CLINICAL REPORT
689 ActaDV ActaDV Advances in dermatology and venereology Acta Dermato-Venereologica
Treatment of Actinic Keratosis with Photodynamic Therapy Using Red or Green Light : A Comparative Study
Beata J . OSIECKA 1 , Piotr NOCKOWSKI 2 and Jacek C . SZEPIETOWSKI 2
1
Department of Pathology , and 2 Department of Dermatology , Venereology and Allergology , Wroclaw Medical University , Wroclaw , Poland
Actinic keratosis ( AK ) is the most common in situ cancerous skin lesion . Compared with other approved treat ment modalities photodynamic therapy is preferred by patients due to faster recovery and improved cosmetic outcome . However , pain during irradiation is an important drawback . The aim of this study was to compare the effectiveness and tolerability of topical aminolaevulinic acid-photodynamic therapy in the treat ment of AK on the head using red and green light . Complete remissions after 3 sessions of photodynamic therapy at 2-week intervals following 9 months of observation were 91.67 % for red light and 86.67 % for green light ( difference not significant ). The mean pain value was significantly greater in areas irradiated with red light compared with green light for all 3 sessions . This comparative study demonstrates that aminolaevulinic acid-photodynamic therapy with green light is of similar efficacy as that with red light in the treatment of middle / moderate AK , but causes less pain .
Key words : photodynamic therapy ; red light ; green light , 5-aminolevulinic acid ; actinic keratosis ; pain .
Accepted Mar 27 , 2018 ; Epub ahead of print Mar 27 , 2018 Acta Derm Venereol 2018 ; 98 : 689 – 693 .
Corr : Jacek C . Szepietowski , Department of Dermatology , Venereology and Allergology , Wroclaw Medical University , ul . Chalubinskiego 1 , PL-50- 368 Wroclaw , Poland . E-mail : jacek . szepietowski @ umed . wroc . pl
SIGNIFICANCE
Actinic keratosis is the most common early non-invasive stage of skin cancer . Compared with other approved treatment modalities photodynamic therapy is preferred by patients due to faster recovery and improved cosmetic outcome . However , pain during irradiation is an important drawback . This study shows that 3 sessions of topical aminolaevulinic acid-photodynamic therapy using green light is of similar efficacy as that with red light in the treatment of middle / moderate actinic keratosis , but irradiation with green light caused significantly less pain compared with red light .
Actinic keratosis ( AK ) is the most common in situ neoplasm of the skin in the white population , particularly in people with skin phototypes I – III . Epidemiological data show a rapid increase in AK morbidity in recent years . Lesions usually present as multiple erythematous or hyperkeratotic yellow , scaly plaques on skin areas damaged by ultraviolet ( UV ) light ( photodamaged skin ). Clinical research shows that 1 – 10 % of AKs progress to cutaneous squamous cell carcinoma ( SCC ).
Common treatments for AKs use various procedures , both ablative ( cryosurgery , laser ablation , curettage , and surgery ) and topical ( 5-fluorouracil , diclofenac 3 % gel , and imiquimod ). Some of these therapies may cause scarring or hyper- or hypo-pigmentation . Because most AKs are found in the sun-exposed skin ( face skin , scalp , and hands ), therapies offering the best cosmetic results are especially desirable .
Topical photodynamic therapy ( PDT ) with 5-aminolaevulinic acid ( 5-ALA ) has been approved as an alternative method of treating various precancerous ( e . g . AK ) and superficial tumours of the skin ( 1 – 3 ). Safety , noninvasiveness , and excellent cosmetic results make PDT competitive with other conventional methods . Clinical studies have shown the effectiveness of ALA-PDT to be comparable to , or even exceed that of , cryotherapy , excisional surgery , or electrodesiccation in the treatment of AK ( 4 – 7 ). Many patients who have previously undergone other FDA-approved treatment modalities for AK prefer PDT because of improved cosmetic outcome and faster recovery compared with cryotherapy and surgical excision . Moreover , PDT is better tolerated than 5-fluorouracil ( 5-FU ) and imiquimod ( 8 ).
PDT is based on the interaction between 3 elements : a photosensitizer , an activating light source of the appropriate wavelength and oxygen . 5-ALA is selectively taken up by premalignant or malignant cells . In the target cells it is converted to protoporphyrin IX ( PpIX ), via the haem synthesis pathway . Exposure to light leads to activation of PpIX , formation of reactive oxygen species ( ROS ) and cytotoxicity of pathological cells ( 9 ). PDT is typically induced by red light because of the optimal depth of light penetration into tissue . However , an important drawback of ALA-PDT is pain , often intense , experienced by patients during irradiation . Several studies have shown that , in the case of patients with AK on the forehead and scalp , PDT causes more pain than in cases of lesions in other areas ( 10 , 11 ). PDT offers clinical efficacy similar to standard treatments , but pain remains the most common adverse event reported . Therefore , new strategies are being sought in order to minimize discomfort during PDT .
The fact that a variety of wavelengths can initiate photodynamic reactions from ALA via PpIX in cells has led to interest in using green light ( which is less penetrating ) to treat superficial skin lesions . A number of clinical studies have reported that green light is effective in the
This is an open access article under the CC BY-NC license . www . medicaljournals . se / acta Journal Compilation © 2018 Acta Dermato-Venereologica . doi : 10.2340 / 00015555-2931 Acta Derm Venereol 2018 ; 98 : 689 – 693