Open Access
Issue
BIO Web Conf.
Volume 14, 2019
The 12th International Conference on the Health Effects of Incorporated Radionuclides (HEIR 2018)
Article Number 07005
Number of page(s) 3
Section Nuclear Medicine, Targeted Therapy and Medical Imaging: Poster presentation
DOI https://doi.org/10.1051/bioconf/20191407005
Published online 07 May 2019

Ruthenium-106 (106Ru) is a beta emitter with a 374 day half-life that is commonly used for brachytherapy of uveal melanoma. Since the beginning of its use in the 1960s, it has been the treatment of choice in Europe unlike North America where it is disfavoured. Compared to other isotopes including beta (Sr-90) and gamma (I-125, Pd-103) emitters, it has a limited penetration depth but the advantage of sparing surrounding normal tissues. Ru-106 plaque radiotherapy has been increasingly used for the treatment of small- to medium-sized tumors up to 5 mm in thickness [1]. 106Ru plaque provides a maximum activity of 1.6 mCi and a recommended radiation dose to the apex of tumors is 85 Gy according to a Collaborative Ocular Melanoma Study (COMS) [2].

The local control, non-recurrence and eye-conserving are the main concerns in uveal tumor treatment, besides the patient survival. Though, the radiation threshold dose, effective for the treatment remains unknown and further examinations are needed to design an optimum dose radiation.

Taking into account of geometric tumour parameters, the dose and the time of treatment are directly correlated to the height and basal diameter of tumors, respectively. Software calculations are designed and developed to provide a robust and optimal dose regarding a loss of visual acuity. In fact, dosimetric tolerance levels to macula, optic nerve and retina are evaluated. The Monte Carlo algorithms are used to simulate a dose distribution in the tissues. Indeed, they need to simulate a spectrum resulting from a beta disintegration complicated by a heterogeneous source distribution. Each device used is beforehand calibrated and dose rate in water phantom is given.

Nevertheless, an assessment of dose calculations into plaques points a difference between homogeneous and heterogeneous plaques. A dose distribution of 106Ru plaque and the normalized surface distribution of the emitter substance into a heterogeneous plaque are illustrated on Fig. 1.

thumbnail Fig. 1

2D dose (Gy) distribution for 18 mm 106Ru plaques [3] (left), experimental emitter dose map for heterogeneous plaque (CCA1364) [4].

A state of art of the use of this radionuclide in terms of dose/response and risk assessment will be presented and the results will be discussed.

References

  • Stannard, C., et al., Radiotherapy for ocular tumours. Eye, 27(2): p. 119-127 (2013) [CrossRef] [Google Scholar]
  • Melia, B.M., et al., Collaborative ocular melanoma study (COMS)randomized trial of I-125 brachytherapy for medium choroidal melanoma.I. Visual acuity after 3 years COMS report no. 16. Ophthalmology,. 108(2):p.348-66 (2001) [CrossRef] [PubMed] [Google Scholar]
  • Wilkinson, D.A., et al., Dosimetric comparison of Ru-106 and I-125 plaquesfor treatment of shallow (<= 5 mm) choroidal melanoma lesions. BritishJournal of Radiology, 81(970): p. 784-789 (2008) [Google Scholar]
  • Zaragoza, F.J., et al., Monte Carlo Estimation of Absorbed DoseDistributions Obtained from Heterogeneous (106)Ru Eye Plaques. OculOncol Pathol, 3(3): p. 204-209 (2017) [Google Scholar]

© The Authors, published by EDP Sciences, 2019

Licence Creative Commons
This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

All Figures

thumbnail Fig. 1

2D dose (Gy) distribution for 18 mm 106Ru plaques [3] (left), experimental emitter dose map for heterogeneous plaque (CCA1364) [4].

In the text

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.