Cardiac and pulmonary dosimetric parameters in lung cancer patients undergoing post-operative radiation therapy across a state-wide consortium

Document Type

Article

Publication Date

2-6-2023

Publication Title

Pract Radiat Oncol

Abstract

PURPOSE/OBJECTIVES: The recently published Lung ART trial reported increased rates of cardiac and pulmonary toxicity in the post-operative radiation therapy (PORT) arm. It remains unknown whether the dosimetric parameters reported in Lung ART are representative of contemporary real-world practice, which remains relevant for patients undergoing post-operative RT for positive surgical margins. The purpose of this study is to examine heart and lung dose exposure in patients receiving post-operative radiation therapy for non-small cell lung cancer (NSCLC) across a statewide consortium.

MATERIALS/METHODS: From 2012 to 2022, demographic and dosimetric data were prospectively collected for 377 patients at 27 academic and community centers within [redacted] undergoing PORT for non-metastatic NSCLC. Dosimetric parameters for target coverage and Organ at Risk (OAR) exposure were calculated using data from dose volume histograms, and rates of 3D-CRT and IMRT utilization were assessed.

RESULTS: Fifty-one percent of patients in this cohort had N2 disease at the time of surgery, 25% had a positive margin. Sixty-six percent of patients were treated with IMRT compared to 32% with 3D-CRT. Planning target volume (PTV) was significantly smaller in patients treated with 3D-CRT (149.2 cc vs. 265.4 cc, p<0.0001). Median mean heart dose for all patients was 8.7 Gy (IQR 3.5, 15.3), median heart V5 was 35.2% (IQR 18.5, 60.2) and median heart V35 was 9% (IQR 3.2, 17.7). Median mean lung dose (MLD) was 11.4 Gy (IQR 8.1, 14.3), median lung V20 was 19.6% (IQR 12.7, 25.4). These dosimetric parameters did not significantly differ by treatment modality (IMRT vs. 3D-CRT) or in patients with positive vs. negative surgical margins.

CONCLUSIONS: With increased rates of IMRT use, cardiac and lung dosimetric parameters in this state-wide consortium are slightly lower than those reported in Lung ART. These data provide useful benchmarks for treatment planning in patients undergoing post-operative RT for positive surgical margins.

PubMed ID

36754278

ePublication

ePub ahead of print

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