Comparison of high-dose rate prostate brachytherapy dose distributions with iridium-192, ytterbium-169, and thulium-170 sources

All the dose distributions optimized with specific 192Ir, 169Yb, and 170Tm sources satisfied the standard clinical criteria for HDR prostate implants, such as those for the Radiation Therapy Oncology Group clinical trial 0321, for combined HDR and external beam treatment for prostate adenocarcinoma. For equivalent clinical target volume dose coverage, the specific 169Yb and 170Tm sources resulted in a statistically significant dose reduction to organs at risk compared with microSelectron V2 HDR 192Ir source. This study indicates that a 170Tm or 169Yb radionuclide source may be an alternative to the 192Ir radionuclide sources in HDR brachytherapy.