Detection of late radiation damage on left atrial fibrosis using cardiac late gadolinium enhancement magnetic resonance imaging

Abstract

PurposeThis is a proof-of-principle study investigating the feasibility of using late gadolinium enhancement magnetic resonance imaging (LGE-MRI) to detect left atrium (LA) radiation damage.Methods and materialsLGE-MRI data were acquired for 7 patients with previous external beam radiation therapy (EBRT) histories. The enhancement in LA scar was delineated and fused to the computed tomography images used in dose calculation for radiation therapy. Dosimetric and normal tissue complication probability analyses were performed to investigate the relationship between LA scar enhancement and radiation doses.ResultsThe average LA scar volume for the subjects was 2.5 cm3 (range, 1.2-4.1 cm3; median, 2.6 cm3). The overall average of the mean dose to the LA scar was 25.9 Gy (range, 5.8-49.2 Gy). Linear relationships were found between the amount of radiation dose (mean dose) (R2 = 0.8514, P = .03) to the LA scar-enhanced volume. The ratio of the cardiac tissue change (LA scar/LA wall) also demonstrated a linear relationship with the level of radiation received by the cardiac tissue (R2 = 0.9787, P < .01). Last, the normal tissue complication probability analysis suggested a dose response function to the LA scar enhancement.ConclusionsWith LGE-MRI and 3-dimensional dose mapping on the treatment planning system, it is possible to define subclinical cardiac damage and distinguish intrinsic cardiac tissue change from radiation induced cardiac tissue damage. Imaging myocardial injury secondary to EBRT using MRI may be a useful modality to follow cardiac toxicity from EBRT and help identify individuals who are more susceptible to EBRT damage. LGE-MRI may provide essential information to identify early screening strategy for affected cancer survivors after EBRT treatment.

Cardiac MRI utilizing late gadolinium enhancement (LGE) and T1 mapping in the detection of radiation induced heart disease

“…On our review, the current study is one of only few to evaluate LGE and T1 mapping sequences in the detection of diffuse left ventricular fibrosis secondary to radiotherapy. Our analysis on LGE most similarly parallels the recently published manuscript by Huang et al [38] In Huang et al, 7 patients with previous thoracic radiotherapy with median time from treatment to CMR of 3.1 years exhibited a linear relationship between EQD2 Dmean and Dmax doses delivered to the left atrium and right atrium and the fibrosis volume on CMR. Interestingly, however, they did not observe any focal left or right ventricle myocardial fibrosis, and did not see a dose relationship within the right atrium scar volume [38].…”

Cardiac MRI utilizing late gadolinium enhancement (LGE) and T1 mapping in the detection of radiation induced heart disease

“…On our review, the current study is one of only few to evaluate LGE and T1 mapping sequences in the detection of diffuse left ventricular fibrosis secondary to radiotherapy. Our analysis on LGE most similarly parallels the recently published manuscript by Huang et al [38] In Huang et al, 7 patients with previous thoracic radiotherapy with median time from treatment to CMR of 3.1 years exhibited a linear relationship between EQD2 Dmean and Dmax doses delivered to the left atrium and right atrium and the fibrosis volume on CMR. Interestingly, however, they did not observe any focal left or right ventricle myocardial fibrosis, and did not see a dose relationship within the right atrium scar volume.…”

“…Interestingly, however, they did not observe any focal left or right ventricle myocardial fibrosis, and did not see a dose relationship within the right atrium scar volume. [38] In our LGE protocol, no images of the right or left atria were acquired as atrial walls are generally thin and reliable LGE measurement is therefore difficult. Interestingly, despite higher prescription doses in our study no dose effect was identified for LGE.…”

Cardiac MRI utilizing late gadolinium enhancement (LGE) and T1 mapping in the detection of radiation induced heart disease

“…There was a trend towards higher T1 values in patients with evidence of LGE, which likely shows the effect of local brosis changes on mean T1 values obtained from larger volumes.On our review, the current study is one of only few to evaluate LGE and T1 mapping sequences in the detection of diffuse left ventricular brosis secondary to radiotherapy. Our analysis on LGE most similarly parallels the recently published manuscript by Huang et al[38] In Huang et al, 7 patients with previous thoracic radiotherapy with median time from treatment to CMR of 3.1 years exhibited a linear relationship between EQD2 Dmean and Dmax doses delivered to the left atrium and right atrium and the brosis volume on CMR. Interestingly, however, they did not observe any focal left or right ventricle myocardial brosis, and did not see a dose relationship within the right atrium scar volume [38].…”

“…Our analysis on LGE most similarly parallels the recently published manuscript by Huang et al[38] In Huang et al, 7 patients with previous thoracic radiotherapy with median time from treatment to CMR of 3.1 years exhibited a linear relationship between EQD2 Dmean and Dmax doses delivered to the left atrium and right atrium and the brosis volume on CMR. Interestingly, however, they did not observe any focal left or right ventricle myocardial brosis, and did not see a dose relationship within the right atrium scar volume [38]. In our LGE protocol, no images of the right or left atria were acquired as atrial walls are generally thin and reliable LGE measurement is therefore di cult.…”