Funding sources This work was supported by the Duchy Health Charity Ltd.
Comparison of protoporphyrin IX accumulation and destruction during methylaminolevulinate photodynamic therapy of skin tumours located at acral and nonacral sites
Article first published online: 13 MAY 2011
© 2011 The Authors. BJD © 2011 British Association of Dermatologists
British Journal of Dermatology
Volume 164, Issue 6, pages 1362–1368, June 2011
How to Cite
Tyrrell, J.S., Morton, C., Campbell, S.M. and Curnow, A. (2011), Comparison of protoporphyrin IX accumulation and destruction during methylaminolevulinate photodynamic therapy of skin tumours located at acral and nonacral sites. British Journal of Dermatology, 164: 1362–1368. doi: 10.1111/j.1365-2133.2011.10265.x
Conflicts of interest C.M., S.M.C. and A.C. have received honoraria for speaking, organized educational events and/or conducted research for Galderma, PhotoCure and/or Phototherapeutics Ltd. J.S.T. has no conflict of interest to declare.
- Issue published online: 25 MAY 2011
- Article first published online: 13 MAY 2011
- Accepted manuscript online: 24 FEB 2011 05:39PM EST
- Accepted for publication 23 January 2011
Background Topical photodynamic therapy (PDT) is successful in the treatment of nonmelanoma skin cancers and associated precancers, but efficacy is significantly reduced in actinic keratosis lesions not located on the face or scalp.
Objectives To compare the changes in protoporphyrin IX (PpIX) fluorescence in lesions undergoing routine methylaminolevulinate (MAL) PDT and the clinical outcome observed 3 months after treatment in lesions located at acral and nonacral sites.
Methods This study was a noninterventional, nonrandomized, observational study, which monitored changes in PpIX fluorescence in 200 lesions during standard dermatological MAL-PDT. These data were subsequently analysed in terms of lesions located at acral and nonacral sites.
Results Clinical clearance was significantly reduced (P < 0·01) in acral skin lesions when compared with lesions located at nonacral sites. The accumulation and destruction of PpIX fluorescence was significantly reduced in these acral lesions (P < 0·05 and P < 0·001, respectively). Specifically, lesion location at acral sites significantly reduced changes in PpIX fluorescence in actinic keratosis lesions during MAL-PDT (P < 0·01 and P < 0·05).
Conclusions These data suggest that reduced PpIX accumulation and the subsequent reduction in PpIX photobleaching within acral lesions result in the reduced responsiveness of these lesions to MAL-PDT. Future work should therefore aim to improve photosensitizer accumulation/photobleaching within lesions located at acral sites.