Objective: To ascertain a clinically meaningful thermal dose unit-temperature equivalent minute (TEM) 42.5 degrees C and the relationship between TEM 42.5 degrees C and tumor response rate.
Methods: From August 1998 to December 2002, 49 patients with recurrent or metastatic malignancies in the pelvis were treated with hyperthermia combined with conventional radiotherapy. Direct thermometry with high resistance lead needle was used whenever possible to measure the temperature by inserting Teflon catheter into the tumor. TEM 42.5 degrees C was used as the thermal dose unit and the relationship between TEM 42.5 degrees C and tumor response rate was monitored.
Results: There was a positive correlation between response rate TEM 42.5 degrees C and the radiation dose. The tumor volume and number of heat treatment showed no influence on response.
Conclusion: Both univariate analysis and multivariate logistic regression analysis indicate that there is a positive correlation between the response rate, TEM 42.5 degrees C and the radiation dose. TEM 42.5 degrees C may act as a useful thermal dose unit in the combination of hyperthermia and radiotherapy. To lower the incidence of complications in thermometry, direct thermometry with high resistance lead needle can be used to measure the temperature by inserting Teflon catheter into the deep-seated malignancies.