New fractionations in breast cancer: a dosimetric study of 3D‐CRT versus VMAT. Issue 2 (22nd September 2021)

• Record Type: Journal Article
• Authors: Piras, Antonio; Menna, Sebastiano; D'Aviero, Andrea; Marazzi, Fabio; Mazzini, Alberto; Cusumano, Davide; Massaccesi, Mariangela; Mattiucci, Gian Carlo; Daidone, Antonino; Valentini, Vincenzo; Boldrini, Luca
• Is Part Of: Journal of medical radiation sciences. Volume 69:Issue 2(2022)
• Page Start: 227
• Page End: 235
• Publication Date: 2021-09-22
• Subjects: early breast cancer -- hypofractionated treatment -- radiotherapy -- three‐dimensional conformal radiation therapy -- volumetric modulated arc therapy; Radiology, Medical -- Periodicals; Radiology, Medical -- Australia -- Periodicals; Radiology, Medical -- New Zealand -- Periodicals; Radiotherapy -- Periodicals; Diagnostic imaging -- Periodicals; 616
• DOI: 10.1002/jmrs.530
• Languages: English
• ISSNs: 2051-3895

Abstract

Abstract: Introduction: Adjuvant radiation therapy (RT) following primary surgery in women affected by early breast cancer (EBC) plays a central role in reducing local recurrences and overall mortality. The FAST‐FORWARD trial recently demonstrated that 1‐week hypofractionated adjuvant RT is not inferior to the standard schedule in terms of local relapse, cosmetic outcomes and toxicity. The aim of this in silico study was to evaluate the dosimetric aspects of a 1‐week RT course, administered through volumetric modulated arc therapy (VMAT), compared with traditional three‐dimensional conformal radiation therapy (3D‐CRT) with tangential fields. Methods: Patients affected by left‐side EBC undergoing adjuvant RT were selected. ESTRO guidelines for the clinical target volume (CTV) delineation and FAST‐FORWARD protocol for CTV to planning target volume (PTV) margin definition were followed. Total prescribed dose was 26 Gy in five fractions. The homogeneity index (HI) and the global conformity index (GCI) were taken into account for planning and dose distribution optimisation purposes. Both 3D‐CRT tangential fields and VMAT plans were generated for each patient. Results: The analysis included 21 patients. PTV coverage comparison between 3D‐CRT and VMAT plans showed significant increases for GCI ( P < 0.05) in VMAT technique; no statistically significant differences were observed regarding HI. For organs at risks (OAR), statistically significant increases were observed in terms of skin V103% ( P < 0.002) and ipsilateral lung V30% ( P < 0.05) with 3D‐CRT and of heart V5% ( P < 0.05) with VMAT technique. Conclusions: This in silico study showed that both 3D‐CRT and VMAT are dosimetrically feasible techniques in the framework of 1‐week hypofractionated treatments for left EBC. Abstract : The aim of this in silico study was to evaluate the dosimetric aspects of 1‐week RT course administered with VMAT technique, compared with 3D‐CRT tangential field traditional irradiation technique in adjuvant treatment of breast cancer. A total of 21 patients with left‐side early breast cancer were selected, and 3D‐CRT tangential fields and VMAT plans were generated for each patient. The results showed that both 3D‐CRT and VMAT are feasible techniques in terms of dosimetric outcomes.