Meeting minutes March 18, 2021 

Agenda

  • Update from focus groups 
  • Determining dates for FUN2021 conference 
  • Presentation from Reporting focus group

Summary

During this meeting, Lennart Verhagen introduced Colette Reniers and Jesse van der Spek who can be contacted for any organizational requests. After this, we received updates from individual working groups. Finally, Kim Butts Pauly presented discussion points about Standardized Reporting. This is work in progress. So please give comments and feedback. This way the Reporting and Safety working groups can use that to make a draft, which will be voted on in a plenary meeting.

Attendance report (non-exhaustive)

-           Andrew Thomas

-           Anton Fomenko

-           Axel Thielscher

-           Benjamin Kop

-           Bradley Treeby

-           Charles Caskey

-           Colette Reniers

-           Cristina Pasquinelli

-           Ellen Bubrick

-           Elly Martin

-           Elsa Fouragnan

-           Fidel Vila-Rodriguez

-           Ghazaleh Darmani

-           Gianmarco Pinton

-           Jean-Francois Aubry

-           Jerome Sallet

-           Jesse van der Spek

-           John Snell

-           José Pineda-Pardo

-           Keith Murphy

-           Kim Butts Pauly

-           Kullervo Hynynen

-           Lennart Verhagen

-           Martin Monti

-           Miriam Klein-Flügge

-           Nathan McDannold

-           Robert Chen

-           Robin Cleveland

-           Samuel Pichardo

-           Seiki Konishi

-           Seung-Schik Yoo

-           Siti Yaakub

-           Sjoerd Meijer

-           Sven Bestmann

-           Takahiro Osada

-           Til Ole Bergmann

-           Tulika Nandi

-           Yasuo Terao

-           Yeruham Shapira

-           Yoshikazu Ugawa

-           Zahra Soltaninejad

-           Zhihai Qiu

Meeting proceedings

Lennart Verhagen: Introduction about organization of the meeting (duration: 1h max), stick with 15.00 GMT (regardless of daylight saving time). We will now hear from all the working groups what progress they made in the last month. Please contact Colette Reniers or Jesse van der Spek for any organizational requests.

Update focus groups

Bradley Treeby (Planning working group): Group had good discussions. Great sessions where literature was summarized. Everyone is helping each other and we are moving forward.

Jean-François Aubry (Safety working group): Review on existing literature is almost done (19 papers in humans), with a plan to add animal papers. Kim will present work on reporting (linked to safety). We already listed risk and inclusion and exclusion criteria (e.g. history of seizures and sensitivities regarding skin). Still have to find a way to report undesirable outcomes and effects. Next time (plenary meeting): presentation of safety limits. A danger is to go too fast and oversimplify things, but we don’t want prohibitively conservative limits, because it will hold us back. There is discussion about this: some of us want simple models and conservative limits, but I think this is not a good idea. There is no consensus yet.

Elly Martin (Equipment working group): We are having a discussion on procedures for consistency checks. Working on a draft for that. Collaboration with the practice focus group to see what equipment is being used for everyone. Also a discussion about safety features that manufacturers should perhaps think about. Still the beginning of that discussion.

Til Ole Bergmann (Practice working group): We don’t want to make a full textbook, but find the right balance. Started to write the guide. Planning phase is finished. Will still take a while of course.

Tulika Nandi (Open working group): Put together a poll on what equipment is being used or will be used in the future in all the labs. Jesse van der Spek or Colette Reiniers will send this out soon. If interested in joining the Open working group, you can mail or send a message on slack to Benjamin Kop, Tulika Nandi or Lennart Verhagen.

Bradley Treeby: Is there a platform on which we communicate and share content?

Lennart Verhagen: There are already platforms in use, which we don’t want to substitute. Part of the objectives of the Open working group is to identify available platforms and promote use through ITRUSST. So Bradly you will hear from us soon, things are coming!

Fidel Vila-Rodriguez (Clinical working group): We are looking at some clinical trials databases. And looking at existing literature. But the safety group already did this, so we will try to see what is overlapping. And we want to prevent this in the future. So we maybe want a survey/interview from all different labs and see what everyone is doing and how. Right, Ellen (Bubrick)?

Ellen Bubrick : Good summary, Fidel. We are a bit afraid that we’re doing redundant work and we don’t want to miss out on helping in other groups. And it’s not ideal if all groups work separately.

Lennart Verhagen: Thanks Ellen. You can be an active member of groups, but you can also be an observer to monitor everything. And we want some sort of objective overview in our open repository. Get in touch with the Open working group, Lennart Verhagen, Jesse van der Spek or Colette Reiniers for sending around surveys. They have an existing infrastructure.

Kim Butts Pauly: We are organizing a symposium, the FUN convention. Did Lennart send a date? (YES) OK, then you can fill this in. Some dates are soon, some are later. Please fill in the doodle sent by Lennart Verhagen.

Lennart Verhagen: Kim Butts Pauly will now give a presentation on Standardized Reporting. This is work in progress. So please give comments and feedback. Then the Reporting working group can use that to make a draft, which we will vote on in the plenary meeting.

Standardized Reporting Presentation (Kim Butts Pauly)

  • What do we call our stimulus modality?
    • Pulse characteristics
    • Spatial
    • Scan Tank
      • Report Intensity: full width at half maximum (FWHM, both axial & lateral)
      • Or x,y,z or provide picture of both, including lots of details
    • In Situ Estimate

Kullervo Hynynen: Do we report spatial characteristics in pressure or intensity?

Robin Cleveland: You should report both.

Anton Fomenko: Do we need a minimum spatial width/xyz dimension we should use?

Kim Butts Pauly: Yes, mention all peaks. But let’s discuss specifics later.

Temporal: Refrain from word ‘bursts’, use pulse, train of pulses, train of train of pulses and so on.

The auggestion is to report all stimulus characteristics in the same manner

Robin Cleveland: Good to get rid of the term ‘bursts’. Good to report your examples, but there are more complicated waveforms. So we should maybe just put the waveform online and make it accessible. Because there is no clean way of describing it.

Keith Murphy: What about a longer temporal duration interval? For example 24 hours compared to 5 minutes.

Kim Butts Pauly: I will answer this at the end, sorry Keith.

There is more we need in terms of reporting

  • What are the current regulatory limits appropriate for TUS? (Which are supposed to be ‘extra’ safe for imaging).
  • Not all of them are relevant for us. The Safety committee should look at which ones are relevant for us. And which aren’t. 

Bradley Treeby: Is there a way to prepare future reporting?

Samuel Pichardo: Maybe we should save everything in OpenScience and then if we miss something we can retrospectively look at it.

Fidel Vila Rodriguez: ZOOM CHAT [It would be interesting to consider what essential elements of the standardised reporting should translate to clinical trials reporting]

Yoshikazu Ugawa: I’m a doctor, and believe temperature change limits are important. Skin temperature change is not a problem for us, so please consider different limits for brain, skull, skin etc.

Kim Butts Pauly: You are right, skin is a different concern.

Jean-François Aubry: You are right. But the numbers do not matter yet. We first need to find out and decide how we can estimate those numbers. The numbers itself will come later. Reporting is more about the ultrasound characteristics. This part is more about the safety part.

Martin Monti: We know exactly how to describe and derive those estimates. It is more important to balance accessibility and decrease borders so that everyone can do those measurements. Make our work transparent, reproducible and don’t set the bar too high or it scares people off.

Kim Butts Pauly: Yes I agree, we do need to make sure everything is safe.

Next point: huge heterogeneity between subjects. We need to work on the derating and find out how it exactly works.

Make standardized derating procedure. It differs for each lab, but you either have full range imaging, imaging with segmentation of the skull or no imaging at all. We need to at least report how the derating is done. In the future we hope to come up with a consensus. Questions?

Anton Fomenko: I found a paper that provides great results with a big database as a starting point for skull density ratio.
[Zoom Chat]: The article I referred to for those interested: Transcranial MR Imaging–Guided Focused Ultrasound Interventions Using Deep Learning Synthesized CT.” American Journal of Neuroradiology 41.10 (2020): 1841-1848. Especially figure 5 & 6.

Kim Butts Pauly: I think we can do better than one number, hopefully, with some beam simulation.

Fidel Vila-Rodriguez:  You have opened a Pandora’s box about all the different variabilities we have to deal with. We want to minimize those as much as possible. So this is very very important.

Lennart Verhagen [interrupts]: I have to close the meeting. I will invite everyone on the calendar. Please contact Kim Butts Pauly if you have any more remarks or comments on the reporting work group.

[discussion of standardized reporting continues in following meeting] 

END OF MEETING