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European Radiology

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01.08.2013 | Magnetic Resonance

CEM43°C thermal dose thresholds: a potential guide for magnetic resonance radiofrequency exposure levels?

verfasst von: Gerard C. van Rhoon, Theodoros Samaras, Pavel S. Yarmolenko, Mark W. Dewhirst, Esra Neufeld, Niels Kuster

Erschienen in: European Radiology | Ausgabe 8/2013

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Abstract

Objective

To define thresholds of safe local temperature increases for MR equipment that exposes patients to radiofrequency fields of high intensities for long duration. These MR systems induce heterogeneous energy absorption patterns inside the body and can create localised hotspots with a risk of overheating.

Methods

The MRI + EUREKA research consortium organised a “Thermal Workshop on RF Hotspots”. The available literature on thresholds for thermal damage and the validity of the thermal dose (TD) model were discussed.

Results/Conclusions

The following global TD threshold guidelines for safe use of MR are proposed:

All persons: maximum local temperature of any tissue limited to 39 °C

Persons with compromised thermoregulation AND

(a)

Uncontrolled conditions: maximum local temperature limited to 39 °C

(b)

Controlled conditions: TD < 2 CEM43°C

Persons with uncompromised thermoregulation AND

(a)

Uncontrolled conditions: TD < 2 CEM43°C

(b)

Controlled conditions: TD < 9 CEM43°C

The following definitions are applied:

Controlled conditions

A medical doctor or a dedicated trained person can respond instantly to heat-induced physiological stress

Compromised thermoregulation

All persons with impaired systemic or reduced local thermoregulation

Key Points

• Standard MRI can cause local heating by radiofrequency absorption.

• Monitoring thermal dose (in units of CEM43°C) can control risk during MRI.

• 9 CEM43°C seems an acceptable thermal dose threshold for most patients.

• For skin, muscle, fat and bone,16 CEM43°C is likely acceptable.

Nur mit Berechtigung zugänglich

This workshop was co-sponsored by the Mobile Manufacturers Forum, the GSM Association, and the US Food and Drug Administration. A selection of the presentations are published in the Special Issue entitled “Thermal Aspects of Radio Frequency Exposure on Human Health”; Int. J. Hyperthermia; 4, 2011. Guest Editor: Joseph Morrissey.

Dewhirst MW, Vujaskovic Z, Jones E, Thrall D (2005) Re-setting the biologic rationale for thermal therapy. Rev Int J Hyperthermia 21:779–790CrossRef

Horsman MR, Overgaard J (2007) Hyperthermia: a potent enhancer of radiotherapy. Clin Oncol 19:418–426CrossRef

Ryan TP, Turner PF, Hamilton B (2010) Interstitial microwave transition form hyperthermia to ablation: historical perspectives and current trends in thermal therapy. Int J Hyperthermia 26:415–433PubMedCrossRef

Rempp H, Hoffmann R, Roland J, Buck A, Kickhefel A, Claussen CD, Pereira PL, Schick F, Clasen S (2012) Threshold-based prediction of the coagulation zone in sequential temperature mapping in MR-guided radiofrequency ablation of liver tumours. Eur Radiol 22:1091–1100PubMedCrossRef

Terraz S, Cernicanu A, Lepetit-Coiffé M, Viallon M, Salomir R, Mentha G, Becker CD (2010) Radiofrequency ablation of small liver malignancies under magnetic resonance guidance: progress in targeting and preliminary observations with temperature monitoring. Eur Radiol 20:886–897PubMedCrossRef

Lepetit-Coiffé M, Laumonier H, Seror O, Quesson B, Sesay MB, Moonen CT, Grenier N, Trillaud H (2010) Real-time monitoring of radiofrequency ablation of liver tumors using thermal-dose calculation by MR temperature imaging: initial results in nine patients, including follow-up. Eur Radiol 20:193–201PubMedCrossRef

Qian GJ, Wang N, Shen Q, Sheng YH, Zhao JQ, Kuang M, Liu GJ, Wu MC (2012) Efficacy of microwave versus radiofrequency ablation for treatment of small hepatocellular carcinoma: experimental and clinical studies. Eur Radiol 22:1983–1990PubMedCrossRef

Marshall J, Martin T, Downie J, Malisza K (2007) A comprehensive analysis of MRI research risks: in support of full disclosure. Can J Neurol Sci 34:11–17PubMed

International Electrotechnical Commission (2010) IEC 60601-2-33: medical electrical equipment—particular requirements for the basic safety and essential performanceof magnetic resonance equipment for medical diagnosis. IEC, Geneva

10.

Murbach M, Cabot E, Neufeld E, Gosselin MC, Christ A, Kuster N (2011) Local SAR enhancements in anatomically correct children and adult models as a function of position within 1.5 T MR body coil. Prog Biophys Mol Biol 3:428–433CrossRef

11.

Nadobny J, Szimtenings M, Diehl D, Stetter E, Brinker G, Wust P (2007) Evaluation of MR-induced hot spots for different temporal SAR modes using a time-dependent temperature gradient treatment. IEEE Trans Biomed Eng 54:1837–1850PubMedCrossRef

12.

Neufeld E, Gosselin MC, Murbach M, Christ A, Cabot E, Kuster N (2011) Analysis of the local worst-case SAR exposure caused by an MRI multi-transmit body coil in anatomical models of the human body. Phys Med Biol 56:4649–4659PubMedCrossRef

13.

Sapareto SA, Dewey WC (1984) Thermal dose determination in cancer therapy. Int J Radiat Oncol Biol Phys 10:787–800PubMedCrossRef

14.

Dewhirst MW, Viglianti BL, Lora-Michiels M, Hanson M, Hoopes PJ (2003) Basic principles of thermal dosimetry and thermal thresholds for tissue damage from hyperthermia. Int J Hyperthermia 19:267–294PubMedCrossRef

15.

Yarmolenko PS, Moon EJ, Landon C, Manzoor A, Hochman DW, Viglianti BL, Dewhirst MW (2011) Thresholds for thermal damage to normal tissues: An update. Int J Hyperthermia 26:1–26

16.

Dewey WC (1994) Arrhenius relationships from the molecule and cell to the clinic. Int J Hyperthermia 10:457–483PubMedCrossRef

17.

Hall EJ, Roizin-Towle L (1984) Biological effects of heat. Cancer Res 44:4708s–4713sPubMed

18.

Field SB, Morris CC (1983) The relationship between heating time and temperature: its relevance to clinical hyperthermia. Radiother Oncol 1:179–186PubMedCrossRef

19.

Ichinoseki-Sekine N, Naito H, Saga N, Ogura Y, Shiraishi M, Giombini A, Giovannini V, Katamoto S (2007) Changes in muscle temperature induced by 434 MHz microwave hyperthermia. Br J Sports Med 41:425–429PubMedCrossRef

20.

Beachy SH, Repasky EA (2011) Toward establishment of temperature thresholds for immunological impact of heat exposure in humans. Int J Hyperthermia 27:344–352PubMedCrossRef

21.

Wetsel WC (2011) Hyperthermic effects on behavior. Int J Hyperthermia 27:353–373PubMedCrossRef

22.

Ziskin MC, Morrissey J (2011) Thermal thresholds for teratogenicity, reproduction, and development. Int J Hyperthermia 27:374–387PubMedCrossRef

23.

Wetsel WC (2011) Sensing hot and cold with TRP channels. Int J Hyperthermia 27:388–398PubMedCrossRef

24.

van Rhoon GC, Aleman A, Kelfkens G et al (2011) The Electromagnetic Fields Committee of the Health Council of the Netherlands Health Council of the Netherlands: no need to change from SAR to time-temperature relation in electromagnetic fields exposure limits. Int J Hyperthermia 27:399–404PubMedCrossRef

25.

Foster KR, Morrissey JJ (2011) Thermal aspects of exposure to radiofrequency energy: report of a workshop. Int J Hyperthermia 27:307–319PubMedCrossRef

26.

Hoopes P, Wishnow K, Bartholomew L et al (2000) Evaluation and comparison of five experimental BPH/prostate cancer treatment modalities. In: A critical review: matching the energy source to the clinical need, CR 75. SPIE Opt Eng Press, Bellingham, Washington, p 519–545

27.

Moritz A, Henriques F (1947) Studies of thermal injury II. The relative importance of time and surface temperature in the causation of thermal burns. Am J Pathol 23:695–720PubMed

28.

Harris A, Erickson L, Kendig J, Mingrino S, Goldring S (1962) Observations on selective brain heating in dogs. J Neurosurg 19:514–521PubMedCrossRef

29.

Prionas SD, Taylor MA, Fajardo LF, Kelly NI, Nelsen TS, Hahn GM (1985) Thermal sensitivity to single and double heat treatments in normal canine liver. Cancer Res 45:4791–4797PubMed

30.

Guy A, Lin J, Kramar P, Emery A (1975) Effect of 2450-MHz radiation on the rabbit eye. IEEE Trans Microw Theory Tech 23:492–498CrossRef

31.

Marigold JC, Hume SP, Hand JW (1985) Investigation of thermotolerance in mouse testis. Int J Radiat Biol Relat Stud Phys Chem Med 48:589–595PubMedCrossRef

32.

Hand JW, Li Y, Hajnal JV (2010) Numerical study of RF exposure and the resulting temperature rise in the foetus during a magnetic resonance procedure. Phys Med Biol 55:913–930PubMedCrossRef

33.

Asakura H (2004) Fetal and neonatal thermoregulation. J Nippon Med Sch 71:360–370PubMedCrossRef

34.

Miller MW, Nyborg WL, Dewey WC, Edwards MJ, Abramowicz JS, Brayman AA (2002) Hyperthermic teratogenicity, thermal dose and diagnostic ultrasound during pregnancy: implications of new standards on tissue heating. Int J Hyperthermia 18:361–384PubMedCrossRef

35.

Heynick LN, Merritt JH (2003) Radiofrequency fields and teratogenesis. Bioelectromagnetics S6:s174–s186CrossRef

36.

Nomoto S, Shibata M, Iriki M, Riedel W (2004) Role of afferent pathways of heat and cold in body temperature regulation. Int J Biometeorol 49:67–85PubMedCrossRef

37.

Yang M, Christoforidis G, Abdujali A, Beversdorf D (2006) Vital signs investigation in subjects undergoing MR imaging at 8T. Am J Neuroradiol 27:922–928PubMed

38.

Bernardi P, Cavagnaro M, Pisa S, Piuzzi E (2003) Specific absorption rate and temperature elevation in a subject exposed in the far-field of radio-frequency sources operating in the 10–900-MHz range. IEEE Trans Biomed Eng 50:295–304PubMedCrossRef

39.

Hirata A, Asano T, Fujiwara O (2008) FDTD analysis of body-core temperature elevation in children and adults for whole-body exposure. Phys Med Biol 53:5223–5238PubMedCrossRef

40.

Bakker JF, Paulides MM, Neufeld E, Christ A, Kuster N, van Rhoon GC (2011) Children and adults exposed to electromagnetic fields at the ICNIRP reference levels: theoretical assessment of the induced peak temperature increase. Phys Med Biol 56:4967–4989PubMedCrossRef

41.

Van der Wal E, Franckena M, Wielheesen DHM, van der Zee J, van Rhoon GC (2008) Steering in locoregional deep hyperthermia: evaluation of common practice with 3D-planning. Int J Hyperthermia 24:682–693PubMedCrossRef

42.

Kiyatkin EA, Sharma HS (2009) Permeability of the blood–brain barrier depends on brain temperature. Neuroscience 161:926–939PubMedCrossRef

43.

Kiyatkin EA (2005) Brain hyperthermia as physiological and pathological phenomena. Brain Res Rev 50:27–56PubMedCrossRef

44.

Versteegh PMR (1980) Gegeneraliseerde Hyperthermie, een klinische methode. PhD thesis. Leiden University, 19 June 1980

45.

Van Rhoon GC, van der Zee J (1983) Cerebral temperature and epidural pressure during whole body hyperthermia in dogs. Res Exp Med 183:47–54CrossRef

46.

Main PW, Lovell ME (1996) A review of seven support surfaces with emphasis on their protection of the spinally injured. J Accid Emerg Med 13:34–37PubMedCrossRef

47.

Suzuki T, Hirayama T, Aihara K, Hirohata Y (1991) Experimental studies of moderate temperature burns. Burns 17:443–451PubMedCrossRef

48.

Greenhalgh DG, Lawless MB, Chew BB, Crone WA, Fein ME, Palmieri TL (2004) Temperature threshold for burn injury: an oximeter safety study. J Burn Care Rehabil 25:411–415PubMedCrossRef

49.

Werner MU, Lassen B, Pedersen JL, Kehlet H (2002) Local cooling does not prevent hyperalgesia following burn injury in humans. Pain 98:297–303PubMedCrossRef

50.

Franco W, Kothare A, Ronan SJ, Grekin RC, McCalmont TH (2010) Hyperthermic injury to adipocyte cells by selective heating of subcutaneous fat with a novel radiofrequency device: feasibility studies. Lasers Surg Med 42:361–370PubMedCrossRef

51.

Martinez AA, Meshorer A, Meyer JL, Hahn GM, Fajardo LF, Prionas SD (1983) Thermal sensitivity and thermotolerance in normal porcine tissues. Cancer Res 43:2072–2075PubMed

52.

Eriksson AR, Albrektsson T (1983) Temperature threshold levels for heat-induced bone tissue injury: a vital-microscopic study in the rabbit. J Prosthetic Dentistry 50:101–107CrossRef

53.

Graesslin I, Homann H, Biederer S, Börnert P, Nehrke K, Vernickel P, Mens G, Harvey P, Katscher U (2012) A specific absorption rate prediction concept for parallel transmission MR. Magn Reson Med 68:1664–1674PubMedCrossRef

54.

Wolf S, Diehl D, Gebhardt M, Mallow J, Speck O (2012) SAR simulations for high-field MRI: How much detail, effort, and accuracy is needed? Magn Reson Med. doi:10.1002/mrm.24329

55.

Fowlkes JB, Abramowicz JS, Jacques S et al (2008) American Institute of Ultrasound in Medicine consensus report on potential bioeffects of diagnostic ultrasound. J Ultrasound Med 27:503–515PubMed

56.

O’Brien WD Jr, Deng CX, Harris GR et al (2008) The risk of exposure to diagnostic ultrasound in postnatal subjects: thermal effects. J Ultrasound Med 27:517–535PubMed

Titel: CEM43°C thermal dose thresholds: a potential guide for magnetic resonance radiofrequency exposure levels?
verfasst von: Gerard C. van Rhoon
Theodoros Samaras
Pavel S. Yarmolenko
Mark W. Dewhirst
Esra Neufeld
Niels Kuster
Publikationsdatum: 01.08.2013
Verlag: Springer Berlin Heidelberg
Erschienen in: European Radiology / Ausgabe 8/2013
Print ISSN: 0938-7994
Elektronische ISSN: 1432-1084
DOI: https://doi.org/10.1007/s00330-013-2825-y

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CEM43°C thermal dose thresholds: a potential guide for magnetic resonance radiofrequency exposure levels?