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BACKGROUND & AIMS The first therapeutic experiences with the conventional photosensitizer dihematoporphyrinester in the treatment of Barrett's esophagus show the curative potential of photodynamic therapy (PDT). The aim of this study was to test 5-aminolevulinic acid (5-ALA)-induced protoporphyrin IX, a photosensitizer with a high mucosa specificity without(More)
BACKGROUND AND OBJECTIVE An early detection of oral cancer might improve the patient's prognosis. We present preliminary results of autofluorescence photodetection of cancerous oral mucosa. MATERIALS AND METHODS 49 patients were investigated altogether. In 30 patients, malignant and healthy oral mucosa were excited with violet light (lambda = 375 to 440(More)
BACKGROUND Semiquantitative fluorescence measurements following topical application of 5-aminolevulinic acid (5-ALA) in 16 patients with neoplastic lesions of the oral cavity were performed. METHODS Time course and type of porphyrin accumulation were analyzed in neoplastic and surrounding healthy tissue by measuring emission spectra of 5-ALA-induced(More)
Topical 5-aminolevulinic acid is used for the fluorescence-based diagnosis and photodynamic treatment of superficial precancerous and cancerous lesions of the skin. Thus, we investigated the kinetics of 5-aminolevulinic acid-induced fluorescence and the mechanisms responsible for the selective formation of porphyrins in tumors in vivo. Using amelanotic(More)
Methods have been sought for the in vivo marking of tiny papillary tumors of the bladder and flat urothelial lesions such as dysplasia or carcinoma in situ, which can easily be missed during conventional endoscopy under white light. A new procedure is reported for the fluorescence detection of urothelial dysplasia and early bladder cancer. The method is(More)
Topical application of 5-aminolevulinic acid (5-ALA), with subsequent synthesis of protoporphyrin IX (PPIX), is a novel outstanding procedure for photodynamic treatment. So far, clinical experience has been reported with creams containing 5-ALA for the therapy of skin cancer, oral application for the treatment of gastrointestinal disease and intravesical(More)
We present a method for estimating the 3-D structure of the cortical surface using an operating microscope whose binocular optics are fitted with two CCD cameras. The cortical surface is then tracked over time and the measured displacement can be used to drive FEM-based models for the recovery of subsurface brain deformations. We show the efficacy of this(More)
OBJECT The authors present their experience with coregistration of preoperative imaging data to intraoperative ultrasonography in the resection of high-grade gliomas, focusing on methodology and clinical observation. METHODS Images were obtained preoperatively and coregistered to intraoperative hand-held ultrasound images by merging the respective imaging(More)
The fluorescence and photosensitivity of endogenously synthesized protoporphyrin IX (PPIX) is increasingly used for the diagnosis and treatment of malignant and certain non-malignant diseases. A selective accumulation of PPIX can be induced by application of 5-aminolevulinic acid (5-ALA), which is a precursor of PPIX in the cellular biosynthetic pathway of(More)
Patient registration, a key step in establishing image guidance, has to be performed in real-time after the patient is anesthetized in the operating room (OR) prior to surgery. We propose to use cortical vessels as landmarks for registering the preoperative images to the operating space. To accomplish this, we have attached a video camera to the optics of(More)