Thresholds of thermal damage
26-28 May 2015
Istanbul, Turkey
A workshop report was drafted by an ICNIRP Task Group and published in Health Physics 111(3):300-306; 2016.
Scope
In view of updating the guidance on limiting exposure to high frequency (HF) fields, ICNIRP reviewed the current scientific knowledge on the thresholds of thermal damage. The current workshop revisited the ICNIRP 1998 concept, namely that the health relevant increase of body core temperature is approximately 1° C and a whole-body exposure with an average SAR of 4 W/kg result in a core temperature increase of less than 1°C within 30 min. Details of this concept as well as thresholds for partial/local body exposures are subjects to review.
Amongst others, the following topics and questions were addressed:
Definition/Specification of the threshold for thermal damage:
a) with respect to - the whole body, - parts of the body (limbs, trunk, head), - different organs (i.e. brain, eye, testis, skin etc.) - different tissues (muscle, fat, nerve, connective tissue) b) regarding frequency dependence
c) with respect to external conditions (cold and hot environment, humidity, clothing)
d) with respect to internal/individual conditions (interindividual variations, age-dependence, health status, metabolic status, medication, compromised thermoregulation, pregnancy,… )
Definition/Specification of the health relevant quantity (SAR, power flux density, temperature, thermal dose/CEM43°C, Arrhenius thermal dose rate)
Is our thermoregulation (evolved to respond to physical work and hot environments) effective in responding to local (internal) HF-induced heating?
Is the averaging time of 6 min and the averaging mass of 10g of contiguous tissue appropriate?
Has exposure duration to be taken into account (even at low exposure levels)?
Program
26 May 201513.30
Welcome
Rüdiger Matthes, ICNIRP
Emilie van Deventer, WHO
Assoc. Prof. Murat Gültekin, Director, Cancer Control Department, Public Health Institute, Turkish Ministry of Health
Prof. Dr. Tunaya Kalkan Istanbul Cerrahpasa University, Biophysics Department
Session 1: From thermosensation to thermoregulation - Chair: Eric van Rongen
14.00
Andreas Flouris, FAME Laboratory, School of Exercise Science, University of Thessaly, Greece
in collaboration with Glen P. Kenny, School of Human Kinetics, University of Ottawa
Thermoregulation: functional architecture of the thermoregulatory system
14.30
Thomas Voets, University of Leuven, Belgium
Thermosensation - Ion channels as molecular thermosensors (and the impact on HF heating)
15.00
Break and refreshments
15.30
Heidi Danker-Hopfe, Charité, Berlin, Germany
Thermoregulation, sleep and ageing
16.00-17.00
Discussion
27 May 2015
Session 2: Thermal sensitivities - Chair Rodney Croft
09.00
Eugene A. Kiyatkin, NIDAIRP Baltimore, US
On the temperature sensitivity of the brain
09.30
Andreas Flouris, FAME Laboratory, School of Exercise Science, University of Thessaly, Greece
Heat load limitations under normal and stress conditions
10.00
Pavel Yarmolenko, The Sheikh Zayed Institute for Pediatric Surgical Innovation, Washington, US
Thresholds for thermal damage of different tissues; thermal dose models
10.30
Break and refreshments
11.00
Masami Kojima, Kanazawa Medical University, Japan
Ocular thermal injury
11.30
Roger Mieusset, CHU Toulouse, France
Genital heat stress and semen quality
12.00-13.00
Discussion
13.00
Lunch
Session 3: Thermal effects due to HF exposure, HF dosimetry - Chair: James C. Lin
14.00
Ken Foster, University of Pennsylvania, Philadelphia, US
(Thermal) mechanisms of interaction between HF and biological systems
14.30
Akimasa Hirata, Nagoya Insitute of Technology, Japan
Computational age dependence of heating, heating of the eye, relationship between SAR and temperature, thermal model for pregnant woman (ambient heat versus HF)
15.00
Marvin Ziskin, Temple University Medical School, Philadelphia, US
Frequency dependence of heating, thermal threshold for teratogenicity, reproduction and development, mm-wave exposure of the skin
15.30
Break and refreshments
16.00
Christopher M Collins, New York University School of Medicine, US
RF pulse sequence and temperature elevation
16.30-17.30
Discussion
Evening
Workshop Dinner - Sinan Bey Boat ride
28 May 2015
Session 4: Lessons learned from medical applications - Chair: Zenon Sienkiewicz
09.00
Gerard van Rhoon, Erasmus MC Cancer Institute, Rotterdam, Netherlands
Mild hyperthermia in cancer therapy
09.30
Elizabeth Repasky, Roswell Park Cancer Institute, Buffalo, US
The role of temperature in cancer immunology
10.00
Theodoros Samaras, Aristotle University of Thessaloniki, Greece
CEM43°C thermal dose thresholds for MRI
10.30
Break and refreshments
11.00
IEC MT40 Working group
Manuel Murbach, IT´IS, ETH Zurich, Switzerland
Tissue heating during MR examination as function of RF exposure and local thermoregulation, consequences for the MR safety standard IEC 60601-2-33
Johan van den Brink, Philips Healthcare, Best, Netherlands
Evaluation of estimated CEM43 values attained for realistic use cases under (local) SAR constraints imposed by IEC60601-2-33
11.30
Earl Zastrow/Niels Kuster, IT'IS, Zurich, Switzerland
Temperature rise due to medical implants
12.00-13.30
Panel Chair: Bernard Veyret
Panel discussion on topics above, including
How well does the SAR reflect the health relevant thermal threshold?
How conservative is the reduction factor of 50 in view of the data set presented?
Reduction factors – as issued by ICNIRP - reflect a safety margin to thermal damage and consider scientific uncertainties like interindividual variability, but are per se not considered as precautionary measures.
Genital heat stress and semen quality
12.00-13.00
Discussion
13.00
Lunch
Session 3: Thermal effects due to HF exposure, HF dosimetry - Chair: James C. Lin
14.00
Ken Foster, University of Pennsylvania, Philadelphia, US
(Thermal) mechanisms of interaction between HF and biological systems
14.30
Akimasa Hirata, Nagoya Insitute of Technology, Japan
Computational age dependence of heating, heating of the eye, relationship between SAR and temperature, thermal model for pregnant woman (ambient heat versus HF)
15.00
Marvin Ziskin, Temple University Medical School, Philadelphia, US
Frequency dependence of heating, thermal threshold for teratogenicity, reproduction and development, mm-wave exposure of the skin
15.30
Break and refreshments
16.00
Christopher M Collins, New York University School of Medicine, US
RF pulse sequence and temperature elevation
16.30-17.30
Discussion
Evening
Workshop Dinner - Sinan Bey Boat ride
28 May 2015
Session 4: Lessons learned from medical applications - Chair: Zenon Sienkiewicz
09.00
Gerard van Rhoon, Erasmus MC Cancer Institute, Rotterdam, Netherlands
Mild hyperthermia in cancer therapy
09.30
Elizabeth Repasky, Roswell Park Cancer Institute, Buffalo, US
The role of temperature in cancer immunology
10.00
Theodoros Samaras, Aristotle University of Thessaloniki, Greece
CEM43°C thermal dose thresholds for MRI
10.30
Break and refreshments
11.00
IEC MT40 Working group
Manuel Murbach, IT´IS, ETH Zurich, Switzerland
Tissue heating during MR examination as function of RF exposure and local thermoregulation, consequences for the MR safety standard IEC 60601-2-33
Johan van den Brink, Philips Healthcare, Best, Netherlands
Evaluation of estimated CEM43 values attained for realistic use cases under (local) SAR constraints imposed by IEC60601-2-33
11.30
Earl Zastrow/Niels Kuster, IT'IS, Zurich, Switzerland
Temperature rise due to medical implants
12.00-13.30
Panel Chair: Bernard Veyret
Panel discussion on topics above, including
How well does the SAR reflect the health relevant thermal threshold?
How conservative is the reduction factor of 50 in view of the data set presented?
Reduction factors – as issued by ICNIRP - reflect a safety margin to thermal damage and consider scientific uncertainties like interindividual variability, but are per se not considered as precautionary measures.
VENUE
The workshop will be held at the Nippon Hotel, a centrally located venue in the Taksim square area in Istanbul.
Venue: Nippon Hotel
www.nipponhotel.com.tr
Address:
Topçu Caddesi No: 6
34437 Taksim - Istanbul
More information related to booking your room there and rates will be available shortly.
How to get there?
Atatürk Airport transfer
1. Havatas Bus
Line: Atatürk Airport - Sahil Yolu - Aksaray - Taksim and return
Stops
International Terminal: follow the bus signs in the terminal.
Taksim: The bus stop is situated in front of the Point Hotel across Divan Hotel. A few minutes walk away from the Workshop venue, the Nippon Hotel
Schedule
At the International Terminal every 30 min, five minutes before the hour and the half hour - from 3.55 till 12.55.
At Taksim: every 30 min on the hour and half hour
Duration: approx. 45 min to 75 min depending on traffic
Costs: 11 TRY (one way)
http://www.havatas.com/yolcuservisi/taksim-ataturkhavalimani.aspx
2. IETT Public Bus
Lines: 96T ATATÜRK AİRPORT - TAKSİM and TH-1 TAKSİM - ATATÜRK AİRPORT
Schedule: run from 6am until midnight
Duration: approx. 1 hr to 1,5 hr depending on traffic
Cost for 2 rides: 6 TRL. Ticket or Istanbul Kart must be purchased beforehand.
http://www.iett.gov.tr/en/main/pages/access-to-airports/798
3. by taxi or hotel shutlle
Duration: between 35 and 65 minutes depending on traffic
Costs from the airport to Taksim Square, Nippon Hotel: approx. 25€
For 40 EUR a shuttle will bring you to the Nippon Hotel. Please email the hotel to make your shuttle reservation at : rezervasyon@nipponhotel.com.tr or resepsiyon@nipponhotel.com.tr.
Sabiha Gokcen International Airport transfer
1. Havatas Bus
Lines
Sabiha Gökçen Airport - Kavacık-FSM Bridge - 1.Levent-Zincirlikuyu Metrobus - Dolapdere - Taksim
Taksim - Beşiktaş - Bosphorus Bridge - Tem Access Road - Sabiha Gökçen Airport (return)
Stops
Airport terminal: follow the bus signs
Taksim: The bus stop is situated in front of the Point Hotel across Divan Hotel. A few minutes walk away from the Workshop venue, the Nippon Hotel
Schedule
At Terminal: every 30 minutes on the hour between 4.00am and 01:00am
At Taksim: every 30 minutes on the half hour between 3.30am and 01:00am
Duration: approx 80 to 110 minutes depending on traffic
Costs: 14 TRY (one way)
http://www.havatas.com/yolcuservisi/taksim-sabihagokcenhavalimani.aspx
2. IETT Public Bus
Lines: Bus E-3 travel between Sabiha Gokcen International Airport and 4.Levent Subway Station
Duration: approx 100 to 120 minutes depending on traffic
Costs: approx 2.5 €. Ticket or Istanbul Kart must be purchased beforehand.
3. by taxi:
Costs from the airport to the Taksim Square costs around 50 €
Duration: between 50 and 90 minutes depending on traffic
Getting around in Istanbul
For general information, see http://www.turkeytravelplanner.com/go/Istanbul/Transport/
If you are going to travel around the city intensively using buses, metros, ferries, funiculars, and tramways, the Istanbul Kart is a good offer. Read more here.
Metro and Tram
http://www.istanbul-ulasim.com.tr/passenger-services/network-maps.aspx
Ferrys
http://www.sehirhatlari.com.tr/en
Bus
http://www.iett.gov.tr/en
The workshop will be held at the Nippon Hotel, a centrally located venue in the Taksim square area in Istanbul.
Venue: Nippon Hotel
www.nipponhotel.com.tr
Address:
Topçu Caddesi No: 6
34437 Taksim - Istanbul
More information related to booking your room there and rates will be available shortly.
How to get there?
Atatürk Airport transfer
1. Havatas Bus
Line: Atatürk Airport - Sahil Yolu - Aksaray - Taksim and return
Stops
International Terminal: follow the bus signs in the terminal.
Taksim: The bus stop is situated in front of the Point Hotel across Divan Hotel. A few minutes walk away from the Workshop venue, the Nippon Hotel
Schedule
At the International Terminal every 30 min, five minutes before the hour and the half hour - from 3.55 till 12.55.
At Taksim: every 30 min on the hour and half hour
Duration: approx. 45 min to 75 min depending on traffic
Costs: 11 TRY (one way)
http://www.havatas.com/yolcuservisi/taksim-ataturkhavalimani.aspx
2. IETT Public Bus
Lines: 96T ATATÜRK AİRPORT - TAKSİM and TH-1 TAKSİM - ATATÜRK AİRPORT
Schedule: run from 6am until midnight
Duration: approx. 1 hr to 1,5 hr depending on traffic
Cost for 2 rides: 6 TRL. Ticket or Istanbul Kart must be purchased beforehand.
http://www.iett.gov.tr/en/main/pages/access-to-airports/798
3. by taxi or hotel shutlle
Duration: between 35 and 65 minutes depending on traffic
Costs from the airport to Taksim Square, Nippon Hotel: approx. 25€
For 40 EUR a shuttle will bring you to the Nippon Hotel. Please email the hotel to make your shuttle reservation at : rezervasyon@nipponhotel.com.tr or resepsiyon@nipponhotel.com.tr.
Sabiha Gokcen International Airport transfer
1. Havatas Bus
Lines
Sabiha Gökçen Airport - Kavacık-FSM Bridge - 1.Levent-Zincirlikuyu Metrobus - Dolapdere - Taksim
Taksim - Beşiktaş - Bosphorus Bridge - Tem Access Road - Sabiha Gökçen Airport (return)
Stops
Airport terminal: follow the bus signs
Taksim: The bus stop is situated in front of the Point Hotel across Divan Hotel. A few minutes walk away from the Workshop venue, the Nippon Hotel
Schedule
At Terminal: every 30 minutes on the hour between 4.00am and 01:00am
At Taksim: every 30 minutes on the half hour between 3.30am and 01:00am
Duration: approx 80 to 110 minutes depending on traffic
Costs: 14 TRY (one way)
http://www.havatas.com/yolcuservisi/taksim-sabihagokcenhavalimani.aspx
2. IETT Public Bus
Lines: Bus E-3 travel between Sabiha Gokcen International Airport and 4.Levent Subway Station
Duration: approx 100 to 120 minutes depending on traffic
Costs: approx 2.5 €. Ticket or Istanbul Kart must be purchased beforehand.
3. by taxi:
Costs from the airport to the Taksim Square costs around 50 €
Duration: between 50 and 90 minutes depending on traffic
Getting around in Istanbul
For general information, see http://www.turkeytravelplanner.com/go/Istanbul/Transport/
If you are going to travel around the city intensively using buses, metros, ferries, funiculars, and tramways, the Istanbul Kart is a good offer. Read more here.
Metro and Tram
http://www.istanbul-ulasim.com.tr/passenger-services/network-maps.aspx
Ferrys
http://www.sehirhatlari.com.tr/en
Bus
http://www.iett.gov.tr/en