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Effect of abdominal compression on target movement and extension of the external boundary of peripheral lung tumours treated with stereotactic radiotherapy based on four-dimensional computed tomography
- Source :
- Radiation Oncology (London, England), Radiation Oncology, Vol 16, Iss 1, Pp 1-8 (2021)
- Publication Year :
- 2021
-
Abstract
- Background This study aimed to investigate the effect of abdominal compression on tumour motion and target volume and to determine suitable planning target volume (PTV) margins for patients treated with lung stereotactic body radiotherapy (SBRT) based on four-dimensional computed tomography (4DCT). Methods Twenty-three patients diagnosed to have a peripheral pulmonary tumour were selected and divided into an all lesions group (group A), an upper middle lobe lesions group (group B), and a lower lobe lesions group (group C). Two 4DCT scans were performed in each patient, one with and one without abdominal compression. Cone beam computed tomography (CBCT) was performed before starting treatment. The gross target volumes (GTVs) were delineated and internal gross target volumes (IGTVs) were defined. IGTVs were generated using two methods: (1) the maximum intensity projections (MIPs) based on the 4DCT were reconstructed to form a single volume and defined as the IGTVMIP and (2) GTVs from all 10 phases were combined to form a single volume and defined as the IGTV10. A 5-mm, 4-mm, and 3-mm margin was added in all directions on the IGTVMIP and the volume was constructed as PTVMIP5mm, PTVMIP4mm, and PTVMIP3mm. Results There was no significant difference in the amplitude of tumour motion in the left–right, anterior–posterior, or superior-inferior direction according to whether or not abdominal compression was applied (group A, p = 0.43, 0.27, and 0.29, respectively; group B, p = 0.46, 0.15, and 0.45; group C, p = 0.79, 0.86, and 0.37; Wilcoxon test). However, the median IGTVMIP without abdominal compression was 33.67% higher than that with compression (p = 0.00), and the median IGTV10 without compression was 16.08% higher than that with compression (p = 0.00). The median proportion of the degree of inclusion of the IGTVCBCT in PTVMIP5mm, PTVMIP4mm, and PTVMIP3mm ≥ 95% was 100%, 100%, and 83.33%, respectively. Conclusions Abdominal compression was useful for reducing the size of the IGTVMIP and IGTV10 and for decreasing the PTV margins based on 4DCT. In IGTVMIP with abdominal compression, adding a 4-mm margin to account for respiration is feasible in SBRT based on 4DCT.
- Subjects :
- Adult
Male
Peripheral pulmonary tumour
Cone beam computed tomography
Lung Neoplasms
Abdominal compression
medicine.medical_treatment
Four-dimensional computed tomography
R895-920
Radiosurgery
Medical physics. Medical radiology. Nuclear medicine
Medicine
Humans
Radiology, Nuclear Medicine and imaging
Prospective Studies
RC254-282
Aged
Four-Dimensional Computed Tomography
Lung
business.industry
Radiotherapy Planning, Computer-Assisted
Research
Neoplasms. Tumors. Oncology. Including cancer and carcinogens
Cone-Beam Computed Tomography
Middle Aged
Compression (physics)
Peripheral
Tumor Burden
Radiation therapy
medicine.anatomical_structure
Oncology
Stereotactic body radiation therapy
Female
Nuclear medicine
business
Volume (compression)
Subjects
Details
- ISSN :
- 1748717X
- Volume :
- 16
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- Radiation oncology (London, England)
- Accession number :
- edsair.doi.dedup.....115ed305e6d336b3305aad71ca2aa00c