Design of a compensating bolus by use of exhalation CT data for covering residual motion in respiratory-gated charged-particle lung therapy: four-dimensional carbon beam dose calculation
| Autor: | Tomoyasu Yashiro, Shinichiro Mori, Masayuki Baba, Masahiro Endo, Hiroshi Asakura, Susumu Kandatsu, Motoki Kumagai, Shuhei Komatsu |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Lung Neoplasms
medicine.medical_treatment Physical Therapy Sports Therapy and Rehabilitation Gating Residual Sensitivity and Specificity Motion medicine Humans Radiology Nuclear Medicine and imaging Four-Dimensional Computed Tomography Aged Aged 80 and over Radiation Lung business.industry Respiration Reproducibility of Results Exhalation Radiotherapy Dosage General Medicine Middle Aged Carbon Radiation therapy medicine.anatomical_structure Maximum intensity projection Nuclear medicine business Charged particle beam Bolus (radiation therapy) Algorithms |
| Zdroj: | Scopus-Elsevier |
| ISSN: | 1865-0341 1865-0333 |
| DOI: | 10.1007/s12194-007-0012-z |
| Popis: | We developed an algorithm which we used to design a compensating bolus by using respiratory-gated CT data for respiratory-gated carbon beam lung therapy and evaluated it by calculating dose distributions as a function of time. Four-dimensional CT (4DCT) images were obtained for seven lung cancer patients under free breathing conditions. The internal target volume (ITV) was calculated by maximum intensity projection processing which use of three types of gross tumor volumes (GTVs): at peak exhalation and with a 5 mm shift of the GTV to both superior and inferior sides. Then a compensating bolus was designed which use of the ITV and applied to 4DCT data at the gating window (around exhalation phase). The carbon beam distribution was calculated by a pencil-beam algorithm as a function of time. The compensating bolus provides a sufficient prescribed dose to the target in the gating window and minimizes any excessive dose to the normal tissues. The metric of dosimetric assessment metrics of D95 in all patients is greater than 96% of the prescribed dose in the gating window. Our results will be beneficial for improving the accuracy of charged-particle radiotherapy for hospitals where 4DCT cannot be used. |
| Databáze: | OpenAIRE |
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