title: A clinical investigation to determine the effect of pressure injection on the penetration of topical methyl aminolevulinate into nodular basal cell carcinoma of the skin.
abstract: This investigation considered a novel method of enhancing penetration of the topical photosensitizing agent methyl aminolevulinate (MAL) into nodular basal cell carcinomas (BCCs) using an oxygen pressure injection device. Oxygen pressure injection (OPI) is a method to drive compounds into skin using pressured oxygen. The study was an observer-blinded pilot of a single application of MAL to nBCCs, with or without the use of OPI. The BCCs were then excised at different time intervals (0-180 min) and the depth of penetration of the MAL examined using microscopic fluorescence photometry to detect the production of the naturally fluorescent active photosensitiser protoporphyrin IX (PpIX). A highly selective and homogeneous distribution of MAL-induced porphyrin fluorescence was seen in all nBCC tumors studied, and showed a high lesion-to-normal-tissue ratio with very little fluorescence in the surrounding normal tissue. Although it was difficult to compare quantitatively, as individual tumors in each of the different study groups varied, a definite trend of increase in relative tumor concentration of MAL-induced PpIX was observed over time, and this was enhanced when OPI was employed.
authors.affiliation: Cornwall Dermatology Research, Peninsula Medical School, Truro, UK. Sandra.campbell@rcht.cornwall.nhs.uk
authors.forename: S M
authors.initials: SM
authors.lastname: Campbell
authors.forename: Andrew
authors.initials: A
authors.lastname: Pye
authors.forename: S
authors.initials: S
authors.lastname: Horton
authors.forename: J
authors.initials: J
authors.lastname: Matthew
authors.forename: P
authors.initials: P
authors.lastname: Helliwell
authors.forename: A
authors.initials: A
authors.lastname: Curnow
mesh_terms: D000622:Aminolevulinic Acid / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000627:therapeutic use; D002280:Basal Cell Carcinoma / Q000378:metabolism / Q000473:pathology / Q000628:therapy; D016503:Drug Delivery Systems / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D015552:Injections, Intralesional; D008856:Microscopy, Fluorescence; D009824:Ointments; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use; D010865:Pilot Projects; D011524:Protoporphyrins / Q000378:metabolism; D012869:Skin Absorption; D012878:Skin Neoplasms / Q000378:metabolism / Q000473:pathology / Q000628:therapy
chemical_list: D009824:Ointments; D017319:Photosensitizing Agents; D011524:Protoporphyrins; C475457:methyl 5-aminolevulinate; D000622:Aminolevulinic Acid