ALA-PDT Versus Vehicle PDT for Treatment of AK and Reduction of New NMSC in Solid Organ Transplant Recipients

20% aminolevulinic acid HCL (ALA) applied topically for 90 +/- 30 minutes prior to treatment with 10 j/cm2 blue light. Up to nine (9) ALA-PDT treatments will be given: The initial four (4) treatments will be given at 4-5 week intervals, with the remaining five (5) treatments given every 6 +/-1 weeks.

Vehicle ingredients only (VEH) applied topically for 90 +/- 30 minutes prior to treatment with 10 j/cm2 blue light. Up to nine (9) VEH-PDT treatments will be given: The initial four (4) treatments will be given at 4-5 week intervals, with the remaining five (5) treatments given every 6 +/-1 weeks.