• To Compare occurrence of new lesions (AK, BCC, SCC and warts) in the treated area with the contralateral control area (symmetrically). [ Time Frame: 3, 9, 15, 21 and 27 months after first treatment ]
• Compare number of AK lesions that show complete response in the treated area with the contralateral control area. [ Time Frame: 3, 9, 15, 21 and 27 months after first treatment ]

• Compare number of BCC lesions that show complete response in the treated area with the contralateral control area. [ Time Frame: 3, 9, 15, 21 and 27 months after first treatment ]
• Compare number of recurrent lesions in treated area with the contralateral control area [ Time Frame: 9, 15, 21 and 27 months after first treatment ]
• Assess the cosmetic outcome. [ Time Frame: 3, 9, 15, 21 and 17 months after first treatment ]
• Investigate product safety in this patient population [ Time Frame: 3, 9, 15, 21 and 27 months after first treatment ]

Patients on immunosuppressive therapy, e.g. organ recipients, have a higher occurrence of AK than the untreated population. Keratotic lesions (i.e. AK lesions and warts) in this population is highly associated with development of SCC also with 10 times higher mortality rate because of SCC than expected.

The risk of developing skin cancer, predominantly SCC and BCC, increases with graft survival time and the length of immunosuppressive treatment period. The higher risk of developing skin malignancy and more aggressive skin malignancies in this population, indicate the need for early removal of these pre-malignant lesions. In this study, two contralateral areas (5x10 cm2) with skin lesions within the patient will be compared. One area will receive Metvix PDT at defined intervals and the other will receive lesion specific treatment at the discretion of the investigator. The primary end-point will be the accumulated number of new lesions during the study and number of AK lesions that show complete response 3 months after baseline. Secondary endpoints will be number of BCC lesions that show complete response, number of recurrent lesions, assessment of cosmetic outcome and safety.

The treatment area (5x10 cm2) will be treated at baseline and at 3, 9 and 15 months visits. At baseline the area will be treated with fractionated Metvix® PDT treatment consisting of two treatment one week apart and at 3, 9, and 15 months visits with single Metvix® PDT treatment. The patients will be evaluated for occurrence of new lesions, lesion response and recurrence at 3 (not recurrence), 9, 15, 21 and 27 months visits. New and recurrent lesions in the treated area will be treated with Metvix® PDT treatment. Lesions with partial response in the treated area will be re-treated with Metvix® PDT and lesions with no response will be treated with lesion specific treatment at the discretion of the investigator.

In the contralateral control area (5x10 cm2), new and recurrent lesions and lesions in non-complete response will be treated with lesion specific treatment at the discretion of the investigator at each study visit.

• Actinic Keratosis
• Warts
• Basal Cell Carcinoma
• Bowens Disease
• Squamous Cell Carcinoma

Inclusion Criteria:

• Transplant recipients with at least 2 clinically diagnosed AK lesion and maximum 10 skin lesions (AK, BCC, SCC in situ and/or warts) in each of the two contralateral areas (diameter 5x10 cm) in the face, the scalp, the extremities or on the trunk/neck.
• Transplant recipients who previously are treated more than once for their skin lesions.
• Transplant recipients who have received immunosuppressive therapy for more than 3 years.
• Males or females above 18 years of age.
• Written informed consent.

Exclusion Criteria:

• Patients with more than 10 skin lesions (AK,BCC,SCC in situ,warts) in one of the two areas.
• Patient with SCC (not SCC in situ) in one of the two areas.
• Patients not previously treated or treated only once for their skin lesions.
• Patient with rosacea in one of the two areas.
• Patients with morpheaform/highly infiltrating BCC
• Known allergy to methyl-aminolevulinate, a similar compound or excipients of the cream
• Participation in other clinical studies either concurrently or within the last 30 days.
• Pregnant or breast-feeding (all women of child-bearing potential must document a negative pregnancy test and use the pill or IUD during the treatments and for at least one month thereafter).
• Conditions associated with a risk of poor protocol compliance