Multi-centre analysis of cardiac events following radical radiotherapy for lung cancer (2019)

Background: Radical radiotherapy (RRT) plays an essential role in the management of early and locally advanced lung cancer. Recent studies suggest cardiac events post radiotherapy worsen survival outcome for patients. This study aims to identify risk factors which predispose patients to cardiac events post radiotherapy. Methods: All patients who received RRT (including Stereotactic Body Radiotherapy (SBRT), radical fractionated radiotherapy and chemoradiotherapy) for lung cancer between 01/01/2010 to 30/12/2016 at 2 UK institutions have been included. Patients were excluded if they had multiple courses of radiotherapy to the chest. Individual patient clinical information has been retrieved from hospital electronic database. Patient and cancer demographics have been collected. Pre-existing cardiac conditions, Charlsons’ Co-morbidity index and Qrisk 3 scores were calculated. Post radiotherapy cardiac events were identified rom electronic patient records and time to cardiac events were calculated. Results: 600 patients have been identified so far and processed. Median follow up is 31 months. Of all patients, 29% had pre-existing cardiac conditions. 52 patients experienced cardiac events following radiotherapy, of which 37% were ischaemic events. Of patients who experienced an ischaemic event, 58% did not have a known pre-existing cardiac condition. 71% of cardiac events post RRT occurred in the first 2 years following RT. Proportionally, patients who underwent radical fractionated radiotherapy and concurrent chemoradiotherapy had the highest incidence of cardiac events. Patient characteristics of those who experienced cardiac toxicity are summarized in the table below.Table72OTotal = 52 (10%)Ischaemic events19 (7 events lead to death – Grade 5)Pericardial(effusion) events8Arrhythmic events13Cardiac failure events12Pre-existing cardiac diagnosisPatients who had ischaemic events8/19 (4 previous MI, 2 IHD, 1 arrythmia and 1 valve abnormalityPatients who had pericardial events1/8 (arrhythmia)Patients who had arrhythmic events6/13 (2 previous MI, 2 IHD, 1 CCF, 1 CCF and arrhythmia)Patients who had CCF events9/12 (2 previous MI, 5 IHD, 2 valvular abnormality)SexMale = 33 Female = 19AgeMedian = 73SmokingNever smoked0Ex-Smoker <10 PY0Ex-smoker <20 PY9Ex-Smoker 20-40PY15Ex-Smoker >40 PY9Current Smoker19Charlson ScoreMedian = 6RT indicationAdjuvant RT4 (12.5% of all Adjuvant RT)SBRT19 (8.7% of all SBRT)Concurrent ChemoRT10 (14.5% of all Concurrent ChemoRT)Sequential ChemoRT0Radical Fractionated RT19 (15.6% of all Radical Fractionated RT)Tumour LocationLeft Upper Lobe(LUL)12 (8% of all LUL tumours)Left Lower Lobe(LLL)11 (17% of LLL tumours)Right Upper Lobe(RUL)16 (9% of RUL tumours)Right Middle Lobe(RML)1 (3% of RML tumours)Right Lower Lobe(RLL)12 (17% of RLL tumours) Open table in a new tab Conclusions: A clinically significant proportion of patients developed cardiac toxicity following radical radiotherapy for lung cancer. Cardiac events occur much sooner after lung cancer radiotherapy than radiotherapy for breast cancer or lymphoma. Work is ongoing to identify greater number of patients and combine local data with data from national registry to aid analysis. Legal entity responsible for the study: The authors. Funding: Yorkshire Cancer Research. Disclosure: All authors have declared no conflicts of interest.