Photodynamic Therapy and Imiquimod Immunotherapy for Basal Cell Carcinomas

Abstract

Photodynamic therapy (PDT) and topical imiquimod immunotherapy (TII) are two recently introduced treatment modalities for certain types of basal cell carcinomas (BCC). We present a review of the relevant literature and report our own findings regarding the efficacy and tolerance of PDT and TII in the treatment of BCCs. According to published studies, the cure rates range from 75-95% for PDT and 42-100% for TII, depending on treatment modalities and BCC type. In our observations, 13 patients with nodular or superficial BCCs were treated by PDT using two courses of 3-hour topical application of methyl aminolevulinate, followed by 8 minutes illumination (lambda = 634 nm, e = 37J/cm2). Biopsies were taken before and one month after PDT. Side effects including pain and crusting were assessed. Eight patients with superficial BCC were treated by TII using 3 monthly courses each consisting of 3 weekly applications for 3 weeks followed by one week out of treatment. Biopsies were taken before and after 3 months of TII. Adverse reactions including erythema, oozing, ulceration, and crusting were recorded. Clinico-histological cure was obtained in 12/13 PDT cases as assessed after 1 month, and in 6/8 TII cases after 3 months. Minimal pain during illumination and crust formation were observed in 7/13 and 3/13 PDT cases, respectively. Variable erythema, oozing, ulceration, and crusting were observed in all TII-treated lesions. It is concluded that PDT represents an active and well tolerated alternative treatment for both nodular and superficial BCCs. TII also shows activity, although the tolerance may be poor and cure needs a longer time to be obtained. The final cosmetic appearance was fine following both PDT and TII procedures. Both PDT and TII may leave intact neoplastic aggregates inside the skin. They cannot be clinically perceived, leading to unexpected recurrences. It is stressed that the currently available efficacy information about PDT and TII deals with short term follow-up periods. A 5-year follow-up must be awaited before drawing firm conclusions.

Guidelines for the management of basal cell carcinoma

“…Histological clearance in the IMQ group was reported in six of eight (all sBCC) vs. 12 of 13 (sBCC and nBCC) in the PDT group 12 weeks after treatment. Cosmetic results in both groups were similar, although patients tolerated IMQ therapy less well 141 …”

Photodynamic therapy for cutaneous verrucous carcinoma

“…12 In recent years, PDT has been successfully used, using topical or systemic photosensitizers, to treat superficial and nodular basal cell carcinomas, actinic keratoses, squamous cell carcinomas, Bowen's disease, cutaneous metastases of mammary cancer, Kaposi's sarcoma, cutaneous T-cell lymphomas, and cutaneous primary B-cell lymphomas. [13][14][15][16][17][18][19][20][21][22] We present an elderly man with a verrucous carcinoma of the front of his leg. As PDT has been reported active in actinic keratoses and squamous cell carcinomas, this treatment was tested in this patient with a successful outcome.…”

Combination of photodynamic therapy and immunotherapy - evolving role in dermatology

“…In general, PDT represents an active and well tolerated alternative treatment for BCCs. Topical imiquimod shows activity but the tolerance may be poor and the cure needs a prolonged treatment, although the final cosmetic appearance is fine following both PDT and TII procedures [12]. In this study, we applied imiquimod before and in between each session of ALA-PDT treatment in several BCC patients.…”

“…Although comparison studies have been reported for the evaluation of PDT and imiqimod immunomodulation for certain types of skin cancers [12], it has not yet been confirmed whether the combination of PDT and imiqimod could further enhance the overall cure rate. Because of a growing understanding of the immune mechanisms within the skin, the opportunity has arisen to assist the body's immune system to effectively treat dermatologic conditions.…”