Early detection of oral premalignant lesions (OPL) and oral cancers (OC) is critical for improved survival. We evaluated if the addition of autofluorescence visualization (AFV) to conventional white-light examination (WLE) improved the ability to detect OPLs/OCs. Sixty high-risk patients, with suspicious oral lesions or recently diagnosed untreated OPLs/OCs, underwent sequential surveillance with WLE and AFV.
View Article and Find Full Text PDFWith the development of new photosensitizers that are activated by light at longer wavelengths, interstitial photodynamic therapy (PDT) is emerging as a feasible alternative for the treatment of larger volumes of tissue. Described here is the application of PDT treatment planning software developed by our group to ensure complete coverage of larger, geometrically complex target volumes such as the prostate. In a phase II clinical trial of TOOKAD vascular targeted photodynamic therapy (VTP) for prostate cancer in patients who failed prior radiotherapy, the software was used to generate patient-specific treatment prescriptions for the number of treatment fibres, their lengths, their positions and the energy each delivered.
View Article and Find Full Text PDFObjective: To report on the efficacy of TOOKAD (WST 09; NegmaLerads, Magny-Les-Hameaux, France) vascular-targeted photodynamic therapy (VTP) as a method of whole-prostate ablation in patients with recurrent localized prostate cancer after the failure of external beam radiotherapy (EBRT).
Patients And Methods: Patients received a fixed photosensitizer dose of 2 mg/kg and patient-specific light doses as determined by computer-aided treatment planning. Up to six cylindrical light-diffusing delivery fibres were placed transperineally in the prostate under ultrasonographic guidance.
Purpose: Tookad is a novel intravascular photosensitizer. When activated by 763 nm light, it destroys tumors by damaging their blood supply. It then clears rapidly from the circulatory system.
View Article and Find Full Text PDFFuture applications of "molecular diagnostic screening" and "molecular image-guided surgery" will demand images of molecular markers with high resolution and high throughput (~ > or =30 frames/second). MRI, SPECT, PET, optical fluorescence tomography, hyper-spectral fluorescence imaging, and bioluminescence imaging do not offer such high frame rates. 2D optical fluorescence imaging can provide surface images with high resolution and high throughput.
View Article and Find Full Text PDFPhotodiagnosis Photodyn Ther
September 2007
With the advent of molecular-targeted fluorescent markers, there is a renewed interest in fluorescence quantification methods that are based on continuous wave excitation and multi-spectral image acquisition. However, little is known about their in vivo quantification performance. We reviewed the performance of five selected methods by analytically describing these and varying input parameters of irradiance, excitation geometry, collection efficiency, autofluorescence, melanin content, blood volume, blood oxygenation and tissue scattering using optical properties representing those for human skin.
View Article and Find Full Text PDFPurpose: To prospectively evaluate the magnetic resonance (MR) imaging appearance of the prostate and periprostatic tissues after vascular targeted photodynamic therapy (VTP) with palladium-bacteriopheophorbide for locally recurrent carcinoma after external beam radiation therapy.
Materials And Methods: Informed consent was obtained from all patients, and approval was obtained from the ethics review boards of all participating institutions. Nonenhanced T2-weighted and dynamic gadolinium-enhanced T1-weighted MR imaging examinations were performed at baseline and 1 week, 4 weeks, and 6 months after VTP in 25 men (age range, 58-83 years; mean age, 73 years) as part of a prospective phase I/II trial.
Purpose: Modern PDT for urological tumors is a potentially selective approach in which in situ photosensitization by a nontoxic drug, locally activated by light, generates cytotoxic reactive oxygen species, causing cell death. While urological clinical experience with PDT is largely limited to treatment for superficial bladder cancer, the advent of novel photosensitizers and technologies for treatment planning, light delivery and dosimetry, PDT for prostate and other urological cancers appears increasingly realistic.
Materials And Methods: We reviewed the current literature on PDT for urological tumors, in addition to recent emerging data from our laboratory and elsewhere.
This study represents the first reported use of photodynamic therapy (PDT) for metastatic bone lesions and specifically, as a treatment for spinal metastases. A model of bone metastasis in rat confirmed the efficacy of benzoporphyrin derivative-monoacid-mediated PDT for treating lesions within the spine and appendicular bone. Fluorimetry confirmed the selective accumulation of drug into the tumor(s) at 3 h post-injection.
View Article and Find Full Text PDFThe feasibility and efficacy of photodynamic therapy (PDT) for the treatment of vertebral metastases using a minimally invasive surgical technique adapted from vertebroplasty was evaluated in a rodent model. Initial validation included photosensitizer (benzoporphyrin-derivative monoacid-ring A) drug uptake studies and in vitro confirmation of PDT efficacy. Intracardiac injection of human MT-1 breast cancer cells was performed in athymic rats.
View Article and Find Full Text PDFPhotodynamic therapy of solid organs requires sufficient PDT dose throughout the target tissue while minimizing the dose to proximal normal structures. This requires treatment planning for position and power of the multiple delivery channels, complemented by on-line monitoring during treatment of light delivery, drug concentration and oxygen levels. We describe our experience in implementing this approach in Phase I/II clinical trials of the Pd-bacteriophephorbide photosensitizer TOOKAD (WST09)-mediated PDT of recurrent prostate cancer following radiation failure.
View Article and Find Full Text PDFFluorescence-guided resection (FGR) and photodynamic therapy (PDT) have previously been investigated separately with the objectives, respectively, of increasing the extent of brain tumour resection and of selectively destroying residual tumour post-resection. Both techniques have demonstrated trends towards improved survival, pre-clinically and clinically. We hypothesize that combining these techniques will further delay tumour re-growth.
View Article and Find Full Text PDFA mobile isocentric C-arm (Siemens PowerMobil) has been modified in our laboratory to include a large area flat-panel detector (in place of the x-ray image intensifier), providing multi-mode fluoroscopy and cone-beam computed tomography (CT) imaging capability. This platform represents a promising technology for minimally invasive, image-guided surgical procedures where precision in the placement of interventional tools with respect to bony and soft-tissue structures is critical. The image quality and performance in surgical guidance was investigated in pre-clinical evaluation in image-guided spinal surgery.
View Article and Find Full Text PDFBackground And Objectives: Fluorescence image-guided brain tumor resection is thought to assist neurosurgeons by visualizing those tumor margins that merge imperceptibly into normal brain tissue and, hence, are difficult to identify. We compared resection completeness and residual tumor, determined by histopathology, after white light resection (WLR) using an operating microscope versus additional fluorescence guided resection (FGR).
Study Design/materials And Methods: We employed an intracranial VX2 tumor in a preclinical rabbit model and a fluorescence imaging/spectroscopy system, exciting and detecting the fluorescence of protoporphyrin IX (PpIX) induced endogenously by administering 5-aminolevulinic acid (ALA) at 4 hours before surgery.
A phase zero evaluation of a new fluorescence imaging technique for diagnosing cervical intraepithelial neoplasia (CIN) was performed. The fluorescence imaging prototype performed quantitative imaging of Protoporphyrin induced by a topically applied aminolevulinic acid using double ratio (DR) fluorescence imaging technique developed by our group. A total of 38 patients were in the protocol, with 16 colposcopically selected for biopsy.
View Article and Find Full Text PDF