The Lack of Consensus of International Contouring Guidelines for the Dorsal Border of the Chest Wall Clinical Target Volume: What is the Impact on Organs at Risk and Relationships to Patterns of Recurrence in the Modern Era?

Authors

Phillip M. Pifer, West Virginia University
Robert P. Bice, West Virginia University
Geraldine M. Jacobson, West Virginia University
Kristin Lupinacci, West Virginia University
Sushil Beriwal, University of Pittsburgh
Hannah W. Hazard, West Virginia University
John A. Vargo, West Virginia University

Document Type

Article

Publication Date

2019

College/Unit

School of Medicine

Department/Program/Center

Radiation Oncology

Abstract

Purpose

Variation exists in cooperative group recommendations for the dorsal border for the chest wall clinical target volume (CTV). We aimed to quantify the impact of this variation on doses to critical organs and examine patterns of chest wall recurrence relative to the pectoralis muscle.

Methods and Materials

We retrospectively assessed patterns of chest wall recurrence quantified to the recommended CTV borders for women treated between 2005 and 2017. We compared treatment plans for 5 women who were treated with left postmastectomy radiation therapy, with the chest wall contoured using varying dorsal borders for CTV: (1) Anterior pleural surface (Radiation Therapy Oncology Group), (2) anterior surface of pectoralis major (European Society for Radiotherapy and Oncology), and (3) anterior rib surface (institutional practice). Treatment plans were generated for 50 Gy in 25 fractions. Doses to organs-at-risk were compared using paired-sample t tests.

Results

Institutional patterns of chest wall recurrence were 64.7% skin and subcutaneous tissue, 23.5% both anterior to and between the pectoralis muscles, and 11.8% isolated to the tissue between the pectoralis major and minor. No chest wall recurrences were noted deep to pectoralis minor. When comparing the plans generated per the Radiation Therapy Oncology Group versus European Society for Radiotherapy and Oncology contouring guidelines, the mean lung V20Gy, heart mean dose, and left anterior descending artery mean dose were 33.5% versus 29.4% (P < .01), 5.2 Gy versus 3.2Gy (P = .02), and 27.3Gy versus 17.8Gy (P = .04), respectively.

Conclusions

The recommended variations in the dorsal chest wall CTV border have significant impact on doses to the heart and lungs. Although our study was limited by small numbers, our institutional patterns of recurrence would support a more anterior dorsal border for the chest wall CTV consistent with older literature

Digital Commons Citation

Pifer, Phillip M.; Bice, Robert P.; Jacobson, Geraldine M.; Lupinacci, Kristin; Beriwal, Sushil; Hazard, Hannah W.; and Vargo, John A., "The Lack of Consensus of International Contouring Guidelines for the Dorsal Border of the Chest Wall Clinical Target Volume: What is the Impact on Organs at Risk and Relationships to Patterns of Recurrence in the Modern Era?" (2019). Faculty & Staff Scholarship. 2350.
https://researchrepository.wvu.edu/faculty_publications/2350

Source Citation

Pifer, P. M., Bice, R. P., Jacobson, G. M., Lupinacci, K., Beriwal, S., Hazard, H. W., & Vargo, J. A. (2019). The Lack of Consensus of International Contouring Guidelines for the Dorsal Border of the Chest Wall Clinical Target Volume: What is the Impact on Organs at Risk and Relationships to Patterns of Recurrence in the Modern Era? Advances in Radiation Oncology, 4(1), 35–42. https://doi.org/10.1016/j.adro.2018.09.008

Comments

2452-1094/! 2018 The Author(s). Published by Elsevier Inc. on behalf of American Society for Radiation Oncology. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).