Eighty basal cell carcinomas (BCCs) in 21 patients, 10 lesions of Bowen's disease in three patients, and four lesions of cutaneous T-cell lymphoma in two patients, were treated with photodynamic laser therapy (PDT), using topical application of the haem precursor delta-amino levulinic acid (ALA). The diagnoses were confirmed histologically prior to treatment. Fifty-five of the BCCs were superficial lesions, and 25 were nodular. Of the 80 BCCs, 39 (49%) were located on the trunk, 36 (45%) on the head and neck region, four (15%) on the leg and one on the arm. The two principal locations of the 10 Bowen's disease lesions were the leg (50%) and the trunk (40%). The T-cell lymphoma lesions were located on the shoulder and on the arm. A water-in-oil based cream containing 20% ALA was applied to the lesions, with a margin of about 10-20 mm beyond the visible tumour border, 4-6 h before the laser procedure. During this period of time the highly fluorescent and photodynamically active substance protoporphyrin IX (Pp IX) is synthesized via the haem cycle. Laser-induced fluorescence (LIF) was used for real-time monitoring of the Pp IX distribution in the tumour and in the normal surrounding skin, before and after treatment in all patients. Before laser treatment the Pp IX distribution demonstrated by LIF showed a demarcation between tumour and normal skin of about 15:1 for BCC and Bowen's disease, and 5:1 for T-cell lymphomas.(ABSTRACT TRUNCATED AT 250 WORDS)

In terms of efficacy, ALA-PDT is comparable with cryosurgery as a treatment modality for BCCs. Retreatments are more often required with PDT than with cryosurgery. This can easily be performed due to the shorter healing time, less scarring and better cosmetic outcome that follows ALA-PDT.

Photodynamic therapy (PDT) with topical methyl aminolevulinate (MAL) administered in two treatment sessions separated by 1 week is an effective treatment for actinic keratoses. This open prospective study compared the efficacy and safety of MAL-PDT given as a single treatment with two treatments of MAL-PDT 1 week apart. Two hundred and eleven patients with 413 thin to moderately thick actinic keratoses were randomized to either a single treatment with PDT using topical MAL (regimen I; n=105) or two treatments 1 week apart (regimen II; n=106). Each treatment involved surface debridement, application of Metvix cream (160 mg/g) for 3 h, followed by illumination with red light using a light-emitting diode system (peak wavelength 634+/-3 nm, light dose 37 J/cm2). Thirty-seven lesions (19%) with a non-complete response 3 months after a single treatment were re-treated. All patients were followed up 3 months after the last treatment. A total of 400 lesions, 198 initially treated once and 202 treated twice, were evaluable. Complete response rate for thin lesions after a single treatment was 93% (95% CI=87-97%), which was similar to 89% (82-96%) after repeated treatment. Response rates were lower after single treatment of thicker lesions (70% (60-78%) vs 84% (77-91%)), but improved after repeated treatment (88% (82-94%)). The conclusion of this study is that single treatment with topical MAL-PDT is effective for thin actinic keratosis lesions; however, repeated treatment is recommended for thicker or non-responding lesions.

In vivo fluorescence imaging for tissue diagnosticsAndersson-Engels, Stefan; af Klinteberg, C; Svanberg, Katarina; Svanberg, Sune General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal Take down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Abstract. Non-invasive fluorescence imaging has the potential to provide in vivo diagnostic information for many clinical specialities. Techniques have been developed over the years for simple ocular observations following UV excitation to sophisticated spectroscopic imaging using advanced equipment. Much of the impetus for research on fluorescence imaging for tissue diagnostics has come from parallel developments in photodynamic therapy of malignant lesions with fluorescent photosensitizers. However, the fluorescence of endogenous molecules (tissue autofluorescence) also plays an important role in most applications. In this paper, the possibilities of imaging tissues using fluorescence spectroscopy as a mean of tissue characterization are discussed. The various imaging techniques for extracting diagnostic information suggested in the literature are reviewed. The development of exogenous fluorophores for this purpose is also presented. Finally, the present status of clinical evaluation and future directions are discussed. In vivo fluorescence imaging for tissue diagnostics

In vivo optical characterization of human prostate tissue using near-infrared timeresolved spectroscopy.Svensson, Tomas; Andersson-Engels, Stefan; Einarsdóttír, Margrét; Svanberg, Katarina General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal Take down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.In vivo optical characterization of human prostate tissue using near-infrared time-resolved spectroscopy Tomas Svensson Stefan Andersson-EngelsLund University Department of Physics SE-221 00 Lund Sweden Margrét Einarsdóttír Katarina SvanbergLund University Hospital Department of Oncology SE-221 00 Lund Sweden Abstract. The development of photodynamic therapy into a modality for treatment of prostate cancer calls for reliable optical dosimetry. We employ, for the first time, interstitial time-resolved spectroscopy to determine in vivo optical properties of human prostate tissue. Nine patients are included in the study, and measurements are conducted prior to primary brachytherapy treatment of prostate cancer. Intrasubject variability is examined by measuring across three tissue volumes within each prostate. The time-resolved instrumentation proves its usefulness by producing good signal levels in all measurements. We are able to present consistent values on reduced scattering coefficients ͑ s Ј͒, absorption coefficients ͑ a ͒, and effective attenuation ͑ eff ͒ at the wavelengths 660, 786, and 916 nm. At 660 nm, s Ј is found to be 9±2 cm −1 , and a is 0.5± 0.

Abstract-The possibilities of using laser-induced fluorescence for tissue diagnostics are discussed. The tissue types investigated arc malignant tumors and atherosclerotic lesions. Studies with natural autofluorescence as well as with fluorescent tumor markers are included in this paper. Fluorescence emission and decay data are presented for some tissue chromophores contributing to tissue autofluorescence. Optical spectroscopic characteristics Of fluorescent malignant tumor markers are analyzed and instrumental designs for clinical applications are discussed. Images recorded with a multicolor fluorescence imaging system developed in Lund are presented.

Abstract. The first results from a clinical study for Temoporfinmediated photodynamic therapy ͑PDT͒ of low-grade ͑T1c͒ primary prostate cancer using online dosimetry are presented. Dosimetric feedback in real time was applied, for the first time to our knowledge, in interstitial photodynamic therapy. The dosimetry software IDOSE provided dose plans, including optical fiber positions and light doses based on 3-D tissue models generated from ultrasound images. Tissue optical property measurements were obtained using the same fibers used for light delivery. Measurements were taken before, during, and after the treatment session. On the basis of these real-time measured optical properties, the light-dose plan was recalculated. The aim of the treatment was to ablate the entire prostate while minimizing exposure to surrounding organs. The results indicate that online dosimetry based on real-time tissue optical property measurements enabled the light dose to be adapted and optimized. However, histopathological analysis of tissue biopsies taken six months post-PDT treatment showed there were still residual viable cancer cells present in the prostate tissue sections. The authors propose that the incomplete treatment of the prostate tissue could be due to a too low light threshold dose, which was set to 5 J/cm 2 .

A system for interstitial photodynamic therapy with ␦-aminolaevulinic acid and multiple optical fibers has been developed. The system enables photodynamic treatment of large embedded tumor volumes and utilizes real-time measurements to allow on-line dosimetry. Important parameters such as light fluence rate, sensitizer fluorescence intensity, and changes in local blood oxygen saturation are measured with the same fibers that deliver the therapeutic light. Data from the first clinical treatments on nodular basal cell carcinomas indicate a major treatment-induced light absorption increase, rapid sensitizer photobleaching, and a relatively constant global tissue oxygen saturation level during the treatment.