Dataset Information

Estimating cancer risk from ^99mTc pyrophosphate imaging for transthyretin cardiac amyloidosis.

ABSTRACT:

Background

Increasing recognition that transthyretin cardiac amyloidosis (ATTR-CA) is much more common than previously appreciated and the emergence of novel disease-modifying therapeutic agents have led to a paradigm shift in which ATTR-CA screening is considered in high-risk populations, such as patients with heart failure with preserved ejection fraction (HFpEF) or aortic stenosis. Radiation risk from ^99mTc-pyrophosphate (^99mTc-PYP) scintigraphy, a test with very high sensitivity and specificity for ATTR-CA, has not been previously determined.

Methods and results

Radiation doses to individual organs from ^99mTc-PYP were estimated using models developed by the Medical Internal Radiation Dose Committee and the International Commission on Radiological Protection. Excess future cancer risks were estimated from organ doses, using risk projection models developed by the National Academies and extended by the National Cancer Institute. Excess future risks were estimated for men and women aged 40-80 and compared to total (excess plus baseline) future risks. All-organ excess cancer risks (90% uncertainty intervals) ranged from 5.88 (2.45,11.4) to 12.2 (4.11,26.0) cases per 100,000 patients undergoing ^99mTc-PYP testing, were similar for men and women, and decreased with increasing age at testing. Cancer risks were highest to the urinary bladder, and bladder risk varied nearly twofold depending on which model was used. Excess ^99mTc-PYP-related cancers constituted?ConclusionVery low cancer risks associated with ^99mTc-PYP testing suggest a favorable benefit-risk profile for ^99mTc-PYP as a screening test for ATTR-CA in high-risk populations, such as such as patients with HFpEF or aortic stenosis.

SUBMITTER: Einstein AJ

PROVIDER: S-EPMC6269210 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature

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Publications

Estimating cancer risk from <sup>99m</sup>Tc pyrophosphate imaging for transthyretin cardiac amyloidosis.

Einstein Andrew J AJ Shuryak Igor I Castaño Adam A Mintz Akiva A Maurer Mathew S MS Bokhari Sabahat S

Journal of nuclear cardiology : official publication of the American Society of Nuclear Cardiology 20180530 1

<h4>Background</h4>Increasing recognition that transthyretin cardiac amyloidosis (ATTR-CA) is much more common than previously appreciated and the emergence of novel disease-modifying therapeutic agents have led to a paradigm shift in which ATTR-CA screening is considered in high-risk populations, such as patients with heart failure with preserved ejection fraction (HFpEF) or aortic stenosis. Radiation risk from <sup>99m</sup>Tc-pyrophosphate (<sup>99m</sup>Tc-PYP) scintigraphy, a test with very ...[more]

PMID: 29850972

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Project description:ObjectivesThe purpose of this study was to examine the diagnostic value of planar 99mTc-pyrophosphate (PYP) imaging at 1 and 3 h after tracer administration in patients with suspected transthyretin cardiac amyloidosis (ATTR-CA) using SPECT as a reference standard. We also tested whether blood pool activity of PYP is associated with renal dysfunction.MethodsPYP images of 109 consecutive patients with suspected ATTR-CA were retrospectively reviewed. The myocardial PYP uptake was visually graded on a scale of 0 to 3 and quantified with the heart-to-contralateral (H/CL) ratio in accordance with the current expert consensus recommendations. The diagnostic value of planar images for identifying positive PYP SPECT was assessed by a receiver-operating characteristic curve analysis with the area under the curve (AUC). The uptake ratios of the ascending and descending aorta, left atrium, and trapezius muscle divided by the liver uptake were measured on SPECT images and compared to the renal function.ResultsA total of 41 patients (38%) had myocardial PYP uptake on SPECT images. In comparison with the visual scores on 1-h anterior planar images, those on 3-h anterior planar images had lower sensitivity (80.5% vs. 97.6%) and higher specificity (86.8% vs. 55.9%) for identifying positive PYP SPECT. The ROC analysis showed that the combination of visual scores on both 1-h and 3-h anterior planar images had significantly higher AUC values in comparison with 1-h anterior planar images alone (0.90 [95% CI 0.83-0.94] vs. 0.83 [95% CI 0.75-0.88]; P < 0.001), which was comparable to the AUC values on 3-h anterior planar images alone (0.88 [95% CI 0.80-0.92]; P = 0.071). In comparison with visual scores on 1-h or 3-h anterior planar images alone, the combination of visual scores and H/CL ratio did not significantly improve the diagnostic value for identifying positive PYP SPECT (P = 0.73 and P = 0.50, respectively). The uptake ratios of ascending aorta/liver, descending aorta/liver, left atrium/liver, and trapezius muscle/liver were not significantly associated with the serum creatinine level or estimated glomerular filtration rate (P > 0.05 for all).ConclusionsIn the assessment of ATTR-CA using PYP imaging, visual scores on 3-h anterior planar images for identifying positive PYP SPECT had lower sensitivity and higher specificity in comparison with those on 1-h anterior planar images. The diagnostic value of the visual scores on 1-h and 3-h anterior planar images was not improved by adding the H/CL ratio. Blood pool activity of PYP was not significantly associated with renal dysfunction.

Project description:BackgroundEchocardiographic deformation-based ratios and novel multi-parametric scores have been suggested to discriminate transthyretin cardiac amyloidosis (ATTR-CM) from other causes of increased left ventricular wall thickness among patients referred for ATTR-CM evaluation. Their relative predictive accuracy has not been well studied. We sought to (1) identify echocardiographic parameters predictive of ATTR-CM and (2) compare the diagnostic accuracy of these parameters in patients with suspected ATTR-CM referred for technetium-99m-pyrophosphate scintigraphy.MethodsEchocardiograms from 598 patients referred to 3 major amyloidosis centers for technetium-99m-pyrophosphate to detect ATTR-CM were analyzed, including longitudinal strain (LS) analysis. Deformation ratios (septal apex to base ratio, relative apical sparing, ejection fraction to global LS), a multi-center European increased wall thickness score, and Mayo Clinic derived ATTR score (transthyretin cardiac amyloidosis score) were calculated. A logistic regression model was used to identify the parameters that best associated with a diagnosis of ATTR-CM. Comparison of the diagnostic capacity of the parameters was performed by receiver operating characteristic curves and the area under the curve (AUC).ResultsOver half of the subjects (54.2%) were diagnosed with ATTR-CM (78% were men, median age of 76 years). Age, inferolateral wall thickness, and basal LS were the strongest predictors of ATTR-CM, AUC of 0.87 (95% CI: 0.83, 0.90), superior to the increased wall thickness score AUC of 0.78 (95% CI: 0.73, 0.83; P=0.004). An inferolateral wall thickness of ≥14 mm (AUC: 0.73) was as accurate as the published cut-offs for transthyretin cardiac amyloidosis score and septal apex to base (AUC: 0.72 and 0.69, P=0.8 and P=0.1, respectively), and was superior to ejection fraction to global LS and relative apical sparing (AUC: 0.64 and 0.53, P<0.001, respectively). A cut-off of ≥-8% for average basal LS (AUC: 0.76, CI: 0.72-0.79) had a similar area under the curve to transthyretin cardiac amyloidosis score (TCAS) (P=0.2); outperforming the other indices (P<0.01).ConclusionInferolateral wall thickness and average basal LS performed as well as or better than more complex echo ratios and multiparametric scores to predict ATTR-CM.

Dataset Information

Estimating cancer risk from ^99mTc pyrophosphate imaging for transthyretin cardiac amyloidosis.

Background

Methods and results

Publications

Estimating cancer risk from <sup>99m</sup>Tc pyrophosphate imaging for transthyretin cardiac amyloidosis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Dataset Information

Estimating cancer risk from 99mTc pyrophosphate imaging for transthyretin cardiac amyloidosis.

Background

Methods and results

Publications

Estimating cancer risk from <sup>99m</sup>Tc pyrophosphate imaging for transthyretin cardiac amyloidosis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets

Estimating cancer risk from ^99mTc pyrophosphate imaging for transthyretin cardiac amyloidosis.