Diagnosing Lymph Node Metastases in Thyroid Cancer With 131-I SPECT/CT
Posted: Monday, June 8, 2020
For detecting and characterizing neck lymph node metastases in patients with differentiated thyroid carcinoma, 131-I SPECT/CT (131-iodine single-photon emission CT/CT) may prove to be an alternative to conventional 131-I planar whole-body imaging, especially in very low–risk cases, cases with inconclusive whole-body scan results, or cases with very low thyroglobulin levels. Giuseppe Madeddu, MD, of the University of Sassari, Italy, and colleagues shared their findings from a retrospective study in BMC Cancer.
“SPECT/CT with [a] diagnostic radioiodine dose proved [to be] a reliable tool to better identify, precisely localize, and characterize neck 131-I–avid foci compared [with a] planar whole-body scan,” wrote the authors. “SPECT/CT routine use is thus suggested.”
The retrospective study included 224 patients with differentiated thyroid carcinoma at the University of Sassari hospital who had already undergone total thyroidectomy and radioiodine therapy. The authors used 131-I SPECT/CT as a diagnostic imaging procedure to identify neck lymph node metastases. A total of 62 patients were at high risk, 64 were at low risk, and 98 were at very low risk of such metastases. The authors observed 449 iodine-avid foci in the neck via SPECT/CT and 322 via whole-body imaging.
SPECT/CT detection improved upon whole-body imaging results in 45.5% of patients. In 30.3% of cases, this improvement changed the therapeutic approach, and in 8% of cases, it identified false-positive results from the whole-body scan. The authors found the improvement especially relevant in cases with inconclusive whole-body scan results, undetectable or very low thyroglobulin levels, and in very low–risk cases with T1aN0M0 disease.
Disclosure: The study authors reported no conflicts of interest.