Mean radiation dose to the heart and risk of Cardiac toxicity in NSCLC treated with definitive radiotherapy.

Beskrivelse

  Mean radiation dose to the heart and risk of cardiac toxicity in NSCLC treated with definitive radiotherapy.

Tine Schytte, Olfred Hansen, Thomine Stolberg-Rohr* and Carsten Brink*.

Department of Oncology and Radiophysic Laboratory* Odense University Hospital, Denmark

Background

Lung and oesophageal toxicity have been regarded as main toxicity in definitive radiotherapy (RT) of non-small cell lung cancer (NSCLC), whereas cardiac toxicity has not been offered much concern. This is probably due to the poor prognosis for patients with unresectable NSCLC. In this study we report the heart toxicities in NSCLC patients (pts) treated with RT in our centre.

Methods and material:

Cardiac toxicity is defined as having a cardiac event either as myocardial infarction (MI), pericardial effusion, cardiac insufficiency (CI), pulmonary embolism (PE), found dead with unknown cause, non specific cardiac disease (CD), supra- or ventricular arrhythmia (SA, VA). The cardiac events (CE) were collected from patient files. From 01.09.1995-28.02.2007 pts with NSCLC (stage I-IIIB and recurrent disease) were treated with RT at our centre with planned dose 60-80 Gy. All RT was applied as 3D-RT in 2 Gy/F without elective nodal irradiation. All patients were followed to death. Median follow-up was 95 months with 36 month as a minimum. In each patient the heart was delineated in following volumes: Left ventricle, both ventricles and the whole heart. Mean dose was calculated for each volume in the treatment plan.

Results:

58 patients had cardiac disease prior to RT. They are excluded from the following analysis. Pts treated with concomitant chemotherapy (9 pts) were excluded as well. 34 pts had a CE: 8 AMI, 5 CI, 2 PE, 5 found dead with unknown cause, 2 CD, 14SA and 1 VA, 1 pericardial excaudate. In 7 pts it was uncertain whether there was a cardiac disease. Median survival was 17.2 month and overall survival for 1, 2 and 5 year was 65%, 37% and 15%, respectively. High mean dose (≥upper quartile) to left ventricle (14.45 Gy), both ventricles (17.2 Gy) or whole heart (24.7 Gy) was not correlated with having a CE.

In a Cox-regression analysis of time to CE,  induction chemotherapy, high mean dose to left + right ventricles, > 65 year, poor PS and high lung V20 were  not a statistically significant factors whereas gender were.

Discussion:

We did not find any correlation between high mean dose to the heart and having a CE.

The occurrence of CE did not influence the overall survival