ESTRO37_ProgrammeBook

SYMPOSIUM What could replace the PTV? 08:45 - 10:00  | ROOM 113-114

SUNDAY 22 APRIL 2018

According to ICRU83 the PTV is defined as follows: “The PTV is... the recommended tool to shape absorbed-dose distributions to ensure that the prescribed dose will actually be delivered to all parts of the CTV with a clinically acceptable probability…” The PTV does not take organs at risk into account explicitly, i.e., there may be multiple PTV’s that have equivalent probability, but are different in terms of organ at risk dose. This has led to the development of probabilistic planning systems where uncertainties are explicitly accounted for during optimization without PTV: M. Witte will talk about full probabilistic systems. Approximate solutions have been derived such as robust planning and coverage probability based ones, which will be discussed by M. Alber. Their main limitations may be that these do not differentiate random and systematic errors. The PTV assumes a dose cloud approach, i.e. dose is assumed invariant under uncertainties. F. Albertini will discuss robustness analysis in proton therapy where dose cloud breaks down. Finally, T. Depuydt will discuss the interaction/balance between robust planning and direct intra-fraction mitigation of shifts/anatomical changes, to answer whether zero margins are possible.

Chair: M. Van Herk (United Kingdom) Co-Chair: M. Zeverino (Switzerland)

08:45 > The challenging path towards clinical adoption of probabilistic planning Speaker: M. Witte (The Netherlands) 09:03 > Coverage probability based dose optimization - first clinical applications Speaker: M. Alber (Germany)

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09:21 > Analysis and reporting of plan robustness Speaker: F. Albertini (Switzerland)

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09:39 > A bright future for the PTV?: gating, tracking, on-line re-planning Speaker: T. Depuydt (Belgium)

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SYMPOSIUM  IGRT, IGART and SGRT 08:45 - 10:00  | ROOM 111 Chair: L. Turtle (United Kingdom) Co-Chair: L. Mullaney (Ireland)

08:45 > IGRT from 2D to 4D, changing the verification paradigm Speaker: M. Rossi (The Netherlands)

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SCIENTIFIC PROGRAMME | Programme and Exhibition Guide

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