High-dose-rate interstitial brachytherapy with hypoxic radiosensitizer KORTUC II for unresectable pelvic sidewall recurrence of uterine cervical cancer: a case report

In order to improve oncologic outcomes in radiotherapy treatments of patients with unresectable pelvic sidewall recurrences of uterine cervical cancer, we combined high-dose-rate interstitial brachytherapy (HDR-ISBT) with newly tested hypoxic radiosensitizer Kochi oxydol-radiation therapy for unresectable carcinomas (KORTUC II), an enzyme-targeting radiosensitization treatment involving intra-tumoral injection of sodium hyaluronate mixed with hydrogen peroxide. We report on a 63-year-old patient referred to our department with an extensive pelvic sidewall recurrence of uterine cervical cancer after initial hysterectomy. The tumor size was 55 × 25 × 80 mm, with a calculated volume of 89.7 cc. Whole pelvic irradiation of 50 Gy in 25 fractions was administered, combined with weekly cisplatin injections. KORTUC II injections were given two times: at day 21 (42 Gy) and at day 24 (48 Gy). After finishing whole pelvic irradiation, HDR-ISBT of 25 Gy in 5 fractions b.i.d. over 3 days was administered. KORTUC II was also injected at the time of implantation. Dose-volume histogram (DVH) values for clinical target volume were D , D , and D of 6.0, 5.0, and 3.5 Gy per fraction, respectively. D values were 2.1, 4.1, 3.2, and 2.0 Gy per fraction for the bladder, rectum, sigmoid colon, and small bowel, respectively. No acute adverse events ≥ grade 3 were observed. Repeated grade 3 pyelonephritis occurred as a late complication at 11, 24, and 26 months after the treatment, and was successfully resolved with antibiotics. Moreover, grade 2 late toxicity was documented, including sciatic neuralgia, lower limb lymphedema, and urinary incontinence. At present, 32 months after HDR-ISBT, the patient remains free of disease, with no toxicity-related deterioration in physical condition.