ABSTRACT
Introduction: Parallel with the emerging results of the FAST-Forward (FF) trial, we implemented ultrahypofractionated radiation therapy (RT) for early-stage breast cancer in our clinic at the beginning of the COVID-19 pandemic [Brunt 2020]. This scheme of 26 Gy in 5 consecutive fractions, was given to all breast cancer patients referred for postoperative RT of the breast only. Uniquely, in view of the pandemic, we also gave a single ultrahypofractionated sequential tumourbed boost of 6 Gy, if indicated according to our local protocol. The aim of this prospective study was to assess 2-year late normal tissue effects in this cohort of breast cancer patients. Method(s): Data was recorded in a prospective database. Early results were published before [Machiels 2020]. A sequential boost of 6 Gy in 1 fraction was delivered to all patients <70 y. Late normal tissue effects were patient-assessed using EORTC QLQ-BR23 breast cancer module, body image scale questionnaire and the FF protocol-specific questions relating to changes to the affected breast (breast appearance, size, induration, and skin appearance) 24 months after treatment. Patient assessments used a four-point scale (i.e., not at all, a little, quite a bit, very much). We performed this 24-month assessment using tele-medicine follow-up as we did during the pandemic. Descriptive statistical analysis of late normal tissue effects was performed;differences were assessed using Pearson chi-square test and p-values <0.05 were considered significant. Result(s): All 68 patients from our earlier cohort were contacted 2 years after completion of RT, of which all but two were available. Forty-two patients received a boost and 24 did not. Median follow-up was 24 months (range;22- 27). Prevalence of the most-reported mild late normal tissue effects was 53% for mild increase in induration, 50% for mild appearance changes and 48% for mild sensitivity (Table 1). Most-reported moderate normal tissue effects was 13% for sensitivity. The only reported marked effects was 3% change in breast appearance. No significant differences between patients receiving a boost and no boost were seen. Conclusion(s): Our findings are similar to the late normal tissue effects reported in the FF trial and endorse the use of ultrahypofractionated RT for early-stage breast cancer. An ultrahypofractionated tumourbed boost did not result in increased late normal tissue effects, which is being further investigated in a randomised trial. No conflict of interest.Copyright © 2022 Elsevier Ltd. All rights reserved
ABSTRACT
Purpose or Objective Early assessment of neutron contamination in IMRT applications was based on delivery techniques [1,2]. Recently these delivery techniques have been optimized and made more efficient with respect to the number of MU required for a certain dose. In fact, the number of MU for many IMRT or VMAT treatments required for a certain fraction dose are now comparable to those required for 3D-conformal techniques. Furthermore, with the Covid-19 pandemic, a new hypofractionated breast treatment protocol was introduced in our department, based on the “Fast Forward” protocol [3,5]. The implementation of higher daily doses demands for stricter constraints. This study was initiated in order to determine a strategy in minimising the out-of-field dose in clinical practice taking into account the risks and benefits related to different treatment techniques and photon energies. Materials and Methods To simulate realistic clinical conditions, an anthropomorphic phantom was used with a right breast prosthesis. The phantom was scanned and appropriate structures (body, breast, lung and PTV) were delineated. Plans were created using Field in Field (FiF), IMRT and VMAT techniques with different energies. The mean dose of the PTV was normalised to the prescribed fraction dose (5.2Gy) in all treatment plans. Surface scanning was used to position the phantom for treatment. Different detectors types were used for measurements (see Table 1). The measurements were performed at 3 positions: one in the lung and two on the surface at 10 cm and 20 cm respectively from isocentre. Results Figures 1 and 2 illustrate the out-of-field dose measurements associated with a specific configuration of delivery technique and beam energy. Application of 15MV, for all delivery techniques combined, produced more neutrons compared to the other energies used in this study, the neutron contribution to the total contamination was up to 13% for 15 MV at 20 cm from isocentre. FiF neutron contribution were comparable to IMRT even if it required the least MU. In terms of photon scatter contribution, VMAT showed the highest doses. The neutron contamination for 10 MV and 10 MV FFF was similar. Considering a treatment fraction of 5.2 Gy delivered in 15MV IMRT mode, a neutron contamination of 5mGy was observed, which can be considered comparable to a CBCT acquisition for patient positioning [4]. Conclusion As IMRT provides better dose homogeneity and OAR sparing it can be preferred over FiF considering comparable contributions in out-of-field dose contamination. For some complex cases, such as irradiating regional lymph nodes for a breast treatment, VMAT can be considered, as the small increase in out-of-field dose might be balanced against an optimal target coverage / OAR sparing. As expected, some neutron contribution can be observed for the higher energies, however, the low levels of it to the total contamination dose as observed in this study might warrant their use in favour of improved target coverage and skin sparing. Appendix (Figure Presented)(Table Presented)
ABSTRACT
The 17th St Gallen International Breast Cancer Consensus Conference in 2021 was held virtually, owing to the global COVID-19 pandemic. More than 3300 participants took part in this important bi-annual critical review of the 'state of the art' in the multidisciplinary care of early-stage breast cancer. Seventy-four expert panelists (see Appendix 1) from all continents discussed and commented on the previously elaborated consensus questions, as well as many key questions on early breast cancer diagnosis and treatment asked by the audience. The theme of this year's conference was 'Customizing local and systemic therapies.' A well-organized program of pre-recorded symposia, live panel discussions and real-time panel voting results drew a worldwide audience of thousands, reflecting the far-reaching impact of breast cancer on every continent. The interactive technology platform allowed, for the first time, audience members to ask direct questions to panelists, and to weigh in with their own vote on several key panel questions. A hallmark of this meeting was to focus on customized recommendations for treatment of early-stage breast cancer. There is increasing recognition that the care of a breast cancer patient depends on highly individualized clinical features, including the stage at presentation, the biological subset of breast cancer, the genetic factors that may underlie breast cancer risk, the genomic signatures that inform treatment recommendations, the extent of response before surgery in patients who receive neoadjuvant therapy, and patient preferences. This customized approach to treatment requires integration of clinical care between patients and radiology, pathology, genetics, and surgical, medical and radiation oncology providers. It also requires a dynamic response from clinicians as they encounter accumulating clinical information at the time of diagnosis and then serially with each step in the treatment plan and follow-up, reflecting patient experiences and treatment response.