title: mTHPC-mediated photodynamic diagnosis of malignant brain tumors.
abstract: Radical tumor resection is the basis for the prolonged survival of patients suffering from malignant brain tumors such as glioblastoma multiforme. We have carried out a phase-II study involving 22 patients with malignant brain tumors to assess the feasibility and the effectiveness of the combination of intraoperative photodynamic diagnosis and fluorescence-guided resection (FGR) mediated by the second-generation photosensitizer meta-tetrahydroxyphenylchlorin (mTHPC). In addition, intraoperative photodynamic therapy (PDT) was performed. Several commercially available fluorescence diagnostic systems were investigated for their applicability in clinical practice. We have adapted and optimized a diagnostic system that includes a surgical microscope, an excitation light source (filtered to 370-440 nm), a video camera detection system and a spectrometer for clear identification of the mTHPC fluorescence emission at 652 nm. Especially in regions of faint fluorescence, it turned out to be essential to maximize the spectral information by optimizing and matching the spectral properties of all components, such as excitation source, camera and color filters. To sum up, on the basis of 138 tissue samples derived from 22 tumor specimens, we have been able to achieve a sensitivity of 87.9% and a specificity of 95.7%. This study demonstrates that mTHPC-mediated intraoperative FGR followed by PDT is a highly promising concept in improving the radicality of tumor resection combined with a therapeutic approach.
authors.affiliation: Institute for Medical Physics, University of Innsbruck, Müllerstr. 44, A-6020 Innsbruck, Austria. andreas.zimmermann@uibk.ac.at
authors.forename: A
authors.initials: A
authors.lastname: Zimmermann
authors.forename: M
authors.initials: M
authors.lastname: Ritsch-Marte
authors.forename: H
authors.initials: H
authors.lastname: Kostron
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001932:Brain Neoplasms / Q000175:diagnosis / Q000188:drug therapy / Q000473:pathology / Q000601:surgery / Q000628:therapy; D017322:Clinical Trials, Phase II as Topic; D003131:Combined Modality Therapy; D004305:Dose-Response Relationship, Drug; D005240:Feasibility Studies; D005260:Female; D005910:Glioma / Q000175:diagnosis / Q000188:drug therapy / Q000601:surgery / Q000628:therapy; D006801:Humans; D007430:Intraoperative Care; D008297:Male; D008652:Mesoporphyrins / Q000627:therapeutic use*; D008856:Microscopy, Fluorescence / Q000379:methods; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control; D010778:Photochemotherapy / Q000379:methods; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D010789:Phototherapy / Q000295:instrumentation* / Q000379:methods*; D011838:Radiation-Sensitizing Agents / Q000627:therapeutic use*; D012680:Sensitivity and Specificity
chemical_list: D000970:Antineoplastic Agents; D008652:Mesoporphyrins; D017319:Photosensitizing Agents; D011838:Radiation-Sensitizing Agents; C072269:temoporfin