Non-surgical therapy and radiologic assessment of stage I breast cancer treatment with novel enzyme-targeting radiosensitization: Kochi Oxydol-Radiation Therapy for Unresectable Carcinomas, type II (KORTUC II).

The new enzyme-targeting radiosensitization treatment, Kochi Oxydol-Radiation Therapy for Unresectable Carcinomas, type II (KORTUC II), markedly enhances the radiotherapeutic effect of treatment for various types of locally advanced malignant neoplasms. Patients who had declined surgical treatment and systemic chemotherapy, as well as a total of 14 stage I breast cancer patients, were enrolled. A maximum of 6 ml of KORTUC II was injected into tumor tissue twice a week under ultrasonographic guidance, immediately prior to each administration of radiation therapy. The median observation period was 21.6 months with a range of 4-48 months, and the therapy was well tolerated. Contrast-enhanced magnetic resonance imaging and [(18)F]-fluorodeoxyglucose positron emission computed tomography revealed that all primary breast tumors completely responded, and none of the subjects experienced local recurrence during the observation period. Ultrasonography depicted tumor-like findings in 2/14 cases after therapy. The intratumoral flow signal on color-Doppler sonography was positive in 4/14 cases before therapy, and the signal disappeared from all cases after therapy. The absence of a flow signal after therapy suggested that the tumor-like findings on ultrasonography were from scar tissue. Excellent local control based on accurate radiological evaluation implies that KORTUC II has the potential to replace surgery as a therapeutic option for stage I breast cancer. Precise evaluation by various radiological modalities helped to gage the success of this therapy.