Baseline cardiac features and the associated risk of radiation induced cardiotoxicity
Gerry Hanna, Marie Curie Chair of Clinical Oncology at
“Just published today in JACC: CardioOncology is our paper, led by Dr Gerard Walls on baseline cardiac features and the associated risk of radiation induced cardiotoxicity available here.
Simple heart features on planning CT were correlated with the risk of specific cardiac events after radiotherapy in patients receiving radiotherapy (RT) for lung cancer (NSCLC, n=478).
Key findings:
- Patients with an enlarged left atrium on their planning scan had a higher risk of supraventricular arrhythmia after RT. We used absolute LA volume (cc), and the association was significant after adjusting for LA dose, alcohol use etc.
- Patients with enlarged left ventricles on their RT planning scan had a higher risk of heart failure after RT. We used LV volume normalised to RV volume, and the association was still significant after adjusting for LV dose, use of ACEi/AR2B etc.
- Patients with coronary artery calcification (CAC) had a higher risk of acute coronary syndromes after RT. We used a basic “any CAC” vs “no CAC” but have reported a semi-quantitative score too. It’s best to use non-contrast scans for CAC so we used the PET-CT where the RTP had contrast. Of note, there weren’t enough events for a multivariate analysis, which is also probably why the result wasn’t statistically significant, but rates were 4% vs 0% for CAC-positive V CAC-negative.
PMHx reflected these imaging findings – the number of previous cardiac events and CV risk factors (non-sig) were associated with risk of cardiac events after RT. This is not overly surprising given these issues underpin the geometric/semantic cardiac features observed on RTP scans.
Similarly, the 10-year CV risk score (which we should be checking pre-RT according to ESTRO-ESC-ICOS guidelines) also shows a relationship with the risk of events. Higher scores were associated with MACE: 22% vs 12% (p=0.042).
One technical RadOnc point – cardiac substructure doses were negligible for superior tumours, so substructure-sparing techniques can be probably be reserved for pts where the PTV extends below the top of the heart. At least for the conventional supine, gantry rotating axially etc…
Putting this together, we think that cardiac features on planning scans and the cardiovascular past medical history potentially have capacity to serve as risk stratification tools, to identify “cardiac high-risk” patients who need extra attention.
In summary, while doses to cardiac substructures are clearly important for the risk of cardiac events, the baseline cardiovascular health of the patient is also crucial to assess if we wish to prospectively identify high-risk patients who might benefit from cardiac optimisation.
Key take home: There is a clear need for Cardiology input for patients at high-risk of cardiotoxicity receiving lung cancer radiotherapy.”
Source: Gerry Hanna/LinkedIn