PURPOSE: The aims of this study were to determine the changes in breast and excision cavity volumes after whole-breast irradiation and the adequacy of using the surgical scar to guide boost planning. METHODS AND MATERIALS: A total of 30 women consecutively treated for 31 breast cancers were included in this study. Simulation CT scans were performed before and after whole-breast irradiation. CT breast volumes were delineated using clinically defined borders. Excision cavity volumes were contoured based on surgical clips, the presence of a hematoma, and/or other surgical changes. Hypothetical electron boost plans were generated using the surgical scar with a 3-cm margin and analyzed for coverage. RESULTS: The mean CT breast volumes were 774 and 761 cc (p = 0.22), and the excision cavity volumes were 32.1 and 25.1 cc (p < 0.0001), before and after 40 Gy (39-42 Gy) of whole-breast irradiation, respectively. The volume reduction in the excision cavity was inversely correlated with time elapsed since surgery (R = 0.46, p < 0.01) and body weight (R = 0.50, p < 0.01). The scar-guided hypothetical plans failed to cover the excision cavity adequately in 62% and 53.8% of cases using the pretreatment and postradiation CTs, respectively. Per the hypothetical plans, the minimum dose to the excision cavity was significantly lower for tumors located in the inner vs. outer quadrants (p = 0.02) and for cavities >20 cc vs. <20 cc (p = 0.01). CONCLUSIONS: This study demonstrates a significant reduction in the volume of the excision cavity during whole-breast irradiation. Scar-guided boost plans provide inadequate coverage of the excision cavity in the majority of cases.
PURPOSE: The aims of this study were to determine the changes in breast and excision cavity volumes after whole-breast irradiation and the adequacy of using the surgical scar to guide boost planning. METHODS AND MATERIALS: A total of 30 women consecutively treated for 31 breast cancers were included in this study. Simulation CT scans were performed before and after whole-breast irradiation. CT breast volumes were delineated using clinically defined borders. Excision cavity volumes were contoured based on surgical clips, the presence of a hematoma, and/or other surgical changes. Hypothetical electron boost plans were generated using the surgical scar with a 3-cm margin and analyzed for coverage. RESULTS: The mean CT breast volumes were 774 and 761 cc (p = 0.22), and the excision cavity volumes were 32.1 and 25.1 cc (p < 0.0001), before and after 40 Gy (39-42 Gy) of whole-breast irradiation, respectively. The volume reduction in the excision cavity was inversely correlated with time elapsed since surgery (R = 0.46, p < 0.01) and body weight (R = 0.50, p < 0.01). The scar-guided hypothetical plans failed to cover the excision cavity adequately in 62% and 53.8% of cases using the pretreatment and postradiation CTs, respectively. Per the hypothetical plans, the minimum dose to the excision cavity was significantly lower for tumors located in the inner vs. outer quadrants (p = 0.02) and for cavities >20 cc vs. <20 cc (p = 0.01). CONCLUSIONS: This study demonstrates a significant reduction in the volume of the excision cavity during whole-breast irradiation. Scar-guided boost plans provide inadequate coverage of the excision cavity in the majority of cases.
Authors: José Luis Guinot; M Isabel Tortajada; María Carrascosa; Vicente Crispín; Ana Otero; Belén Ríos; Eleonor Rivin; Miguel Santos; Pablo Soler; Leoncio Arribas Journal: Clin Transl Oncol Date: 2012-02 Impact factor: 3.405
Authors: Maria C De Santis; Luigia Nardone; Barbara Diletto; Roberta Canna; Michela Dispinzieri; Lorenza Marino; Laura Lozza; Vincenzo Valentini Journal: Br J Radiol Date: 2016-07-25 Impact factor: 3.039
Authors: Christopher Jason Tien; Robert Ebeling; Jessica R Hiatt; Bruce Curran; Edward Sternick Journal: Front Oncol Date: 2012-08-06 Impact factor: 6.244