Temporal optimization and personalization of the radiation treatment course

 

Chairs

 Thomas Bortfeld (USA), Jan Unkelbach (CH)

 

Motivation

The problem of optimizing the spatial dose distribution has received a lot of attention for many decades. The question of how to optimally deliver dose over time has been studied much less, and it has traditionally not been an area with a lot of physics involvement. By and large, most patients with a certain type of cancer receive the same amount of radiation dose distributed equally over a pre-determined number of treatment fractions. Even though more and more patients get treated with hypo-fractionation, taking advantage of the greater normal tissue protection thanks to modern treatment techniques, the paradigm of equal fractions at regular time intervals remains unchanged.

The workshop aims to discuss ideas and approaches to design and optimize radiotherapy schedules that deviate from this traditional paradigm. Potential topics of the workshop (depending on the participants) include:

1) Optimal stopping

When should the treatment be stopped? Optimal stopping techniques are emerging that allow the total dose to be individualized during the treatment course, based on the response of the patient.

2) Beyond uniform fractionation

What rationales are there to deviate from the delivering the same dose in each fraction? One such concept is spatiotemporal fractionation, which aims to hypofractionate complementary parts of the tumor in different fractions while achieving more uniform fractionation in normal tissues. A more radical departure from uniform fractionation is Pulsar, an approach that delivers ablative dose pulses separated by weeks or months. In part motivated by immune response, this paradigm is beginning to shake up the 100-year-old dose fractionation paradigm even more.

3) Future directions, cancer as a chronic disease, oligo-residual situation

Radiotherapy has found its role in the management of metastatic cancer patients. SRS for multiple brain metastases and SBRT for oligometastatic disease are now established treatment paradigms. Repeat radiotherapy, i.e. treating patients with multiple courses of SRS/SBRT separated by several months became common practice. What approaches are there to optimize treatment schedules over longer periods of time to optimize the balance of treatment efficacy and quality of life for metastatic cancer patients?

 

Outcomes

• Discuss approaches and their rationale to deviate from the traditional paradigm of delivering a predefined prescription dose uniformly distributed over daily fractions, and share these emerging developments in this area with the community.
• Provide a forum to find collaborators, to get involved and shape future developments in the field of temporal optimization of radiotherapy schedules.
• Write a white paper together.

 

Invited Speakers

Iuliana Toma-Dasu (Stockholm)

Jan Unkelbach / Nathan Torelli (University of Zürich)

Maximilian Niyazi (University of Tübingen)

 

Programme

Day 1	Friday 13 October
09:00-09:15	Introduction of the meeting. Overall chair of workshop All participants together
09:15-10:00	Opening lecture All participants together
10:00-10:30	Coffee
10:30-12:30	Opening of the workshop 1st topic: Optimal stopping (OSRT) Invited lecture: Iuliana Toma-Dasu Participants’ pitches related to OSRT (5 minutes each)
12:30-13:30	Lunch
13:30-15:30	Continuation participants’ pitches and discussion Action items
15:30-16:00	Coffee
16:00-17:00	Progress report of the different topics (12 min per topic) All participants together

 

 

 

Day 2	Saturday 14 October
08:00-10:00	Wrap-up from day 1 2nd topic : Beyond uniform fractionation Invited lecture : Jan Unkelbach / Nathan Torelli Participants’ pitches related to fractionation (5 minutes each) Discussion, action items
10:00-10:30	Coffee
10:30-12:30	3rd topic : Future directions, oligo-metastasis Invited lecture : Maximilian Niyazi Participants’ pitches (5 minutes each) Discussion, action items
12:30-13:30	Lunch
13:30-14:30	Discussion of next steps; take home messages; identify open issues for further research (1hr)
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	Close