Ambulatory photodynamic therapy of skin cancer

Abstract

s / Photodiagnosis and Photodynamic Therapy 12 (2015) 325–375 331 concentrations. We show that with this additional constraint, the uncertainties of photochemical parameters can be reduced. http://dx.doi.org/10.1016/j.pdpdt.2015.07.028 Ambulatory photodynamic therapy of skin cancer I.D.W. Samuel1, O. Kulyk1, A. McNeill 1, H. Moseley2, J. Ferguson2, S. Ibbotson2 1 Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews KY16 9SS, UK 2 Photobiology Unit, University of Dundee, Ninewells Hospital, Dundee DD1 9SY, UK Photodynamic therapy is an effective treatment for superficial non-melanoma skin cancers and pre-cancers. We report the development of wearable light sources for PDT, and also a camera used to measure the distribution of protoporphyrin IX, and clinical results of the use of these devices. Two factors limiting the widespread use of PDT are the availability of suitable light sources, and pain encountered by patients during treatment. Our work shows that recent advances in optoelectronics including organic light-emitting diodes provide an attractive path to compact wearable light sources, and sensors for medical applications. These light sources can be disposable and could remove the need for prolonged hospital visits for PDT. In addition to enabling convenient ambulatory treatment, they enable treatment to be delivered with lower light intensity for a longer time. Our clinical studies show that this approach leads to effective treatment and furthermore greatly reduces pain. Of 78 patientswith 124 lesions (mainly superficial basal cell carcinoma and Bowen’s disease), the median visual analogue (VAS) pain score for ambulatory PDT was 2 (range 0–9) comparedwith6 (range1–10) forhospital-basedconventional PDT. Seventy-eight patients with 87 lesions have been followed up to one year after treatment and clearance was seen in 79 patients (91%). We will also present results from a camera that quantitatively measures fluorescence from protoporphyrin IX, enabling its formation and distribution to studied. http://dx.doi.org/10.1016/j.pdpdt.2015.07.029 Computerized dosimetry planning for Vascular Targeted Photodynamic therapy with WST-11 for prostate cancer N. Betrouni1, S. Boukris2, B. Gaillac3, A.R. Azzouzi4, F. Benzaghou3 1 INSERM, U1189, Lille University Hospital, France 2 Device Department, Steba Biotech, Paris, France 3 Medical Department, Steba Biotech, Paris, France 4 University Hospital, Angers, France WST11 TOOKAD® Soluble is an intravascular photosensitizer drug administrated to patient in the operating room and activated by light diffusing optical fibers inserted transperineally inside the prostate under ultrasound guidance to target the focus. Phase 3 clinical trials ofWST11 are on-going. A drug dose (4mg/patient kg) wasdefinedasoptimal. It is activatedusingawavelengthof753nm. Light is delivered through cylindrical light diffusers at the rate of 0.15W/cm during 1333 s. The last issue that has to be solved is the determination of the light dose to be applied. It is expressed in term of light diffusers: number, lengths and positions inside the prostate gland. A first solutionwas introduced based on the resolution of the light diffusion equation. In this study,wepropose a novel approach. It presents the advantage of being fast and suitable for clinical conditions.Wehave defined amean actionmodel ofWST11 in prostate tissues by retrospective analysis of previous trials data. The model is applied in an optimization process to determine the light dose. Evaluation of the platform on clinical data showed that prediction of the therapy outcome was possible with an accuracy of 90%. http://dx.doi.org/10.1016/j.pdpdt.2015.07.030 Micro-vascular effects of photodynamic therapy in tumors evaluated with dynamic contrast-enhanced MRI Tom Schreurs, Gustav Strijkers, Holger Grull, Klaas Nicolay Biomedical Engineering Department, Eindhoven University of Technology, The Netherlands Tumor heterogeneity and complex dosimetry make prediction of PDT outcome challenging. Therefore, the aim of this studywas to use dynamic contrast-enhanced (DCE-)MRI for early monitoring of treatment efficacy. Mice with subcutaneous CT26 tumors received the photosensitizer Bremachlorin intravenously, activated 6h later by 655nm light. DCE-MRI, using Gd-DOTA, was performed before, 3h, and 24h after treatment. Tumor contrast enhancement and derived perfusion/permeability parameter Ktrans were spatially compared to histologically determined tissue viability. Viability staining showed that control tumors were largely viable. Treated tumors were mostly viable after 3h, but largely non-viable after 24h. DCE-MRI revealed that the average non-enhanced tumor fraction increased from 3.2% before PDT, to 24% after 3h, and 77% after 24h. The average Ktrans decreased from 0.25 to 0.09min−1 right after PDT. DCE-MRI could be used to visualize reduction in perfusion 3h after PDT, and nearly complete vascular shutdown after 24h. These effects could not be correlated to tumor viability yet, due to the lack of heterogeneity in the viability results. Additional experiments will be performed with milder treatment, to obtain more dispersion in viability. Previous results did suggest spatial correlation between remaining Gd-DOTA uptake after 24h, and tumor recurrence after multiple days. http://dx.doi.org/10.1016/j.pdpdt.2015.07.031 Performance characterization of a low-cost spatial frequency domain imaging system for the determination of optical properties in tissue-simulating phantoms and in vivo Arash Darafsheh, Emily A. Kraus, Michele M. Kim, Timothy C. Zhu, Jarod C. Finlay Department of Radiation Oncology, University of