BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//CERN//INDICO//EN
BEGIN:VEVENT
SUMMARY:Physical Modelling for Proton Therapy Planning and Beam Delivery
DTSTART;VALUE=DATE-TIME:20130322T150000Z
DTEND;VALUE=DATE-TIME:20130322T160000Z
DTSTAMP;VALUE=DATE-TIME:20260629T151115Z
UID:indico-event-1903@indico.ific.uv.es
DESCRIPTION:Over the past decade it has been demonstrated that intensity m
 odulated radiation therapy can be safely delivered to patient with both ph
 otons and/or ions. With protons (or other ions) this technique is known as
  intensity modulated proton (or particle) therapy (IMPT). IMPT offers much
  better spare of organs at risk with the potential to further escalate tar
 get-dose compared to classical proton therapy. The underlying paradigm of 
 this presentation is the following: “The best technique to fulfil the mis
 sion assigned to radiation therapy is IMPT\, that is\, the ability to modu
 late each particle pencil beam to obtain an inhomogeneous dose distributio
 n within the target per field direction”. This paradigm holds in particul
 ar when we think of the great potential that biological dose targeting may
  play in the future. We would then bring intensity modulated therapy to it
 s extreme\, in which not only the dose per field is inhomogeneous but also
  the overall dose distribution over all fields. What improvements are ther
 efore necessary to be able to use IMPT to its full potential? In this rega
 rd we will consider the status and improvements of current physical modell
 ing for proton therapy planning and beam delivery\, in particular we will 
 focus on:\n• Modelling of nuclear interactions: nuclear interactions affe
 ct both the integral depth dose curve as well as the lateral profile. Up t
 o 9% dose differences could be observed between measured and calculated do
 se when nuclear interactions are not taken into account. • Pencil beam an
 gular-spatial distribution and multiple Coulomb scattering in different ma
 terials: the challenge of low density tissues\, e.g. lung. • Beam deliver
 y: o the need of small pencil beams o the challenge of delivering the dose
  to shallow tumours • Biology aspects: o RBE modelling for protons: even 
 though a constant global RBE value of 1.1 is widely accepted for protons\,
  studies have shown that also for protons RBE may change as a function of 
 LET\, i.e.\, at the distal fall-off RBE could be as high as 20. Therefore\
 , RBE may cause an increased biological dose (10-20%) in some localised po
 sitions and extend the biologically effective range by 1-2 mm. However\, s
 ince RBE is also dependent on the end-point\, dose\, dose-rate and cell-ty
 pe it may still be premature to move away from the global value of 1.1\; t
 he biological uncertainties are just too large. • Range uncertainties: ev
 en though in water we can achieve very good agreements between calculation
 s and measurements\, the patient may\, to some extent\, reduce this confid
 ence. Range uncertainties are indeed the biggest challenge in proton thera
 py. The redistribution of pencil beams within the target by the introducti
 on of robust optimization methods can improve the robustness of the IMPT p
 lans against range errors.\n\nhttps://indico.ific.uv.es/event/1903/
LOCATION:Edf. Institutos de Investigación Sala Seminarios IFIC
URL:https://indico.ific.uv.es/event/1903/
END:VEVENT
END:VCALENDAR