Poster Presentation Clinical Oncology Society of Australia Annual Scientific Meeting 2023

Can coronary artery calcium score identified on thoracic Radiotherapy planning CT scans be used and actioned to identify patients at high risk of cardiac events: a feasibility study in patients with cancer undergoing radiotherapy (RO-CARDIAC) (#250)

YVONNE ZISSIADIS 1 , nina stewart 2 , Kathryn Hogan 1 , peter purnell 3 , Daniel Cehic 4 , jamie morton 4 , Jo Toohey 5 , Jack Dalla Via 6 , mary kennedy 6
  1. Genesiscare, Hollywood Private Hospital, Fiona Stanley Hospital, WA, Australia
  2. Genesiscare, Bunbury, WA, Australia
  3. Advara Heartcare, Perth, WA, Australia
  4. Advara Heartcare, adelaide, SA, Australia
  5. Genesiscare, St Vincent's Private Hospital, Sydney, NSW, A
  6. Edith Cowen University, Perth, WA, Australia

Introduction:  Patients undergoing thoracic radiotherapy for cancer treatment routinely undergo a planning CT scan, which presents a unique opportunity to identify those at the highest risk of cardiac events. Radiation dose to the heart can lead to cardiotoxicity and accelerate pre-existing atherosclerosis. 

Aims: To investigate the feasibility of using Coronary Artery Calcium (CAC) scores calculated on thoracic RT planning CT scans to identify a subset of patients at increased risk of future cardiac events, to establish and evaluate a referral pathway for assessment and management in a cardio-oncology clinic. 

Methods: This is an ongoing observational, prospective study of 101 cancer patients commencing radiotherapy. Participants had CAC scored from thoracic radiotherapy planning CT scans. Patients with CAC score>0 (double-read) were referred to a cardio-oncology clinic. Feasibility, adherence to the recommended pathway, and impact on quality of life and anxiety were assessed. Ethics approval obtained.

Results: A total of 101 eligible participants were enrolled in the study. The median age was 59 years and 99/101 patients had breast ca.  CAC scores were zero for 68 participants and more than zero for 32 participants (32%).  

At present, Cardio-oncology outcomes are available for 28 participants with elevated CAC, of which 24 were referred to a cardio-oncology clinic. Following referral, 22 (of 24) of the participants attended the cardio-oncology clinic as recommended, one did not and the outcome for one participant is unknown. 

Conclusions: Early results show thoracic radiotherapy planning CT scans successfully calculated CAC scores. The accumulating data indicates that patients with elevated CAC scores who are referred onto a cardio-oncology clinic are highly compliant with attending this appointment. This study has significant implications in proactively addressing ways of reducing late cardio-toxicity in survivors of cancer.

References: 

Langendijk JA, et al. Is the coronary artery calcium score associated with acute coronary events in breast cancer patients treated with radiotherapy? Radiother Oncol. 2018;126(1):170-6.