This technique paper describes a new treatment strategy which involves the combination of 125I brachytherapy and intraoperative radiotherapy (IOERT) in the treatment of recurrent colorectal adenocarcinoma. IOERT is used to encompass the areas of presumed microscopic disease with the IOERT dose being kept below the threshold for severe neuropathy. Brachytherapy with 125I is used to boost areas of gross disease within the IOERT treated area that would otherwise require potentially neurotoxic IOERT doses to achieve local control. The outcome results of patients treated with this technique will be reported at a later date after further patient actual and longer follow-up.