Inclusion of heart substructures in the optimization process of volumetric modulated arc therapy techniques may reduce the risk of heart disease in Hodgkin’s lymphoma patients

Intensity modulated proton therapy compared to volumetric modulated arc therapy in the irradiation of young female patients with hodgkin’s lymphoma. Assessment of risk of toxicity and secondary cancer induction

“…The excess relative risk was fixed to 7.4 and 9.0% per Gy, respectively for LAD and LV. The choice of applying the van Nimwegen model using as input the mean dose to the LAD is somehow arbitrary in the absence of definitive data on sensitivity of substructures but is consistent with other similar investigations such as, e.g., Levis et al [28].…”

“…In this case the Nimwegen-Darby models [25][26][27] were applied and also in this case treatments with IMPT have the potential to reduce the risk on average. Levis [28] applied the same models for RR in a comparison among two variants of VMAT. They found that RR for the LV was 1.3 ± 0.6 while RR for the coronaries (all together) was 2.0 ± 0.6 in comparison with the 1.26 ± 0.20 and 1.41 ± In addition, the data presented in those studies were derived from photon treatments and therefore the models might not be strictly applicable also to protons.…”

Hierarchical clustering applied to automatic atlas based segmentation of 25 cardiac sub-structures

“…Cardiac toxicity has surfaced relatively recently as an issue to be considered in breast radiotherapy (RT), with very basic dose-volumetoxicity relationships having been proposed so far [1], though preliminary data suggest that some cardiac sub-structures may be more problematic than others, particularly highlighting coronary arteries [2,3] and ventricular walls [4]. As recently illustrated by Jacob et al [5], within the framework of the BACCARAT study, the mean heart dose (MHD) is not enough to analyze the correlation between cardiac sub-structures (especially the left anterior descending artery) exposure to therapeutic radiation and resulting toxicity; moreover, the dose distribution in the heart is not homogeneous, neither for traditional tangent irradiation, nor for more recent Intensity Modulated Radiation Therapy (IMRT) approaches [6]. Highest cardiac radiation doses can be observed in the apex and in the apical-anterior segment for tangents and some hot spots > 50 Gy may be applied to some parts of the heart, particularly with tangent treatments, while, with IMRT, typically larger volumes of the heart are exposed to low and intermediate doses.…”

Fondazione Italiana Linfomi (FIL) expert consensus on the use of intensity-modulated and image-guided radiotherapy for Hodgkin’s lymphoma involving the mediastinum

“…Individualized estimates for the risk of development of secondary cancers and cardiovascular disease have been calculated by Koh et al [40] Hodgson et al [41], Weber et al [24], Maraldo et al [7] and Filippi et al [8]. The potential for risk reduction with more conformal therapy was investigated by Weber et al [42] Filippi et al [8], Levis et al [43] and Maraldo et al [34]. Across these studies, IMRT techniques were not associated with an increased risk of radiation-induced secondary cancers, except for Maraldo et al [7], where full-arc VMAT without low-dose constraints for breasts and lungs was tested.…”

“…For cardiovascular disease, again, Maraldo et al compared 3D-CRT with VMAT and found that risk estimates for cardiovascular disease were not significantly reduced with VMAT compared with 3D-CRT [7,44]. Filippi et al [8] and Levis et al [43] subsequently showed that optimized multi-arcs VMAT, including low-dose constraints, was able to reduce heart disease risk in comparison with 3D-CRT, independently of the anatomical presentation (mediastinal disease alone or plus neck or unilateral axilla).…”