Background Radiotherapy (RT) is part of the curative treatment of approximately 70% of breast cancer (BC) patients. Wide practice variation has been reported in RT dose, fractionation and its... Show moreBackground Radiotherapy (RT) is part of the curative treatment of approximately 70% of breast cancer (BC) patients. Wide practice variation has been reported in RT dose, fractionation and its treatment planning for BC. To decrease this practice variation, it is essential to first gain insight into the current variation in RT treatment between institutes. This paper describes the development of the NABON Breast Cancer Audit-Radiotherapy (NBCA-R), a structural nationwide registry of BC RT data of all BC patients treated with at least surgery and RT. Methods A working group consisting of representatives of the BC Platform of the Dutch Radiotherapy Society selected a set of dose volume parameters deemed to be surrogate outcome parameters, both for tumour control and toxicity. Two pilot studies were carried out in six RT institutes. In the first pilot study, data were manually entered into a secured web-based system. In the second pilot study, an automatic Digital Imaging and Communications in Medicine (DICOM) RT upload module was created and tested. Results The NBCA-R dataset was created by selecting RT parameters describing given dose, target volumes, coverage and homogeneity, and dose to organs at risk (OAR). Entering the data was made mandatory for all Dutch RT departments. In the first pilot study (N = 1093), quite some variation was already detected. Application of partial breast irradiation varied from 0 to 17% between the 6 institutes and boost to the tumour bed from 26.5 to 70.2%. For patients treated to the left breast or chest wall only, the average mean heart dose (MHD) varied from 0.80 to 1.82 Gy; for patients treated to the breast/chest wall only, the average mean lung dose (MLD) varied from 2.06 to 3.3 Gy. In the second pilot study 6 departments implemented the DICOM-RT upload module in daily practice. Anonymised data will be available for researchers via a FAIR (Findable, Accessible, Interoperable, Reusable) framework. Conclusions We have developed a set of RT parameters and implemented registration for all Dutch BC patients. With the use of an automated upload module registration burden will be minimized. Based on the data in the NBCA-R analyses of the practice variation will be done, with the ultimate aim to improve quality of BC RT. Trial registration Retrospectively registered. Show less
The studies in this thesis contribute to more accurate risk assessment and prognosis prediction for DCIS and to better response evaluation of IBC treatment.For the Ductal Carcinoma In Situ (DCIS)... Show moreThe studies in this thesis contribute to more accurate risk assessment and prognosis prediction for DCIS and to better response evaluation of IBC treatment.For the Ductal Carcinoma In Situ (DCIS) studies, unbiased cohorts were used within the international Grand Challenge PRECISION consortium, funded by Cancer Research UK and KWF Dutch Cancer Society. DCIS is graded as low-, intermediate-, or high-grade depending on how abnormal the DCIS-cells look like. However, we showed that pathologists often disagree on grade. To overcome this limitation, we found that almost all DCIS scored as non-high-grade by the majority of pathologists express the estrogen receptor (ER) and are negative for the growth factor receptor HER2, whereas high-grade DCIS is mixed in expression for ER and HER2. We also provided insights in the recurrence risks of DCIS after treatment. See also https://cancergrandchallenges.org/teams/precision.The studies on Invasive Breast Cancer (IBC) were performed on a hospital-based cohort. We found for example substantial variation in tumour response evaluation for HER2-positive IBC after pre-operative chemotherapy due to different guidelines used. For accurate outcome analysis, reducing such variation is mandatory. Therefore, we are working on reaching international consensus of response evaluation. Show less
Preclinical and clinical studies reveal that left-sided breast cancer radiotherapy is associated with an increased rate of major coronary events. Consequently, when irradiating women with left... Show morePreclinical and clinical studies reveal that left-sided breast cancer radiotherapy is associated with an increased rate of major coronary events. Consequently, when irradiating women with left-sided breast cancer, specific measures should be taken to decrease the heart dose as much as possible and to avoid radiation-induced coronary artery disease. This thesis focuses on several strategies to optimise the radiation treatment for patients with left-sided breast cancer. With respect to whole breast irradiation we concluded that: __ the routine use of MR images in addition to the CT scan, when delineating either the glandular breast tissue or the lumpectomy cavity, does not have added value. __ tangential IMRT technique combined with a breath-hold technique should be the treatment technique of choice for left-sided breast cancer. __ a breath-hold technique should and can be used in all left-sided breast cancer patients, regardless of age and breast size. __ breath-hold in left-sided whole breast radiotherapy results in a less pronounced increase of coronary calcium score and, hence, could result in less radiation-induced cardio vascular damage. Show less
Mast, M.; Coerkamp, E.; Heijenbrok, M.; Scholten, A.; Jansen, W.; Kouwenhoven, E.; ... ; Struikmans, H. 2014
Prognostic factors are used for making treatment decisions regarding adjuvant systemic therapy. The major prognostic variables that are used in clinical practice are the number of positive axillary... Show morePrognostic factors are used for making treatment decisions regarding adjuvant systemic therapy. The major prognostic variables that are used in clinical practice are the number of positive axillary lymph nodes and tumour size. A number of other variables are associated with disease recurrence and survival as well. In particular UPA and PAI-1 appear to be strong prognostic variables. No differences in prognostic value of oestrogen receptor and progesterone receptor detected by immunocytochemical assay or enzyme immuno assay were found. In the study presented no significant association between mitotic counts and disease recurrence or survival was found, which was explained by the favourable tumour characteristics of the group of patients and the associated low number of events. Several tools have been developed to make individualised estimates of baseline prognosis and absolute survival benefit of adjuvant systemic therapy. Two of these tools, Adjuvant! and Numeracy, were compared. Adjuvant! was the preferred prognostic model. The administration of adjuvant chemotherapy concurrently with radiotherapy appeared too toxic. As anthracyclin-containing regimens have become standard for adjuvant chemotherapy in early breast cancer which are considered more toxic than the regimens studied the concurrent administration of adjuvant chemotherapy and radiotherapy is dissuaded. Show less
