Bone-Seeking Radionuclide for Therapy
Ionising radiation is utilised in a variety of situations in the management of prostate cancer. Beyond the scope of this book is the use of brachytherapy and external beam radiotherapy (EBRT) as efficacious, radical treatment modalities in the management
- PDF / 227,012 Bytes
- 15 Pages / 504.567 x 720 pts Page_size
- 69 Downloads / 223 Views
16
Joe O’Sullivan and Phil Turner
16.1
Introduction
Ionising radiation is utilised in a variety of situations in the management of prostate cancer. Beyond the scope of this book is the use of brachytherapy and external beam radiotherapy (EBRT) as efficacious, radical treatment modalities in the management of localised prostate cancer. Earlier chapters have covered the use of EBRT as a therapeutic option for the treatment of symptomatic bone metastases. This chapter focuses on the place of radionuclide therapy for the management of bone metastases. Recent development of radium-223 dichloride has reinvigorated this field of therapy. Here, analysis is made of the history of radionuclides and their current role in the modern treatment paradigm; the chapter closes by horizonscanning for the potential future applications of radionuclide therapy, both as part of novel combinations with other agents and in new settings beyond current licensed indications. Radionuclides are radioactive forms of chemical elements. Chemical elements are composed of atoms, and most chemical elements generally exist in a non-radioactive form. Atoms can be described in terms of two numbers, the atomic number and
mass number. The atomic number describes the number of protons in the nucleus. The mass number describes the number of protons plus the number of neutrons in the nucleus. The atomic number defines elements; for example, any atom containing 6 protons will always have an atomic number of 6 and will always be the element carbon. However it is possible for elements to exist in different forms – the atomic number (number of protons) remains constant but the number of neutrons, and therefore the mass number, changes. Stable carbon atoms containing 6 protons and 6 neutrons have a mass number of 12; carbon can also occur as atoms containing 6 protons and 8 neutrons, having a mass number of 14, the so-called carbon-14. These different forms are said to be isotopes of the element. There is an optimal ratio of protons and neutrons, and the isotope with this ratio will exist as the stable form of the element. Deviations from this optimal ratio form unstable isotopes. These unstable isotopes can convert to a more stable form by altering their nuclear configuration of neutrons and protons; the process by which they do this is radioactive decay. This is covered in more detail in Sect. 16.3 below.
16.2 J. O’Sullivan (*) • P. Turner Queen’s University Belfast, University Road, Belfast, Ulster BT7 1NN, Ireland e-mail: [email protected]
Bone-Seeking Compounds
The physiology of bone metastases has been covered in earlier chapters. To summarise, there is evidence that tumour cells utilise similar
© Springer International Publishing Switzerland 2017 F. Bertoldo et al. (eds.), Bone Metastases from Prostate Cancer, DOI 10.1007/978-3-319-42327-2_16
193
J. O’Sullivan and P. Turner
194
mechanisms used by haematopoietic stem cells to home into the haematopoietic stem cell niche [1]. A milieu of signalling pathways are engaged which result in the
Data Loading...
