The impact of modulated electrohyperthermia (oncothermia) in achieving adequate tumor response in patients with locally advanced cervical cancer IIB-IVA FIGO

The key point in local control (LC) and disease-free survival (DFS) for cervical cancer IIb - IVa FIGO patients is to achieve optimal HR-CTV at the beginning of intracavitary brachytherapy, especially when one has no options for hybrid technologies. However, 30% of locally advanced cervical cancer (LACC) patients, with tumor ≥4 cm, lateral parametrium, middle and lower thirds of the vagina involved, failed to achieve such an effect after standard platinum-based chemoradiation. Modulated electrohyperthermia (mEHT) is another and rather new for LACC method to modify the tumor response, where one uses an alternating electric field of 13.56 MHz, modulated by fractal harmonic oscillations of 0-5 KHz, due to the capacitive coupling of asymmetric electrodes.We tried to assess if oncothermia can improve tumor response after chemoradiation before brachytherapy in LACC patients. 133 patients LACC IIb - IVa FIGO were included, who underwent conformal external beam radiation therapy (EBRT) 45-50 Gy to the pelvis (1,8-2 Gy in 25-28 fractions), with weekly Cisplatin 40 mg/m2 or Carboplatin AUC2, followed by image-guided 192Ir brachytherapy. In research arm (I) 68 patients oncothermia (MEHT) session was proceed (EHY-2000) before EBRT, 60-90 min, 110-130 W, 3 times a week, 9-14 sessions per course. 65 comparable patients were included in control arm (II).Objective response after chemoradiation at the beginning of brachytherapy was significantly (p≤0.05) better in arm I. We observed: complete response in 42.9% vs 4.7% for IIb and 11.5% vs 2.5% for IIIa-c pts.; partial response ≥80% - in 42.9% vs 14.3% for IIb and in 30.8% vs 10.0% IIIa- c pts.; optimal HR-CTV ≤ 30 cm3 at the beginning of brachytherapy - in 55.9% vs 13.8% (p= 0.027), complete resorption of parametrial infiltration - 64.7%±4.4% vs. 13.8%±7.4 % (p=0.002) in arms I and II respectively. DFS rates were significantly better in study group, starting from the second year of observation, 80.7%±5.0% vs. 64.8%±6.1% for 36 months, 72.1%±6.7% vs. 58.3%± 6.4% for 60 months respectively (p≤0.05). There was a significant improvement of LC in study group - 92.7%±8.7% vs. 78.5%±9.4% (p=0.048) for 60 months in arms I and II respectively.