ESTRO 37 Abstract book

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ESTRO 37

Conclusion A spectrum of cardiovascular conditions was observed over variable latency after adjuvant therapy. Monitoring of cardiovascular health remains an important survivorship issue. Future directions include elucidating any effect of laterality, RT volume, and specific attribution to cancer therapies in an expanded cohort. EP-1307 Radiotherapy significantly contributes to loss of cardiac function after treatment for breast cancer V.A.B. Van den Bogaard 1 , P. Van Luijk 1 , Y.M. Hummel 2 , P. Van der Meer 2 , L.M. Boerman 3 , S.W.M.C. Maass 3 , J.A. Gietema 4 , G.H. De Bock 5 , A.J. Berendsen 3 , W.G.J.M. Smit 6 , J.A. Langendijk 1 , A.P.G. Crijns 1 , J.H. Maduro 1 1 University Medical Center Groningen, Radiotherapy, Groningen, The Netherlands 2 University Medical Center Groningen, Cardiology, Groningen, The Netherlands 3 University Medical Center Groningen, General Practice, Groningen, The Netherlands 4 University Medical Center Groningen, Medical Oncology, Groningen, The Netherlands 5 University Medical Center Groningen, Epidemiology, Groningen, The Netherlands 6 Radiotherapy Institute Friesland, Radiotherapy, Leeuwarden, The Netherlands Purpose or Objective Radiotherapy (RT) increases the risk of acute coronary events (ACE) in breast cancer (BC) patients with about 16% in the rate of ACE per Gy mean heart dose (MHD) in the first 9 years after treatment. However, the association between thoracic RT and myocardial dysfunction is less clear. Insight into the functional effects of RT dose on the heart and its substructures will facilitate possibilities for optimizing RT treatment plans by lowering the dose to critical cardiac substructures or using alternative radiation technologies, such as proton therapy. The main aim of this study was to test the hypothesis that low dose to the heart is associated with changes in systolic and diastolic cardiac function in BC patients. Material and Methods In this cross-sectional study, systolic and diastolic function was assessed by echocardiography in 109 consecutive female BC patients treated with postoperative RT between 2005 and 2011. For each patient, dose-volume histogram (DVH) parameters of the whole heart and its substructures, including the coronary arteries, were collected from three-dimensional (3D) CT planning data. As a measure of severe function changes, left ventricle ejection fraction (LVEF) was assessed. To detect subclinical changes in systolic function, the global longitudinal strain (GLS) of the left ventricle (LV) was determined. Diastolic function was defined by the relaxation velocity of the myocardium in early diastole (average e’ at the lateral and septal region). To test the relationship between radiation dose to the heart and cardiac substructures stepwise multivariable linear regression analysis was used. Results Median time between BC diagnosis and echocardiography was 7 years (range 4-10). No relation between DVH parameters and LVEF were found. The GLS of the LV was associated with the MHD (median: 2.24, range: 0.61- 11.34), V5 of the left ventricle (median: 1.74, range: 0.00-87.10) and dose to the left main coronary artery (LMCA) (median: 1.78, range: 0.45-7.42). The strongest association was found with the maximum dose to the LMCA (p=0.013). Decreased diastolic function was associated with higher maximum dose to the ascending aorta (p=0.003) (median: 3.18, range: 1.04-11.50) and with higher age (p<0.001) and presence of hypertension (p=0.009). Thus, both systolic and diastolic function were associated with radiation dose to cardiac structures.

radiotherapy fields covering level 1-4 axillary volumes according to the ESTRO contouring guideline. EP-1306 Cardiovascular sequelae in breast cancer patients receiving adjuvant therapy A. Satchithanandha 1 , A. Hopkins 1,2 , J. Otton 1,2 , B. Kiely 3 , S. Tang 1,4,5 , M. Field 1,5 , V. Batumalai 4,5 , L. Holloway 1,5,6,7,8 , G.P. Delaney 1,4,5 , E.S. Koh 1,4,5 1 University of New South Wales, South Western Sydney Clinical School, Sydney, Australia 2 Liverpool Hospital, Cardiology, Sydney, Australia 3 Liverpool and Macarthur Cancer Therapy Centre, Medical Oncology, Sydney, Australia 4 Liverpool and Macarthur Cancer Therapy Centre, Radiation Oncology, Sydney, Australia 5 Liverpool Hospital, Ingham Institute of Applied Medical Research, Sydney, Australia 6 Liverpool and Macarthur Cancer Therapy Centre, Medical Physics, Sydney, Australia 7 University of Wollongong, Centre of Medical Radiation Physics, Sydney, Australia 8 University of Sydney, Sydney Medical School, Sydney, Australia Purpose or Objective Cardiovascular (CV) toxicity in breast cancer (BC) survivors is increasingly recognised as an important post- treatment sequela. This study aimed to determine the incidence and nature of new or worsening CV conditions in BC patients receiving adjuvant therapy. Material and Methods From 2006-2010, all Stage I-III BC patients diagnosed and treated with curative intent within South Western Sydney were identified. Clinico-demographic and BC treatment details including chemotherapy (CT), immunotherapy (IT), radiotherapy (RT) and endocrine therapy (ET), was extracted from hospital records and matched with a cardiology database to identify symptomatic patients with new and/or worsening CV conditions post cancer treatment. These "index” cases were coded into CV conditions, as per the ICD-10 classification with known CV risk factors documented. Time intervals between BC diagnosis and CV condition were documented, with 0-6 months defined as 'acute”, 6-24 months as 'sub-acute” and >2 years as 'chronic”. Overall cohort and index group details were summarised descriptively. For left-sided irradiated index cases, mean heart dose (MHD) and left anterior descending artery (LAD) dose were documented. Results There were n=716/1637 Stage I, n=693/1637 Stage II and n=228/1637 Stage III patients, aged 36-95 years (mean 58 years), with n=616/1637 (38%) receiving CT, n=142/1637 (23%) IT, n=1247/1637 (76%) RT and n=900/1637 ET (55%). "FEC” and "FEC-Docetaxel” were the most common CT regimens in overall and index cases. There were n=99/1637 (6%) index cases with n=157 CV conditions including n=16/157 (10%) pre-existing but worsened. CV conditions spanned valvular heart disease (n=47/157), ischaemic heart disease (n=38/157), heart failure (n=37/157), arrhythmia (n=30/157), cardiomyopathy (n=3/157) and pericardial effusion (n=2/157), with n=42/99 "index" cases having multiple CV conditions. Of these, n=11/157 (7%) were categorised as acute, n=34/157 (22%) sub-acute, n=92/157 (59%) chronic. Of the index cases, 43% had ≥2 CV risk factors, with n=36/99 (36%) receiving CT and n=13/99 (13%) IT. Of 73/99 (74%) receiving RT, n=35/73 received 50Gy/25 and n=29/73 received 42.4Gy/16 fractions, with n=54/73 (74%) tangential RT and n=17/73 (26%) having additional regional nodal RT. Fifty-six percent of index cases received >1 adjuvant therapy. Of 32/33 evaluable left- sided RT cases, MHD was 0.63-4.86Gy (mean=2.0Gy) and LAD doses 1.57-31.31Gy (mean=13.60Gy). There were n=13 right-sided versus 11 left-sided irradiated index cases with IHD.