title: Doppler optical coherence tomography to monitor the effect of photodynamic therapy on tissue morphology and perfusion.
abstract: We investigated the feasibility of using optical coherence tomography (OCT) for noninvasive real-time visualization of the vascular effects of photodynamic therapy (PDT) in normal and tumor tissue in mice. Perfusion control measurements were initially performed after administrating vaso-active drugs or clamping of the subcutaneous tumors. Subsequent measurements were made on tumor-bearing mice before and after PDT using the photosensitizer meta-tetrahydroxyphenylchlorin (mTHPC). Tumors were illuminated using either a short drug light interval (D-L, 3 h), when mTHPC is primarily located in the tumor vasculature or a long D-L interval (48 h), when the drug is distributed throughout the whole tumor. OCT enabled visualization of the different layers of tumor, and overlying skin with a maximal penetration of < or =0.5-1 mm. PDT with a short D-L interval resulted in a significant decrease of perfusion in the tumor periphery, to 20% of pre-treatment values at 160 min, whereas perfusion in the skin initially increased by 10% (at 25 min) and subsequently decreased to 60% of pre-treatment values (at 200 min). PDT with a long D-L interval did not induce significant changes in perfusion. The concept of using noninvasive OCT measurements for monitoring early, treatment-related changes in morphology and perfusion may have applications in evaluating effects of anti-angiogenic or antivascular (cancer) therapy.
authors.affiliation: University of Amsterdam, Academic Medical Center, Laser Center, Meibergdreef 9, 1105 AZ, Amsterdam, The Netherlands. M.C.Aalders@amc.uva.nl
authors.forename: Maurice C G
authors.initials: MC
authors.lastname: Aalders
authors.forename: Martijn
authors.initials: M
authors.lastname: Triesscheijn
authors.forename: Marjan
authors.initials: M
authors.lastname: Ruevekamp
authors.forename: Martijn
authors.initials: M
authors.lastname: de Bruin
authors.forename: Paul
authors.initials: P
authors.lastname: Baas
authors.forename: Dirk J
authors.initials: DJ
authors.lastname: Faber
authors.forename: Fiona A
authors.initials: FA
authors.lastname: Stewart
mesh_terms: D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000473:pathology*; D004360:Drug Therapy, Computer-Assisted / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008652:Mesoporphyrins / Q000627:therapeutic use*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D010778:Photochemotherapy / Q000379:methods*; D011379:Prognosis; D011838:Radiation-Sensitizing Agents / Q000627:therapeutic use; D041623:Tomography, Optical Coherence / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D008652:Mesoporphyrins; D011838:Radiation-Sensitizing Agents; C072269:temoporfin