New proposal for the treatment of nodular basal cell carcinoma with intralesional 5-aminolevulinic acid

Intralesional Agents in Dermatology: Pros and Cons

Since introduced in 1961, intralesional (IL) agent has become an essential part of the dermatological practice. The term IL referred to the direct delivery of agent percutaneously into skin lesions. This therapeutic approach is relatively safe, easy to perform and applicable for a broad range of dermatological conditions. On the other hand, immediate side effects, including pain during administration, bleeding, high risk of infection and allergic reaction, and subsequent side effects involving skin changes such as atrophy, telangiectasia, pigmentary changes, and striae are usually associated with this modality. This review paper highlights the pros and cons of IL agents in modern dermatology practice.

Current trends in needle-free jet injection: an update

Background

Jet injection can be defined as a needle-free drug delivery method in which a high-speed stream of fluid impacts the skin and delivers a drug. Despite 75 years of existence, it never reached its full potential as a strategic tool to deliver medications through the skin.

Objective

The aim of this review was to evaluate and summarize the evolution of jet injection intradermal drug delivery method including technological advancements and new indications for use.

Methods

A review of the literature was performed with no limits placed on publication date.

Results

Needleless injectors not only reduce pain during drug delivery but also confine the drug more evenly in the dermis. Understanding skin properties of the injection site is a key factor to obtain optimal results as well as setting the right parameters of the jet injector. Until the advent of disposable jet injectors/cartridges, autoclaving of the injector remains the only reliable method to eliminate the risk of infection. Needle-free intradermal injection using corticosteroids and/or local anesthetics is well documented with promising indications being developed.

Limitations

Limitations of the review include low-quality evidence, small sample sizes, varying treatment parameters, and publication bias.

Conclusion

New developments may help reconsider the use of jet injection technology. Future studies should focus on measurable optimized parameters to insure a safe and effective outcome.

Non-melanoma Skin Cancer in Canada Chapter 2: Primary Prevention of Non-melanoma Skin Cancer

BACKGROUND

Non-melanoma skin cancer (NMSC), including basal and squamous cell carcinoma (BCC and SCC), represents the most common malignancy.

OBJECTIVE

To provide guidance to Canadian health care practitioners regarding primary prevention of NMSC.

METHODS

Structured literature searches were conducted, using search terms including prevention, sunscreen, and sun prevention factor. All recommendations concern guidance that physicians should regularly discuss with their patients to help establish photoprotection habits. The GRADE system was used to assign strength to each recommendation.

RESULTS

Ultraviolet exposure is the major modifiable risk factor for NMSC. Aspects of photoprotection, including effective sunscreen use and avoidance of both the midday sun and artificial tanning, are discussed. Several widespread misunderstandings that undermine responsible public health measures related to sun safety are addressed.

CONCLUSIONS

Photoprotection represents both an individual priority and a public health imperative. By providing accurate information during routine patient visits, physicians reinforce the need for ongoing skin cancer prevention.

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.

Intralesional therapy for psoriasis

Localized resistant plaques of psoriasis often remain despite highly effective anti-psoriasis treatment. Intralesional therapy is often used to treat various malignant, infectious or inflammatory cutaneous diseases, including psoriasis. Despite the presence of many review articles on the treatment of psoriasis, no articles exist which review the use of intralesional therapy for psoriasis. In this article, we review the published literatures of intralesional therapy for psoriasis. Corticosteroids, methotrexate, cyclosporin, biologics, botulinum toxin type-A, 15-hydroxyeicosatetraenoic acid, and chemotherapy agents such as 5-fluorouracil are discussed. Also, agents which may be used intralesionally and have the potential to treat psoriasis will also be reviewed such as bleomycin, vincristine or vinblastine, mitomycin-C, aminophylline, 5-aminolevulinic acid, rituximab, bevacizumab and pentoxifylline are included.

Successful treatment of cutaneous leishmaniasis with intralesional aminolevulinic acid photodynamic therapy

Leishmaniasis is a protozoan infectious disease that often affects the skin and may acquire a chronic and difficult to treat course. Topical photodynamic therapy (PDT) is a novel treatment which involves the selective uptake of a photosensitizing agent. Exposure to an appropriate light source in the presence of oxygen leads to formation of reactive oxygen species and destruction of the target cells. We report on the successful treatment of a 69-year-old patient with a relapse of long-standing cutaneous leishmaniasis using intralesional aminolevulinic acid-PDT.

Photodynamic therapy based on 5-aminolevulinic acid and its use as an antimicrobial agent

Exogenous 5-aminolevulinic acid (ALA) is taken up directly by bacteria, yeasts, fungi, and some parasites, which then induces the accumulation of protoporphyrin IX (PPIX). Subsequent light irradiation of PPIX leads to the inactivation of these organisms via photodamage to their cellular structures. ALA uptake and light irradiation of PPIX produced by host cells leads to the inactivation of other parasites, along with some viruses, via the induction of an immune response. ALA-mediated PPIX production by host cells and light irradiation result in the inactivation of other viruses via either the induction of a host cell response or direct photodynamic attack on viral particles. This ALA-mediated production of light-activated PPIX has been extensively used as a form of photodynamic therapy (PDT) and has shown varying levels of efficacy in treating conditions that are associated with microbial infection, ranging from acne and verrucae to leishmaniasis and onychomycosis. However, for the treatment of some of these conditions by ALA-based PDT, the role of an antimicrobial effect has been disputed and in general, the mechanisms by which the technique inactivates microbes are not well understood. In this study, we review current understanding of the antimicrobial mechanisms used by ALA-based PDT and its role in the treatment of microbial infections along with its potential medical and nonmedical applications.

No-needle jet intradermal aminolevulinic Acid photodynamic therapy for recurrent nodular Basal cell carcinoma of the nose: a case report

Photodynamic therapy (PDT) with aminolevulinic acid (ALA) to treat nodular basal cell carcinoma (BCC) has been shown to be beneficial. The success rate of ALA-PDT in the treatment of nodular BCC is dependent on optimal penetration of the photosensitizing agent and subsequent PpIX production. To enhance topical delivery of drugs intradermally, a needleless jet injection (NLJI), which employs a high-speed jet to puncture the skin without the side effects of needles, was used in one patient with recurrent BCC of the nose. Photoactivation was then performed using red light emitting diode [CW @ λ 630 nm, irradiance 50 mW/cm², total fluence 51 J/cm²] for 17 minutes. Excellent cosmesis was obtained. Aside from mild crusting present for six days, no other adverse signs were noted. Clinically, there was no recurrent lesion up two years postintervention. Additional studies in larger samples of subjects are needed to further evaluate this promising technique.

Intralesional agents in the management of cutaneous malignancy: a review

Intralesional agents have a role in the management of cutaneous malignancies. In this article, the efficacy, side effects, strengths, limitations, costs, and practical considerations regarding the use of intralesional agents to treat basal cell carcinoma, squamous cell carcinoma, selected cutaneous lymphomas, and even metastatic melanoma are reviewed. Intralesional administration of 5-fluorouracil, interferon, interleukin-2, bleomycin with electrochemotherapy, and aminolevulinic acid with photodynamic therapy are discussed as treatment modalities in basal cell carcinoma. Interferon (∼1.5 M IU, 3 times weekly × 3 weeks) is perhaps the most widely used regimen for basal cell carcinoma. With regard to squamous cell carcinoma, treatment with 5-fluorouracil, methotrexate, interferon, and bleomycin are reviewed. Methotrexate (∼0.3-2.0 mL of 12.5 or 25 mg/mL, two injections ∼2 weeks apart) was perhaps the most widely used agent. Interferon (3 M IU × 3 times weekly for ∼8.5 weeks) and rituximab (10-30 mg per lesion, 3 times weekly for 1 week, possibly repeated 4 weeks later) are sometimes used in the management of primary cutaneous B-cell lymphomas, whereas in primary cutaneous CD30(+) lymphoma intralesional methotrexate (0.4-0.5 mL of 50 mg/mL weekly for 2 weeks) has been used. Finally, the roles of BCG vaccine, cidofovir, rose bengal, and bleomycin with electrochemotherapy for the palliation of metastatic melanoma are reviewed. Intralesional management appears most useful when surgical intervention is not a viable option, for cases in which the cosmetic outcome may be superior, or for situations in which the side effects from systemic chemotherapeutic agents are to be minimized.

Bioavailability of aminolaevulinic acid and methylaminolaevulinate in basal cell carcinomas: a perfusion study using microdialysis in vivo

BACKGROUND

Photodynamic therapy is becoming a popular treatment for superficial nonmelanoma precancerous and cancerous lesions, showing excellent cosmetic results. Nevertheless, the reported cure rates vary and the transdermal penetration of drugs has been discussed as a limiting factor, particularly for treatment of nodular basal cell carcinoma (BCC).

OBJECTIVES

To investigate the transdermal penetration of aminolaevulinic acid (ALA) and methylaminolaevulinate (MAL) in BCC in vivo using a microdialysis technique. The different prodrugs were compared and the effect of curettage was studied.

METHODS

Twenty patients with 27 histologically verified BCCs (13 superficial, 14 nodular) were included. All lesions were located at the front of the body (head and face excluded). The first 10 patients included were treated with MAL (13 BCCs), and the following 10 patients with ALA (14 BCCs). A light curettage was performed on every second lesion (curettage, n = 13; noncurettage, n = 14). Microdialysis catheters were inserted into the tumours at tissue depths varying from 0.4 to 1.9 mm. Dialysates were collected at 15-30-min intervals for 4 h and the interstitial concentrations of MAL and ALA were determined using high-performance liquid chromatography.

RESULTS

No significant difference in interstitial drug concentration was observed between lesions treated with ALA or MAL during the 4-h measurement period. However, for the lesions with deeper catheter locations, i.e. at or below 1 mm (n = 11), drug concentrations above the detection limit were obtained in only six lesions. All but one BCC with superficial catheter location, i.e. < 1 mm (n = 16), exhibited detectable drug concentration (P = 0.026). The interstitial peak concentrations were reached within 90 min in 23 of the 27 BCCs, but were not found to be correlated with the depth of the catheters. No difference was found when comparing superficial and nodular BCCs, and the effect of curettage was found to be negligible.

CONCLUSIONS

The results imply that there is no significant difference in transdermal penetration of ALA and MAL in tumour tissue. Detectable levels of drug were not obtained in almost 50% of the lesions where catheters were situated 1-1.9 mm in the lesion. Curettage was not found to affect the interstitial concentration, indicating that penetration of drug indeed might be a problem when treating BCCs thicker than 1 mm.

Prostate PDT dosimetry

We provide a review of the current state of dosimetry in prostate photodynamic therapy (PDT). PDT of the human prostate has been performed with a number of different photosensitizers and with a variety of dosimetry schemes. The simplest clinical light dose prescription is to quantify the total light energy emitted per length (J/cm) of cylindrical diffusing fibers (CDF) for patients treated with a defined photosensitizer injection per body weight. However, this approach does not take into account the light scattering by tissue and usually underestimates the local light fluence rate, and consequently the fluence. Techniques have been developed to characterize tissue optical properties and light fluence rates in vivo using interstitial measurements during prostate PDT. Optical methods have been developed to characterize tissue absorption and scattering spectra, which in turn provide information about tissue oxygenation and drug concentration. Fluorescence techniques can be used to quantify drug concentrations and photobleaching rates of photosensitizers.

Photodynamic therapy of cerebral glioma – A review Part II – Clinical studies

Photodynamic therapy (PDT) is a binary treatment modality that has been used to treat malignant brain tumours for 25 years. The treatment involves the selective uptake of a photosensitizer (PS) by the tumour cells followed by irradiation of the tumour with light of the appropriate wavelength to excite and activate the PS resulting in selective tumour destruction and is a potentially valuable adjunct to surgical excision and other conventional therapies. PDT has undergone extensive laboratory studies and clinical trials with a variety of PS and tumour models. These are discussed with reference mainly to clinical studies involving the PDT of brain tumours.

Photodynamic therapy of cerebral glioma – A review Part I – A biological basis

Photodynamic therapy (PDT) has been investigated extensively in the laboratory for decades, and for over 25 years in the clinical environment, establishing it as a useful adjuvant to standard treatments for many cancers. A combination of both photochemical and photobiological processes occur that lead to the eventual selective destruction of the tumour cells. It is a potentially valuable adjuvant therapy that can be used in conjunction with other conventional therapies for the treatment of cerebral glioma. PDT has undergone extensive laboratory studies and clinical trials with a variety of photosensitizers (PS) and tumour models of cerebral glioma. Many environmental and genetically based factors influence the outcome of the PDT response. The biological basis of PDT is discussed with reference to laboratory and preclinical studies.