Treatment planning comparison of conventional, 3D conformal, and intensity-modulated photon (IMRT) and proton therapy for paranasal sinus carcinoma.
OBJECTIVE
To determine the potential improvements in patients with paranasal sinus carcinoma by comparing proton and intensity-modulated radiotherapy (IMRT) with conventional and conformal photon treatment planning techniques.


METHODS
In 5 patients, comparative treatment planning was performed by comparing proton plans and related conventional, conformal, and IMRT photon plans. The evaluations analyzed dose-volume histogram findings of the target volumes and organs at risk (OARs, i.e., pituitary gland, optical pathway structures, brain, nontarget tissue).


RESULTS
The mean and maximal doses, dose inhomogeneities, and conformity indexes for the planning target volumes were comparable for all techniques. Photon plans resulted in greater volumes of irradiated nontarget tissues at the 10-70% dose level compared with the corresponding proton plans. The volumes thereby increased by a factor of 1.3-3.1 for conventional, 1.1-3.8 for conformal, and 1.1-3.7 for IMRT. Compared with conventional techniques, conformal and IMRT photon treatment planning options similarly reduced the mean dose to the OARs. The use of protons further reduced the mean dose to the OARs by up to 65% and 62% compared with the conformal and IMRT technique, respectively.


CONCLUSIONS
Compared with conventional treatment techniques, conformal RT and IMRT similarly enabled dose reductions to the OARs. Additional improvements were obtained using proton-based treatment planning modalities.
Mock
Ulrike
U
Department of Radiotherapy and Radiobiology, University Hospital Vienna, Vienna, Austria. u.mock@utanet.at
Georg
Dietmar
D
Bogner
Joachim
J
Auberger
Thomas
T
Pötter
Richard
R
D006801:Humans; D010255:Paranasal Sinus Neoplasms / Q000532:radiotherapy*; D010256:Paranasal Sinuses / Q000000981:diagnostic imaging; D017785:Photons / Q000627:therapeutic use; D061766:Proton Therapy; D011878:Radiotherapy / Q000379:methods; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D020266:Radiotherapy, Conformal / Q000379:methods; D014057:Tomography, X-Ray Computed; D011522:Protons
D011522:Protons