Non-ievasive Controlled Radiofrequency Hyperthermia Using an MR Scanner and a Paramagnetic Thulium Complex

摘要

An MR technique has been developed to administer controlled radiofrequency (RF) hyperthermia (HT) to treat sc-implanted tumors using an MR scanner and its components. The method uses the ~1H chemical shift of TmDOTA~- to monitor tumor temeprature non-invasively. The desired HT temeprature is achieved and maintained using a feedback loop mechanism that uses a proportional-derivative (PD) controller. The RF HT techqinue has been able to heat the tumor from 33 to 45 °C in ~ 10 min and was able to mainatain the tumor temeprature within ±0.2 °C of the target temperature. Simultaneous monitoring of the metabolic changes with RF HT using multinuclear MRS techniques showed a significant increase in the [Na_i]~+ as measured by TQF ~(23)Na MRS and a significant decrease in cellular bio-energetics and pH as measured by ~(31)P MRS.