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A multicentre study of the evidence for customized margins in photon breast boost radiotherapy.
- Source :
-
The British journal of radiology [Br J Radiol] 2016; Vol. 89 (1058), pp. 20150603. Date of Electronic Publication: 2015 Nov 20. - Publication Year :
- 2016
-
Abstract
- Objective: To determine if subsets of patients may benefit from smaller or larger margins when using laser setup and bony anatomy verification of breast tumour bed (TB) boost radiotherapy (RT).<br />Methods: Verification imaging data acquired using cone-beam CT, megavoltage CT or two-dimensional kilovoltage imaging on 218 patients were used (1574 images). TB setup errors for laser-only setup (dlaser) and for bony anatomy verification (dbone) were determined using clips implanted into the TB as a gold standard for the TB position. Cases were grouped by centre-, patient- and treatment-related factors, including breast volume, TB position, seroma visibility and surgical technique. Systematic (Σ) and random (σ) TB setup errors were compared between groups, and TB planning target volume margins (MTB) were calculated.<br />Results: For the study population, Σlaser was between 2.8 and 3.4 mm, and Σbone was between 2.2 and 2.6 mm, respectively. Females with larger breasts (p = 0.03), easily visible seroma (p ≤ 0.02) and open surgical technique (p ≤ 0.04) had larger Σlaser. Σbone was larger for females with larger breasts (p = 0.02) and lateral tumours (p = 0.04). Females with medial tumours (p < 0.01) had smaller Σbone.<br />Conclusion: If clips are not used, margins should be 8 and 10 mm for bony anatomy verification and laser setup, respectively. Individualization of TB margins may be considered based on breast volume, TB and seroma visibility.<br />Advances in Knowledge: Setup accuracy using lasers and bony anatomy is influenced by patient and treatment factors. Some patients may benefit from clip-based image guidance more than others.
- Subjects :
- Adult
Aged
Aged, 80 and over
Anatomic Landmarks
Breast Neoplasms pathology
Female
Humans
Middle Aged
Neoplasm Recurrence, Local
Patient Positioning
Photons
Radiographic Image Interpretation, Computer-Assisted
Radiotherapy Planning, Computer-Assisted
Radiotherapy, Image-Guided
United Kingdom
Breast Neoplasms diagnostic imaging
Breast Neoplasms radiotherapy
Cone-Beam Computed Tomography methods
Radiotherapy Setup Errors prevention & control
Subjects
Details
- Language :
- English
- ISSN :
- 1748-880X
- Volume :
- 89
- Issue :
- 1058
- Database :
- MEDLINE
- Journal :
- The British journal of radiology
- Publication Type :
- Academic Journal
- Accession number :
- 26585543
- Full Text :
- https://doi.org/10.1259/bjr.20150603