Efficacy of Radioembolization with 166 Ho-Microspheres in Salvage Patients with Liver Metastases: A Phase 2 Study

J Nucl Med. 2018 Apr;59(4):582-588. doi: 10.2967/jnumed.117.197194. Epub 2017 Sep 15.


Radioembolization of liver malignancies with 166Ho-microspheres has been shown to be safe in a phase 1 dose-escalation study. The purpose of this study was to investigate the efficacy of 166Ho radioembolization. Methods: In this prospective single-arm study, 56 patients were enrolled, all with liver metastases refractory to systemic therapy and ineligible for surgical resection. The primary outcome was a response by 2 target lesions on triphasic liver CT scans 3 mo after therapy, as assessed using RECIST, version 1.1. Secondary outcomes included overall tumor response, time to imaging progression, overall survival, toxicity, quality of life, and quantification of the microspheres on SPECT and MRI. Results: Between May 2012 and March 2015, 38 eligible patients were treated, one of whom was not evaluable. In 27 (73%) of 37 patients, the target lesions showed complete response, partial response, or stable disease (disease control) at 3 mo (95% confidence interval [CI], 57%-85%). The median overall survival was 14.5 mo (95% CI, 8.6-22.8 mo). For colorectal cancer patients (n = 23), the median overall survival was 13.4 mo (95% CI, 8.2-15.7 mo). Grade 3 or 4 toxic events after treatment (according to the Common Terminology Criteria for Adverse Events, version 4.03) included abdominal pain (in 18% of patients), nausea (8%), ascites (3%), fatigue (3%), gastric stenosis (3%), hepatic failure (3%), liver abscesses (3%), paroxysmal atrial tachycardia (3%), thoracic pain (3%), upper gastrointestinal hemorrhage (3%), and vomiting (3%). On SPECT, 166Ho could be quantified with high accuracy and precision, with a mean overestimation of 9.3% ± 7.1% in the liver. Conclusion: Radioembolization with 166Ho-microspheres induced a tumor response with an acceptable toxicity profile in salvage patients with liver metastases.

Keywords: SIRT; gastrointestinal; holmium; liver; radioembolization; radionuclide therapy.

Publication types

  • Clinical Trial, Phase II
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Embolization, Therapeutic*
  • Female
  • Holmium / chemistry*
  • Holmium / therapeutic use*
  • Humans
  • Liver Neoplasms / diagnostic imaging
  • Liver Neoplasms / pathology*
  • Liver Neoplasms / radiotherapy*
  • Male
  • Microspheres*
  • Middle Aged
  • Neoplasm Metastasis
  • Positron Emission Tomography Computed Tomography
  • Quality of Life
  • Radioisotopes / chemistry*
  • Radioisotopes / therapeutic use*
  • Radiotherapy Dosage
  • Salvage Therapy*


  • Holmium-166
  • Radioisotopes
  • Holmium