Computed Tomography-Based Evaluation of Volume and Position Changes of the Target Region and Organs at Risk During Radiotherapy for Esophageal Cancer: A Pilot Study
| Autor: | Xiaowu Deng, Qiwen Li, Jun Zhang, Hui Liu, Ya-Ru Ma, Bo Qiu, Yinglin Peng, Yimei Liu, Guanzhu Shen, Li-Rong Fu, Meining Chen |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Cancer Research
medicine.medical_treatment Planning target volume Computed tomography Volume change 03 medical and health sciences 0302 clinical medicine medicine esophageal cancer geometric center deviation RC254-282 Original Research medicine.diagnostic_test business.industry Isocenter Neoplasms. Tumors. Oncology. Including cancer and carcinogens Esophageal cancer medicine.disease Gross tumor volume Radiation therapy volume changed ratio Oncology adaptive radiotherapy 030220 oncology & carcinogenesis target retraction business Nuclear medicine 030217 neurology & neurosurgery Volume (compression) |
| Zdroj: | Frontiers in Oncology, Vol 11 (2021) Frontiers in Oncology |
| DOI: | 10.3389/fonc.2021.702400/full |
| Popis: | ObjectiveTo analyze changes in volume and position of target regions and organs at risk (OARs) during radiotherapy for esophageal cancer patients.MethodsOverall, 16 esophageal cancer patients who underwent radiotherapy, including 10 cases of intensity-modulated radiation therapy (IMRT) and six of three-dimensional conformal radiotherapy (3D-CRT), were enrolled. The prescription doses for the planning target volumes (PTVs) were as follows: PTV1, 64 Gy/32 fractions; and PTV2, 46 Gy/23 fractions. Repeat computed tomography (CT) was performed for patients after the 5th, 10th, 15th, 20th, and 25th fractions. Delineation of the gross tumor volume (GTV) and OAR volume was determined using five repeat CTs performed by the same physician. The target and OAR volumes and centroid positions were recorded and used to analyze volume change ratio (VCR), center displacement (ΔD), and changes in the distance from the OAR centroid positions to the planned radiotherapy isocenter (distance to isocenter, DTI) during treatment.ResultsNo patient showed significant changes in target volume (TV) after the first week of radiotherapy (five fractions). However, TV gradually decreased over the following weeks, with the rate slowing after the fourth week (40 Gy). The comparison of TV from baseline to 40 Gy (20 fractions) showed that average GTVs decreased from 130.7 ± 63.1 cc to 92.1 ± 47.2 cc, with a VCR of −29.21 ± 13.96% (ppConclusionDuring radiotherapy for esophageal cancer, Targets and OARs change significantly in volume and position during the 2nd–4th weeks. Image-guidance and evaluation of dosimetric changes are recommended for these fractions of treatment to appropriate adjust treatment plans. |
| Databáze: | OpenAIRE |
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