The use of somatostatin receptor (SSTR) positron emission tomography/computed tomography (PET/CT) is better than computed tomography alone in terms of assisting with therapeutic decision-making in patients with medullary thyroid carcinoma (MTC), according to a new study published in Endocrine.

The researchers reported switching between surgery and systemic treatment with tyrosine kinase inhibitors (TKIs) in over two-thirds of cases based on the SSTR-PET CT findings.

“Functional imaging using [SSTR] directed [PET/CT] has proven useful to detect sites of disease, with a tabulated detection rate of more than 86% in selected cases,” the authors wrote. “As such, given the increasing use of SSTR-targeted imaging for MTC, we aimed to assess the role of this functional imaging modality as a therapeutic decision aid in a real-world scenario.”

Continue Reading

Read more about MTC testing

The research team retrospectively included 23 consecutive patients diagnosed with MTC at a single center, all of whom underwent SSTR-directed PET/CT with iodine contrast. The findings were compared with those from computed tomography alone and both patient-centric and lesion-based analyzes were performed.

An interdisciplinary tumor board discussed the results and determined the need for any therapeutic changes, which were then carried out by the patients’ attending physicians. The impact of management changes on patient outcomes was also assessed.

The use of SSTR-directed PET/CT was superior to computed tomography alone in both the patient-centric and lesion-based analyses, and it led to therapeutic changes in over two-thirds of the cases. In most patients, a switch to either surgery or TKI treatment was indicated, and the switch resulted in disease control in 75% of the cases on follow-up.

The authors recommend larger prospective studies in the future that also evaluate more easily accessible imaging modalities such as ultrasound.


Serfling SE, Zhi Y, Megerle F, et al. Somatostatin receptor-directed molecular imaging for therapeutic decision-making in patients with medullary thyroid carcinoma. Endocrine. Published online June 25, 2022. doi:10.1007/s12020-022-03116-6