A dosimetry study of post-mastectomy radiation therapy with AeroForm tissue expander Journal Article
| Authors: | Lim, S. B.; Kuo, L. C.; Li, G.; Kuo, H. C.; McCormick, B.; Cahlon, O.; Powell, S.; Hong, L. X. |
| Article Title: | A dosimetry study of post-mastectomy radiation therapy with AeroForm tissue expander |
| Abstract: | Purpose: To evaluate the dosimetric effects of the AeroFormTM (AirXanpders®, Palo Alto, CA) tissue expander in-situ for breast cancer patients receiving post-mastectomy radiation therapy. Methods and Materials: A film phantom (P1) was constructed by placing the metallic canister of the AeroForm on a solid water phantom with EBT3 films at five depths ranging from 2.6 mm to 66.2 mm. A breast phantom (P2), a three-dimensional printed tissue-equivalent breast with fully expanded AeroForm in-situ, was placed on a thorax phantom. A total of 21 optical luminescent dosimeters (OLSDs) were placed on the anterior skin–gas interface and the posterior chest wall–metal interface of the AeroForm. Both phantoms were imaged with a 16-bit computed tomography scanner with orthopedic metal artifact reduction. P1 was irradiated with an open field utilizing 6 MV and 15 MV photon beams at 0°, 90°, and 270°. P2 was irradiated using a volumetric modulated arc therapy plan with a 6 MV photon beam and a tangential plan with a 15 MV photon beam. All doses were calculated using Eclipse (Varian, Palo Alto, CA) with AAA and AcurosXB (AXB) algorithms. Results: The average dose differences between film measurements and AXB in the region adjacent to the canister in P1 were within 3.1% for 15 MV and 0.9% for 6 MV. Local dose differences over 10% were also observed. In the chest wall region of P2, the median dose of OLSDs in percentage of prescription dose were 108.4% (range 95.4%–113.0%) for the 15MV tangential plan and 110.4% (range 99.1%–113.8%) for the 6MV volumetric modulated arc therapy plan. In the skin–gas interface, the median dose of the OLSDs were 102.3% (range 92.7%–107.7%) for the 15 MV plan and 108.2% (range 97.8–113.5%) for the 6 MV plan. Measured doses were, in general, higher than calculated doses with AXB calculations. The AAA dose algorithms produced results with slightly larger discrepancies between measurements compared with AXB. Conclusions: The AeroForm creates significant dose uncertainties in the chest wall–metal interface. The AcurosXB dose calculation algorithm is recommended for more accurate calculations. If possible, post-mastectomy radiation therapy should be delivered after the permanent implant is in place. © 2020 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals LLC on behalf of American Association of Physicists in Medicine. |
| Keywords: | breast cancer; film dosimetry; aeroform tissue expander; olsd dosimetry; post-mastectomy radiation therapy |
| Journal Title: | Journal of Applied Clinical Medical Physics |
| Volume: | 21 |
| Issue: | 9 |
| ISSN: | 1526-9914 |
| Publisher: | American College of Medical Physics |
| Date Published: | 2020-09-01 |
| Start Page: | 33 |
| End Page: | 38 |
| Language: | English |
| DOI: | 10.1002/acm2.12962 |
| PUBMED: | 32614518 |
| PROVIDER: | scopus |
| PMCID: | PMC7497932 |
| DOI/URL: | |
| Notes: | Article -- Export Date: 1 October 2020 -- Source: Scopus |
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