Professor Katarina Svanberg
Lund University Hospital, Lund University
Department of Oncology
SE-221 85 Lund, Sweden
Lund University Medical Laser Centre
S-221 85 Lund, Sweden
Applications of optical and laser spectroscopy to the medical field, including photodynamic therapy (PDT) and laser-induced fluorescence diagnostics (LIF) for cancer treatment and diagnostics, respectively, will be presented. Photodynamic therapy, when delivered as a superficial illumination to the target area, has a limitation due to restricted light penetration through tissue. One way of overcoming this is interstitial illumination (IPDT) in which the light is transmitted to the tumour via optical fibres. Interactive feed-back dosimetry is of importance for optimising the modality and such a concept has been developed and will be presented.
The most important prognostic factor for cancer patients is early tumour discovery. If malignant tumours are detected during the non-invasive stage, most tumours show a high cure rate of more than 90%. There is a variety of conventional diagnostic procedures, such as X-ray imaging. More advanced results are given in computerised investigations, such as CT-, MRI- or PET-scanning. Laser-induced fluorescence (LIF) for tissue characterisation is a technique that can be used for monitoring the biomolecular changes in tissue under transformation from normal to dysplastic and cancer tissue before structural tissue changes are seen at a later stage. The technique is based on UV or near-UV illumination for fluorescence excitation. The fluorescence from endogenous chromophores in the tissue alone, or enhanced by exogenously administered tumour seeking substances can be utilised. The technique is non-invasive and gives the results in real-time. LIF can be applied for point monitoring or in an imaging mode for larger areas, such as the vocal cords or the portio of the cervical area. The possibility to combine LIF and PDT will be discussed and illustrated with clinical examples from many specialities, such as dermatology, gynaecology and laryngology.
K. Svanberg, N. Bendsoe, J. Axelsson, S. Andersson-Engels and S. Svanberg, “Photodynamic therapy: superficial and interstitial illumination,” J. Biomed. Opt. 15, 041502 (2010).