Early post-treatment FDG PET predicts survival after 90Y microsphere radioembolization in liver-dominant metastatic colorectal cancer

Eur J Nucl Med Mol Imaging. 2015 Mar;42(3):370-6. doi: 10.1007/s00259-014-2935-z. Epub 2014 Oct 29.


Purpose: The aim of this study was to evaluate the predictive value of early metabolic response 4 weeks post-treatment using (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT in patients with unresectable hepatic metastases of colorectal cancer (CRC) undergoing radioembolization (RE) with (90)Y-labelled microspheres.

Methods: A total of 51 consecutive patients with liver-dominant metastases of CRC were treated with RE and underwent (18)F-FDG PET/CT at baseline and 4 weeks after RE. In each patient, three hepatic metastases with the highest maximum standardized uptake value (SUVmax) were selected as target lesions. Metabolic response was defined as >50 % reduction of tumour to liver ratios. Survival analyses using Kaplan-Meier and multivariate analyses were performed to identify prognostic factors for overall survival (OS). Investigated baseline characteristics included age (>60 years), performance status (Eastern Cooperative Oncology Group >1), bilirubin (>1.0 mg/dl), hepatic tumour burden (>25 %) and presence of extrahepatic disease.

Results: The median OS after RE was 7 months [95 % confidence interval (CI) 5-8]; early metabolic responders (n = 33) survived longer than non-responders (p < 0.001) with a median OS of 10 months (95 % CI 3-16) versus 4 months (95 % CI 2-6). Hepatic tumour burden also had significant impact on treatment outcome (p < 0.001) with a median OS of 5 months (95 % CI, 3-7) for patients with >25 % metastatic liver replacement vs 14 months (95 % CI 6-22) for the less advanced patients. Both factors (early metabolic response and low hepatic tumour burden) remained as independent predictors of improved survival on multivariate analysis.

Conclusion: These are the first findings to show that molecular response assessment in CRC using (18)F-FDG PET/CT appears feasible as early as 4 weeks post-RE, allowing risk stratification and potentially facilitating early response-adapted treatment strategies.

Publication types

  • Evaluation Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Colorectal Neoplasms / diagnostic imaging*
  • Colorectal Neoplasms / pathology
  • Colorectal Neoplasms / radiotherapy
  • Embolization, Therapeutic*
  • Female
  • Fluorodeoxyglucose F18
  • Humans
  • Liver Neoplasms / diagnostic imaging*
  • Liver Neoplasms / radiotherapy
  • Liver Neoplasms / secondary
  • Male
  • Microspheres*
  • Middle Aged
  • Multimodal Imaging
  • Positron-Emission Tomography*
  • Predictive Value of Tests
  • Radiopharmaceuticals* / therapeutic use
  • Survival Analysis
  • Tomography, X-Ray Computed
  • Yttrium Radioisotopes / therapeutic use


  • Radiopharmaceuticals
  • Yttrium Radioisotopes
  • Fluorodeoxyglucose F18