Are heart doses associated with survival in patients with non-small cell lung cancer who received post-operative thoracic radiotherapy?

Abstract

The aim of this retrospective national cohort study is to assess the association between various radiation heart dosimetric parameters (RHDPs), acute myocardial infarct (AMI) and overall survival (OS) outcomes in non-small cell lung cancer (NSCLC) patients treated with post-operative thoracic radiotherapy (PORT) using contemporary radiation techniques.We identified patients with stage I to III NSCLC treated with PORT at the 2 national cancer institutions from 2007 to 2014. We linked their electronic medical records to the national AMI and death registries. Univariable Cox regression was performed to assess the association between various RHDPs, AMI, and OS.We included 43 eligible patients with median follow-up of 36.6 months. Median age was 64 years. Majority of the patients had pathological stage III disease (72%). Median prescription dose was 60Gy. Median mean heart dose (MHD) was 9.4Gy. There were no AMI events. The 5-year OS was 34%. Univariable Cox regression showed that age was significantly associated with OS (hazard ratio, 1.06; 95% confidence interval, 1.01 to 1.10; P = .008). Radiation heart doses, including MHD, volume of heart receiving at least 5, 25, 30, 40, 50Gy and dose to 30% of heart volume, were not significantly associated with OS.There is insufficient evidence to conclude that RHDPs are associated with OS for patients with NSCLC treated with PORT in this study. Studies with larger sample size and longer term follow-up are needed to assess AMI outcome.

Higher Lung and Heart Doses Decrease Early and Long-Term Survival, Respectively, in Patients With Non-Small Cell Lung Cancer Undergoing Postoperative Radiation

“…One study concluded that heart doses were not associated with OS (heart V50: HR, 1.01; P = .868); however, the small sample size (43 cases) limited the statistical power. 14 The other study included 284 cases and found a strong correlation between increasing heart dose and OS; however, this study included 55 patients (19.4%) with R1 resection, nonuniform stages (I-III), and a heterogeneous radiation dose (45-70 Gy). 15 Patients who underwent R1 resection had poor survival and tended to receive a high administrative dose, suggesting R1 resection may confound the relationship between the heart dose and OS.…”

“… 11 , 12 , 13 Moreover, to our knowledge, only 2 studies have investigated whether the heart dose in PORT affects OS. One study had a limited sample size of 43 patients, 14 and the other had 289 patients but included patients with incomplete resection (R1) who had nonuniform stages (I-III), and it used a heterogeneous radiation dose (45-70 Gy). 15 Therefore, the conclusions were not convincing.…”

Postoperative radiotherapy in pIIIA-N2 non–small cell lung cancer after complete resection and adjuvant chemotherapy: A meta-analysis

“…[ 21 , 22 ] However, it was reported that radiation heart dosimetric parameters were not associated with OS. [ 23 ] In support of this hypothesis, a meta-analysis was conducted based on modern PORT. [ 11 ] The results reported modern PORT could decrease local recurrences and increase OS in patients with stage pIIIA-N2 NSCLC.…”

The Role of Postoperative Radiation Therapy for pN2 Non–small-cell Lung Cancer

“…29 Finally, a small national-level cohort study investigated radiation PORT for pN2 NSCLC e12 -Clinical Lung Cancer January 2021 heart dose parameters in patients receiving PORT for N2 or margin-positive disease and found no association with OS. 30 In contrast to the SEER databases, the National Cancer Database (NCDB) has comprehensive baseline characteristics and treatmentrelated details, including receipt of chemotherapy. Multiple NCDB analyses have demonstrated a benefit of PORT for pN2 disease.…”