An indirect in vivo dosimetry system for ocular proton therapy.
Secondary radiation, particularly neutron radiation, is a cause of concern in proton therapy. However, one can take advantage of its presence by using it to retrieve useful information on the primary proton beam. At the Centre Antoine Lacassagne the secondary radiation in the treatment room has been studied in function of the beam modulation. A strong correlation was found between the secondary ambient dose equivalent per proton dose H*(10)/D and proton dose rate D/MU. A large volume ionisation chamber fixed on the wall at 2.5 m from the nozzle was used with an in-house computer interface to retrieve the value of D/MU derived from the measurement of photon H*(10) integrated over treatment time, using the correlation curve. This system enables the verification of D and D/MU to be made independently of the monitoring of the primary beam and represents a first step towards an alternative in vivo dosimetry in proton therapy.
Cyclotron Biomédical, Centre Antoine Lacassagne, 227 Avenue de la Lanterne, 06200 Nice, France.
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Carnicer
Centre de protonthérapie, Institut Curie, Campus Universitaire d'Orsay, bâtiment 101, 91898 Orsay Cedex, France.
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Letellier
Centre de radiothérapie St Louis, Hôpital de la Croix Rouge, rue André Blondel, 83100 Toulon France.
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Rucka
Cyclotron Biomédical, Centre Antoine Lacassagne, 227 Avenue de la Lanterne, 06200 Nice, France.
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Angellier
Universitätsklinikum Essen, Strahlenklink, 45122 Essen, Germany.
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Sauerwein
Cyclotron Biomédical, Centre Antoine Lacassagne, 227 Avenue de la Lanterne, 06200 Nice, France joel.herault@nice.unicancer.fr.
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Hérault
D000465:Algorithms; D003198:Computer Simulation; D004867:Equipment Design; D005123:Eye / Q000528:radiation effects*; D005160:Facility Design and Construction; D006801:Humans; D015233:Models, Statistical; D009010:Monte Carlo Method; D009502:Neutrons; D017785:Photons; D061766:Proton Therapy / Q000295:instrumentation / Q000379:methods*; D011786:Quality Control; D011835:Radiation Protection / Q000295:instrumentation / Q000379:methods*; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods*; D011879:Radiotherapy Dosage; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D011522:Protons
D011522:Protons