prolonged recruitment phase

The purpose of this study is to compare two different therapies for actinic keratoses in organ transplant recipients with regard to efficacy and tolerability. The investiagtors are planning to examine treatment with Imiquimod 5% cream versus treatment with Methyl-aminolaevulinate 16% cream and subsequent irradiation with red light, so-called photodynamic therapy, in this patients' group. A secondary objective of our study is to investigate the reduction in the field cancerisation after both treatments using fluorescence diagnostic method and digital imaging.

Organ transplant patients (OTP) require lifelong immunosuppressive therapy and consequently are prone to develop skin tumors, i.e skin cancer is the most frequent malignancy in organ transplant recipients. OTP frequently develop extensive areas of actinic damage, epidermal dysplasia, wich accounts for increased risk of aggressive skin cancer development in susceptible patients, and are referred to as "field cancerisation". Therefore the whole area of field cancerisation has to be treated. In our study we will treat this areas with two different methods and not only the single visible lesions of actinic keratoses.In this open prospective randomized intraindividual study one half of the patients' scalp or face will be treated with Imiquimod 5% cream for 4 weeks, 3 times a week, and the other half with Methyl-aminolaevulinate 16% cream photodynamic therapy, two applications in two weeks interval. The pre- and post treatment extension of field cancerisation will be assessed by means of a highly sensitive digital fluorescence imaging system.

Inclusion Criteria:

• Age 18 years or older
• Patients who had received a kidney, liver, lung or heart transplant more than 3 years prior to inclusion into the study
• Patients who had been treated at least 6 months prior to study entry with a stable twofold or threefold immunosuppressive treatment
• Patients who had clinically confirmed epithelial dysplasia (actinic keratoses) in at least two anatomically separated contralateral areas on the face and/or scalp with comparable size and extension and minimum distance of 5 cm

Exclusion Criteria:

• Invasive squamous cell carcinoma or basal cell carcinoma in the treatment area
• Known allergy to imiquimod and/or methyl-aminolaevulinate and/or one of the other components of the investigational products and/or peanut oil
• Patients who have received retinoids, interferons or investigational drugs within 4 weeks of study initiation
• Patients who are participating in othe dermatological study
• Persistent Hepatitis B or C infections
• Any evidence of systemic cancer
• Patients who have received any systemic cancer chemotherapy or radiation therapy
• Pregnant or lactating women
• Patients