 3 nm, 8 ± 3 nm and 16 ± 3 nm for structures with Au:Ag molar ratios 1:1, 1:2 and 2:1, respectively. The FTIR band absorption, SEM-EDS analysis and basic elemental composition obtained by XPS confirmed that these nanostructures are stabilized by protein(s). Diode laser with the peak-power wavelength ʎ = 650 nm (output power of 40 mW; power density of 105 mW cm^-2) was used as a light source. The mixture of AlPcS₂+Au/Ag-NPs (Au:Ag = 2:1) can be considered as an effective photosensitizer, because eradication of C. albicans, as required by the American Society of Microbiology (99.9 %), was achieved at a low dose of light of 31.5 J cm^-2. It was postulated that this low dose of light applied to the photo-induced fungicidal effect may be painless for potential patients.

Household light source for potent photo-dynamic antimicrobial effect and wound healing in an infective animal model

Photodynamic antimicrobial chemotherapy (PACT) is considered a promising alternative to conventional antibiotic approach. We have previously developed a novel PS containing five lysine amino acids, pentalysine-β-carbonylphthalocyanine Zinc (ZnPc(Lys)₅), which in the presence of light, is highly toxic against a range of bacterial strains, including hospital isolated, drug resistant Acinetobacter baumannii. Here, we study the effect of light fluence of the two light sources on the PACT potency of ZnPc(Lys)₅. We observed that an exposure of E.coli to a red LED light for only 2 seconds (light fluence of 0.15 J/cm²) in the presence of ZnPc(Lys)₅ significantly eradicated 80% of the E.coli. We further demonstrated that a light fluence of 4.5 J/cm² from a household light source induced a noticeable photodynamic effect in vitro and in vivo animal model. This study points to a new research direction of reducing light illumination time by increasing potency of PS.

Photodynamic therapy with green light for the treatment of vulvar lichen sclerosus - Preliminary results

INTRODUCTION

The standard treatment for lichen sclerosus (LS) is symptomatic and is primarily based on the chronic use of corticosteroids, sometimes resulting in unsatisfactory effects. Therefore, other non-pharmacological methods are being sought, which are less aggravating for the patient. LS can be treated topically by using photodynamic therapy (PDT) based on 5-aminolevulinic acid (5-ALA). Unfortunately, therapy with the red light is often connected with severe local pain during the illumination. Green light can also be characterised by its ability to turn on photodynamic reactions in cells.

MATERIALS AND METHODS

The aim of this study was an evaluation into the efficacy and tolerance of 5-ALA-PDT with a green light (540nm±15nm) in 11 patients with chronic LS that were characterised by severe itching. The disease lasted from 1.5 to 4 years. All the patients were treated with three sessions of PDT.

RESULTS

Following treatment with PDT, a significant improvement of local status, as well as a reduction of the main symptom (pruritus), were observed. No patient complained of severe pain during the sessions that would have required an interruption of irradiation or local application of analgesics.

CONCLUSIONS

Our preliminary results of using green light in PDT for superficial skin non-oncological lesions are very promising but require further studies.

Light-emitting diodes in photodynamic therapy in non-melanoma skin cancers--own observations and literature review

Photodynamic therapy (PDT) employs light activation of tissue-localized photosensitizer in an oxygen-dependent process which initiates oxidative stress, inflammation, and cell death. There are many indications for PDT, although the main ones are still non-melanoma skin cancers. The light sources used include coherent and non-coherent ones, but we would like to focus on the use of light-emitting diodes (LED) in PDT. We present four patients with skin lesions successfully treated with LED-based photodynamic therapy. The main advantage of that source is narrow emission spectrum that can correspond well with maximum absorption photosensitizers. Also, using LED source seems to be cheaper and simpler, and the field of irradiation is larger. The data showed good clinical and cosmetic outcome of LED-based PDT in actinic keratosis, basal cell carcinoma, and Bowen's disease. Since these diseases often appear on sun-exposed skin, aesthetic results are very important. The effect of LED treatment is as good or in some data even better than those in older types of PDT.

Photodynamic therapy with methyl aminolevulinate in the treatment of basal cell carcinoma

The article presents the results of the studies on the effectiveness of treatment basal cell carcinoma of the skin with photodynamic therapy with 5-aminolevulinic acid and methyl aminolevulinate. The results of the comparing trials between photodynamic therapy with methyl aminolevulinate and different other treatment modalities are presented.

Photodynamic therapy using systemic administration of 5-aminolevulinic acid and a 410-nm wavelength light-emitting diode for methicillin-resistant Staphylococcus aureus-infected ulcers in mice

Bacterial resistance to antibiotics has become a worldwide problem. One potential alternative for bacterial control is photodynamic therapy. 5-aminolevulinic acid is a natural precursor of the photosensitizer protoporphyrin IX. Relatively little is known about the antibacterial efficacy of photodynamic therapy using the systemic administration of 5-aminolevulinic acid; a few reports have shown that 5-aminolevulinic acid exerts photodynamic effects on methicillin-resistant Staphylococcus aureus (MRSA) in vitro. In this study, we evaluated the effectiveness of photodynamic therapy using 5-aminolevulinic acid and a 410-nm wavelength light-emitting diode in vitro and in vivo for the treatment of MRSA. We found that 5-aminolevulinic acid photodynamic therapy with the light-emitting diode had an in-vitro bactericidal effect on MRSA. In vivo, protoporphyrin IX successfully accumulated in MRSA on ulcer surfaces after intraperitoneal administration of 5-aminolevulinic acid to mice. Furthermore, 5-aminolevulinic acid photodynamic therapy accelerated wound healing and decreased bacterial counts on ulcer surfaces; in contrast, vancomycin treatment did not accelerate wound healing. Our findings indicate that 5-aminolevulinic acid photodynamic therapy may be a new treatment option for MRSA-infected wounds.

Photodynamic Therapy for Bowen's Disease of the Vulva Area

Bowen's disease is a squamous cell carcinoma in situ and has the potential to progress to a squamous cell carcinoma. The authors treated two female patients (a 39-year-old and a 41-year-old) with Bowen's disease in the vulva area using topical photodynamic therapy (PDT), involving the use of 5-aminolaevulinic acid and a light-emitting diode device. The light was administered at an intensity of 80 mW/cm(2) for a dose of 120 J/cm(2) biweekly for 6 cycles. The 39-year-old patient showed excellent clinical improvement, but the other patient achieved only a partial response. Even though one patient underwent a total excision 1 year later due to recurrence, both patients were satisfied with the cosmetic outcomes of this therapy and the partial improvement over time. The common side effect of PDT was a stinging sensation. PDT provides a relatively effective and useful alternative treatment for Bowen's disease in the vulva area.

Spotlighting the role of photodynamic therapy in cutaneous malignancy: an update and expansion

BACKGROUND

Topical photodynamic therapy (PDT) is an option for the treatment of cutaneous malignancy.

OBJECTIVE

To present an update and expansion on a previous review of the use of PDT in the current literature in the treatment of actinic keratoses (AK), superficial and nodular basal cell carcinoma (sBCC, nBCC), squamous cell carcinoma (SCC), Bowen's disease, cutaneous T cell lymphoma (CTCL), malignant melanoma, and its use in chemoprevention.

METHODS

Extensive PubMed search January 2013.

RESULTS AND CONCLUSIONS

We find sufficient evidence to recommend the use of PDT in certain patients in the treatment of AK, Bowen's disease, sBCC, and nBCC. It is especially useful in those with contraindications to surgery, widespread areas of involvement, and large lesions. Not only can it be considered superior to other therapies as far as recovery time, tolerance, and cosmetic outcomes, but it also should be considered, when indicated, as first-line treatment in the above conditions. Investigations continue for the use of PDT in the treatment of melanoma, SCC, chemoprevention, and CTCL.

Correlations between photoactivable porphyrins' fluorescence, erythema and the pain induced by PDT on normal skin using ALA-derivatives

BACKGROUND

Photodynamic therapy (PDT) with precursors of photoactivable porphyrins is a well-established treatment modality for skin pathologies as well as hair removal. Pain is a major side effect thereof, and it affects the treatment compliance and acceptance.

METHODS

Five male subjects underwent a PDT procedure on normal skin, either with a diode laser (635 nm) or a lamp (405 nm), 3 or 6h after application of various precursors of photoactivable porphyrins (ALA 1M; Metvix(®) 1M; ALA-DGME 1M; ALA-DGME 3.66 M). Light doses ranged from 30 to 150 J/cm(2) and irradiances were 100 or 180 mW/cm(2). Fluorescence measurements were performed just before PDT, pain was quantified during PDT, and erythema was determined 24h afterwards.

RESULTS

Because precursor ALA-DGME was very selective for the pilosebaceous apparatus vs. the epidermis, we solely carried out the PDTs using this precursor. In the absence of light, no pain was reported. An increase in pain was observed when increasing the irradiance. A correlation was observed between the follicular fluorescence and the maximal pain score during PDT. A correlation was observed between follicular fluorescence and skin erythema, and between pain score and skin erythema.

CONCLUSIONS

With our well-controlled PDT parameters and homogenous subjects' conditions, we showed that pain could be reduced by reducing irradiance during PDT procedures. With the various correlations observed, we conclude that both pain and PaP fluorescence are useful tools to predict the post-PDT tissue effects (side effects and outcome). We suggest that A∂ nerve fibres would be the best candidate as first generators of PDT-induced pain.

Interventions for cutaneous Bowen's disease

BACKGROUND

Bowen's disease is the clinical term for in situ squamous cell carcinoma of the skin. Cutaneous lesions present as largely asymptomatic, well-defined, scaly erythematous patches on sun-exposed skin. In general, people with Bowen's disease have an excellent prognosis because the disease is typically slow-growing and responds favourably to treatment. Lesions are persistent and can be progressive, with a small potential (estimated to be 3%) to develop into invasive squamous cell carcinoma. The relative effectiveness of the available treatments is not known for Bowen's disease, and this review attempts to address which is the most effective intervention, with the least side-effects, for cutaneous Bowen's disease.

OBJECTIVES

To assess the effects of therapeutic interventions for cutaneous Bowen's disease.

SEARCH METHODS

We searched the following databases up to September 2012: the Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library (2012, Issue 9), MEDLINE (from 1946), EMBASE (from 1974), PsycINFO (from 1806), and LILACS (from 1982). We also searched online trials registers. We checked the bibliographies of included and excluded studies and reviews, for further references to relevant randomised controlled trials (RCTs).

SELECTION CRITERIA

We included all randomised controlled trials assessing interventions used in Bowen's disease, preferably histologically proven.

DATA COLLECTION AND ANALYSIS

Two authors independently carried out study selection and assessment of methodological quality.

MAIN RESULTS

The primary outcome measures were complete clearance of lesions after the first treatment cycle and recurrence rate at 12 months. Our secondary outcomes included the number of lesions that cleared after each treatment cycle, the number of treatment cycles needed to achieve clearance, the recurrence rates at > 12 months, cosmetic outcome, quality of life assessment, and adverse outcomes as reported by both participant and clinician.We included 9 studies, with a total of 363 participants. One study demonstrated statistically significantly greater clearance of lesions of Bowen's disease with MAL-PDT (methyl aminolevulinate with photodynamic therapy) when compared with placebo-PDT (RR (risk ratio) 1.68, 95% CI (confidence interval) 1.12 to 2.52; n = 148) or cryotherapy (RR 1.17, 95% CI 1.01 to 1.37; n = 215), but there was no significant difference when MAL-PDT was compared to 5-FU (5-fluorouracil). One study demonstrated statistically significantly greater clearance of lesions with ALA-PDT (5-aminolevulinic acid with photodynamic therapy) versus 5-FU (RR 1.83, 95% CI 1.10 to 3.06; n = 66), but no statistically significant difference in recurrence rates at 12 months (RR 0.33, 95% CI 0.07 to 1.53).Cryotherapy showed no statistically significant difference in clearance rates (RR 0.99, 95% CI 0.78 to 1.26) or recurrences at 1 year (RR 1.48, 95% CI 0.53 to 4.17) when compared to 5-FU in 1 study of 127 participants.One study compared imiquimod to placebo and demonstrated statistically significantly greater clearance rates in the imiquimod group (9/15 lesions) compared to placebo (0/16) (Fisher's Exact P value < 0.001). The imiquimod group did not report any recurrences at 12 months, but at 18 months, 2/16 participants in the placebo group had developed early invasive squamous cell carcinoma.

AUTHORS' CONCLUSIONS

Overall, there has been very little good-quality research on treatments for Bowen's disease. There is limited evidence from single studies to suggest MAL-PDT is an effective treatment. Although cosmetic outcomes appear favourable with PDT, five-year follow-up data are needed. Significantly more lesions cleared with MAL-PDT compared to cryotherapy. No significant difference in clearance was seen when MAL-PDT was compared with 5-FU, but one study found a significant difference in clearance in favour of ALA-PDT when compared to 5-FU. There was no significant difference in clearance when cryotherapy was compared to 5-FU.The lack of quality data for surgery and topical cream therapies has limited the scope of this review to one largely about PDT studies. The age group, number, and size of lesions and site(s) affected may all influence therapeutic choice; however, there was not enough evidence available to provide guidance on this. More studies are required in the immunosuppressed populations as different therapeutic options may be preferable. Specific recommendations cannot be made from the data in this review, so we cannot give firm conclusions about the comparative effectiveness of treatments.

Pr3+-doped heavy metal germanium tellurite glasses for irradiative light source in minimally invasive photodynamic therapy surgery

Pr3+-doped medium-low phonon energy heavy metal germanium tellurite (NZPGT) glasses have been fabricated and the intense multi-peak red fluorescence emissions of Pr3+ are exhibited. Judd-Ofelt parameters Ω2 = 3.14 × 10(-20)cm(2), Ω4 = 10.67 × 10(-20)cm(2) and Ω6 = 3.95 × 10(-20)cm(2) indicate a high asymmetrical and covalent environment in the optical glasses. The spontaneous emission probabilities A(ij) corresponding to the 1D2→3H4, 3P0→3H6, and 3P0→3F2 transitions are derived to be 1859.6, 6270.1 and 17276.3s(-1), respectively, and the relevant stimulated emission cross-sections σ(em) are 5.20 × 10(-21), 14.14 × 10(-21) and 126.77 × 10(-21)cm(2), confirming that the effectiveness of the red luminescence in Pr3+-doped NZPGT glasses. Under the commercial blue LED excitation, the radiant flux and the quantum yield for the red fluorescence of Pr3+ are solved to be 219μW and 11.80%, respectively. 85.24% photons of the fluorescence in the visible region are demonstrated to be located in 600-720nm wavelength range, which matches the excitation band of the most photosensitizers (PS), holding great promise for photodynamic therapy (PDT) treatment and clinical trials.

Pain in photodynamic therapy: mechanism of action and management strategies

Photodynamic therapy involves administration of a photosensitizing drug and its subsequent activation by irradiation with a light source at wavelengths matching the absorption spectrum of the photosensitizer. In many countries around the world, topical photodynamic therapy has been approved for treatment of cutaneous oncologic conditions such as actinic keratosis, Bowen's disease, and superficial basal cell carcinoma. Multicenter, randomized, controlled studies have confirmed its efficacy and superior cosmetic outcomes compared to conventional therapies. Nevertheless, this therapeutic method presents some adverse effects, such as erythema, edema, pigmentation, pustules, and pain. There is no doubt that pain is the most severe of the adverse effects, being sometimes responsible for definitive treatment interruption. The pain mechanism has not yet been fully understood, which makes complete pain control a challenge to be conquered. In spite of that, this literature review presents some useful pain management strategies as well as the most important pain-related factors in photodynamic therapy.

Ruthenium oligonucleotides, targeting HPV16 E6 oncogene, inhibit the growth of cervical cancer cells under illumination by a mechanism involving p53

High-risk Human Papillomaviruses (HPV) has been found to be associated with carcinomas of the cervix, penis, vulva/vagina, anus, mouth and oro-pharynx. As the main tumorigenic effects of the HPV have been attributed to the expression of E6 and E7 genes, different gene therapy approaches have been directed to block their expression such as antisense oligonucleotides (ASO), ribozymes and small interfering RNAs. In order to develop a gene-specific therapy for HPV-related cancers, we investigated a potential therapeutic strategy of gene silencing activated under illumination. Our aim according to this antisense therapy consisted in regulating the HPV16 E6 oncogene by using an E6-ASO derivatized with a polyazaaromatic ruthenium (Ru(II)) complex (E6-Ru-ASO) able, under visible illumination, to crosslink irreversibly the targeted sequence. We examined the effects of E6-Ru-ASO on the expression of E6 and on the cell growth of cervical cancer cells. We demonstrated using HPV16(+) SiHa cervical cancer cells that E6-Ru-ASO induces after illumination, a reactivation of p53, the most important target of E6, as well as the inhibition of cell proliferation with a selective repression of E6 at the protein level. These results suggest that E6-Ru ASOs, activated under illumination and specifically targeting E6, are capable of inhibiting HPV16(+) cervical cancer cell proliferation.

Liposomes in topical photodynamic therapy

INTRODUCTION

Topical photodynamic therapy (PDT) refers to topical application of a photosensitizer onto the site of skin disease which is followed by illumination and results in death of selected cells. The main problem in topical PDT is insufficient penetration of the photosensitizer into the skin, which limits its use to superficial skin lesions. In order to overcome this problem, recent studies tested liposomes as delivery systems for photosensitizers.

AREAS COVERED

This paper reviews the use of different types of liposomes for encapsulating photosensitizers for topical PDT. Liposomes should enhance the photosensitizers' penetration into the skin, while decreasing its absorption into systemic circulation. Only few photosensitizers have currently been encapsulated in liposomes for topical PDT: 5-aminolevulinic acid (5-ALA), temoporfin (mTHPC) and methylene blue.

EXPERT OPINION

Investigated liposomes enhanced the skin penetration of 5-ALA and mTHPC, reduced their systemic absorption and reduced their cytotoxicity compared with free drugs. Their high tissue penetration should enable the treatment of deep and hyperkeratotic skin lesions, which is the main goal of using liposomes. However, liposomes still do not attract enough attention as drug carriers in topical PDT. In vivo studies of their therapeutic effectiveness are needed in order to obtain enough evidence for their potential clinical use as carriers for photosensitizers in topical PDT.

Do lasers or topicals really work for nonmelanoma skin cancers?

Novel strategies are urgently needed to address the millions of nonmelanoma skin cancers treated in the United States annually. The need is greatest for those patients who are poor surgical candidates or those prone to numerous nonmelanoma skin cancers and therefore at risk for marked disfigurement. Traditional treatment strategies include electrosurgery with curettage, radiation therapy, cryotherapy, excision, and Mohs micrographic surgery. Alternatives to traditional treatment, including topical medications and light or laser therapies, are becoming popular; however, there are various degrees of efficacy among these alternative tactics. These alternatives include topical retinoids, peels, 5-fluorouracil, imiquimod, photodynamic therapy, and lasers. The purpose of this paper is to review the available data regarding these alternative strategies and permit the reader to have a sense of which therapies are reasonable options for care.

Effectiveness of photodynamic therapy in Bowen's disease: an observational and descriptive study in 51 lesions

INTRODUCTION

Bowen disease (BD) or squamous cell carcinoma (SCC) in situ affects both skin and mucous membranes and has the potential to progress to invasive SCC. Photodynamic therapy (PDT) has been approved recently for the treatment of BD. Some studies have demonstrated its efficacy and good cosmetic outcome.

OBJECTIVE

To assess the efficacy of PDT in the treatment of BD.

PATIENTS AND METHODS

We carried out an observational, retrospective and descriptive study. A total of 47 patients with 51 lesions of BD were included. All the lesions were confirmed with previous cutaneous biopsy. All patients were treated with the standard protocol. Topical methyl-aminolaevulinic acid was occluded during 3 h and followed by illumination with red-light (630 nm, 38 J/cm2, 7.5 min). Clinical and fluorescence photographs images were taken before each session. All patients received two sessions one week apart. Clinical response was classified in partial or complete response. Fluorescence response was classified in negative, intermediate or intense. The follow-up period and the adverse events observed including pain were also collected.

RESULTS

A total of 20 men and 27 women with a mean age of 75.57 years old were treated with PDT. Lesions were most frequently located in the lower limbs. Globally, 76.09% of the lesions achieved complete response after 2 sessions with a medium follow-up of 16.61 months. Fluorescence of the lesions disappeared when clinical response was achieved, but not always. The most common adverse effect was an immediate burning sensation. All lesions showed an excellent cosmetic result.

CONCLUSION

Photodynamic therapy is an effective treatment for BD in terms of both clinical remission and cosmetic results, with good tolerance and minimal adverse effects.

A review of pain experienced during topical photodynamic therapy--our experience in Dundee

BACKGROUND

Topical photodynamic therapy (PDT) using 5-aminolaevulinic acid (ALA) and its methylated ester, methyl aminolevulinate (MAL) is widely used to treat superficial non-melanoma skin cancer (NMSC). It has been proposed that ALA PDT is more painful than MAL PDT. The aim of this paper was to compare pain scores of MAL PDT with ALA PDT in our patients and to analyse the relationship between various parameters and pain during PDT.

METHODS

We retrospectively reviewed case notes and electronic records for all patients with superficial NMSC treated with PDT from June 2007 to March 2009.

RESULTS

On univariate analysis of patients with single lesions only, we observed no association between pain and lesion diameter or pro-drug or dose or diagnosis. Pre-treatment PpIX fluorescence was significantly associated with pain. However on univariate analysis of all patients (whether single or multiple lesions) treated with PDT, MAL was associated with significantly less pain than ALA. When all the recorded variables were taken into account (multivariate analysis), diagnosis, pre-treatment PpIX fluorescence and lesion diameter were associated with pain.

CONCLUSIONS

Our data lends some support to previous published reports suggesting that the MAL PDT regime is less painful than that for ALA PDT. However, PDT pain is multifactorial and choice of photosensitiser is probably not a major pain determining factor. A prospective randomised study, with the same incubation periods for each pro-drug, is needed to definitively answer the question as to whether or not MAL PDT causes less pain than ALA PDT.

5-Aminolevulinic acid-mediated photodynamic therapy to superficial malignant skin tumors using Super Lizer

Photodynamic therapy (PDT) using topically applied 5-aminolevulinic acid (ALA) has become a generally accepted treatment modality for superficial malignant skin tumors. However, the costly excimer-dye laser, diode laser and light-emitting diode (LED) frequently used to administrate PDT are impractical to use in most dermatology clinics. This study evaluated the effectiveness of ALA-mediated PDT using a Super Lizer (Tokyo Iken, Tokyo, Japan) equipped with band-pass filters in 38 patients with superficial malignant skin tumors (33 cases of actinic keratosis and five cases of Bowen's disease). Twenty-one cases (18 cases of actinic keratosis and three cases of Bowen's disease) were successfully treated, and the other 17 cases (15 cases of actinic keratosis and two cases of Bowen's disease) showed partial remission after single or repeated administration of PDT. PDT repeated three times at weekly intervals was more effective against actinic keratosis than randomly repeated procedures. The Super Lizer is easy to handle and move, and is less expensive than other known machinery and is useful for PDT in dermatology, especially under the protocol of three times at weekly intervals for the treatment of actinic keratosis.

Dermatologic management, sun avoidance and vitamin D status in organ transplant recipients (OTR)

It is well known that skin cancer, especially cutaneous squamous cell carcinoma (SCC), in organ transplant recipients (OTRs) has higher incidence rates, behaves more aggressively and has higher rates of metastasis. OTRs who have been treated for many years with immunosuppressive medication are at the highest risk for developing malignant skin tumors. Protection against solar and artificial UV-radiation is crucial to prevent skin cancer in OTRs. However, investigations have revealed that solar UV-B-exposure and serum 25(OH)D levels positively correlate with decreased risk for various internal malignancies (e.g. breast, colon, prostate, and ovarian cancer) and other severe diseases. Therefore, it is important to detect and treat vitamin D deficiency in OTRs. This review discusses guidelines for the optimal management of these patients, that require communication between the transplant teams, the treating dermatologist and other clinicians.

An overview of topical photodynamic therapy in dermatology

This article is a review of the use of topical photodynamic therapy in dermatology and its current role in 2009 and future developments. The content of this article was presented at the EPPM in Wroclaw, September 2009.

Pain associated with aminolevulinic acid-photodynamic therapy of skin disease

BACKGROUND

Pain during topical aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) limits the use of this treatment of skin diseases.

OBJECTIVE

We sought to summarize the effectiveness of interventions to reduce ALA-PDT-related pain, and to explore factors contributing to pain induction.

METHODS

A PubMed search was performed to identify all clinical PDT trials (2000-2008) that used ALA or methyl-ALA, enrolled at least 10 patients per trial, and used a semiquantitative pain scale.

RESULTS

In all, 43 articles were identified for review. Pain intensity is associated with lesion size and location and can be severe for certain diagnoses, such as plaque-type psoriasis. Results are inconsistent for the correlation of pain with light source, wavelength of light, fluence rate, and total light dose. Cooling represents the best topical intervention.

LIMITATIONS

Pain perception differs widely between patients and can contribute to variability in the reported results.

CONCLUSION

Gamma-aminobutyric acid receptors, cold/menthol receptors (transient receptor potential cation channel, subfamily M, member 8), and vanilloid/capsaicin receptors (transient receptor potential cation channel, subfamily V, member 1) may be involved in pain perception during ALA-PDT and are therefore worthy of further investigation.

Porphyrin and nonporphyrin photosensitizers in oncology: preclinical and clinical advances in photodynamic therapy

Photodynamic therapy (PDT) is now a well-recognized modality for the treatment of cancer. While PDT has developed progressively over the last century, great advances have been observed in the field in recent years. The concept of dual selectivity of PDT agents is now widely accepted due to the relative specificity and selectivity of PDT along with the absence of harmful side effects often encountered with chemotherapy or radiotherapy. Traditionally, porphyrin-based photosensitizers have dominated the PDT field but these first generation photosensitizers have several disadvantages, with poor light absorption and cutaneous photosensitivity being the predominant side effects. As a result, the requirement for new photosensitizers, including second generation porphyrins and porphyrin derivatives as well as third generation photosensitizers has arisen, with the aim of alleviating the problems encountered with first generation porphyrins and improving the efficacy of PDT. The investigation of nonporphyrin photosensitizers for the development of novel PDT agents has been considerably less extensive than porphyrin-based compounds; however, structural modification of nonporphyrin photosensitizers has allowed for manipulation of the photochemotherapeutic properties. The aim of this review is to provide an insight into PDT photosensitizers clinically approved for application in oncology, as well as those which show significant potential in ongoing preclinical studies.