Abstract
PurposeKochi Oxydol-Radiation Therapy for Unresectable Carcinomas II (KORTUC II) is currently the most widely used radiosensitizer in clinical use in Japan. Its use sensitizes tumors to radiation by injecting hydrogen peroxide into the tumors to neutralize antioxidant enzymes and, simultaneously, increase intratumor oxygen tension. KORTUC II has achieved significant local effects with no notable adverse events. We report on the cases where KORTUC II was used to treat patients with locally advanced breast cancer (LABC) or recurrent breast cancer (LRBC).Methods and MaterialsThirty patients treated with KORTUC II for LABC (n = 9) or LRBC (n = 21), who were followed up for at least 3 months after treatment, were included in the study. This sensitizer is a solution consisting of 0.83% sodium hyaluronate and 0.5% hydrogen peroxide by volume. The mixture was injected intratumorally several times during the treatment period under ultrasound guidance, just before RT doses. RT was administered for local control. The irradiation dose and extent fields were determined by the attending physicians considering patient factors. Maximum tumor shrinkage (MTS) was measured by Computed Tomography. The duration of loco-regional control (LC) and progression free survival (PFS) after the completion of RT were determined using the Kaplan–Meier method.ResultsThe median irradiation dose was 60.4 Gy3.5 (43.6–76.1 Gy3.5) based on the calculation of EQD2, and median total number of sensitizer treatments was 5 (2–7). The median MTS was 97.0%. Fifteen patients (50%) were assessed to have achieved a clinical complete response. The proportion of patients with LC at 1, 2, and 3 years was 100%, 94.7%, and 75.4%. The proportion with PFS after RT at 1 and 2 years was 59.0%, and 24.1%, respectively.ConclusionsKORTUC II treatment demonstrated high rates of local tumor control for LABC and LRBC. KORTUC II is expected to be an inexpensive and extremely promising RT with an excellent radio-sensitizing effect.Trial registrationOsaka Medical College Clinical Trials Registry, trial no. 1973, date. May 10, 2010UMIN Clinical Trials Registry, trial no. UMIN000003734, date. June 10, 2010
New enzyme‑targeting radiosensitizer (KORTUC II) treatment for locally advanced or recurrent breast cancer
