False Positive Radioiodine Post-Ablation Scan in Scalp Region in a Woman who Used Hair Coloring Revealed by SPECT/CT

Abstract

Objective: Radioiodine ablation with iodine-131 is a standard therapeutic procedure for patients diagnosed with differentiated thyroid carcinoma (DTC). We present a contamination artifact on whole-body scan (WBS), after radioiodine ablation due to papillary thyroid carcinoma. The hybrid imaging resolved the question of metastasis versus contamination. Methods: In the case of 35-year-old female patient we used a General Electric hybrid gamma camera with a high-energy-general-purpose collimator for performing WBS, and single photon emission computed tomography combined with low dose computed tomography (SPECT/CT) for the detection of any residual thyroid tissue or meta-static disease and at the same time ablation and treatment of any confirmed metastasis. Results: A thyroid scan showed activity in the remnant thyroid tissue of the right lobe, but also laterally in the calvaria (left temporal region). The patient's neck ultra-sound and thyroglobulin level were not in favor of metastasis. A false positive finding due to hair coloring was concluded with SPECT/CT hybrid imaging. Conclusion: SPECT/CT scan can contribute to establishing a final diagnosis in patients being evaluated for atypical locations of radioactive iodine accumulation after ablative doses of radioactive iodine, distinguishing between metastases from DTC and false positive accumulations or artifacts.

Statistical calculation of beta radiotherapy dose using I-131: analysis and simulation method.

“…Radioiodine 131 I ablation is a standard treatment procedure for differentiated thyroid cancer (DTC) patients. This is followed by a whole-body scan (WBS) to discover leftover thyroid tissue or metastatic illness and ablation and treatment of any confirmation [16][17][18][19][20]. Differentiated thyroid…”

“…Previous study only spoke about gamma particles that patients emitted after receiving radioactive sources 131 I but never addressed beta particles that treated thyroid carcinoma cells [11][12][13][14][15].Radioiodine 131 I ablation is a standard treatment procedure for differentiated thyroid cancer (DTC) patients. This is followed by a whole-body scan (WBS) to discover leftover thyroid tissue or metastatic illness and ablation and treatment of any confirmation [16][17][18][19][20]. Differentiated thyroid…”