title: Broadband reflectance measurements of light penetration, blood oxygenation, hemoglobin concentration, and drug concentration in human intraperitoneal tissues before and after photodynamic therapy.
abstract: We evaluate Photofrin-mediated photodynamic therapy (PDT) in a phase 2 clinical trial as an adjuvant to surgery to treat peritoneal carcinomatosis. We extract tissue optical [reduced scattering (mu(s)'), absorption (mu(a)), and attenuation coefficients (mu(eff))] and physiological [blood oxygen saturation (%S(t)O2), total hemoglobin concentration (THC), and photosensitizer concentration (c(Photofrin))] properties in 12 patients using a diffuse reflectance instrument and algorithms based on the diffusion equation. Before PDT, in normal intraperitoneal tissues %S(t)O2 and THC ranged between 32 to 100% and 19 to 263 microM, respectively; corresponding data from tumor tissues ranged between 11 to 44% and 61 to 224 microM. Tumor %S(t)O2 is significantly lower than oxygenation of normal intraperitoneal tissues in the same patients. The mean (+/-standard error of mean) penetration depth (delta) in millimeters at 630 nm is 4.8(+/-0.6) for small bowel, 5.2 (+/-0.67) for large bowel, 3.39(+/-0.29) for peritoneum, 5.19(+/-1.4) for skin, 1.0(+/-0.1) for liver, and 3.02(+/-0.66) for tumor. c(Photofrin) in micromolars is 4.9(+/-2.3) for small bowel, 4.8(+/-2.3) for large bowel, 3.0 (+/-1.0) for peritoneum, 2.5(+/-0.9) for skin, and 7.4(+/-2.8) for tumor. In all tissues examined, mean c(Photofrin) tends to decrease after PDT, perhaps due to photobleaching. These results provide benchmark in-vivo tissue optical property data, and demonstrate the feasibility of in-situ measurements during clinical PDT treatments.
authors.affiliation: University of Pennsylvania, Department of Physics and Astronomy, 209 South 33rd Street, Philadelphia, Pennsylvania 19104-6396, USA. hwwang@physics.upenn.edu
authors.forename: Hsing-Wen
authors.initials: HW
authors.lastname: Wang
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Zhu
authors.forename: Mary E
authors.initials: ME
authors.lastname: Putt
authors.forename: Michael
authors.initials: M
authors.lastname: Solonenko
authors.forename: James
authors.initials: J
authors.lastname: Metz
authors.forename: Andreea
authors.initials: A
authors.lastname: Dimofte
authors.forename: Jeremy
authors.initials: J
authors.lastname: Miles
authors.forename: Douglas L
authors.initials: DL
authors.lastname: Fraker
authors.forename: Eli
authors.initials: E
authors.lastname: Glatstein
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Hahn
authors.forename: Arjun G
authors.initials: AG
authors.lastname: Yodh
mesh_terms: D000465:Algorithms; D017024:Chemotherapy, Adjuvant; D017323:Dihematoporphyrin Ether / Q000493:pharmacokinetics* / Q000627:therapeutic use; D006414:Hematoporphyrin Photoradiation; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D008027:Light; D008099:Liver / Q000378:metabolism; D009994:Osmolar Concentration; D010100:Oxygen / Q000097:blood*; D010534:Peritoneal Neoplasms / Q000188:drug therapy* / Q000601:surgery; D010537:Peritoneum / Q000378:metabolism*; D012542:Scattering, Radiation; D012867:Skin / Q000378:metabolism; D014018:Tissue Distribution
chemical_list: D006454:Hemoglobins; D017323:Dihematoporphyrin Ether; D010100:Oxygen