Hyperthermia induces T1 relaxation and blood flow changes in tumors. A MRI thermometry study in vivo

Peller, Michael; Kurze, Volker; Loeffler, Ralf B.; Pahernik, Sascha; Dellian, Marc; Goetz, Alwin E.; Issels, Rolf D.; Reiser, Maximilian

doi:10.1016/s0730-725x(03)00070-5

Cited by 38 publications

(32 citation statements)

References 33 publications

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“…The T1 relaxation time is a suitable candidate to provide additional information because it indicates the temperature increase in fat and depends less on perfusion (49). As the dependency on perfusion is different for T1 and phases (PFS), both observables together incorporate information about perfusion changes induced by hyperthermia.…”

Section: Discussionmentioning

confidence: 99%

Noninvasive Magnetic Resonance Thermography of Recurrent Rectal Carcinoma in a 1.5 Tesla Hybrid System

Gellermann¹,

Wlodarczyk²,

Hildebrandt³

et al. 2005

Cancer Research

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To implement noninvasive thermometry, we installed a hybrid system consisting of a radiofrequency multiantenna applicator (SIGMA-Eye) for deep hyperthermia (BSD-2000/3D) integrated into the gantry of a 1.5 Tesla magnetic resonance (MR) tomograph Symphony. This system can record MR data during radiofrequency heating and is suitable for application and evaluation of methods for MR thermography. In 15 patients with preirradiated pelvic rectal recurrences, we acquired phase data sets (25 slices) every 10 to 15 minutes over the treatment time (60-90 minutes) using gradient echo sequences (echo time = 20 ms), transformed the phase differences to MR temperatures, and fused the color-coded MR-temperature distributions with anatomic T1-weighted MR data sets. We could generate one complete series of MR data sets per patient with satisfactory quality for further analysis. In fat, muscle, water bolus, prostate, bladder, and tumor, we delineated regions of interest (ROI), used the fat ROI for drift correction by transforming these regions to a phase shift zero, and evaluated the MR-temperature frequency distributions. Mean MR temperatures (T MR ), maximum T MR , full width half maximum (FWHM), and other descriptors of tumors and normal tissues were noninvasively derived and their dependencies outlined. In 8 of 15 patients, direct temperature measurements in reference points were available. We correlated the tumor MR temperatures with direct measurements, clinical response, and tumor features (volume and location), and found reasonable trends and correlations. Therefore, the mean T MR of the tumor might be useful as a variable to evaluate the quality and effectivity of heat treatments, and consequently as optimization variable. Feasibility of noninvasive MR thermography for regional hyperthermia has been shown and should be further investigated. (Cancer Res 2005; 65(13): 5872-80)

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Section: Discussionmentioning

confidence: 99%

Noninvasive Magnetic Resonance Thermography of Recurrent Rectal Carcinoma in a 1.5 Tesla Hybrid System

Gellermann¹,

Wlodarczyk²,

Hildebrandt³

et al. 2005

Cancer Research

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“…From these maps the temperature increase is calculated and optimized using the finite element method (FEM) [4,5]. These calculations are helpful for treatment planning [6], but calculated temperature distributions often differ from measurements because an "ideal applicator" is used in calculations and because of tissue perfusion [7] or change of other tissue parameters with temperature [8]. Thus, a non-invasive 3D temperature monitoring technique is required to assess HT treatment-induced temperature changes.…”

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confidence: 99%

Fast PRF-based MR thermometry using double-echo EPI: in vivo comparison in a clinical hyperthermia setting

Dadakova

Gellermann

Voigt

et al. 2014

Magn Reson Mater Phy

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“…Again, blood flow is affected when heating the tissue. The blood flow rate in hamsters was found to increase rapidly as the tissue temperature is raised from 32 • C to 37 • C, and then it was found to continue to increase at a slower rate as the tissue is heated to 44 • C [3]. Likewise, hemorrhagic coagulation necrosis was shown to occur when prostate tissue is heated above 45 • C, and enhanced results were noted when the intraprostatic temperatures were raised above 50 • C [4].…”

Section: Basic Hyperthermia Treatmentsmentioning

confidence: 95%

Using Microwave Energy to Treat Tumors

Ibrahim¹

2008

PIER B

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Abstract-Recently, hyperthermia has been investigated as an alternate therapy for the treatment of tumors. This paper explored the feasibility of preferential hyperthermia as a method of treating deep seated tumors. The overall goal of this research was to determine theoretically if preferential heating could be used to attain the desired thermal dose (DTD) for a two cm diameter tumor. The simulations in this work show that, when using a single rod insert, the model cannot provide enough energy for an entire 2 cm diameter tumor to receive the DTD. However, when using an enhanced design model with multiple (4) rods inserts, the DTD could be attained in a tumor up to 3.5 cm in diameter. This study involved using the model a spherical 2 cm tumor, assuming the tumor is located in deep tissue with a constant perfusion rate and no major blood vessels nearby. This tumor was placed in the center of a cube of healthy tissue. To achieve the preferential heating of the tumor, a rod insert was placed in the center of the tumor and microwave energy was applied to the insert (in the form of volumetric heating). The thermal modeling of this system was based on the Pennes Bioheat equation with a maximum temperature limitation of 80 • C. Additional enhanced design models were also examined. These models include 2 cm and 4 cm tumors with four rod inserts symmetrically placed about the tumor and a 4 cm tumor model using a single rod insert with antennae attached to insert to increase energy distribution to the tumor. The simulations show that only the enhanced design cases with four rods inserts can achieve the DTD for an entire 2 cm tumor. The main purpose of this research was to determine if a minimally invasive treatment system using one or more rod inserts could be used to preferentially heat (and attain the DTD) a 2 cm diameter (or larger) tumor. Achieving the DTD for a 2 cm or larger tumor was important because currently the maximum diameter tumor that can be treated via hyperthermia is approximately

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Hyperthermia induces T1 relaxation and blood flow changes in tumors. A MRI thermometry study in vivo

Cited by 38 publications

References 33 publications

Noninvasive Magnetic Resonance Thermography of Recurrent Rectal Carcinoma in a 1.5 Tesla Hybrid System

Noninvasive Magnetic Resonance Thermography of Recurrent Rectal Carcinoma in a 1.5 Tesla Hybrid System

Fast PRF-based MR thermometry using double-echo EPI: in vivo comparison in a clinical hyperthermia setting

Using Microwave Energy to Treat Tumors

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