TY - JOUR
T1 - Quantifying radiation dose delivered to individual shoulder muscles during breast radiotherapy
AU - Lipps, David B.
AU - Sachdev, Sean
AU - Strauss, Jonathan B.
N1 - Funding Information:
We acknowledge financial support for this work from NIH T32-HD07418 and Susan G. Komen Postdoctoral Clinical Fellowship PDF15329262. The study sponsors had no involvement in the study design, in the collection, analysis and interpretation of data; in the writing of the manuscript; and in the decision to submit the manuscript for publication.
Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2017/3/1
Y1 - 2017/3/1
N2 - Background and purpose Radiotherapy is an effective treatment for managing breast cancer, but patients may experience shoulder morbidity after completing radiotherapy. There is a knowledge gap regarding how the inclusion of the regional lymphatics in radiation treatment regimens influence the radiation dose delivered to the underlying shoulder musculature. Material and methods Five standardized radiation treatment regimens were developed from the computed tomography (CT) scans of 11 patients: tangent fields only (T), high tangent fields (HT), T + supraclavicular fossa and axillary apex with an anterior oblique beam (SCV), T + SCV + axillary nodes with an anterior oblique beam (SCV + AX), and T + SCV + AX with the nodal regions treated with a directly opposed beam configuration (DO). The muscle volumes for nine shoulder muscles anatomically located with the treatment regimens were segmented from the same CT scans. The effect of the nine muscles and five treatment regimens on the percentage of each muscle receiving at least 48 Gy (V48 Gy) was analyzed with two-way and one-way repeated measures ANOVAs. Results A statistically significant interaction existed between the nine shoulder muscles and five treatment regimens (p < 0.001) on the V48 Gy dose. Subsequent one-way analyses found statistically significant main effects of treatment plan on the V48 Gy dose for each muscle (p < 0.001). The pectoralis major and minor had the greatest V48 doses across the five treatments regimens. The HT, SCV + AX and DO treatment regimens produced statistically significant increases in the V48 dose of the latissimus dorsi and teres major. The infraspinatus, subscapularis, supraspinatus, teres minor, and trapezius only observed statistically significant V48 doses when treated with a DO plan. Conclusions These findings highlight the muscles (pectoralis major, pectoralis minor, latissimus dorsi, and teres major) that may exhibit future morbidity after radiation, and indicate that nodal RT delivered with a DO beam arrangement delivers the highest muscle dose.
AB - Background and purpose Radiotherapy is an effective treatment for managing breast cancer, but patients may experience shoulder morbidity after completing radiotherapy. There is a knowledge gap regarding how the inclusion of the regional lymphatics in radiation treatment regimens influence the radiation dose delivered to the underlying shoulder musculature. Material and methods Five standardized radiation treatment regimens were developed from the computed tomography (CT) scans of 11 patients: tangent fields only (T), high tangent fields (HT), T + supraclavicular fossa and axillary apex with an anterior oblique beam (SCV), T + SCV + axillary nodes with an anterior oblique beam (SCV + AX), and T + SCV + AX with the nodal regions treated with a directly opposed beam configuration (DO). The muscle volumes for nine shoulder muscles anatomically located with the treatment regimens were segmented from the same CT scans. The effect of the nine muscles and five treatment regimens on the percentage of each muscle receiving at least 48 Gy (V48 Gy) was analyzed with two-way and one-way repeated measures ANOVAs. Results A statistically significant interaction existed between the nine shoulder muscles and five treatment regimens (p < 0.001) on the V48 Gy dose. Subsequent one-way analyses found statistically significant main effects of treatment plan on the V48 Gy dose for each muscle (p < 0.001). The pectoralis major and minor had the greatest V48 doses across the five treatments regimens. The HT, SCV + AX and DO treatment regimens produced statistically significant increases in the V48 dose of the latissimus dorsi and teres major. The infraspinatus, subscapularis, supraspinatus, teres minor, and trapezius only observed statistically significant V48 doses when treated with a DO plan. Conclusions These findings highlight the muscles (pectoralis major, pectoralis minor, latissimus dorsi, and teres major) that may exhibit future morbidity after radiation, and indicate that nodal RT delivered with a DO beam arrangement delivers the highest muscle dose.
KW - Axillary radiotherapy
KW - Breast cancer
KW - Computed tomography
KW - Dose–volume histograms
KW - Radiotherapy morbidity
KW - Radiotherapy treatment planning
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U2 - 10.1016/j.radonc.2016.12.032
DO - 10.1016/j.radonc.2016.12.032
M3 - Article
C2 - 28129897
AN - SCOPUS:85010223449
SN - 0167-8140
VL - 122
SP - 431
EP - 436
JO - Radiotherapy and Oncology
JF - Radiotherapy and Oncology
IS - 3
ER -
