Towards a consensus on pre treatment verification in particle therapy

 

Chairs

Marie Vidal (FR), Liliana Stolarczyk (DK)

 

Motivation

Measurement-based PSQA for PBS proton therapy is typically a time-consuming process. At a recent EPTN workshop on PSQA (September 2019), 10 different European proton therapy centres reported times of between up to three hours or more for large and complex cases (e.g. CSI), with a mean time of 45 minutes per plan. However, procedures, measurement devices and evaluation tools vary considerably across centres. In addition, the value of measurement-based PSQA is being more and more questioned in the community, particularly given the time typically invested in these measurements. As such, we believe there is an urgent need to have consensus in the community on requirements, measurement devices and evaluation metrics for PBS proton therapy PSQA, and a roadmap towards measurement-less PSQA, for example, log-file based PSQA and/or independent dose calculation. Synergistically, this is also fostered by the substantial translational developments towards online-adaptive proton therapy, which per definition requires a measurement-less pre-treatment QA.

 

Potential outcomes

The outcomes of this workshop are as follows

• Pre-meeting survey on the current status of pre-treatment QA
• Bringing together international experts participating
• Consensus in the definition and scope of patient-specific QA in PT
• Recommendations for PSQA in terms of measurements and evaluation metrics will be based on clinical practice and experience of participating proton centers
• Roadmap towards measurement-less PSQA will be prepared jointly by academic, clinical and industrial participants
• Requirements for commercial PSQA tools will be specified.
• Summary of the workshop will be presented at the next ESTRO conference and in the ESTRO newsletter. A publication in an ESTRO journal is also foreseen.
• Outcome will be followed up within the WP2 and WP5 of EPTN to ensure sustainable improvement and continuation of the collaboration within the whole community

 

Programme

Online Pre-meeting (18 September) – Preliminary program

A Survey about the status of pre-treatment verification in their center will be sent to the registered participants at least one month before the online pre-meeting.

14:00–14:30	Introduction: Workshop concept, Scope of pre-meeting, the scope of life workshop, intended outcome – incl. questions
14:30-15:30	Participant's pitches and expectations from the workshop
15:30-15:50	Results of the survey: current practice in PT centers
15:50-16:10	PTCOG initiatives about PSQA (Daniel Robertson, PhD)
16:10-16:30	PSQA perspectives for adaptive RT (Prof. Dr. Daniela Thorwarth)
16:30-17:00	Presentation of the working groups and discussion on potential outcomes
17:00	End of the online pre-meeting

 

ESTRO Physics workshop (13-14th October) — Preliminary program

Day 1: October 13th
9:00–10:00	ESTRO physics workshop opening keynote lecture
10:00-10:30	Coffee break
10:30-10:50	Invited talk: Definition of PSQA – Tony Lomax (PSI)
10:50-11:20	Discussion (plenary session)
11:20-12:30	WG 1 & WG 2 – definitions below
12:30-13:30	Lunch
13:30-13:50	Invited talk: Clinical implementation of PSQA workflow – Stefan Both (UMCG)
13:50-15:10	WG 1 & WG 2
15:10-15:30	Conclusions of the day of each working group (all PSQA workshop participants)
15:30-16:00	Coffee break
16:00-17:00	Progress report of the different topics (12 min per topic) All participants together

 

Day 2: October 14th
8:00–9:00	Invited talks: Existing solutions - In-house developed solution talk 1: Loïc Grevillot (MEDAustron) - In-house developed solution talk 2: Ilaria Rinaldi (MAASTRO, Mevion) - Vendors contribution
9:00-10:00	WG 2 / WG 3 / WG 4
10:00-10:30	Coffee break
10:30-12:10	WG 2 / WG 3 / WG 4
12:10-12:30	Discussion and consensus: conclusions of each working group
12:30-13:30	Lunch
13:30-14:30	Discussion of next steps; take home messages; identify open issues for further research; roadmap towards measurement-less PSQA - All PSQA workshop participants
14:30-15:30	Wrap up: highlights and planned next steps of the different workshops (12 min per topic) - All participants together
15:30-15:45	Closing remarks

 

Working Groups

WG 1: Definition of PSQA
What do we expect from PSQA? What needs should be covered? Risk management approach to decide to which point measurement-based PSQA could be reduced. Balance and periodicity between machine QA and PSQA.

WG 2: Workflow of future/optimal PSQA
How would the future measurement-less PSQA procedure look like? What elements will be mandatory, and which will be optional? Implementation and validation. Do we need to consider MDR Certifications? How to handle PSQA in an adaptive PT workflow? What would this imply for the vendors (requirements) and how does this fit the current products roadmap?

WG 3: Intervention criteria of PSQA
What triggers/criteria make us react with the new tools compared to the less sensitive measurements? User cases to be prepared in advance to open discussion. What do you do in case of failure in PSQA?

WG 4: Optional Working Group
If needed during the online pre-meeting or the in-person meeting, a fourth working group can be opened on demand.