I-131 Postablation SPECT/CT Predicts Relapse of Papillary Thyroid Carcinoma more Accurately than Whole Body Scan

In Vivo. 2019 Nov-Dec;33(6):2255-2263. doi: 10.21873/invivo.11731.

Abstract

Background/aim: The aim of the study was to prospectively compare I-131 postablation Whole Body scan (WBS) and Single Photon Emission Computerized Tomography/Computerized Tomography (SPECT/CT) scan on thyroid cancer patients.

Patients and methods: Overall, 58 patients with papillary thyroid carcinoma were submitted to total thyroidectomy and I-131 remnant ablation. Post-ablation WBS and SPECT/CT scans performed on the same day were compared. Results of SPECT/CT were confirmed by neck and upper mediastinum ultrasound scan and on specific cases by a fully diagnostic CT scan, other tests and definitive histology acting as the gold standard. A total of 36/58 patients were followed-up for 5 years to detect relapse.

Results: Mac Nemar Chi square and Fisher's exact tests disclosed statistically significant differences between WBS and SPECT/CT scan, concerning cervical lymphadenopathy detection (p=0.031) and relapse prediction by NM stage (p=0.033), respectively; SPECT/CT was more accurate in both comparisons.

Conclusion: In papillary thyroid carcinoma I-131 post-ablation SPECT/CT scan detects cervical lymphadenopathy and predicts relapse by NM stage more accurately than WBS.

Keywords: I-131 postablation scan; Papillary thyroid carcinoma; SPECT/CT; whole body scan.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Biomarkers
  • Female
  • Humans
  • Iodine Radioisotopes*
  • Male
  • Middle Aged
  • Recurrence
  • Sensitivity and Specificity
  • Thyroid Cancer, Papillary / diagnosis*
  • Thyroid Cancer, Papillary / therapy
  • Tomography, Emission-Computed, Single-Photon* / methods
  • Tomography, Emission-Computed, Single-Photon* / standards
  • Tomography, X-Ray Computed* / methods
  • Tomography, X-Ray Computed* / standards
  • Whole Body Imaging* / methods
  • Whole Body Imaging* / standards

Substances

  • Biomarkers
  • Iodine Radioisotopes
  • Iodine-131