The Prognostic Power of Preablation Stimulated Thyroglobulin in Children With Differentiated Thyroid Cancer.

OBJECTIVE: To analyze prognostic factors in children with differentiated thyroid carcinoma (DTC) who have been treated in a single center in the last 27 years. METHODS: We studied 126 children (≤18 years old) who have been treated with near-total thyroidectomy followed by radioiodine therapy and thyroid hormone replacement. Follow-up of the patients was done 2, 6, and 12 months after treatment and then by yearly evaluation. Response to treatment was defined according to the American Thyroid Association guidelines. RESULTS: Papillary thyroid cancer was the main pathology (93.7%), and 52.4% of the patients had lymph node metastasis at presentation, which was extensive (>5) in 30% of the patients. Distant metastasis was seen in 8.8%. The mean initial dose of I-131 was 74 ± 42.2 MBq/kg. The median follow-up was 59 months and the median time to achieve an excellent response was 29 months. The preablation stimulated thyroglobulin (psTg) level was 202.4 ± 301.8 ng/mL in patients with first-year incomplete response compared with 11.2 ± 17.5 ng/mL in others (P =.001). Furthermore, using logistic regression, the psTg level was found to be the only significant predictor of distant metastasis, and psTg ≥ 13.75 ng/mL was the most powerful predictor of first-year incomplete response. Moreover, distant metastasis was more common in boys than in girls, and it took longer time for boys to achieve an excellent response. CONCLUSION: The psTg level was the only significant predictor of distant metastases in children with DTC, and psTg ≥ 13.75 ng/mL was the most powerful predictor of first-year incomplete response.

Unilateral Chronic Parotitis With 68 Ga-DOTA-FAPI-04 PET/CT and 18 F-FDG PET/CT Imaging in a Case of a Patient With Papillary Thyroid Carcinoma.

ABSTRACT: The 68 Ga-FAPI (fibroblast activation protein inhibitor) radiotracer is a novel and versatile tool in nuclear medicine, exhibiting potential for use in various conditions due to its significant upregulation in cancerous and inflammatory conditions, particularly those involving fibrotic and infectious processes. In this report, we present the case of a patient with papillary thyroid carcinoma who underwent total thyroidectomy and iodine therapy. He was referred because of high thyroglobulin despite negative diagnostic radioiodine imaging (TENIS syndrome). The patient underwent 18 F-FDG and 68 Ga-DOTA-FAPI-46 PET/CT imaging for metastatic workup and treatment planning. FAPI uptake was observed in the right parotid gland (with no FDG uptake), prompting a 99m TcO 4- salivary scintigraphy. Subsequently, a diagnosis of chronic sialadenitis was made.

Incidental Synchronous 99mTc-HYNIC-TOC Avid Lesion of the Neck in a Patient with Metastatic Melanoma: A Metastatic Lymph Node or a Carotid Body Tumor Masquerading As a Lymph Node?

A 53-year-old woman with a plantar malignant melanoma lesion was referred to our tertiary clinic for sentinel lymph node mapping. Lymphoscintigraphy with 99mTc-Phytate detected ipsilateral inguinal and popliteal sentinel nodes. After total resection of nodes, the pathology report confirmed that all specimens were involved by the tumor. As part of an institutional study evaluating somatostatin receptor avidity of melanoma by 99mTc-HYNIC-TOC scan, she also underwent a whole-body octreotide scan, which surprisingly showed intense tracer uptake in the right cervical region, confining in SPECT/CT images to a mass at the C2 spinal level, adjacent to the right carotid bifurcation. Neck surgery with gamma probe after injection of another dose of 99mTc-HYNIC-TOC was performed successfully, and the pathology report was consistent with a carotid body tumor. To best our knowledge, our case is the first one in the literature, which reports an incidental paraganglioma with 99mTc-HYNIC-TOC scan which resected via radio-guided surgery, again with 99mTc-HYNIC-TOC tracer.

Prostate-Specific Membrane Antigen Radioguided Surgery for Salvage Pelvic Lymph Node Dissection in a Man With Prostate Cancer.

ABSTRACT: A 75-year-old man with evidence of recurrent prostate cancer on 68Ga-prostate-specific membrane antigen (PSMA) PET/CT after radical prostatectomy was referred to our department for 99mTc-PSMA radioguided surgery. Intraoperatively, lymph nodes with high count rates were localized using a handheld gamma probe. High-count specimens were resected from the exact locations as reported by 68Ga-PSMA PET/CT. The total prostate-specific antigen value decreased 6 weeks after surgery. Our case shows the feasibility of radioguided surgery with 99mTc-PSMA for salvage lymphadenectomy in prostate cancer.