Use of combined pre- and intraoperative radiotherapy for rectal cancer involving metastases to regional lymph nodes failed to lower incidence of loco-regional recurrences or improve 5-year results, as compared with pre-operative radiotherapy alone. Besides, distant metastasis rates remained rather high (ca.30%). However, pre-operative radiotherapy plus local SHF-hyperthermia were followed by a significant drop in loco-regional recurrence incidence (to 2.3%), as compared with surgery alone and combined treatment using pre-operative hyper-fractionated-radiotherapy (TTD 25 Gy). Distant metastasis rates dropped to 25%. Also, 5-year survival increased significantly.