Correlation of Iodine Quantification and FDG Uptake in Early Therapy Response Assessment of Non-small Cell Lung Cancer: Possible Benefit of Dual-energy CT Scan as an Integral Part of PET/CT Examination

Anticancer Res. 2020 Jun;40(6):3459-3468. doi: 10.21873/anticanres.14332.

Abstract

Aim: To compare iodine-related and fluorine-18 fluorodeoxyglucose (18F-FDG) parameters during staging of lung cancer as well as during early follow-up, while investigating potential use and possible substitutability in the assessment of therapeutic response or prediction.

Patients and methods: Patients (n=45) with confirmed lung cancer underwent 18F-FDG positron-emission tomography (PET) using single-source dual-energy computed tomography was performed for staging and early follow-up. Correlation of FDG uptake and iodine-related parameters was assessed and comparison with therapy response was performed.

Results: A strong correlation was found between the volumetric FDG parameters metabolic tumour volume (MTV) and total lesion glycolysis (TLG) and iodine uptake (IU) in staging (IU vs. MTV: rs=0.894; p<0.001 and IU vs. TLG: rs=0.874; p<0.001) and follow-up (IU vs. MTV: rs=0.934, p<0.001 and IU vs. TLG: rs=0.935, p<0.001). We also found significant correlation of change in these values between timepoints. We observed a significant correlation of IU, MTV and TLG with early therapy response and IU was found as a possible strong predictor.

Conclusion: Strong correlation of IU and volume-based FDG parameters was proved in staging, follow-up and change during therapy. Potential role of IU in prediction of early therapy-response was identified. Our study suggests a significant benefit of using the dual-energy computed tomography as a part of 18F-FDG PET/CT in patients with lung cancer.

Keywords: Multidetector computed tomography; dual-energy; fluorodeoxyglucose; iodine; lung cancer; positron-emission tomography.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Carcinoma, Non-Small-Cell Lung / diagnosis*
  • Carcinoma, Non-Small-Cell Lung / therapy*
  • Chemotherapy, Adjuvant
  • Female
  • Humans
  • Iodine
  • Lung Neoplasms / diagnosis*
  • Lung Neoplasms / therapy*
  • Male
  • Middle Aged
  • Neoplasm Staging
  • Positron Emission Tomography Computed Tomography* / methods
  • ROC Curve
  • Radiopharmaceuticals
  • Tomography, X-Ray Computed* / methods
  • Treatment Outcome

Substances

  • Radiopharmaceuticals
  • Iodine