Implementation of Novel Treatment Planning Strategies to Reduce Cardiac Dose in Locally Advanced Non-Small Cell Lung Cancer Patients

Document Type

Conference Proceeding

Publication Date

6-1-2022

Publication Title

Med Phys

Abstract

Purpose: For locally advanced, non-small cell lung cancer (NSCLC) patients, recent trials have demonstrated the importance of limiting cardiac dose without sacrificing target coverage or significantly increasing lung dose. To accomplish these goals, a set of novel treatment planning strategies were designed and evaluated. Methods: Three novel planning strategies were retrospectively implemented for a set of 20 previously treated, locally advanced, NSCLC patients originally prescribed to 60-66Gy that received a mean heart dose (MHD) ≥ 10 Gy. Of the planning strategies, the first was a multi-isocentric arc-based approach (Heart-MI) utilizing two isocenters at least 10cm apart longitudinally. The second was a non-coplanar, arc-based approach (Heart-NCP) that added a set of up to three large couch angles combined with short anterior arcs to a standard arc at a couch angle of 0. The last utilized a hybrid approach (Heart-HYBRID) that implemented the Heart-NCP strategy for 2/3 of treatment fractions and an oppositeopposed planning strategy angled to avoid the heart for the remaining fractions. Results: Target coverage was maintained, and non-heart organ-at-risk doses were kept within prescribed levels. With respect to cardiac dose reduction, there were statistically significant decreases in Heart V30, V50, and mean dose for the Heart-MI (6.2 vs. 13.1% (p<0.001), 2.3 vs. 3.3% (p=0.01), 9.8 vs. 15.4 Gy (p<0.001), respectively), Heart-NCP (5.8 vs. 13.1% (p<0.001), 2.2 vs. 3.3% (p=0.02), 9.2 vs. 15.4 Gy (p<0.001), respectively), and Heart-HYBRID (5.0 vs. 13.1% (p<0.001), 2.3 vs. 3.3% (p=0.02), 7.9 vs. 15.4 Gy (p<0.001), respectively) strategies. Conclusion: The Heart-NCP strategy represented the best compromise between cardiac dose reduction and maintaining plan quality metrics. Use of this strategy resulted in mean heart dose reductions of 37.6 + 12.9% (6.2 + 3.4 Gy) relative to original plans and brought mean heart dose below 10 Gy for 16 of 20 patients.

Volume

49

Issue

6

First Page

e293

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