Cardiac exposure in lung cancer radiotherapy: systematic review of heart doses published 2013-2020
Kearney, M. Keys, Maeve Wang, Z. Aznar, Marianne Camille Duane, F.
Kearney, M.
Keys, Maeve
Wang, Z.
Aznar, Marianne Camille
Duane, F.
Citations
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Abstract
Purpose or Objective
Lung cancer radiotherapy increases the risk of acute and late cardiotoxicity. Increased radiation dose to the heart has been
associated with poorer survival. This study aims to describe heart radiation doses exposure from lung cancer radiotherapy
and to summarise the treatment strategies in the modern era leading to a reduction in such exposure.
Materials and Methods
A systematic review of studies reporting heart radiation doses published between 2013-2020 was undertaken. Doses were
compared according to laterality, region irradiated, treatment modality (stereotactic ablative body radiotherapy (SABR) or
non-SABR), radiation modality (photon beam therapy or particle beam therapy), and use of respiratory motion
management. Dose optimisation objectives and dose volume constraints (DVCs) for the heart were extracted for intensity
modulated radiotherapy and particle therapy regimens to determine the priority placed on the heart in inverse planning
optimisation.
Results
The average mean whole heart dose (MHD) across 560 regimens in 140 studies was 8.4 Gy (range 0.1-48.4). Average
exposure was not significantly different between left and right-sided tumours. For 392 non-SABR regimens in 105 studies,
the average MHD was 10.3 Gy (range 0-48.4). MHD was similar in the IMRT and 3DCRT groups (10.9 Gy versus 10.6 Gy) and
lower in the particle therapy group (proton 7.0 Gy; carbon-ion 1.9 Gy) (Fig 1). MHD was lower in studies using
respiratory motion management (7.4 Gy versus 11.4 Gy ) (Fig 2).
For non-SAR studies, optimisation dose objectives were described in only 2 studies while heart DVCs were described in
only 37% (23/62) of IMRT studies and 21% (3/14) particle therapy studies reporting mean and/or maximum heart dose. The
most commonly described DVC was MHD <26 Gy.
For 168 SABR regimens in 35 studies, the average MHD was 4.0 Gy (range 0.0-32.4) and lowest for carbon ion SABR
regimens (0.5 Gy) (Fig 1). Dose optimisation objectives were described in only 1 study while heart DVCs were described in
only 37% (23/62) of IMRT studies and 21% (3/14) particle therapy studies reporting mean and/or maximum heart dose. The
dose received by 15cc of the heart was the commonly described DVC with the threshold dose dependant on the dose
fractionation. MHD was lower in studies using active (2.4 Gy) compared to non-active (5.0Gy) respiratory motion
management techniques. Conclusion
In most lung cancer radiotherapy studies the planning priority is rarely placed on the heart. For IMRT, the most common
technique used, more stringent planning optimisation objectives for the heart may decrease the delivered dose to the
heart. Advanced radiotherapy techniques and technologies including active respiratory motion management or particle based therapy may be considered where cardiac dose is high.
Description
Date
2022
Publisher
Collections
Keywords
Type
Meetings and Proceedings
Citation
Kearney M, Keys M, Faivre-Finn C, Wang Z, Aznar M, Duane F. Cardiac Exposure in Lung Cancer Radiotherapy: Systematic Review of Heart Doses Published 2013-2020. Radiotherapy and Oncology. 2022 May;170:S331-S3. PubMed PMID: WOS:000806759200330.