Potential Benefits of Scanned Intensity-Modulated Proton Therapy Versus Advanced Photon Therapy With Regard to Sparing of the Salivary Glands in Oropharyngeal Cancer

Journal Article · Tue Mar 15 00:00:00 EDT 2011 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2010.05.012· OSTI ID:21491668

Water, Tara A. van de, ^[1]; Lomax, Antony J ^[2]; Bijl, Hendrik P; Jong, Marije E. de; Schilstra, Cornelis ^[1]; Hug, Eugen B ^[2]; Langendijk, Johannes A ^[1]

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1. Department of Radiation Oncology, University Medical Center Groningen/University of Groningen, Groningen (Netherlands)
2. Center for Proton Therapy, Paul Scherrer Institute, Villigen-PSI (Switzerland)

Purpose: To test the hypothesis that scanned intensity-modulated proton therapy (IMPT) results in a significant dose reduction to the parotid and submandibular glands as compared with intensity-modulated radiotherapy with photons (IMRT) and three-dimensional conformal radiotherapy (3D-CRT) for oropharyngeal cancer. In addition, we investigated whether the achieved dose reductions would theoretically translate into a reduction of salivary dysfunction and xerostomia. Methods and Materials: Ten patients with N0 oropharyngeal carcinoma were used. The intensity-modulated plans delivered simultaneously 70 Gy to the boost planning target volume (PTV2) and 54 Gy to the elective nodal areas (PTV1). The 3D-CRT technique delivered sequentially 70 Gy and 46 Gy to PTV2 and PTV1, respectively. Normal tissue complication probabilities were calculated for salivary dysfunction and xerostomia. Results: Planning target volume coverage results were similar for IMPT and IMRT. Intensity-modulated proton therapy clearly improved the conformity. The 3D-CRT results were inferior to these results. The mean dose to the parotid glands by 3D-CRT (50.8 Gy), IMRT (25.5 Gy), and IMPT (16.8 Gy) differed significantly. For the submandibular glands no significant differences between IMRT and IMPT were found. The dose reductions obtained with IMPT theoretically translated into a significant reduction in normal tissue complication probability. Conclusion: Compared with IMRT and 3D-CRT, IMPT improved sparing of the organs at risk, while keeping similar target coverage results. The dose reductions obtained with IMPT vs. IMRT and 3D-CRT varied widely per individual patient. Intensity-modulated proton therapy theoretically translated into a clinical benefit for most cases, but this requires clinical validation.

• OSTI ID: 21491668
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Journal Name: International Journal of Radiation Oncology, Biology and Physics Journal Issue: 4 Vol. 79; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BARYONS
BODY
BOSONS
CARCINOMAS
DISEASES
DOSES
ELEMENTARY PARTICLES
FERMIONS
GLANDS
HADRONS
HEAD
MASSLESS PARTICLES
MEDICINE
NECK
NEOPLASMS
NUCLEAR MEDICINE
NUCLEONS
ORGANS
PHOTONS
PROTONS
RADIATION DOSES
RADIOLOGY
RADIOTHERAPY
SALIVARY GLANDS
THERAPY
THREE-DIMENSIONAL CALCULATIONS