- Treatment of lesions (actinic keratosis (AK), BCC, SCC, Bowens disease, melanoma) ≤12 weeks prior to first PDT, except physical treatments (eg cryosurgery, excision surgery) that will not be allowed ≤6 weeks prior to first PDT (Visit 2). Lesion(s) that seemed eligible clinically which could not be confirmed by biopsy, and which are located ≥10cm to an eligible lesion should timely be removed physically only