Intralesional photodynamic therapy: a comment on 'Pretreatment to enhance protoporphyrin IX accumulation in photodynamic therapy' by Gerritsen et al.

application in photodynamic therapy (PDT). The authors did not mention intralesional PDT, a seldom used technique which potential, though, is in our opinion underrecognized and underestimated. As shown in table 1 , intralesional PDT has been reported to be an effective and safe treatment for skin metastases of breast cancer [2] , superficial and nodular basal-cell carcinoma [3, 4, 6, 7] , squamous-cell carcinoma [4–7] , Paget’s disease [5] and acne vulgaris [8] . We have also successfully treated anogenital condylomata [unpubl. data]. Performing intralesional PDT is less time-consuming than several other pretreatment procedures [1] . Moreover, a study showed that the fluorescence induced by the intralesional injection of the prodrug was present as early as 4 h [9] ; nonetheless, the time necessary to allow the conversion of the prodrug into the final photosensitizer is likely to be much shorter, as incubations