Blood flow in human tumors during local hyperthermia
| Autor: | Frank M. Waterman, Leslie Tupchong, James Matthews, Rudolph E. Nerlinger |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Hyperthermia
Cancer Research Lung Neoplasms Coefficient of variation Breast Neoplasms Adenocarcinoma Tumor temperature Neoplasms Humans Medicine Radiology Nuclear Medicine and imaging Melanoma Radiation business.industry Bioheat equation Hyperthermia Induced Blood flow Thermal conduction medicine.disease Oncology Flow (mathematics) Head and Neck Neoplasms Local Hyperthermia Anesthesia Carcinoma Squamous Cell business Blood Flow Velocity Biomedical engineering |
| Zdroj: | International Journal of Radiation Oncology*Biology*Physics. 20:1255-1262 |
| ISSN: | 0360-3016 |
| DOI: | 10.1016/0360-3016(91)90236-w |
| Popis: | The response of tumor blood flow during local hyperthermia was studied at 40 different points in 15 superficial human tumors. Hyperthermia was administered for 60 minutes by use of 915 MHz microwaves. Blood flow was determined from the rate of thermal clearance by use of the bioheat equation. The rate of thermal clearance was sampled at 10-15 minutes intervals by turning the applied power off for 30 seconds. A correction was made for thermal conduction from orthogonal profiles of the tumor temperature. No measurements were made during the first 10-15 minutes of heating. The response of tumor blood flow was found to be independent of temperature in the range of 40-44 degrees C. The mean blood flow rate increased 10-15% between 15 and 30 minutes, but remained nearly constant thereafter. The coefficient of variation in this pattern is 15-20%. No evidence of a sharp reduction in flow was observed. Furthermore, the mean temperature elevation, net forward power, and rate of thermal conduction all remained nearly constant with time, providing further evidence of stability in the blood flow rate. Data obtained in one tumor suggest that a reduction in flow may occur at temperatures above 44 degrees C. The mean blood flow rates obtained in this study range from 0-34 ml/100g/min with an average value of 15 ml/100g/min. |
| Databáze: | OpenAIRE |
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