Chairs

Pietro Mancosu (Humanitas Research Hospital, Italy),

Nuria Jornet (Hospital de la Santa Creu i Sant Pau, Spain)

Motivation:

High radiation doses to small lesions with short fractionation schemes are characteristics of stereotactic body radiation therapy (SBRT) aiming high dose conformity to the target and to spare healthy surrounding tissues. The rapid increase in the use of SBRT could benefit from the sharing and standardization of dosimetric and treatment strategies.

The harmonization of the radiotherapy treatment planning process is a major challenge for SBRT treatments. At this time there is still not clear consensus on dose prescription (homogeneous as stated by ICRU81 or inhomogeneous as stated by AAPM101) and also on dose calculation algorithms for plan optimization. In order to compare plans, ad hoc quality scores could help but there is no consensus on the best scores to be considered. Sub-optimal scores could lead to sub-optimal plans with relapse to the patient. In particular, it is advisable to solely refer to a single score to capture the true quality of a treatment plan in terms of conflicting clinical goal by a mathematical ranking method. This may lead to pursuing a specific score using non-practical non-clinical methods, which strongly depends on the score function itself.

In this workshop we will discuss the principles how to design, validate and implement strategies for SBRT planning harmonization from both developer/research and end-user prospective, aiming:

1. Share experiences of SBRT harmonization (i.e. multi-planning, trials, audits, …).
2. Discuss methods to select the plan quality scores (absolute/relative), dose distribution criteria (homogeneous vs inhomogeneous), plan optimization and calculation strategies, and calculation algorithms.
3. Discuss methodologies for the evaluation of plan quality scores robustness and quantify their uncertainties.
4. Define and validate metrics for comparing treatment plans, aiming to increase the overall plan quality.
5. Discuss how to transfer them in daily practice, in which no specific feedback would be provided.
6. Develop potential recommendations and guidelines for the implementation of large scale SBRT planning harmonization.

Being a workshop we want to encourage an active participation and interactions between the participants to foster collaboration and networking. For this reason, participant will be requested to prepare a short presentation to describe their research in the field allowing identification of common points of interest and share experiences.

Outcomes:

Write a paper for defining and ranking relevant quality scores in SBRT.

Industrial “TPS developer” partners: to include quality scores in the plan optimization and plan evaluation.

Industrial “data mining” partners: Data analysis on big data and consortium for grant application.

Reference: Giglioli FR, Garibaldi C, Blanck O, et al. Dosimetric multicenter planning comparison studies for SBRT: methodology and future prospective Int J Radiat Oncol Biol Phys 2020;106(2):403-412. review.

 

Agenda

20th May

14:00 Introduction to the ESTRO Physics workshop by Catharine Clark (ESTRO Physics Committee chair) 

14:30 Introduction to what we want to achieve on our group/topic, and practicalities. Núria Jornet  (Sant Pau Hospital, Barcelona, Spain)

15:00 Oligocare project: clinical needs. Piet Ost (UZ Gent, Belgium)

15:45 Confounding factors due to dose Optimization and dose calculation in SBRT. Jan Seuntjens  (McGill University, Montreal,Canada)

16:30 End First day

 

21st May

9:00 Confounding factors due Motion management strategies in SBRT. Paul Keall (University of Sydney, Sydney, Australia)

9:45 Peritumoral lung density as a biomarker for recurrence in lung SBRT (Angela Davey, University of Manchester, UK)

10:00 Pitches by participants (5 min each)

12:00 Discussion and further steps  Pietro Mancosu (Humanitas Cancer Center, Milano, Italy)

13:00 End of Second day

 

Division in sub-groups depending on the pitches

Online part 2  (October 2021, TBC)

1. Overview of state of the art. Francesca R. Giglioli (Città della Salute e della Scienza di Torino, Italy)
2. A national physicist WG on SBRT view. Oliver Blanck (Klinik für Strahlentherapie Universitätsklinikum Schleswig-Holstein Kiel, Germany)
3. A national database: report of the paper “Stereotactic ablative body radiotherapy in patients with oligometastatic cancers: a prospective, registry-based, single-arm, observational, evaluation study” – The Lancet Oncol 2021. Antony Carver (University Hospitals Birmingham – UK)
4. Summary of the pitches by participants
5. Discussion on ideal scores for SBRT. Pro and Cons of relative and absolute scores
6. Discussion with industrial partners: TPS developers, Data mining analyzers
7. Summary and discussion of next steps; take home messages; open issues for further collaborations: Proposal for an European consortium to automatize the score computation