Cone-Beam CT-based position verification for oesophageal cancer: Evaluation of registration methods and anatomical changes during radiotherapy

Autor: M. Van der Sangen, M. van Boxtel, A. Van Nunen, P. M. A. van Haaren
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Cone beam computed tomography
medicine.medical_treatment
030218 nuclear medicine & medical imaging
law.invention
0302 clinical medicine
law
Setup variations
OAR
Organs at Risk
Anatomical changes
skin and connective tissue diseases
Diaphragm (optics)
PET/CT
Positron Emission Tomography/Computed Tomography
SCC
Squamous Cell Carcinoma
Oncology (nursing)
Health Policy
Oesophageal cancer
PTV
Planning Target Volume
Soft tissue
lcsh:Neoplasms. Tumors. Oncology. Including cancer and carcinogens
TPS
Treatment Planning System
CTV
Clinical Target Volume
030220 oncology & carcinogenesis
CBCT
Cone Beam Computed Tomography
IMRT
Intensity Modulated Radiotherapy
Radiology
Cone-Beam CT
lcsh:Medical physics. Medical radiology. Nuclear medicine
medicine.medical_specialty
Setup margins
lcsh:R895-920
lcsh:RC254-282
EPID
Electronic Portal Imaging Device
03 medical and health sciences
Position (vector)
Research article
medicine
Radiology
Nuclear Medicine and imaging
Care Planning
Reduction (orthopedic surgery)
Image-guided radiation therapy
PET-CT
SAL
Shrinking Action Level
business.industry
GTV
Gross Tumor Volume
equipment and supplies
AC
Adenocarcinoma
EUS
Endoscopic UltraSound
Radiation therapy
IGRT
Image Guided RadioTherapy
sense organs
business
Nuclear medicine
Zdroj: Technical Innovations & Patient Support in Radiation Oncology, Vol 3, Iss C, Pp 30-36 (2017)
Technical Innovations & Patient Support in Radiation Oncology
ISSN: 2405-6324
Popis: Highlights • Different registration methods for position verification of oesophageal cancer. • Clipbox around PTV and vertebrae with soft tissue match was best suited. • Tumour location influences the required setup margins. • A large variety of anatomical changes is revealed when using kV-CBCT. • GTV Reduction and diaphragm position changes were most common anatomical changes.
Purpose To evaluate different registration methods, setup margins and number of corrections for CBCT-based position verification for oesophageal cancer and to evaluate anatomical changes during the course of radiotherapy treatment. Methods From 50 patients, 440 CBCT-scans were registered automatically using a soft tissue or bone registration algorithm and compared to the clinical match. Moreover, relevant anatomical changes were monitored. A sub-analysis was performed to evaluate if tumour location influenced setup variations. Margin calculation was performed and the number of setup corrections was estimated. Results were compared to a patient group previously treated with MV-EPID based position verification. Results CBCT-based setup variations were smaller than EPID-based setup variations, resulting in smaller setup margins of 5.9 mm (RL), 7.5 mm (CC) and 4.7 mm (AP) versus 6.0 mm, 7.8 mm and 5.5 mm, respectively. A reduction in average number of setup corrections per patient was found from 0.75 to 0.36. From all automatically registered CBCT-scans, a clipbox around PTV and vertebras combined with soft tissue registration resulted in the smallest setup margins of 5.9 mm (RL), 7.7 mm (CC), 4.8 mm (AP) and smallest average number of corrections of 0.38. For distally located tumours, a setup margin of 7.7 mm (CC) was required compared to 5.6 mm for proximal tumours. Reduction of GTV volume, heart volume and change in diaphragm position were observed in 16, 10 and 15 patients, respectively. Conclusions CBCT-based set-up variations are smaller than EPID-based variations and vary according to tumour location. When using kV-CBCT a large variety of anatomical changes is revealed, which cannot be observed with MV-EPID.
Databáze: OpenAIRE
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