A mathematical model for light dosimetry in photodynamic destruction of human endometrium
| Autor: | Beverly Sansone, Steen J. Madsen, Mathias K. Fehr, Bruce J. Tromberg, Lars O. Svaasand, Yona Tadir, Pius Wyss |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
Pathology
medicine.medical_specialty Hot Temperature Light medicine.medical_treatment Photodynamic therapy Optical power Endometrium Fluence medicine Humans Light Dosimetry Dosimetry Radiology Nuclear Medicine and imaging Irradiation Radiological and Ultrasound Technology Phantoms Imaging business.industry Uterus Dose-Response Relationship Radiation Models Theoretical medicine.anatomical_structure Photochemotherapy Premenopause Female Uterine cavity business Mathematics Biomedical engineering |
| Zdroj: | Physics in Medicine and Biology. 41:223-237 |
| ISSN: | 1361-6560 0031-9155 |
| DOI: | 10.1088/0031-9155/41/2/002 |
| Popis: | We are involved in the development of photodynamic therapy (PDT) as a minimally invasive method for treating dysfunctional uterine bleeding, one of the primary clinical indications for hysterectomy. In this paper, we analyse light propagation through the uterus in order to specify the requirements for a light delivery system capable of effectively performing endometrial PDT. Our approach involves developing an analytical model based on diffusion theory to predict optical fluence rate distributions when cylindrical and spherical optical applicators are placed in the uterine cavity. We apply the results of our model calculations to estimate the thermal effects of optical irradiation and the effective photodynamic optical dose. Theoretical fluence rate calculations are compared to fluence rate measurements made in fresh, surgically removed human uteri. Our results show that a trifurcated cylindrical optical applicator inserted into the human uterus can provide a light dose that is sufficient to cause photodynamic destruction of the entire endometrium. When the optical power per unit length of each cylindrical applicator is 100 mW cm-1 (at 630 nm), a fluence rate of 40 mW cm-2 is delivered to the boundary layer between the endometrium and the myometrium (a depth of about 4-6 mm). The optical fluence delivered to the boundary layer after 20 min of exposure is 50 J cm-2, a level that is generally accepted to cause tissue damage throughout the endometrium in most patients. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|