Physics in Medicine & Biology
Jun 18, 2012
Tumour control probability derived from dose distribution in homogeneous and heterogeneous models: assuming similar pharmacokinetics, 125Sn–177Lu is superior to 90Y–177Lu in peptide receptor radiotherapy
Stephan Walrand, François-Xavier Hanin, Stanislas Pauwels and François Jamar 2012 Phys. Med. Biol. 57 4263
Association of a short beta range radionuclide (RN) with a long beta range RN appears well adapted to simultaneously treat small homogeneous and large heterogeneous tumours. Recent clinical trials on 177Lu-90Y therapy used empirical activity ratios and RN with larger beta maximal range could still favourably replace 90Y. Tumour control probabilities (TCP) of several RN in combination with 177Lu were computed for various homogeneous and heterogeneous tumour models. Using 177Lu–90Y with 75–25% activity proportions provided the best TCP. However, 177Lu–125Sn with 80–20% activity proportions achieved significantly better TCP. In addition,125Sn production and its coupling to somatostatin analogue appear feasible. Clinical trials using RN combinations should use RN proportions tuned to the patient dosimetry. 125Sn is potentially the best RN for combination with 177Lu in peptide receptor radiotherapy justifying pharmacokinetics studies in rodents of 125Sn labelled somatostatin analogues.
About the author
Stephan Walrand, François-Xavier Hanin, Stanislas Pauwels and François Jamar (Center of Nuclear Medicine, Université Catholique de Louvain, Brussels, Belgium )