For the mention of a cold nodule; cold nodules may be thyroid carcinoma, thyroid lymphoma, or metastatic (rare). https://next.amboss.com/us/article/bg0HF2?q=thyroid%20nodule#Z39253f1aa7bfa8f5dc23572740b1feca
Secondly, I-123 is preferred for the diagnosis of thyroid disorders, not I-131. The AMBOSS article lists only I-123 in reference to radioactive uptake studies. UpToDate mentions I-123 as the preferred isotope for thyroid scintigraphy and radioactive iodine uptake. https://www.uptodate.com/contents/diagnostic-approach-to-and-treatment-of-thyroid-nodules?search=i-123%20scintigraphy&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1
Also, "further biopsy" is incorrect as no biopsies would have been done this point in the diagnostic workup. A FNA biopsy may be warranted based on the results of the scan. See above UpToDate link for reference.
Minor proposition: For formatting of isotopes, there are two common formats: the added one is the name or symbol of the particular element, immediately following by a hyphen and the mass number. (https://isotopes.gov/isotope-basics).
