Comparison of CT images with average intensity projection, free breathing, and mid‐ventilation for dose calculation in lung cancer

Autor: Chirapha Tannanonta, Sangutid Thongsawad, Sasikarn Chamchod, Chirasak Khamfongkhruea
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Organs at Risk
medicine.medical_specialty
87.57.-S
Lung Neoplasms
Dose calculation
medicine.medical_treatment
87.53.Kn
dose calculation
030218 nuclear medicine & medical imaging
mid‐ventilation
03 medical and health sciences
0302 clinical medicine
average intensity projection
medicine
Image Processing
Computer-Assisted
Radiation Oncology Physics
Humans
Radiology
Nuclear Medicine and imaging
Four-Dimensional Computed Tomography
Projection (set theory)
Lung cancer
Instrumentation
87.55.d
Mathematics
87.55.-X
4DCT
Contouring
Radiation
business.industry
Radiotherapy Planning
Computer-Assisted
Respiration
Radiotherapy Dosage
medicine.disease
Intensity (physics)
87.57.q
Radiation therapy
lung cancer
030220 oncology & carcinogenesis
Breathing
Radiology
Radiotherapy
Intensity-Modulated
Radiotherapy
Conformal
Nuclear medicine
business
Tomography
X-Ray Computed
Free breathing
Zdroj: Journal of Applied Clinical Medical Physics
ISSN: 1526-9914
Popis: The purpose of this study was to compare three computed tomography (CT) images under different conditions—average intensity projection (AIP), free breathing (FB), mid‐ventilation (MidV)—used for radiotherapy contouring and planning in lung cancer patients. Two image sets derived from four‐dimensional CT (4DCT) acquisition (AIP and MidV) and three‐dimensional CT with FB were generated and used to plan for 29 lung cancer patients. Organs at risk (OARs) were delineated for each image. AIP images were calculated with 3D conformal radiotherapy (3DCRT) and intensity‐modulated radiation therapy (IMRT). Planning with the same target coverage was applied to the FB and MidV image sets. Plans with small and large tumors were compared regarding OAR volumes, geometrical center differences in OARs, and dosimetric indices. A gamma index analysis was also performed to compare dose distributions. There were no significant differences (P > 0.05) in OAR volumes, the geometrical center differences, maximum and mean doses of the OARs between both tumor sizes. For 3DCRT, the gamma analysis results indicated an acceptable dose distribution agreement of 95% with 2%/2 mm criteria. Although, the gamma index results show distinct contrast of dose distribution outside the planning target volume (PTV) in IMRT, but within the PTV, it was acceptable. All three images could be used for OAR delineation and dose calculation in lung cancer. AIP image sets seemed to be suitable for dose calculation while patient movement between series acquisition of FB images should be considered when defining target volumes on 4DCT images.
Databáze: OpenAIRE
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