Cardiac changes after stereotactic radiotherapy for early stage NSCLC cancer or lung metastasis - HALO

For lung cancer patients that receive thoracic irradiation, cardiac toxicity
was not considered to play a role, because it was expected to occur many years
after treatment. However, recently several studies have shown higher death
rates for lung cancer patients receiving higher cardiac doses, possibly due to
cardiac toxicity. Most knowledge on cardiac toxicity that we have is based on
patients that receive conventionally fractionated radiation treatment, where
the heart receives a relatively low dose of radiation. For patients that
receive stereotactic body radiation therapy (SBRT), which gives high fraction
doses, the heart may receive peak doses of radiation, especially for centrally
located tumours. This type of therapy is standard of care for early stage lung
cancer patients, with very high local control that is similar to surgically
treated patients. In order to improve the radiation treatment for these early
stage lung cancer patients, detailed knowledge on cardiac toxicity in these
patients is necessary.

We aim to optimize the radiation treatment of early stage lung cancer patients.
Cardiac sparing is possible, but it comes at the cost of an increased mean lung
dose. Without proof of cardiac toxicity, cardiac sparing will not be
(routinely) applied. Therefore, we need detailed understanding of the type of
toxicity and the location of these toxicities for patients who receive high
fraction doses. These have not been measured in this category of patients
before, therefore our primary research question is: is it possible to measure
changes in cardiac condition 3 or 12 months after radiotherapy, with respect to
cardiac arrhythmias, tissue fibrosis, hemodynamic function change and
pericarditis? If indeed cardiac changes can be measured, these results will be
used to set up a larger trial to determine a dose effect relation for cardiac
toxicity in early stage lung cancer patients treated with high fraction doses.

Twenty five patients with early stage lung cancer who are treated with SBRT
will be enrolled in an observational prospective cohort study and treated
following standard clinical practice. Condition of the heart will be examined
before treatment using ECG, cardiac MRI, echocardiography and blood biomarkers.
These tests will be repeated 3 and 12 months after treatment.

The patient will have 3 sessions with several diagnostic tests; ECG, cardiac
MRI, echocardiography and blood sampling, and will fill out 3 questionnaires.
Limited side effects of these tests are expected. Cardiac tests will be
evaluated by a cardiologist and dedicated radiologist and reported to the
radiation oncologist who will inform the patient and refer to the cardiologist
if needed. The burden for these patients will be, next to the time spent for
the diagnostic tests and travel time; an intravenous blood sampling and
administration of MRI contrast agent. The additional time spent for diagnostic
tests per session are: echo (30 min), ECG (5 min), vena puncture (5 min) and
MRI (45 min) + time in the waiting room. Filling out the 3 questionnaires will
take 15 min each.
The possible benefit for the patient is the extensive cardiac screening. Should
a problem come to light, the patient will be referred to the cardiologist.
Results from this patient cohort are directly relatable to all early stage
NSCLC who are treated with SBRT, and possibly oesophageal cancer patients as
well. Should this study show that cardiac dose causes cardiac toxicity in this
time frame, we should aim to improve treatment for all patients who are
comparable. Ergo; patients who receive cardiac dose because of their tumour
location, and who are generally unfit for surgery because of their physical
condition (early stage NSCLC patients and oesophageal cancer patients).