PET-CT Best Imaging Method for Detecting Neuroendocrine Tumours Metastases to the Heart, researchers presented at the 7th Annual European Neuroendocrine Tumor Society (ENETS) Conference.

"There is as of yet no detailed study on the best imaging method for the detection of this rare site of metastases," the authors wrote.

Researchers from the Zentralklinik Bad Berka GmbH, Bad Berka, Germany examined 713 patients with progressive neuroendocrine tumours with Ga-68 DOTA Somatostatin-Receptor (SMS-R) positron emission tomography ( PET )/ computed tomography ( CT ), and 2D echocardiography. A total of 28 patients had heart metastases.

Magnetic resonance imaging ( MRI ) was performed in 12 patients, and fluorodeoxyglucose-PET-CT was available in 24. All imaging studies were reviewed independently by 2 different experts. The diagnostic accuracy of SMS-R-PET-CT, echocardiography, cardiac MRI, and thoracic CT scan studies was compared.

Cardiac metastases were confirmed in at least 2 functional and morphological imaging studies in 22 patients and by 1 modality in 6 patients.

The time of diagnosis from the primary tumour to the detection of cardiac metastasis was 7.6 +- 5.9 years

Sites of cardiac metastases were 15 pericardial (P), 17 myocardial (M), 1 intracardiac (I), and one epicardial (E).

The detection rate (positive/negative) of the different imaging modalities according to the different sites of metastases were: Echocardiography, 16/12 (M: 10, P: 6, I: 1, E: 1); SMS-R PET- CT, 26/2 (M: 15, P: 14, I: 1, E: 1); MRI, 9/2 (M: 5, P: 4, I: 1); FDG PET-CT, 3/21 (M: 1, P: 2); CT, 9/19 (M: 5, P: 5, I: 1). Echo detected 2 cardiac metastases that were not receptor-positive.

MRI and SMS-R PET/CT were concordant in about 91% of the cases.

Sensitivity of SMS-R PET/CT, echo, CT, and FDG PET-CT were 92%, 57%, 32%, and 12%, respectively.

Although MRI is a very good method for detecting heart metastases, the presence of arrhythmias in two-thirds of the patients with cardiac metastases can reduce its diagnostic accuracy.

The study authors concluded that Ga-68 SMS-R PET-CT is highly sensitive and far superior to echo, or CT alone, in the detection of heart metastases.

Source: ENETS

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