Set-Up Errors, Organ Motion, Tumour Regression and its Implications on Internal Target Volume–Planning Target Volume During Cervical Cancer Radiotherapy: Results From a Prospective Study
| Autor: | Supriya Chopra, Shyamkishore Shrivastava, A. Dheera, D. Epili, Umesh Mahantshetty, P. Naga, Libin Scaria, Yogesh Ghadi, G. Lavanya, A. Nachankar |
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| Rok vydání: | 2022 |
| Předmět: |
Tumour regression
medicine.medical_treatment Planning target volume Uterine Cervical Neoplasms Anterior margin Cervix Uteri Radiotherapy Setup Errors Organ Motion medicine Humans Radiology Nuclear Medicine and imaging Prospective Studies Prospective cohort study Image-guided radiation therapy Cervical cancer business.industry Radiotherapy Planning Computer-Assisted Radiotherapy Dosage Cone-Beam Computed Tomography medicine.disease Radiation therapy Oncology Female business Nuclear medicine Radiotherapy Image-Guided |
| Zdroj: | Clinical Oncology. 34:189-197 |
| ISSN: | 0936-6555 |
| DOI: | 10.1016/j.clon.2021.10.010 |
| Popis: | Uterocervical motions and organ filling during cervical cancer conformal radiotherapy is complex. This prospective, observational study investigated set-up margins (clinical target vo, ume [CTV] to planning target volume [PTV]) for pelvic nodal CTV and internal margin (CTV to internal target volume [ITV]) expansions for uterocervical movements during cervical cancer radiotherapy.During cervical cancer radiotherapy, a daily kilovoltage, cone-beam computed tomography (CBCT) scan was acquired. Bony anatomy-based rigid co-registration and matching to vessels/pelvic nodal region was carried out to document shifts, errors (systematic and random) and to calculate CTV to PTV margins. Subsequently, soft-tissue matching was carried out at the mid-cervical region and uterine fundus to record shifts, errors and to calculate CTV to ITV margins.In 67 patients, 1380 CBCT scans were analysed. The mean (±standard deviation) couch shifts for CTV pelvic nodal region in all directions were within 4.5-5.3 mm, systematic and random errors 3.0-3.6 mm and set-up margins of within 10 mm (except anterior margin 10.3 mm). For the mid-cervical region, mean shifts were 4.5-5.5 mm, systematic and random errors 2-4 mm amounting to10 mm internal margins (CTV-ITV for cervix) and for uterine fundus mean (±standard deviation) shifts were larger in the superior direction (12.1 mm) but 4.0-7.5 mm in other directions, systematic and random errors 2-7 mm amounting to anisotropic margins in various directions (10 mm in anterior-posterior and lateral directions, 12-20 mm in superior-inferior directions) (CTV-ITV for uterine fundus).Our study suggests anisotropic CTV to ITV and CTV to PTV margins for cervical cancer radiotherapy. |
| Databáze: | OpenAIRE |
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