Photodynamic therapy and laser-based diagnostic studies of malignant tumours

Research output: ThesisDoctoral Thesis (compilation)

Abstract

Two non-thermal regimens of light interaction with biological tissue, that are in a natural way connected, are discussed in the present thesis. These are photodynamic therapy (PDT) for the treatment of malignant tumours and laser-induced fluorescence (LIF) for tissue characterization.

In PDT, a photochemical reaction is induced by non-ionizing electromagnetic irradiation in tissue where photosensitizing agents and oxygen are present. Instead of using pre-formed photosensitizers for intravenous administration, a new way of sensitization was exploited. A porphyrin precursor, (delta)-aminolevulinic acid (ALA) was utilized for the induction of protoporphyrin IX (PpIX). Photodynamic therapy was used in the treatment of non-melanoma malignant skin tumours, mainly basal cell carcinomas (BCCs). A randomized, clinical trial was conducted in the treatment of BCCs, where PDT was compared to cryosurgery.

Laser-induced fluorescence (LIF) can be applied for non-invasive, real time spectroscopic tissue characterization. Laser light is used for fluorescence excitation. The fluorescence signal in pre-malignant and malignant tissue exhibits some characteristics that deviate from those of normal tissue. In addition, the contrast can be increased by employing fluorescent tumour markers. Laser-induced fluorescence measurements were performed in malignancies of the skin and benign, pre-malignant and malignant lesions in the head-and-neck region. Again, ALA-induced PpIX was used. The build-up and the photodegradation of PpIX were also studied.

Another non-invasive, real time method for tissue diagnostics is laser-Doppler imaging (LDI), for detection of the blood perfusion in superficial tissue. In the present work, the modality was used in connection with ALA-PDT of non-melanoma malignant skin tumours, for identifying lesions, characterize the vascular effects induced by the PDT and follow the healing process after treatment.

Details

Authors
  • Ingrid Wang
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Atom and Molecular Physics and Optics

Keywords

  • protoporphyrin IX (PpIX), (delta)-aminolevulinic acid (ALA), photosensitizer, basal cell carcinoma (BCC), Photodynamic therapy (PDT), laser-induced fluorescence (LIF), Cytology, oncology, cancerology, Cytologi, onkologi, cancer
Original languageEnglish
QualificationDoctor
Awarding Institution
Supervisors/Assistant supervisor
  • [unknown], [unknown], Supervisor, External person
Award date1999 Feb 18
Publisher
  • Lund University Medical Laser Centre, Department of Oncology, Lund University Hospital
Print ISBNs91-628-3352-9
Publication statusPublished - 1999
Publication categoryResearch

Bibliographic note

Defence details Date: 1999-02-18 Time: 13:15 Place: The Lecture Hall, Department of Oncology, Lund University Hospital External reviewer(s) Name: Moan, Johan Title: Professor Affiliation: Institute of Cancer Research, The Norwegian Radium Hospital, Oslo --- Article: I. I. Wang, S. Andersson-Engels, G.E. Nilsson, K. Wårdell and K. Svanberg, Superficial blood flow following photodynamic therapy of malignant skin tumours measured by laser Doppler perfusion imaging, Br. J. Dermatol. 136, 184-189 (1997). Article: II. I. Wang, B. Bauer, S. Andersson-Engels, S. Svanberg and K. Svanberg, Photodynamic therapy utilising topical (delta)-aminolevulinic acid in non-melanoma skin malignancies of the eyelid and the periocular skin, Acta Ophthalmol. Scand. 77, in press (1999). Article: III. K. Svanberg, T. Andersson, D. Killander, I. Wang, U. Stenram, S. Andersson-Engels, R. Berg, J. Johansson and S. Svanberg, Photodynamic therapy of non-melanoma malignant tumours of the skin using topical (delta)-amino levulinic acid sensitization and laser irradiation, Br. J. Dermatol. 130, 743-751 (1994). Article: IV. I. Wang, L. Pais Clemente, R.M.G. Pratas, E. Cardoso, M. Pais Clemente, S. Montán, S. Svanberg and K. Svanberg, Fluorescence diagnostics and kinetic studies in the head and neck region utilising low-dose (delta)-aminolevulinic acid sensitisation, Cancer Letters 135, 11-19, (1999). Article: V. I. Wang, N. Bendsoe, C. af Klinteberg, A.M.K. Enejder, S. Andersson-Engels, S. Svanberg and K. Svanberg, Photodynamic therapy versus cryosurgery of basal cell carcinomas; results of a Phase III randomized clinical trial, Manuscript (1999). Article: VI. C. af Klinteberg, I. Wang, A.M.K. Enejder, S. Andersson-Engels, S. Svanberg and K. Svanberg, (delta)-Aminolevulinic acid-induced protoporphyrin IX fluorescence in basal cell carcinomas of the skin, Manuscript (1999). Article: VII. C. af Klinteberg, A.M.K. Enejder, I. Wang, S. Andersson-Engels, S. Svanberg and K. Svanberg, Kinetic fluorescence studies of (delta)-aminolevulinic acid-induced protoporphyrin IX in basal cell carcinomas, Submitted (1999). Article: VIII. A.M.K. Enejder, C. af Klinteberg, I. Wang, S. Andersson-Engels, N. Bendsoe, S. Svanberg and K. Svanberg, Blood perfusion studies on basal cell carcinomas in conjunction with photodynamic- and cryotherapy employing laser-Doppler imaging, Submitted (1999).