Togsverd-Bo K, et al. - Researchers in this Scandinavian study compared the efficacy and acceptability of photodynamic therapy (PDT) (administered at a hospital visit) and imiquimod (applied 3 times a week for 4 weeks by the patient at home) cream for solar keratoses in a group of organ transplant patients. In this group of high-risk patients, for reducing the number of persistent solar keratoses, photodynamic therapy was more effective than imiquimod. Nonetheless, compared to imiquimod PDT was more painful, therefore for this reason patients did not prefer one treatment over the other.