Abstract
To inform clinical practice for women receiving post-mastectomy radiotherapy (PMRT),
this study demonstrates the dosimetric impact of removing daily bolus on skin and
subcutaneous tissue. Two planning strategies were used: clinical field-based (n = 30) and volume-based planning (n = 10). The clinical field-based plans were created with bolus and recalculated without
bolus for comparison. The volume-based plans were created with bolus to ensure a minimum
target coverage of the chest wall PTV and recalculated without bolus. In each scenario,
the dose to superficial structures, including skin (3 mm and 5 mm) and subcutaneous
tissue (a 2 mm layer, 3 mm deep from surface) were reported. Additionally, the difference
in the clinically evaluated dosimetry to skin and subcutaneous tissue in volume-based
plans were recalculated using Acuros (AXB) and compared to the Anisotropic Analytical
Algorithm (AAA) algorithm. For all treatment planning strategies, chest wall coverage
(V90%) was maintained. As expected, superficial structures demonstrate significant
loss in coverage. The largest difference observed in the most superficial 3 mm where
V90% coverage is reduced from a mean (± standard deviation) of 95.1% (± 2.8) to 18.9%
(± 5.6) for clinical field-based treatments with and without bolus, respectively.
For volume-based planning, the subcutaneous tissue maintains a V90% of 90.5% (± 7.0)
compared to the clinical field-based planning coverage of 84.4% (± 8.0). In all skin
and subcutaneous tissue, the AAA algorithm underestimates the volume of the 90% isodose.
Removing bolus results in minimal dosimetric differences in the chest wall and significantly
lower skin dose while dose to the subcutaneous tissue is maintained. Unless the skin
has disease involvement, the most superficial 3 mm is not considered part of the target
volume. The continued use of the AAA algorithm is supported for the PMRT setting.
Keywords
To read this article in full you will need to make a payment
Purchase one-time access:
Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online accessOne-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:
Subscribe to Medical DosimetryAlready a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
References
- Evaluation of skin dose associated with different frequencies of bolus applications in post-mastectomy three-dimensional conformal radiotherapy.J. Exp. Clin. Cancer. Res. 2009; 28: 1-7
- Local failure and acute radiodermatological toxicity in patients undergoing radiation therapy with and without postmastectomy chest wall bolus: Is bolus ever necessary?.Pract. Radiat. Oncol. 2017; 7: 167-172
- Prospective evaluation of severe skin toxicity and pain during postmastectomy radiation therapy.Int. J. Radiat. Oncol. 2015; 91: 157-164
- Outcomes in patients treated with post-mastectomy chest wall radiotherapy without the routine use of bolus.Clin. Oncol. 2018; 30: 427-432
- The effect of bolus on local control for patients treated with mastectomy and radiation therapy.Int. J. Radiat. Oncol. 2021; 110: 1360-1369
- Variability in radiation oncologists’ opinion on the indication of a bolus in post-mastectomy radiotherapy: An international survey.Clin. Oncol. 2007; 19: 115-119
- The use of bolus in postmastectomy radiation therapy for breast cancer: A systematic review.Crit. Rev. Oncol. Hematol. 2021; 163103391
- A Delphi study and international consensus recommendations: The use of bolus in the setting of postmastectomy radiation therapy for early breast cancer.Radiother. Oncol. 2021; 164: 115-121
- Spatial location of local recurrences after mastectomy: a systematic review.Breast Cancer Res. Treat. 2020; 183: 263-273
- The effect of different lung densities on the accuracy of various radiotherapy dose calculation methods: Implications for tumour coverage.Radiother. Oncol. 2009; 91: 405-414
- Dose distributions in SBRT of lung tumors: Comparison between two different treatment planning algorithms and Monte-Carlo simulation including breathing motions.Acta. Oncol. (Madr). 2006; 45: 978-988
- Pareto front analysis of 6 and 15 MV dynamic IMRT for lung cancer using pencil beam, AAA and Monte Carlo.Phys. Med. Biol. 2010; 55: 4521-4533
- The impact of photon dose calculation algorithms on expected dose distributions in lungs under different respiratory phases.Phys. Med. Biol. 2008; 53: 2375-2390
- Dosimetric validation of the Acuros XB Advanced Dose Calculation algorithm: fundamental characterization in water.Phys. Med. Biol. 2011; 56: 2885
Hypofractionated LocoRegional Radiotherapy in Breast Cancer (RHEAL) 2020. Available at: https://www.clinicaltrials.gov/ct2/show/NCT04228991.
Regional Radiotherapy in Biomarker Low-Risk Node Positive and T3N0 Breast Cancer (TAILOR RT) 2018. Available at: https://clinicaltrials.gov/ct2/show/NCT03488693.
Breast cancer atlas for radiation therapy planning: Consensus definitions 2018. Available at: https://www.nrgoncology.org/Portals/0/ScientificProgram/CIRO/Atlases/BreastCancerAtlas_corr.pdf?ver=2018-04-18-144201-270.
- Technique and outcome of post-mastectomy adjuvant chest wall radiotherapy—the role of tissue-equivalent bolus in reducing risk of local recurrence.Br. J. Radiol. 2016; 8920160060
- The Effect of Adjuvant Postmastectomy Radiotherapy Bolus Technique on Local Recurrence.Int. J. Radiat. Oncol. 2011; 81: e165-e171
- Post-mastectomy radiation therapy without usage of a bolus may be a reasonable option.J. Radiat. Res. 2017; 58: 66-70
- Acute radiation dermatitis in breast cancer patients: Challenges and solutions.Breast Cancer Targets Ther. 2017; 9: 313-323
- Correlation between toxicity and dosimetric parameters for adjuvant intensity modulated radiation therapy of breast cancer: a prospective study.Sci. Rep. 2021; 11: 3626
- ESTRO consensus guideline on target volume delineation for elective radiation therapy of early stage breast cancer.Radiother. Oncol. 2015; 114: 3-10
- A feasibility study of 2-mm bolus for postmastectomy radiation therapy.Pract. Radiat. Oncol. 2017; 7: 161-166
- Dosimetric assessment of bolus for postmastectomy radiotherapy.Med. Dosim. 2021; 46: e1-e4
- Predictive factors for local recurrence in breast cancer.Semin. Radiat. Oncol. 2012; 22: 100-107
- Clinical implementation of AXB from AAA for breast: Plan quality and subvolume analysis.J. Appl. Clin. Med. Phys. 2018; 19: 243-250
- On the dosimetric impact of inhomogeneity management in the Acuros XB algorithm for breast treatment.Radiat. Oncol. 2011; 6: 103
Article info
Publication history
Published online: March 10, 2023
Accepted:
January 27,
2023
Received in revised form:
January 26,
2023
Received:
November 4,
2022
Publication stage
In Press Corrected ProofFootnotes
Written as desired for publication including highest academic degree.
Identification
Copyright
© 2023 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.
