1. ¹Unit of Academic Radiotherapy and Clinical Oncology, Royal Marsden NHS Trust, Sutton, Surrey SM2 5PT, UK
2. ²Department of Nuclear Medicine, Royal Marsden NHS Trust, Sutton, Surrey SM2 5PT, UK
3. ³Department of Physics, Royal Marsden NHS Trust, Sutton, Surrey SM2 5PT, UK
4. ⁴Department of Statistics, Royal Marsden NHS Trust, Sutton, Surrey SM2 5PT, UK
5. ⁵Bob Champion Research Unit, Royal Marsden NHS Trust, Sutton, Surrey SM2 5PT, UK
6. ⁶Department of Haematology and Institute of Cancer Research, Royal Marsden NHS Trust, Sutton, Surrey SM2 5PT, UK

Correspondence: J M O'Sullivan, E-mail: drjoeosullivan@ireland.com

Received 13 December 2001; Revised 4 March 2002; Accepted 19 April 2002.

Abstract

We tested the feasibility and toxicity of high activities Rhenium-186 hydroxyethylidene diphosphonate, with peripheral blood stem cell rescue in patients with progressive hormone refractory prostate cancer metastatic to bone. Twenty-five patients received between 2500 and 5000 MBq of Rhenium-186 hydroxyethylidene diphosphonate followed 14 days later by the return of peripheral blood peripheral blood stem cells. Activity limiting toxicity was defined as grade III haematological toxicity, lasting at least 7 days, or grade IV haematological toxicity of any duration or any serious unexpected toxicity. Activity limiting toxicity occurred in two of six who received activities of 5000 MBq and maximum tolerated activity was defined at this activity level. Prostate specific antigen reductions of 50% or more lasting at least 4 weeks were seen in five of the 25 patients (20%) all of whom received more than 3500 MBq of Rhenium-186 hydroxyethylidene diphosphonate. The actuarial survival at 1 year is 54%. Administered activities of 5000 MBq of Rhenium-186 hydroxyethylidene diphosphonate are feasible using autologous peripheral blood peripheral blood stem cell rescue in patients with progressive hormone refractory prostate cancer metastatic to bone. The main toxicity is thrombocytopaenia, which is short lasting. A statistically significant activity/prostate specific antigen response was seen. We have now commenced a Phase II trial to further evaluate response rates.