Abstract | BACKGROUND AND PURPOSE: Aeration in the nasal cavity and paranasal sinus (NCPS) was investigated during the course of proton therapy (PT), and the influence of aeration on the dose distribution was determined. MATERIAL AND METHODS: Twenty patients with NCPS cancer (10 nasal cavity, 10 paranasal sinus) were analyzed. All the patients received a total proton beam irradiation dose of 38-78.4 Gray equivalents (GyE). Two to five CT examinations were performed during the course of treatment. The aeration ratio inside the cavity/sinus was calculated for each CT observation. Moreover, a simulation study supposing that the first treatment plan had been continued until the end of treatment was performed using the subsequent CT findings. RESULTS: The aeration ratio was increased in 18 patients. The largest increase was from 15% to 82%. Three patients had a simulated maximum cumulative dose in the brainstem of beyond 60 GyE, while 10 patients had a simulated maximum cumulative dose in the optic chiasm of beyond 50 GyE. The shortest simulated time period to reach the dose limitation was 21 days. CONCLUSIONS: Aeration in the NCPS is altered during the course of PT treatment and can greatly alter the dose distribution in the brainstem and optic chiasm.
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Authors | Nobuyoshi Fukumitsu, Hitoshi Ishikawa, Kayoko Ohnishi, Toshiyuki Terunuma, Masashi Mizumoto, Haruko Numajiri, Teruhito Aihara, Toshiyuki Okumura, Koji Tsuboi, Takeji Sakae, Hideyuki Sakurai |
Journal | Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology
(Radiother Oncol)
Vol. 113
Issue 1
Pg. 72-6
(Oct 2014)
ISSN: 1879-0887 [Electronic] Ireland |
PMID | 25245554
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Copyright | Copyright © 2014 Elsevier Ireland Ltd. All rights reserved. |
Topics |
- Adult
- Aged
- Aged, 80 and over
- Air
- Brain Stem
(radiation effects)
- Female
- Humans
- Male
- Middle Aged
- Nasal Cavity
- Nose Neoplasms
(radiotherapy)
- Optic Chiasm
(radiation effects)
- Paranasal Sinus Neoplasms
(radiotherapy)
- Proton Therapy
(methods)
- Radiotherapy Dosage
- Retina
(radiation effects)
- Retrospective Studies
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