@Article{RSM:Car98,
  author =       "D. L. Carter and J. R. MacFall and S. T. Clegg and X.
                 Wan and D. M. Prescott and H. C. Charles and T. V.
                 Samulski",
  title =        "Magnetic resonance thermometry during hyperthermia for
                 human high-grade sarcoma",
  journal =      "Int J Radiat Oncol Biol Phys",
  volume =       "40",
  number =       "4",
  pages =        "815--822",
  abstract =     "PURPOSE: To determine the feasibility of measuring
                 temperature noninvasively with magnetic resonance
                 imaging during hyperthermia treatment of human tumors.
                 METHODS: The proton chemical shift detected using
                 phase-difference magnetic resonance imaging (MRI) was
                 used to measure temperature in phantoms and human
                 tumors during treatment with hyperthermia. Four adult
                 patients having high-grade primary sarcoma tumors of
                 the lower leg received 5 hyperthermia treatments in the
                 MR scanner using an MRI-compatible radiofrequency
                 heating applicator. Prior to each treatment, an average
                 of 3 fiberoptic temperature probes were invasively
                 placed into the tumor (or phantom). Hyperthermia was
                 applied concurrent with MR thermometry. Following
                 completion of the treatment, regions of interest (ROI)
                 were defined on MR phase images at each temperature
                 probe location, in bone marrow, and in gel standards
                 placed outside the heated region. The median phase
                 difference (compared to pretreatment baseline images)
                 was calculated for each ROI. This phase difference was
                 corrected for phase drift observed in standards and
                 bone marrow. The observed phase difference, with and
                 without corrections, was correlated with the fiberoptic
                 temperature measurements. RESULTS: The phase difference
                 observed with MRI was found to correlate with
                 temperature. Phantom measurements demonstrated a linear
                 regression coefficient of 4.70 degrees phase difference
                 per degree Celsius, with an R2 = 0.998. After human
                 images with artifact were excluded, the linear
                 regression demonstrated a correlation coefficient of
                 5.5 degrees phase difference per degree Celsius, with
                 an R2 = 0.84. In both phantom and human treatments,
                 temperature measured via corrected phase difference
                 closely tracked measurements obtained with fiberoptic
                 probes during the hyperthermia treatments. CONCLUSIONS:
                 Proton chemical shift imaging with current MRI and
                 hyperthermia technology can be used to monitor and
                 control temperature during treatment of large tumors in
                 the distal lower extremity.",
  keywords =     "Adult Feasibility Studies Heat Humans *Hyperthermia,
                 Induced *Magnetic Resonance Imaging Models, Anatomic
                 Sarcoma/*therapy",
  year =         "1998",
}