Serenella Russo1, Marco Esposito2, Victor Hernandez3, Jordi Saez4, Francesca Rossi5, Lisa Paoletti5, Silvia Pini2, Paolo Bastiani5, Giacomo Reggiori6, Giorgia Nicolini7, Eugenio Vanetti7, Stefano Tomatis6, Marta Scorsetti8, Pietro Mancosu6. 1. Medical Physics Unit, AUSL Toscana Centro, Florence, Italy. Electronic address: serenella.russo@uslcentro.toscana.it. 2. Medical Physics Unit, AUSL Toscana Centro, Florence, Italy. 3. Department of Medical Physics, Hospital Universitari Sant Joan de Reus, Tarragona, Spain. 4. Radiation Oncology Department, Hospital Clinic de Barcelona, Barcelona, Spain. 5. Radiotherapy Unit, AUSL Toscana Centro, Florence, Italy. 6. Medical Physicist Group of Radiotherapy and Radiosurgery Dept., Humanitas Clinical and Research Hospital IRCCS, Milan-Rozzano, Italy. 7. Medical Physics Team, Radiqa Developments, Bellinzona, Switzerland. 8. Radiotherapy and Radiosurgery Dept, Humanitas Clinical and Research Hospital IRCCS, Milan-Rozzano, Italy; Department of Biomedical Sciences, Humanitas University, Milan-Rozzano, Italy.
Abstract
PURPOSE: Volumetric modulated arc therapy (VMAT) for left breast treatments allows heart sparing without compromising PTV coverage. However, this technique may require highly complex plans. Deep Inspiration Breath Hold (DIBH) procedure increases the heart-to-breast distance, facilitating the dose sparing of the heart. The aim of the present work was to investigate if the cardiac-sparing benefits of the DIBH technique were achieved with lower plan modulation and complexity than Free Breathing (FB) treatments. METHODS AND MATERIALS: Ten left side breast cases were considered by two centers with different treatment planning systems (TPS) and Linacs. VMAT plans were elaborated in FB and DIBH according to the same protocol. Plan complexity was evaluated by scoring several complexity indices. A new global score index accounting for both plan quality and dosimetric parameters was defined. Pre-treatment QA was performed for all VMAT plans using EPID and Epiqa software. RESULTS: DIBH-VMAT plans were associated with significant PTV coverage improvement and mean heart dose reduction (p < 0.003), increasing the resulting global score index. All the evaluated complexity indices showed lower plan complexity for DIBH plans than FB ones, but only in few cases the results were statistically significant. All plans passed the gamma analysis with the selected criteria. CONCLUSIONS: The DIBH technique is superior to the FB technique when the heart needs further sparing, allowing a reduction of the doses to OARs with a slightly lower degree of plan complexity and without compromising plan deliverability. These benefits were achieved regardless of the technological scenarios adopted.
PURPOSE: Volumetric modulated arc therapy (VMAT) for left breast treatments allows heart sparing without compromising PTV coverage. However, this technique may require highly complex plans. Deep Inspiration Breath Hold (DIBH) procedure increases the heart-to-breast distance, facilitating the dose sparing of the heart. The aim of the present work was to investigate if the cardiac-sparing benefits of the DIBH technique were achieved with lower plan modulation and complexity than Free Breathing (FB) treatments. METHODS AND MATERIALS: Ten left side breast cases were considered by two centers with different treatment planning systems (TPS) and Linacs. VMAT plans were elaborated in FB and DIBH according to the same protocol. Plan complexity was evaluated by scoring several complexity indices. A new global score index accounting for both plan quality and dosimetric parameters was defined. Pre-treatment QA was performed for all VMAT plans using EPID and Epiqa software. RESULTS: DIBH-VMAT plans were associated with significant PTV coverage improvement and mean heart dose reduction (p < 0.003), increasing the resulting global score index. All the evaluated complexity indices showed lower plan complexity for DIBH plans than FB ones, but only in few cases the results were statistically significant. All plans passed the gamma analysis with the selected criteria. CONCLUSIONS: The DIBH technique is superior to the FB technique when the heart needs further sparing, allowing a reduction of the doses to OARs with a slightly lower degree of plan complexity and without compromising plan deliverability. These benefits were achieved regardless of the technological scenarios adopted.
Authors: Sophie Chiavassa; Igor Bessieres; Magali Edouard; Michel Mathot; Alexandra Moignier Journal: Br J Radiol Date: 2019-07-24 Impact factor: 3.039
Authors: Sara Poeta; Younes Jourani; Alex De Caluwé; Robbe Van den Begin; Dirk Van Gestel; Nick Reynaert Journal: Radiat Oncol Date: 2021-04-20 Impact factor: 3.481