European Conference on Embolotherapy
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ProgrammeSneak peeksFuture evolution and outlook of TARE

Future evolution and outlook of TARE


Three reasons why you cannot miss my lecture

  1. You will gain an understanding of the main differences between TARE products
  2. You will learn the principles of dosimetry-based personalized treatment
  3. We will discuss the future of TARE

Prof. Marnix G.E.H. Lam
Speaker bio

Make sure to add this session to your calendar!

Currently, three different types of radioactive microspheres are commercially available: yttrium-90 (90Y) resin (SIR-Spheres®, SIRTeX), 90Y glass (TheraSphere®, Boston Scientific)  and holmium-166 (166Ho) microspheres (Quiremspheres®, Terumo)(1).

The characteristics of these three types of microspheres are listed in Table 1.

Characteristic90Y resin90Y glass166Ho
Half-life (h)
Type of radiationβββ,γ
Decay productZirconium-90Zirconium-90Erbium-166
Diameter (µm)32.5 ± 2.525 ± 1030 ± 15
Density (g/mL)
Typical activity / microsphere (Bq)40-70 *2500 **250-400
Typical number per dose30-50 million3-5 million **20 million

*Within FlexDose program activity/microsphere is higher; ** Depending on day post-calibration

The most apparent differences between the three types of microspheres are the type of radiation they emit and their specific activity. 166Ho emits γ-radiation, which allows it to be visualized by SPECT/CT. It is also paramagnetic, so it can be visualized by MRI as well. On the contrary, imaging of 90Y is possible by using either bremsstrahlung-SPECT/CT or PET/CT.

The differences in specific activity are significant: typically low for 90Y resin and high for 90Y glass, with 166Ho having a specific activity in between. This has many consequences: first, the difference in specific activity is translated into the number of particles injected, leading to a larger embolic effect (and potential stasis) for 90Y resin and 166Ho than for 90Y glass. Also, the tolerability of the liver is different for the three types of microspheres, leading to a difference in safety thresholds. A higher number of microspheres leads to a higher number of targeted liver clusters (i.e. healthy liver parenchyma) and a more homogeneous distribution in the liver. [2] With 90Y glass microspheres, there generally is a more heterogeneous distribution of the microspheres, leading to a greater tolerability at high absorbed doses to the healthy liver. This explains why the thresholds for safety are different for the three types of microspheres. Likewise, a more homogeneous distribution, as obtained with 90Y resin and 166Ho, most likely also requires lower tumour absorbed doses to be equally effective. This is indeed reflected in the thresholds found in the literature. [1]

Dose thresholds depend on the microsphere type, but also on the tumour type. Hepatocellular carcinomas are generally hypervascular, and will receive a high tumour absorbed dose, whereas colorectal carcinoma metastases are generally more hypovascular, resulting in a lower tumour absorbed dose and higher absorbed dose in the healthy liver tissue. In any patient, TARE should therefore be performed by using a personalized treatment plan based on a sufficient tumour absorbed dose and safe healthy liver absorbed dose.

This is especially true when treating with a combination of systemic treatment and TARE. Based on multiple RCTs in colorectal carcinoma in the first line setting (SIRFLOX, FOXFIRE and FOXFIRE-Global studies), the combination of first line chemotherapy and TARE cannot be recommended at this time. However, even without using a personalized treatment plan (i.e. a one-size-fits-all approach was used, which likely lead to underdosing of most patients), a statistically significant difference in cumulative incidence of first progression in the liver was still found. [3] EPOCH confirmed this positive signal in the second line setting with a significant improvement not only in hepatic PFS, but also in overall PFS. [4] Similarly, no overall survival benefit could be established in the SORAMIC study when combining sorafenib with TARE in HCC. [5] But, with an individualized treatment plan in the DOSISPHERE-01 study, a very clear anti-tumour effect was found in HCC. [6] Most ongoing studies therefore include personalized treatment as a basis for state-of-the-art TARE.

State-of-the-art TARE, also including high-quality pre-, peri- and post-procedural imaging guidance, paves the way towards new treatment scenarios and new indications in and outside the liver.


Marnix G.E.H. Lam

University Medical Center Utrecht, Utrecht/NL

Prof. Dr. Lam is a Professor of Nuclear Medicine and the Chief of Nuclear Medicine at the University Medical Center Utrecht, Department of Radiology and Nuclear Medicine. He is trained as a nuclear medicine physician and radiologist. He has been a staff member of the Department of Radiology and Nuclear Medicine at the UMC Utrecht since 2007. During his ‘Dutch Cancer Society (KWF)’ research fellowship on translational and clinical research (2010 – 2014), he completed a 2-year research fellowship at Stanford University. In 2013, he was appointed chief of nuclear medicine, and in 2016 he was appointed professor of nuclear medicine. Translational research in molecular medicine has been the scope of Prof. Lam's scientific work, with a special focus on oncology. His aim is to bring new radiopharmaceuticals to clinical practice. This specifically resulted in the introduction of new oncological treatment modalities in the Netherlands, such as bone seeking radiopharmaceuticals for the palliation of metastatic bone pain (153Sm-EDTMP, 188Re-HEDP, 223Ra-chloride), protein-receptor radionuclide therapy (177Lu-PSMA, 177Lu-HA-dotatate), and radioembolization for treatment of hepatic malignancies (90Y microspheres and 166Ho microspheres). Prof. Lam's current research focusses on dosimetry of therapeutic radiopharmaceuticals, image-guided treatment technology, alfa- and beta-emitting isotopes for therapeutic purposes, intra-arterial and intra-tumor treatment approaches, and radio-immunotherapy.



  1. Weber M, Lam M, Chiesa C, Konijnenberg M, Cremonesi M, et al. EANM procedure guideline for the treatment of liver cancer and liver metastases with intra-arterial radioactive compounds. Eur J Nucl Med Mol Imaging. 2022 Apr;49(5):1682-1699.
  2. Pasciak AS, Abiola G, Liddell RP, Crookston N, Besharati S, et al. The number of microspheres in Y90 radioembolization directly affects normal tissue radiation exposure. European journal of nuclear medicine and molecular imaging. 2020;47(4):816-27.
  3. Wasan HS, Gibbs P, Sharma NK, Taieb J, Heinemann V, et al. First-line selective internal radiotherapy plus chemotherapy versus chemotherapy alone in patients with liver metastases from colorectal cancer (FOXFIRE, SIRFLOX, and FOXFIRE-Global): a combined analysis of three multicentre, randomised, phase 3 trials. Lancet Oncol. 2017 Sep;18(9):1159-1171.
  4. Mulcahy MF, Mahvash A, Pracht M, Montazeri AH, Bandula S, et al. Radioembolization With Chemotherapy for Colorectal Liver Metastases: A Randomized, Open-Label, International, Multicenter, Phase III Trial. J Clin Oncol. 2021 Dec 10;39(35):3897-3907.
  5. Ricke J, Klümpen HJ, Amthauer H, Bargellini I, Bartenstein P, et al. Impact of combined selective internal radiation therapy and sorafenib on survival in advanced hepatocellular carcinoma. J Hepatol. 2019 Dec;71(6):1164-1174.
  6. Garin E, Tselikas L, Guiu B, Chalaye J, Edeline J, et al. Personalised versus standard dosimetry approach of selective internal radiation therapy in patients with locally advanced hepatocellular carcinoma (DOSISPHERE-01): a randomised, multicentre, open-label phase 2 trial. Lancet Gastroenterol Hepatol. 2021 Jan;6(1):17-29.